Article

Phytoremediation of BTEX from Indoor Air by Zamioculcas zamiifolia

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  • department of agriculture, thailand
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Abstract

Zamioculcas zamiifolia has the potential to reduce the concentration of benzene, toluene, ethylbenzene, and xylene (BTEX) from contaminated indoor air. It can remove all four pollutant gases. Benzene, toluene, ethylbenzene, and xylene uptake per unit area of Z. zamiifolia leaf were about 0.96 ± 0.01, 0.93 ± 0.02, 0.92 ± 0.02, and 0.86 ± 0.07 mmol m−2 at 72 h of exposure, respectively. The physicochemical properties of each BTEX may affect its removal. Benzene, a smaller molecule, is taken up by plants faster than toluene, ethylbenzene, and xylene. The toxicity of BTEX on plant leaves and roots was not found. The chlorophyll fluorescence measurement (F v/F m) showed no significantly difference between controlled and treated plants, indicating that a concentration of 20 ppm of each gas is not high enough to affect the photosynthesis of the plants. The ratio of stomata and cuticles showed that 80 % of benzene, 76 % of toluene, 75 % of ethylbenzene, and 73 % of xylene were removed by stomata pathways, while 20, 23, 25, and 26 % of them were removed by cuticles. The BTEX removal efficiency by well-watered Z. zamiifolia was involved with day stomata opening and night closing, while the BTEX removal efficiency by water-stressed Z. zamiifolia can occur both day and night at a slightly lower rate than well-watered plants.

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... Engl. It is a stem-less tropical herbaceous monocotyledonous originating from eastern Africa, from southern Kenya to northeastern South Africa, growing on the stony ground or tropical moist forest floor [1]. Zamioculcas (commonly named as 'ZZ plant') differs from most other aroids in possessing pinnate leaves [2]. ...
... It is grown as a medicinal-ornamental plant, mostly for its attractive glossy foliage and some pharmaceutical metabolites. Moreover, ZZ plant has the potential to reduce the concentration of pollutant gases such as benzene, ethylbenzene, xylene, and toluene from contaminated indoor air [1]. It is drought-resistant, can grow under low light conditions, and generates short sprouts from a thick underground tuber-like rhizome that stores water [3,4]. ...
... Yu et al. [35] achieved a compact callus mass from leaf and petiole explants in Anthurium andreanum Linden ex André by a combination of 2,4-D and BA, from which plant formation was obtained. Leaflet and petiole explants of Z. zamiifolia were cultured onto a callus induction medium composed of 1 2 MS salts, 4 mg·L −1 2,4-D, and 0.2 mg·L −1 BA by [15]. The cultures were transferred to a fresh medium biweekly and stored in the dark at a temperature of 25-27 • C. Callus was visible on the explants after about 4.5 weeks. ...
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Zamioculcas zamiifolia, a drought-resistant plant in the family Araceae, is a popular ornamental potted foliage plant originating from tropical east and subtropical southeast Africa. The growth and propagation rate of this species is low in conventional propagation methods. Therefore, the current study aimed at developing a complete in vitro propagation protocol of black-leaved Raven® ZZ plant (Z. zamiifolia ‘Dowon’)—a novelty on the floricultural market. In order to initiate an axenic culture, the disinfection of leaf explants was performed with sodium hypochlorite and mercury chloride. Next, leaf segments were cultured on the Murashige and Skoog (MS) medium with the addition of 6-benzyladenine (BA) and/or ɑ-naphthalene acetic acid (NAA) at various concentrations. The highest number of shoots (11) and leaves (22) per explant was obtained in a medium enriched with 2 mg·L−1 BA together with 0.5 mg·L−1 NAA. The maximum number of roots (3.33) was produced in microshoots cultured on the medium supplemented with 2 mg·L−1 NAA. On the other hand, the longest roots (2.66 cm) were produced on a medium containing 2 mg·L−1 NAA and 0.5 mg·L−1 BA. The combination of 0.5 mg·L−1 BA and 0.5 mg·L−1 NAA was most effective in stimulating callus formation (78.33%). Rooted plantlets were transferred to plastic pots filled with coco peat and acclimatized to ambient greenhouse conditions with an average 68.19% survival rate. This is the first report on a complete micropropagation protocol of black-leaved zamioculcas.
... The first is the static chamber method. The VOC uptake rate was determined as the decrease of VOC concentrations in the chamber (Orwell et al., 2004;Sriprapat and Thiravetyan, 2013). Loss of soluble compounds to condensed water, soil and chamber surfaces is likely to be major problem with this method (Tani and Hewitt, 2009). ...
... The removal of MAHs by plants has been investigated in several studies (for review, see Dela Cruz et al., 2014). In most experiments, their concentrations were controlled at several to several tens of ppmv (=µmol mol − 1 ) levels (Liu et al., 2007;Mosaddegh et al., 2014;Orwell et al., 2004;Sriprapat et al., 2014;Sriprapat and Thiravetyan, 2013;Wolverton et al., 1989), which are 10 3 to 10 4 times higher than their concentrations in urban, sub-urban and rural atmosphere (Garzón et al., 2015;Tiwari et al., 2010). All the above-cited studies, except for Liu et al. (2007), used static chamber method and enclosed whole potted plants; therefore, it is unclear which parts of the potted plants remove MAHs, that is leaves, soils, condensed water, or other parts inside the chambers. ...
... In previous studies, benzene and toluene were fumigated to potted plants in closed chambers at several hundreds of ppbv to several tens of ppmv levels (Liu et al., 2007;Mosaddegh et al., 2014: Orwell et al., 2004Sriprapat et al., 2014;Sriprapat and Thiravetyan, 2013;Wolverton et al., 1989). The concentration range was too high to be extrapolated to the evaluation of plant VOC removal capability in the surrounding atmosphere. ...
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Large amounts of monocyclic aromatic hydrocarbons (MAHs) are emitted into the atmosphere, but it is unclear which compounds among MAHs are effectively removed by the above-ground parts of plants. Although fumigation experiments of MAHs at unrealistically high concentrations (~ppmv) have been conducted, experiments with ambient concentrations have scarcely been conducted. In the present study, MAHs, including benzene, toluene, phenol, benzaldehyde, and benzyl alcohol, with concentrations ranging from several to several tens ppbv, were individually fumigated to four plant species, and the uptake was monitored using proton-transfer-reaction mass spectrometry and gas chromatography-mass spectrometry. No detectable uptake was observed for benzene and toluene, but phenol, benzaldehyde, and benzyl alcohol were significantly taken up by the plants. The uptake rate normalized to fumigated concentration varied from 3 to 50 mmol m⁻²s⁻¹ during the light period, depending on light intensity and compounds. The difference in uptake capability may be attributed not only to different metabolic activities but also to different values of Henry’s law constant, which regulates the partitioning of these compounds into the liquid phase in leaves. The uptake of phenol, benzaldehyde, and benzyl alcohol was affected by stomatal conductance, suggesting that stomatal opening is the main factor regulating the uptake of the three MAHs. This is the first observation that anisole is emitted when phenol is fumigated to Spathiphyllum clevelandii, suggesting that phenol is methylated to anisole within plant leaves. Anisole is more volatile than phenol, meaning that methylation enhances the emission of xenobiotics into the atmosphere by converting them to more volatile compounds. This conversion ratio decreased with an increase in phenol concentration (from 1.3 to 143 ppbv). Considering low reaction rate coefficient of anisole with OH radicals and low conversion ratio from phenol to anisole, it is concluded that plants act to effectively remove oxygenated MAHs from the atmosphere.
... Also, the findings proved that BTEX did not cause plant poisoning, and the concentration of 20 ppm of these vapors was not so high that would stop the plant's photosynthesis. About 73-80% of these pollutants were removed through the stomata and about 23-26% by the cuticle (Sriprapat and Thiravetyan 2013). These findings were in agreement with the phytoremediation of formaldehyde by Chamaedorea elegans and Nephrolepis Obliterata due to the plants' growth throughout the test even in fumigation concentrations of 16.4 mg m −3 and 11 mg m −3 respectively (Teiri et al. 2018b, a). ...
... The entry of contaminants into the leaf occurs through an open stoma in the epidermis or via penetration into the wax cuticle (Thomas et al. 2015). Benzene and toluene are mainly absorbed by the plant through the stomata, but some studies have concluded that the stomata have no major role in the removal of volatile organic hydrocarbons (Sriprapat and Thiravetyan 2013;Popek et al. 2018). The cuticle wax layer allows both lipophilic and hydrophilic molecules to penetrate the plant. ...
... Most of the ornamental plants do not need higher light intensity than room natural light, even some of them are vulnerable to higher light intensity than their optimum light level and some others stomata open at night to purify indoor air like Zamioculcas zamiifolia (Sriprapat and Thiravetyan 2013;Torpy et al. 2014). However, in indoor environments with low or without natural light, low energy-consuming lamps or luminescent solar concentrators can be used (Pedron et al. 2021). ...
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In recent decades, indoor air pollution has become a major concern due to its adverse health effects on the inhabitants. The presence of fine particles (PM2.5) and hazardous volatile organic compounds (VOCs), such as formaldehyde and benzene, in indoor air and their proven carcinogenic effects, has raised the attention of health authorities. Their very difficult and expensive removal by chemical and mechanical methods has led researchers to seek an economical and environmentally friendly technique. The use of plants in different ways such as potted plants or green walls is considered as a potential green solution for the improvement of indoor air quality and the health level of its inhabitants. A review of the literature cited in this paper suggests that plants absorb some of the pollutants, such as particles directly and remove some pollutants such as VOCs indirectly through biological transfer or by using microorganisms. This review paper discusses the types of plants that have been used for the phytoremediation of airborne pollutants and the routes and mechanisms for removing the pollutants. Removal pathways of the pollutants by aerial parts of the plants, the growth media along with the roots and their microorganisms in the rhizosphere part were also discussed. Sensitive analysis of extracted data from the literature outlined the most useful types of plants and the appropriate substrate for phytoremediation. Also, it showed that factors affecting the removal efficiency such as light intensity and ambient temperature, behave differently depending on pollutants and plants types.
... Engl. has great efficiency to reduce xylene from contaminated air (Sriprapat and Thiravetyan 2013;Sriprapat et al. 2014a). In addition, this plant was tolerant under high BTEX contamination and showed high BTEX removal efficiency (Sriprapat and Thiravetyan 2013). ...
... has great efficiency to reduce xylene from contaminated air (Sriprapat and Thiravetyan 2013;Sriprapat et al. 2014a). In addition, this plant was tolerant under high BTEX contamination and showed high BTEX removal efficiency (Sriprapat and Thiravetyan 2013). In addition, Chlorophytum comosum (Thunb.) ...
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Particulate matters (PM) and volatile organic compounds (VOCs) are the sources of toxic substances that hurt human health and can cause human carcinogens. An active living wall was applied to reduce PM and VOC contamination, while Sansevieria trifasciata cv. Hahnii, a high-performance plant for VOC removal, was selected to grow on the developing wall and used to treat PM and VOCs. The active living wall operating in a 24 m³ testing chamber showed the ability to remediate more than 90% PM within 12 h. The VOC removal can be approximately 25–80% depending on each compound. In addition, the suitable flow velocity of the living wall was also investigated. The flow rate of 1.7 m³ h⁻¹ in front of the living wall was found as the best inlet flow velocity for the developed active living wall. The suitable condition for PM and VOC removal in the active living wall application on the real side was presented in this study. The result confirmed that the application of an active living wall for PM phytoremediation can be an alternative effective technology.
... Reduction of BTEX levels especially in indoor environments is crucial to protect human health. Sriprapat et al., [188] researched Zamioculcas zamiifolia (Z. zamiifolia) for phytoremediation of BTEX in indoor air. ...
... Overall, to create a safer environment, more efforts need to be done to protect human health and be ecologically sustainable. Table 8 The pros and cons of different removal techniques [12,13,[161][162][163][164][165]180,187,188,[190][191][192][193][194][195]. ...
Article
BTEX are highly toxic environmental compounds that have carcinogenic and mutagenic effects in humans. These components are ubiquitous in environmental samples like water, air, and soil, which increase the risk of human exposure. Therefore, it is necessary to develop rapid, inexpensive, accurate, sensitive, and efficient sample-preparation and analytical methods to detect BTEX, thus reducing the harmful effect of BTEX on the environment and human health. This research reviewed the sources, fate, and distribution of BTEX in the general environment. In addition, a comprehensive summary and comparison of the current determination methods and different removal techniques in various environmental samples is discussed in detail. Also, the analytical and removal challenges and the futuristic development strategies established for BTEX are provided. In conclusion, the current review presents comprehensive evaluation on cutting-edge technologies in the field of BTEX determination and removal.
... In view of phytoremediation, studies show that the openings (cuticle and stomata) of plant bodies are responsible for potential VOC uptake, predominantly via stomata during the daytime when the stomata are open, unless it is a CAM plant (Weyens et al., 2015). Additionally, the occupied amount of VOCs on the waxy layer determine the potential of cuticular absorption (Treesubsuntorn and Thiravetyan, 2012;Sriprapat and Thiravertyan 2013). Once inserted into the plant system, either the VOCs undergo sequential degradation through the plant itself thereby transforming them into harmless constituents or the excretion and storage method in case degradation fails to occur (Weyens et al., 2015). ...
... The potted plants enable the decomposition of VOCs and were reported to reduce benzene by 15% (Lim et al., 2009). Nonetheless, to observe the VOC removal capacity of aerial parts, in a few experiments the aboveground part of the plant was subjected to a physical barrier and isolated from the rest of the substrate, along with the root zone, which showed a positive response independently (Tani et al., 2007;Tani and Hewitt, 2009;Treesubsuntorn and Thiravetyan, 2012;Treesubsuntorn et al., 2013;Sriprapat and Thiravertyan, 2013;Sriprapat et al., 2014a, b). Aydogan and Montoya (2011) set an experiment to observe the efficiency of the formaldehyde-removal capacity of plant root zones and aerial parts separately. ...
... The size of a molecule of pollutants is another factor in removal efficiency. In other words, the pollutant with a small size shows higher uptake according to Fick's law [147]. For example, Z. zamiifolia, et al. showed that benzene, toluene, ethylbenzene, and xylene had higher uptake by plants, especially benzene with due to its small size, and xylene while the lowest removal rate. ...
... For example, Z. zamiifolia, et al. showed that benzene, toluene, ethylbenzene, and xylene had higher uptake by plants, especially benzene with due to its small size, and xylene while the lowest removal rate. Also, benzene removal had a higher uptake rate in dark conditions [147,148]. ...
Article
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Urban civilization has a high impact on the environment and human health. The pollution level of indoor air can be 2–5 times higher than the outdoor air pollution, and sometimes it reaches up to 100 times or more in natural/mechanical ventilated buildings. Even though people spend about 90% of their time indoors, the importance of indoor air quality is less noticed. Indoor air pollution can be treated with techniques such as chemical purification, ventilation, isolation, and removing pollutions by plants (phytoremediation). Among these techniques, phytoremediation is not given proper attention and, therefore, is the focus of our review paper. Phytoremediation is an affordable and more environmentally friendly means to purify polluted indoor air. Furthermore, studies show that indoor plants can be used to regulate building temperature, decrease noise levels, and alleviate social stress. Sources of indoor air pollutants and their impact on human health are briefly discussed in this paper. The available literature on phytoremediation, including experimental works for removing volatile organic compound (VOC) and particulate matter from the indoor air and associated challenges and opportunities, are reviewed. Phytoremediation of indoor air depends on the physical properties of plants such as interfacial areas, the moisture content, and the type (hydrophobicity) as well as pollutant characteristics such as the size of particulate matter (PM). A comprehensive summary of plant species that can remove pollutants such as VOCs and PM is provided here. This review will help in making informed decisions about integrating plants into the interior building design.
... They estimated that 57 m 2 of leaf area could absorb or eliminate approximately 13 % of the CO 2 produced per person in an average unventilated room, indicating that hydroculture might enhance the air purification abilities of indoor plants, with larger leaf areas leading to increased CO 2 removal. Sriprapat and Thiravetyan [47] investigated the ability of Zamioculcas zamiifolia's ability to remediate benzene, toluene, ethylbenzene, and xylene from indoor air, highlighting its potential for improving indoor air quality. They determined that cuticular absorption in Z. zamiifolia contributed to 20 % of benzene, 23 % of toluene, 25 % of ethylbenzene, and 26 % of xylene uptake. ...
Article
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In natural environments, persistent pollutants such as heavy metals and organic compounds, are frequently sequestered in sediments, soils, and mineral deposits, rendering them biologically unavailable. This study examines phytoremediation, a sustainable technology that uses plants to remove pollutants from soil, water, and air. It discusses enhancing techniques such as plant selection, the use of plant growth-promoting bacteria, soil amendments, and genetic engineering. The study highlights the slow removal rates and the limited availability of plant species that are effective for specific pollutants. Furthermore, it investigates bioavailability and the mechanisms underlying root exudation and hyperaccumulation. Applications across diverse environments and innovative technologies, such as transgenic plants and nanoparticles, are also explored. Additionally, the potential for phytoremediation with bioenergy production is considered. The purpose of this study is to provide researchers, practitioners, and policymakers with valuable resources for sustainable solutions.
... Subsequently, there is phytovolatilization, which releases volatile primary pollutants and degradation products in plants into the air. Organic substances in the BTEX group are examples of pollutants that can undergo a phytovolatilization process (Sriprapat & Thiravetyan, 2013). ...
Article
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Background: It is more challenging than designing buildings, people have difficulty improving indoor air quality (IAQ) affordably in existing buildings with limited area. This paper presents indoor phytoremediation solutions-based quotations, which are affordable to the public, besides being able to work to remediate air simultaneously. Methods: Literature sources are primarily Mendeley reference managers and expanded from open-access reputable journals worldwide. The indoor phytoremediation solution was obtained from an up-to-date literature review covering processes of all plants and related sections. Results: The study identified three categories of indoor phytoremediation: plant-related bioremediation, rhizosphere bioremediation, and plant processes. To improve indoor air quality, plant-related bioremediation is a suitable process to be escalated while still paying attention to ameliorating the plant processes and inhibiting bioaerosols. For practical applications, narrow-leaved plant species can enhance phylloremediation, growth media amendments to enhance rhizosphere bioremediation, and support separating biodegradable waste. Placing one decorative plant anywhere indefinitely improves the IAQ for buildings with a limited area because plants are essential biota of a living ecosystem. Conclusion: Based on the suitability of the process for indoor air pollutants, the main contribution of plants to remediate indoor air is plant-related bioremediation, followed by plant processes, and rhizosphere bioremediation.
... Wolverton et al. (1984) initiated the most well-known early application of air phytoremediation. In 2013, a study concerning the phytoremediation of benzene, toluene, ethylbenzene and xylene (BTEX) was published (Sriprapat and Thiravetyan 2013). This technology can also remove ozone (Pheomphun et al. 2019), PM and heavy metals (Popek et al. 2017;Permana et al. 2024aPermana et al. , 2024b. ...
Article
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Particulate matter (PM) is one of the most hazardous atmospheric pollutants. Several plant species show high potential to reduce air pollutants and are widely used as green belts to provide clean outdoor spaces for human well-being. However, high PM concentrations cause physiological changes and stress in plants. In this study, 11 species of Thai native perennial plants were exposed to PM generated from tobacco smoke. Wrightia religiosa (Teijsm. & Binn.) Benth. ex Kurz, Bauhinia purpurea DC. ex Walp. and Tectona grandis L.f. reduced PM effectively (which is in the typical range of 43.95 to 52.97%) compared to other plant species. In addition, the responses of perennial plants under PM stress at the proteomic level were also evaluated. Proteomic analysis of these three plant species showed that plants respond negatively to high PM concentrations, such as reducing several photosynthetic-related proteins and increasing plant stress response proteins. To improve PM phytoremediation efficiency and reduce plant stress from PM, perennial plant–microbe interactions were investigated. W. religiosa was inoculated with Acinetobacter indicus PS1, and high biosurfactant-producing strains clearly showed a higher PM removal efficiency than non-inoculated plants (9.48, 9.5 and 12.6% for PM1.0, PM2.5 and PM10, respectively). Inoculating W. religiosa with A. indicus PS1 maintained chlorophyll a and b concentrations. Moreover, the malondialdehyde (MDA) concentration of W. religiosa inoculated with A. indicus PS1 was lower than that of non-inoculated W. religiosa. The leaf wax content (µg/cm²) and biosurfactant (µg/cm²) of W. religiosa inoculated with A. indicus PS1 were also higher than those of non-inoculated W. religiosa. This study clearly showed that inoculating plants with A. indicus PS1 can help plants remediate PM and improve their PM stress response.
... In addition, the ZZ plant has the potential to reduce the concentration of polluting gases such as benzene, ethylbenzene, xylene, and toluene from contaminated indoor air. It has the properties of traditional medicine due to the presence of steroids, triterpenoids, flavonoids, and polyphenols [8]. The extract is also a source of antioxidants and the juice is used in Tanzania to treat earaches. ...
Article
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Dracaena trifasciata (Snake plant) and Zamioculcas zamiifolia (ZZ plant) are widely used ornamental plants. This research aimed to investigate the phytochemistry and in vitro antioxidant activity of D.trifasciata and Z. zamiifolia leaves. Freshly prepared juice of D. trifasciata contains flavonoids, phenol, glycosides, terpenoids, monosaccharides, and amino acids, and Z. zamiifolia contains only carbohydrates. In vitro antioxidant studies have shown potential effects in scavenging DPPH and hydrogen peroxide in a concentration-dependent manner. These activities may be due to phytochemicals present in the selected ornamental plants.
... Cellulosic fibers are increasingly being used in industry, but current procurement tactics and output levels cannot keep up with the rising demand. [17] Many natural fibers such as Prosopis juliflora fibers, [18] Parthenium hysterophorus stem fiber, [19] Catharanthus roseus stem fiber, [20] Acacia leucophloea fiber, [21] Himalayacalamus falconeri culms, [22] Olea europaea, [23] Dracaena refexa, [24] Zamioculcas zamiifolia, [25] Eichhornia crassipes, [26] and Aristida adscensionis [27] have been discovered by investigators and represent a possible filler material for the polymer matrices. The novel Hibiscus canescens stem fibers (HCSFs) were studied in the search for adaptable natural fibers. ...
Article
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This work focuses on characterizing Hibiscus canescens stem fibers (HCSFs), which were manually retrieved from the plant stem. After treating the retrieved fibers with 5% NaOH (alkali), the optimum alkali treatment period for alkalized fibers (60 min) was determined by measuring their cellulose content. Then, the characteristics of optimally alkalized HCSFs were compared with raw HCSFs. Physicochemical study, Fourier-transform infrared spectroscopy, X-ray diffraction, thermogravimetric investigation, atomic force microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopic analysis, and single-fiber tensile tests were used to investigate the distinct behavior of raw and optimally alkalized HCSFs. According to the results, the cellulose content of optimally alkalized HCSFs augmented by 9.03% compared to raw HCSFs whereas the fiber density increased by 2.06%. The abolition of noncellulosic elements (hemicellulose, lignin, and wax) from optimally alkalized HCSFs was confirmed by their high crystallinity index (54.43%) and crystallite size (1.84 nm). Using thermogravimetric analysis, the char residue for raw and optimally alkalized HCSFs increased from 28.2 to 43.6%, respectively. The maximum degradation temperature of alkalized HCSFs increased 1.06 times (426/454 °C) of raw HCSFs. Optimally alkalized HCSFs displayed a superior surface roughness feature and remarkable pulling strength (435.4 ± 13.99 MPa) compared with raw HCSFs (394.9 ± 14.42 MPa). Fiber-reinforced polymer composites could potentially be produced with the assistance of optimally alkalized HCSFs due to their enhanced properties.
... Sulphate in PM is stored in the vacuole or assimilated into S-containing amino acids (Yang et al. 2018). Plant cuticular wax has the ability to remove certain VOCs such as benzene, toluene, and xylene (BTEX) (Sriprapat & Thiravetyan 2013, 2016Thiravetyan et al. 2015). The use of plants to remove PM and VOC is mostly related with an active botanical biofilter, which manipulates airflow and attracts pollutants directly to the plants. ...
Article
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Phytoremediation has become famous for removing particulate matter (PM) and volatile organic compounds (VOC) in situ. Plants for removing PM and VOC were associated with botanical biofilters to attract pollution to the plant. On the other hand, persistent pollution exposure can lower plant health and phytoremediation effectiveness; therefore, improving plant tolerance against stress is necessary. Various elicitors can enhance plant tolerance to certain stressors. This study aims to investigate different elicitors to maintain plant health and improve the use of plants in phytoremediation for PM and VOC pollution. This experiment used Sansevieria trifasciata hort. ex Prain under PM and VOC stress. Exogenous elicitors, such as proline, ornithine, and a commercial product, were applied to the leaf parts before exposure to PM and VOC stress. The initial concentrations of PM1, PM2.5, and PM10 were 300–350, 350–450, and 400–500 µg m⁻³, respectively, while the VOC concentration was 2.5–3.0 mg m⁻³. The plant was stressed for 7 days. The result indicated that ornithine 10 mM is vital in improving plant tolerance and inducing antioxidant enzymes against PM and VOC, while proline 50 mM and a commercial product could not reduce plant stress. This study suggests that ornithine might be an important metabolite to improve plant tolerance to PM and VOC.
... and 0.86±0.07 mmol m −2 setelah 72 jam paparan (Sriprapat & Thiravetyan, 2013). ...
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Zamioculcas zamiifolia is an ornamental aroid plant that can be propagated vegetatively through leaf, stem, and petiole cuttings. Cultivation efforts are needed to increase the viability of cuttings as well as faster root and shoot induction, one of which is by using planting media and adding ZPT. This study aims to determine the effect of the application of the hormone auxin and foliar fertilizer on the growth of zamia leaf cuttings in aqueous media. The research was carried out at the Stiper Agricultural Institute, Yogyakarta, from June 1 to August 10, 2021. The method used was a factorial experiment arranged in a completely randomized design (CRD). The first factor is the concentration of the auxin hormone which consists of 3 levels, namely 0; 2.5; and 5 ppm. The second factor is the concentration of foliar fertilizer consisting of 4 levels, namely 0; 0.25; 0.5; and 0.75 g/l. The results showed that the 0.25 ppm auxin treatment was able to induce root elongation. Foliar fertilizers have an important influence on root formation, keeping the cuttings green, tuber induction, shoot growth percentage, and the addition of fresh weight. The most optimal concentration of foliar fertilizer is 0.5 g/l.
... This study represents one of the first investigations to quantify the ability of passive botanical systems to reduce realistic concentrations of real-world azeotropic VOC mixtures and to quantify the removal efficiency for all detectable VOCs present within petrochemical vapour. Previous studies have assessed the efficiency of potted plants to remove individual constituents which are present in gasoline vapour; however no previous work has tested a VOC mixture of the complexity used in the current work (Kim et al. 2016;Kim et al. 2014;Mosaddegh et al. 2014;Sriprapat and Thiravetyan 2013). Testing azeotropic mixtures of VOCs is likely to represent a more realistic test of phytoremediation capacity, where interactions between VOC species may occur , as was observed in this study (Fig. 4). ...
Article
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The capacity for indoor plants including green wall systems to remove specific volatile organic compounds (VOCs) is well documented in the literature; however under realistic settings, indoor occupants are exposed to a complex mixture of harmful compounds sourced from various emission sources. Gasoline vapour is one of the key sources of these emissions, with several studies demonstrating that indoor occupants in areas surrounding gasoline stations or with residentially attached garages are exposed to far higher concentrations of harmful VOCs. Here we assess the potential of a commercial small passive green wall system, commercially named the ‘LivePicture Go’ from Ambius P/L, Australia, to drawdown VOCs that comprise gasoline vapour, including total VOC (TVOC) removal and specific removal of individual speciated VOCs over time. An 8-h TVOC removal efficiency of 42.45% was achieved, along with the complete removal of eicosane, 1,2,3-trimethyl-benzene, and hexadecane. Further, the green wall also effectively reduced concentrations of a range of harmful benzene derivatives and other VOCs. These results demonstrate the potential of botanical systems to simultaneously remove a wide variety of VOCs, although future research is needed to improve upon and ensure efficiency of these systems over time and within practical applications.
... Several technologies are exploited to remove BTEX from air streams. However, the success achieved with using adsorption technique is because of its easiness and lower costs, compared to other methods [61][62][63][64]. Activated carbons can adsorb BTEX via several mechanisms like π-π interactions, pore filling, and/or hydrogen bonds. ...
Article
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The poor indoor air quality can be associated with the released volatile organic compounds (VOCs) from different sources. The extent of the concern may increase depending on the presence of benzene, toluene, ethylbenzene, and xylene (BTEX) and exposure to them in the indoor air. Adsorption with activated carbon, which is a very effective method, is preferred to eliminate highly volatile gaseous pollutants and reduce the extend of their negative impact. In this work, the removal efficiency of a novel activated carbons (MSRACs), prepared from stems of Corylus colurna (CCBW) by chemical processes using H2SO4, H3PO4, and HCl, was scrutinized towards BTEX pollutants. The adsorbents acquired from this lignin-based waste were investigated from porosity and surface chemistry aspects. The highest surface area of 1424 m²/g and micropore volume of 0.46 cm³/g were attained after activation of MSRAC11 adsorbent sample by H2SO4-70wt%. The performances of the fabricated adsorbent samples were evaluated and the order of MSRAC11>MSRAC24>MSRAC36 was obtained in the multiple concentrations of BTEX. This study introduces an easy method for producing efficient adsorbents from lignin-based waste for filtering indoor air and designing BTEX-capturing systems for various applications.
... The effects are highly variable as influenced by the plant species, concentration of VOCs, and time of exposure. Benzene has been reported to cause a reduction in stomatal conductance, photosynthetic, and transpiration rates of Spathiphyllum wallisii, Hedera helix, Cissus rhombifolia, and Syngonium podophyllum (Yoo et al. 2006); chlorosis, necrosis, and wilting in C. comosum (Sriprapat and Thiravetyan 2013); expanded and damaged chloroplast in Epipremnum aureum and C. comosum (Sriprapat et al. 2014); and decreased chlorophyll concentration in Sansevieria trifasciata, Epipremnum aureum, C. comosum, and Hedera helix (Lu et al. 2018;Gong et al. 2019). Formaldehyde also imparts toxic effects on plants such as necrosis and destruction of palisade and spongy parenchyma cells in Epipremnum aureum, Ficus japonica, and Rhapis excelsa (Kim et al. 2013) and a reduction in chlorophyll content and increased permeability of plasma membranes in Tillandsia velutina plants . ...
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Volatile organic compounds (VOCs) such as formaldehyde and benzene are among the key contributors to indoor air pollution. The current situation of environmental pollution is alarming, especially indoor air pollution is becoming a challenge as affecting plants and humans. VOCs are known to adversely affect indoor plants by causing necrosis and chlorosis. In order to withstand these organic pollutants, plants are naturally equipped with an antioxidative defense system. The current research study aimed to evaluate the combined effect of formaldehyde and benzene on the antioxidative response of selected indoor C3 plants including Chlorophytum comosum, Dracaena mysore, and Ficus longifolia. After the combined application of different levels (0, 0; 2, 2; 2, 4; 4, 2; and 4, 4 ppm) of benzene and formaldehyde respectively, in an airtight glass chamber, the enzymatic and non-enzymatic antioxidants were analyzed. Analysis of total phenolics showed a significant increase (10.72 mg GAE/g) in F. longifolia; C. comosum (9.20 mg GAE/g); and D. mysore (8.74 mg GAE/g) compared to their respective controls as 3.76, 5.39, and 6.07 mg GAE/g. Total flavonoids (724 µg/g) were reported in control plants of F. longifolia which were increased to 1545.72 µg/g from 724 µg/g (in control) followed by 322.66 µg/g in D. mysore (control having 167.11 µg/g). Total carotenoid content also increased in D. mysore (0.67 mg/g) followed by C. comosum (0.63 mg/g) in response to increasing the combined dose compared to their control plants having 0.62 and 0.24 mg/g content. The highest proline content was exhibited by D. mysore (3.66 μg/g) as compared to its respective control plant (1.54 μg/g) under a 4 ppm dose of benzene and formaldehyde. A significant increase in enzymatic antioxidants including total antioxidants (87.89%), catalase (59.21 U/mg of protein), and guaiacol peroxidase (52.16 U/mg of protein) was observed in the D. mysore plant under a combined dose of benzene (2 ppm) and formaldehyde (4 ppm) with respect to their controls. Although experimental indoor plants have been reported to metabolize indoor pollutants, the current findings indicate that the combined application of benzene and formaldehyde is also affecting the physiology of indoor plants as well.
... The atmosphere of the International Space Station (ISS) cabin is contaminated with various airborne pollutants such as halocarbons, ketones, aldehydes, alcohols, siloxanes, aromatic hydrocarbon, methane, hydrogen, and carbon monoxide [2,3]. Aromatic hydrocarbon gaseous pollutants such as benzene, toluene, ethylbenzene, and xylene (BTEX) are common in air pollution and harm the human body [4,5]. Toluene may contaminate the air and can enter the human body through breathing. ...
Article
Air phytoremediation is one of the sustainable and eco-friendly biotechnology to remedy polluted atmospheric environment. The microgravity environment in International Space Station (ISS) cabin is contaminated with various traces of volatile organic compounds (VOCs), such as toluene. The mature plant showed the capability to remove air pollution under simulated microgravity (μG). However, generally, plants are brought to space in seed form. In this study, we tried to observe gaseous toluene phytoremediation by Vigna radiata seedlings grown under μG started from the seeds form and evaluate its effect on seedling's growth and plant stress response through endogenous hormones auxin and gibberellin. V. radiata could remove toluene under μG generated by Random Positional Machine at 24 h, 72 h, and 120 h and seem better compared to V. radiata under 1G. Under μG, V. radiata with or without toluene showed strange hypocotyl bending direction, and some roots grew to aerial parts. Gibberellic acid (GA3) showed higher under μG compared to under 1G. Indole-3-acetic acid (IAA) content in shoots of V. radiata under μG + toluene showed similar to that of V. radiata under μG and 1G, whereas V. radiata under 1G + toluene had higher IAA almost two times compared to other treatments. V. radiata under 1G + toluene likewise showed shorter hypocotyl length and lower fresh weight compared to other treatments. This study demonstrated that IAA of V. radiata under μG was maintained at a suitable level, although being exposed to 50 ppm toluene resulted in preventing stunted growth.
... Indoor plants function as air purifiers by converting CO 2 to O 2 through photosynthesis (Smith and Pitt 2011). Previously, the ability of indoor plants to phytoremediate indoor air pollutants, including benzene and trimethylamine, has been well studied (Boraphech and Thiravetyan 2015;Sriprapat and Thiravetyan 2013). The studies indicated that the efficiency of using plants to purify indoor air depends on plant health status. ...
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Nowadays, people are interested to use plants, especially air-purifying plants, in residential and other indoor settings to purify indoor air and increase the green area in the building. In this study, we investigated the effect of water deficit and low light intensity on the physiology and biochemistry of popular ornamental plants, including Sansevieria trifasciata, Episcia cupreata and Epipremnum aureum. Plants were grown under low light intensity in the range of 10–15 μmol quantum m⁻² s⁻¹ and 3 days of water deficit. The results showed that these three ornamental plants responded to water deficit with different pathways. Metabolomic analysis indicated that water deficit affected Episcia cupreata and Epipremnum aureum by inducing a 1.5- to 3-fold increase of proline and a 1.1- to 1.6-fold increase in abscisic acid compared to well-watered conditions, which led to hydrogen peroxide accumulation. This resulted in a reduction of stomatal conductance, photosynthesis rate and transpiration. Sansevieria trifasciata responded to water deficit by significantly increasing gibberellin by around 2.8-fold compared to well-watered plants and proline contents by around 4-fold, while stomatal conductance, photosynthesis rate and transpiration were maintained. Notably, proline accumulation under water deficit stress could be attributed to both gibberellic acid and abscisic acid, depending on plant species. Therefore, the enhancement of proline accumulation in ornamental plants under water deficit could be detected early from day 3 after water deficit conditions, and this compound can be used as a key compound for real-time biosensor development in detecting plant stress under water deficit in a future study.
... With the decrease in the formaldehyde concentration in the chamber, the capacity of plants to remove formaldehyde gradually decreased. Although the stomata of CAM plants were only open at night, which was also shown by Sriprapat and Thiravetyan (Sriprapat and Thiravetyan 2013), the capacity of D. maculata to remove formaldehyde during the day was still stronger than that at night. In addition to stomatal conductance, the adsorption of waxy layer and metabolic strength of plants have been hypothesized to play an important role in the phytoremediation of formaldehyde (Dela Cruz et al. 2014a). ...
Article
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Phytoremediation technology is an effective method to remove formaldehyde indoors, but the purification capacity and physiological response of plants to formaldehyde under the simultaneous influence of light and CO2 have not been examined in previous studies. In this study, formaldehyde fumigation experiments were conducted on the C3 plants Epipremnum aureum A. and Chlorophytum comosum L., and the crassulacean acid metabolism (CAM) plant Dieffenbachia maculate A. The phytoremediation performance and physiological response of plants were studied. The initial concentration of formaldehyde was established at 11.950 ± 1.442 [Formula: see text]; the light intensities were 448 ± 7 [Formula: see text], 1628 ± 22 [Formula: see text], and 3259 ± 22 [Formula: see text], respectively; and the concentrations of CO2 were 455 ± 29 [Formula: see text], 978 ± 50 [Formula: see text], 2020 ± 66 [Formula: see text], and 3006 ± 95 [Formula: see text], respectively. The results indicated that the highest purification rates of formaldehyde by E. aureum, D. maculata, and C. comosum were 55.8%, 43.7%, and 53.2%, respectively. The light intensity had a positive effect on the formaldehyde purification rates of all three plants and positively stimulated peroxidase (POD) activity, while the CO2 concentration had no significant impact on the formaldehyde purification capacity and plants' physiological characteristics. Exposure to formaldehyde inhibited formaldehyde dehydrogenase (FADH) activity and positively stimulated catalase (CAT) activity. The superoxide dismutase (SOD) activity positively correlated with the formaldehyde purification capacity of plants.
... Few researchers have suggested the role of cuticle wax quantity and its chemical structure in the elimination of VOCs (Treesubsuntorn et al. 2013). The removal of benzene, toluene, ethylbenzene, and xylene has been reported in Dracaena sanderiana and Z. zamiifolia (Treesubsuntorn and Thiravetyan 2012;Sriprapat and Thiravetyan 2013). The chemical properties of VOCs also determine the rate of VOC removal by plants. ...
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Environmental pollution, especially indoor air pollution, has become a global issue and affects nearly all domains of life. Being both natural and anthropogenic substances, indoor air pollutants lead to the deterioration of the ecosystem and have a negative impact on human health. Cost-effective plant-based approaches can help to improve indoor air quality (IAQ), regulate temperature, and protect humans from potential health risks. Thus, in this review, we have highlighted the common indoor air pollutants and their mitigation through plant-based approaches. Potted plants, green walls, and their combination with bio-filtration are such emerging approaches that can efficiently purify the indoor air. Moreover, we have discussed the pathways or mechanisms of phytoremediation, which involve the aerial parts of the plants (phyllosphere), growth media, and roots along with their associated microorganisms (rhizosphere). In conclusion, plants and their associated microbial communities can be key solutions for reducing indoor air pollution. However, there is a dire need to explore advanced omics technologies to get in-depth knowledge of the molecular mechanisms associated with plant-based reduction of indoor air pollutants.
... Oyabu et al. (2003) also showed that potted plants are able to remove gasoline from air; however, compound specifications and concentrations were not given. Benzene, toluene, ethylbenzene, and m-xylene have all previously been found to be removed by potted plants Sriprapat and Thiravetyan 2013) as has pentane, hexane, and octane (Cornejo et al. 1999;Wood et al. 2002;Yang et al. 2009). ...
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Microorganisms in the soil of potted plants are important for removal of volatile organic compounds (VOCs) from indoor air, but little is known about the subject. The aim of this study was therefore to obtain a better understanding of the effect of VOCs on the microbial community in potted plants. Hedera helix was exposed to gasoline vapors under dynamic chamber conditions for 21 days and three main parameters were investigated. These were (1) removal of the target compounds heptane, 3-methylhexane, benzene, toluene, ethylbenzene, m,p-xylene, and naphthalene from the gasoline mixture; (2) toluene mineralization; and (3) bacterial abundance and bacterial community structure. H. helix was able to reduce the concentration of the target compounds in the continuously emitted gasoline by 25–32%, except for naphthalene, which was too low in concentration. The soil microcosm of gasoline exposed plants had for an initial 66 h increased toluene mineralization rate compared to the soil microcosm in the soil of plants exposed to clean air. Bacterial abundance was decreased in response to gasoline exposure while bacterial community structure was changed. The change in bacterial community structure was, however, different between the two experiments indicating that several taxonomic units can degrade gasoline components. Especially the genera Rhodanobacter and Pseudonorcardia significantly increased in abundance in response to gasoline vapors. Bauldia, Devosia, and Bradyrhizobium, on the other hand, decreased.
... Plant systems are able to remediate air contaminants by three different routes: removal through aerial parts of the plant and phyllospheric organisms (Wei et al. 2017), removal by soil microorganisms (rhizosphere) and removal by the growing media (Aydogan and Montoya 2011) (Fig. 2). Since the initial experiments conducted by Wolverton et al. (1982Wolverton et al. ( , 1984, numerous laboratory chamber test studies of both passive and active potted systems have demonstrated the potential for significant improvement in indoor air quality (IAQ) ( (Aydogan and Montoya 2011;Hörmann et al. 2018;Irga et al. 2013;Kim et al. 2010Kim et al. , 2014Orwell et al. 2004;Sriprapat and Thiravetyan 2013;Su and Liang 2015;Teiri et al. 2018;Torpy et al. 2013;Wood et al. 2006Wood et al. , 2002. While the contribution of the aerial plant parts is significantly smaller when compared to the rhizosphere, several studies have shown that plant foliage is able to remove some gaseous VOCs (Sriprapat et al. 2014a, b;Tani and Hewitt 2009;Treesubsuntorn et al. 2013) to a measurable degree. ...
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Poor indoor air quality has become of particular concern within the built environment due to the time people spend indoors, and the associated health burden. Volatile organic compounds (VOCs) off-gassing from synthetic materials, nitrogen dioxide and harmful outdoor VOCs such benzene, toluene, ethyl-benzene and xylene penetrate into the indoor environment through ventilation and are the main contributors to poor indoor air quality with health effects. A considerable body of literature over the last four decades has demonstrate the removal of gaseous contaminants through phytoremediation, a technology that relies on plant material and technologies to remediate contaminated air streams. In this review we present a state-of-the-art on indoor phytoremediation over the last decade. Here we present a review of 38 research articles on both active and passive phytoremediation, and describe the specific chemical removal efficiency of different systems. The literature clearly indicates the efficacy of these systems for the removal of gaseous contaminants in the indoor environment, however it is evident that the application of phytoremediation technologies for research purposes in-situ is currently significantly under studied. In addition, it is common for research studies to assess the removal of single chemical species under controlled conditions, with little relevancy to real-world settings easily concluded. The authors therefore recommend that future phytoremediation research be conducted both in-situ and on chemical sources of a mixed nature, such as those experienced in the urban environment like petroleum vapour, vehicle emissions, and mixed synthetic furnishings off-gassing. The assessment of these systems both in static chambers for their theoretical performance, and in-situ for these mixed chemical sources is essential for the progression of this research field and the widespread adoption of this technology.
... They can be used for relatively less polluted air, their efficiency and decontaminating efficiency cannot be controlled. Still, PPs play their role in controlling air pollution and some plants have been found very proficient in eliminating VOCs, such as formaldehyde Teiri et al. 2018a), toluene (Kim et al. 2011), benzene, ethylbenzene, xylene (Sriprapat and Thiravetyan 2013), and inorganic gaseous pollutants like CO 2 (Torpy et al. 2017) and ammonia (Ortakci et al. 2019), etc. They suffer from certain limitations in addition to the abovementioned, i.e., they need soil which is not least desired in some houses and their maintenance is somehow a challenge. ...
Article
Formaldehyde evolves from various household items and is of environmental and public health concern. Removal of this contaminant from the indoor air is of utmost importance and currently, various practices are in the field. Among these practices, indoor plants are of particular importance because they help in controlling indoor temperature, moisture, and oxygen concentration. Plants and plant materials studied for the purpose have been reviewed hereunder. The main topics of the review are, mechanism of phytoremediation, plants and their benefits, plant material in formaldehyde remediation, and airtight environmental and health issues. Future research in the field is also highlighted which will help new researches to plan for the remediation of formaldehyde in indoor air. The remediation capacity of several plants has been tabulated and compared, which gives easy access to assess various plants for remediation of the target pollutant. Challenges and issues in the phytoremediation of formaldehyde are also discussed. Novelty statement: Phytoremediation is a well-known technique to mitigate various organic and inorganic pollutants. The technique has been used by various researchers for maintaining indoor air quality but its efficiency under real-world conditions and human activities is still a question and is vastly affected relative to laboratory conditions. Several modifications in the field are in progress, here in this review article we have summarized and highlighted new directions in the field which could be a better solution to the problem in the future.
... Several studies have reported the uptake of BTEX by different species such as Poplar, Ruscus hyrcanus, Danae racemosa, Dracaena deremensis, Opuntia microdasy, Canna x generalis, and Zamioculcas zamiifolia (Burken and Schnoor, 1998, Collins et al., 2002, Fooladi et al., 2019, Mosaddegh et al., 2014, Boonsaner et al., 2011, Sriprapat and Thiravetyan, 2013, Wilson et al., 2013. Nonetheless, plants still show negative effects, including chlorosis, holonecrosis, and hydrosis, when exposed to BTEX. ...
Preprint
Benzene, toluene, ethylbenzene, and xylenes (BTEX) are important environmental pollutants around the world. The uptake and transformation of BTEX by plants are well understood, but not the molecular mechanisms for BTEX stress response. In the current study, we combined transcriptomic and physiology analysis of two Arabidopsis thaliana accessions with contrasting BTEX tolerance and a reverse genetic approach to identify BTEX-tolerance related genes. Physiology and gene expression were analyzed in seedlings exposed for 5 days to BTEX compounds separately and combined. Our results showed reduced root length, high proline accumulation, and decreased chlorophyll content in the susceptible accession (Ct-1) after BTEX exposure, whereas the tolerant accession (Kn-0) did not show a statistically significant difference. RNA-seq revealed 1593, and 717 DEGs in Ct-1, and Kn-0, respectively, under BTEX stress, with 234 genes in common. DEGs were associated with pathways such as “glutathione transferase activity”, “photosynthesis light harvesting in photosystem I”, “cellular response to ethylene”, and “cellular amino acid catabolic process and found to be upregulated in Kn-0 in stress . DEGs partaking to “response to chitin”, “cellular response to hypoxia”, “plant-pathogen interaction”, and “anthocyanin-containing compound biosynthetic process” were noted to be downregulating in stress mitigation. Moreover, compared with the wild type, BTEX sensitivity increased in T-DNA knockout (KO) lines for two genes, including basic region/leucine zipper motif 60 (BZIP60) (At1G42990) and a hypothetical protein (At2G16190). Our study explored mechanisms underlying the stress involving BTEX compounds in Arabidopsis and the identification of genes responsible for BTEX stress tolerance.
... The utilization of plants or botanical systems were found to improve the indoor air quality via active botanical biofiltration [2]. However, most of the air pollution health research has focused on single pollutants rather than multiple pollutants [3], although in reality, we breathe in a complex [4]. More in-depth research is required to evaluate the efficiency of phytoremediation technology in removing the mixed pollutants from the indoor environment [5]. ...
... Both hydrophilic and hydrophobic pollutants can adhere to the surface of the cuticular wax and penetrate into the plant when the concentration of pollutants on the leaf surface exceeds the equilibrium value (Kvesitadze et al. 2006). The adsorption of cuticular wax comprises 46% of the capacity of Dracaena sanderiana to remove benzene (Treesubsuntorn and Thiravetyan 2012), and 20%, 23%, 25%, and 26% of the capacity of Zamioculcas zamiifolia Engl. to remove benzene, toluene, ethylbenzene, and xylene, respectively (Sriprapat and Thiravetyan 2013). Formaldehyde can also enter the plant directly through the opened stomata, which play a significant role in the purification of pollutants in the aerial part. ...
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Decorative plants can efficiently purify formaldehyde and improve the quality of indoor air. The existing studies primarily revealed that the aerial and underground parts of plants’ capacity to purify formaldehyde, while the performance of stems is unclear. A formaldehyde fumigation experiment was conducted on Epipremnum aureum and Rohdea japonica in a sealed chamber. Results showed the stems could remove formaldehyde. The efficiency of removal by the stems of each plant was 0.089 and 0.137 mg∙m−3∙h−1, respectively, the rate of purification was 40.0 and 61.6%, respectively. Both were related to plant species and the latter was affected by other factors like exposed area. To further explore the mechanism of phytoremediation, the correlation between the concentration of formaldehyde and CO2 during the experiment was investigated. Results showed when leaves of plants were exposed to formaldehyde, the concentration of CO2 increased with the decrease in concentration of formaldehyde, and the change in concentration of CO2 could be used as an indicator of the degree of decontamination of formaldehyde by the plants.
... Many studies report the accumulation of several pollutants indoors such as benzene, toluene, ethylbenzene, xylene, and formaldehyde (Chikara et al. 2009). High BTEX, formaldehyde, ozone, and trimethylamine concentrations are frequently found in indoor conditions (Treesubsuntorn et al., 2012;Sriprapat and Thiravetyan 2013;Boraphech and Thiravetyan 2015;Chen et al. 2018;Li et al. 2019). Taking in these compounds in high concentration can affect human systems such as the nervous and respiratory systems. ...
Article
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High-rise residential developments are rapidly increasing in urban areas. Smaller residential units in this high rise bring a reduction in windows, resulting in poor indoor air ventilation. In addition, materials used in interiors can emit volatile organic compounds (VOCs), which can significantly affect human health. Since people spend 90% of their time indoors, an evaluation of indoor air quality is especially important for high-rise residential buildings with an analysis of determining factors. This study aims to measure the concentrations of VOCs, formaldehyde, and particulate matter (PM2.5 and PM10) in 9 high-rise residential buildings in Bangkok by using the accidental sampling method (n = 252) and to investigate possible important determining factors. The results show that the average concentrations of VOCs, formaldehyde, PM2.5, and PM10 in 9 high-rise residential buildings were at good to moderate levels in the indoor air quality index (IAQI) and that high pollutant concentrations were rarely found except in new constructions. Moreover, it was found that the age of buildings shows strong correlations with all pollutants (p value < 0.0001). Old buildings showed significantly lower pollutant concentrations than new and under-construction buildings at a 95% confidence level. The findings from this investigation can be used as part of sustainable well-being design guidelines for future high-rise residential developments.
... Additionally, the energy costs will rise due to the higher air conditioning needs required to heat or cool the intake air. Conversely, there are suitable biological technologies with the potential to detoxify organic compounds, such as some plants that efficiently and cost-effectively remove contaminants from the air (Sriprapat and Thiravetyan, 2013). ...
Article
Currently, the population spends most of the time in indoor environments, which makes Indoor Air Quality (IAQ) very important for health and comfort. As vegetation can act as a biofilter capturing air pollutants, this study aims to assess the effectiveness of a living wall module in the removal of the Total Volatile Organic Compounds (TVOCs) for IAQ improvement. An airtight glass chamber was used to release contaminants, monitoring the TVOCs both with the chamber empty (control) and with a small Fytotextile® living wall module planted with Nephrolepis exaltata L. A substantial reduction of TVOCs was observed when the living wall was inside the chamber. In few hours, TVOCs levels were reduced below the recommended limit (following Spanish regulations). More tests are recommended considering different plant species and other variables related to the IAQ.
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Dracaena trifasciata, commonly known as the Snake Plant, has gained popularity as an indoor plant due to its purported air-purifying properties. This review examines existing research on the effectiveness of Dracaena trifasciata in reducing indoor air pollutants, its benefits, and potential drawbacks. The analysis highlights the plant's ability to remove volatile organic compounds (VOCs) from the air, its low maintenance needs, and its aesthetic appeal. Conversely, considerations such as its potential toxicity to pets and limitations in air purification efficacy are discussed. This paper aims to provide a comprehensive overview for both researchers and indoor gardeners interested in the utility of Dracaena trifasciata.
Chapter
Air pollution is a growing environmental concern worldwide, which is closely associated with climate variation and change as well as global warming whose effects are deleterious. Phytoremediation describes a technique of using plants and plant-based microbes to detoxify air pollutants and is a promising technique to reverse the current pollution state. This book chapter explores on the various subsets of phytoremediation and their applicability in detoxifying air of pollutants such as particulate matter, volatile organic compounds, and inorganic pollutants. Findings based on literature show that the method is widely used and attracting contemporary scientific research due to its viability and eco-friendly nature. Several examples of microbes and their host plants used in this process as well as the pollutants they decontaminate are provided herein. In conclusion, the application of the technique should be enhanced and optimized through further research.
Article
Volatile organic compounds, such as BTEX, have been the subject of numerous debates due to their detrimental effects on the environment and human health. Human beings have had a significant role in the emergence of this situation. Even though US EPA, WHO, and other health-related organizations have set standard limits as unhazardous levels, it has been observed that within or even below these limits, constant exposure to these toxic chemicals results in negative consequences as well. According to these facts, various studies have been carried out all over the world – 160 of which are collected within this review article, so that experts and governors may come up with effective solutions to manage and control these toxic chemicals. The outcome of this study will serve the society to evaluate and handle the risks of being exposed to BTEX. In this review article, the attempt was to collect the most accessible studies relevant to risk assessment of BTEX in the atmosphere, and for the article to contain least bias, it was reviewed and re-evaluated by all authors, who are from different institutions and backgrounds, so that the insights of the article remain unbiased. There may be some limitations to consistency or precision in some points due to the original sources, however the attempt was to minimize them as much as possible.
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The drastic increase in industrialization has led to numerous adverse effects on the environment and human health. Respiratory tract disorders are one of the major emerging global health issues that lead to a high mortality rate every year. The quality of indoor and outdoor air has lowered in the last decade.The quality of indoor air has deteriorated by cooking, smoking, and burning incense sticks or smoke. The smoke released from incense and incense sticks contains gaseous products (carbon monoxide, nitrogen dioxide, and oxide of sulfur), particular matter (PM10, PM2.5), volatile organic compounds (VOCs), and polycyclic aromatic hydrocarbons (PAHs). These toxic components released from various incense sources pose a significant risk to human health and the environment. The inhalation and exposure of smoke from various incenses is hazardous to health as it inevitably culminates in deadly organ‐related diseases. With such insights, the present review article focuses on the characteristic attributes of particulate matter released from incense and other sources emphasizing healthcare and environmental concerns.
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A large part of the civilizational progress has been achieved at the expense of the natural environment, which recently reached the stages that threaten its creator. Plants play an important role in various areas of our lives, and it turned out that we can rely on them to reduce this threat. The ability of living organisms and the systems they create to protect and restore the environment is at the core of a technology called environmental biotechnology. Advances in science and technology have created a plant-based discipline known as phytoremediation. This technology allows us to remove or reduce the level of pollutants in our surroundings. We can phytoextract heavy metals from contaminated soil and water with the help of resistant plant species and recover noble metals and rare elements. When the soil or water is contaminated with organic compounds, we try to eliminate them completely with the help of plants and their microbiome. Phytoextraction from water is related to the accumulation of pollutants in water and sediments, in which macrophytes from all water groups participate, including free-floating submerged and emerged plants. The task of these plants, apart from the accumulation of metals or organic toxins, is also the uptake of phosphorus and nitrogen to prevent the eutrophication of water. In recent years, the quality of air has deteriorated. Nowadays, 90% of the population breathes air that does not meet WHO standards. It should be emphasized that in the case of outdoor air, there is no industrial system for removing pollutants. In fact, we can only count on nature: rainfall and plants. Indoor air is sometimes even more polluted than outside and, therefore, we should be safe in it with the help of plants that are able to create a refuge. Additionally, it fulfills biofilling desires and improves our mood.
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Salvadora persica (SP) is an important medicinal plant. Numerous articles have been conducted on the leaf, the roots, and the stem of the plant, but there is little information about the seed. Thus, the present work tries to identify the chemical composition of SP seed bio-oil and investigates its use as an adsorbent for cyclohexane removal. This study extracted bio-oil from seeds using different polar and non-polar organic solvents. Two techniques have been used to determine the chemical composition of the bio-oil extracted: FTIR and GC-MS. Results show that the extracted bio-oil presented 13 new major organic bio-compounds in n-hexane and ethanol SP seed extracts. Moreover, the analytical results showed that the two extracts are complex and contained thiocyanic acid, benzene, 3-pyridine carboxaldehyde, benzyl nitrile, ethyl tridecanoate, ethyl oleate, and dodecanoic acid ethyl ester. Additionally, each technique of analysis showed that the extracted bio-oils from SP seeds are rich in non-polar compounds. Indeed, the major fatty acids obtained are pentadecylic acid, myristic acid, lauric acid, oleic acid, margaric acid, and tricosanoic acid. This work provides guidelines for identifying these compounds, among others, and offers a platform for using SP seeds as a herbal alternative for various chemical, industrial, and medical applications. Furthermore, the capacity of SP extracts for air pollution treatment, namely, the removal of cyclohexane in batch mode, was investigated. Results showed that cyclohexane adsorption could be a chemical process involving both monolayer and multilayer adsorption mechanisms. The pores and the grooves on the surface of the SP bio-oil extract helped in adsorbing the cyclohexane with an outstanding maximum removal capacity of about 674.23 mg/g and 735.75 mg/g, respectively, for the ethanol and hexane SP extracts, which is superior to many other recent adsorbents.
Article
With the synchronous development of highway construction and the urban economy, automobiles have entered thousands of households as essential means of transportation. This paper reviews the latest research progress in using phytoremediation technology to remediate the environmental pollution caused by automobile exhaust in recent years, including the prospects for stereoscopic forestry. Currently, most automobiles on the global market are internal combustion vehicles using fossil energy sources as the primary fuel, such as gasoline, diesel, and liquid or compressed natural gas. The composition of vehicle exhaust is relatively complex. When it enters the atmosphere, it is prone to a series of chemical reactions to generate various secondary pollutants, which are very harmful to human beings, plants, animals, and the eco-environment. Despite improving the automobile fuel quality and installing exhaust gas purification devices, helping to reduce air pollution, the treatment costs of these approaches are expensive and cannot achieve zero emissions of automobile exhaust pollutants. The purification of vehicle exhaust by plants is a crucial way to remediate the environmental pollution caused by automobile exhaust and improve the environment along the highway by utilizing the ecosystem's self-regulating ability. Therefore, it has become a global trend to use phytoremediation technology to restore the automobile exhaust pollution. Now, there is no scientific report or systematic review about how plants absorb vehicle pollutants. The screening and configuration of suitable plant species is the most crucial aspect of successful phytoremediation. The mechanisms of plant adsorption, metabolism, and detoxification are reviewed in this paper to address the problem of automobile exhaust pollution.
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Indoor air quality (IAQ), specifically after the COVID-19 pandemic, has become an international issue, as humans spend 80–90% of their time in indoor microenvironments. Poor IAQ has been related to the sick-building syndrome, nasal and ocular irritations, allergies, and respiratory dysfunction, including premature deaths. Phytoremediation is a novel strategy to absorb, adsorb, assimilate or transfer/reduce air pollutants and improve the IAQ using plants. Hence, the current review aims to explore indoor plants' role in improving indoor air quality, including their purification capabilities. There is increasing evidence that various plant species (e.g., Ficus benjamina, Chlorophytum comosum, Draceana) or their parts can reliably reduce the concentration of numerous air pollutants in the indoor microenvironment and promote human wellbeing. However, the indoor air pollutants removal efficiency depends on the species of plant, various plant characteristics such as leaf size, thickness, area, photosynthetic activity, light intensity and part of plant involved, i.e., roots, leaves, wax, cuticle and stomata. Using indoor plants is one of the most cost-effective and reliable methods of making a healthier indoor environment. Better public health can be maintained at a lower cost, with less strain on the health care system, if more emphasis is placed on creating a biophilic atmosphere and increasing the use of indoor plants. However, there are no established criteria for the best indoor plants and the impact of indoor plants on various factors such as interior ventilation, temperature, humidity, etc. Therefore, further experimental research is needed that simulates the interior environment to monitor the impacts of indoor plants on factors such as humidity, temperature, ventilation, etc., in improving the microenvironment of a closed space/room.
Chapter
Nowadays, air pollutants such as particulate matter, volatile organic compounds, carbon monoxide (CO), nitrogen dioxide (NO2), and sulfur dioxide (SO2) can have significant effects on human health and environment. Air pollutants can harm to the human respiratory system; alter the heart rate; enhance blood coagulation; and decrease lung function, chronic obstructive pulmonary diseases, lung cancer mortality, and cardiovascular problems. Therefore, air pollutants can be managed by using conventional physical and chemical technologies depending on the type of pollutants. Phytoremediation is an alternative method based on green technology that can decrease global warming and is environmentally friendly. Phytoremediation is a technology that uses plants to degrade organic pollutants and use them as a carbon source. In nature, plants are always associated with microorganisms, and they help each other to deal with pollutants by increasing hormones and antioxidant enzymes in the plant cell. Understanding of how plant-microbes remove the pollutants can be used to create an active living wall/botanical biofilter to solve the problem of air pollutants. In order to solve air pollution problems, forested areas should be created in the cities/industrial areas.
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Air pollution is a major cause of concern globally. The origin of airborne pollutants is attributed to the industrial revolution and large‐scale use of fossil fuels. There are numerous evidences from epidemiologic research on the adverse effects of air pollutants on human health, such as chronic obstructive pulmonary diseases, lung cancer, premature mortality. Current mitigation strategies focus mostly on specific technical measures and are not sufficient to meet the challenges posed by the deteriorating environment. Despite several measures undertaken cities like Delhi are severely polluted throughout the year. Ambient air pollution is composed of a high variety of pollutants, mainly including particulate matter (PM), volatile organic compounds (VOCs) like benzene, formaldehyde, and inorganic pollutants (NO x , SO 2 , O 3 ). Many of these outdoor air pollutants are also found indoor, in concentrations that often can be higher than the outdoors. Phytoremediation is an effective plant‐based, environmentally friendly biotechnology to remediate indoor and outdoor air pollutants. Plants are known to scavenge significant amounts of air pollutants via processes like phytostabilisation, phytoaccumulation, phytodegradation phytovolatilisation, and rhizodegradation. Several plant enzymes such as nitroreductase, dehalogenase, laccase, and peroxidase aid these processes. Plants are known to be associated with symbiotic microbes such as fungi and bacteria that alleviate abiotic and biotic stresses in them and enhance their growth. Plant–microbe mutualism also plays an important role during phytoremediation by degrading, detoxifying, or sequestrating the pollutants. Plants and associated microorganisms maintain biodiversity and ecological sustainability of urban green infrastructures, and studies on this symbiosis are imperative for human health and environmental sustainability. The incorporation of green areas comprising plants remediating air pollution among concrete jungles would have a substantial positive influence on the health of urban dwellers. In cities, the uses of plants improve the microclimate and alleviate side effects of climate change, for example, by blocking excessive sun radiation during summer. In addition, plants can also be exploited to intensively reduce carbon footprint by absorbing CO 2 and provide long‐term carbon sequestration. Phytoremediation of air pollutants is still an emerging concept and the potential and suitability of individual species for specific pollutants require basic as well as applied research. The selection of the plant–soil–microbe system would vary depending on the abiotic factors of the region. Phytoremediation is a slow removal process, hence attempts should be made to combine it with other remediation strategies to achieve enhanced rates of decontamination. Policies must be executed to incorporate urban forestry with city planning, particularly for the rapidly urbanising cities of the developing world.
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Human activities have become the source of myriad pollutants and have accelerated the pressure on natural resource depletion. Intensive farming, urbanization, rapid industrialization, and other human activities have resulted in land deterioration and degradation, a polluted environment, and a downturn in crop productivity across various sectors of agriculture. Several alternative methods have been designed and developed, but often, these processes risk environmental damage by producing secondary pollutants. Biological treatment systems have diversified applications, such as the cleanup of site contaminants in soil, water, streams, and sludge. Bioremediation, an efficacious and lucrative eco-friendly management tool, utilizes microorganisms to degrade or reduce the concentration of hazardous wastes at the contaminated site without causing additional deterioration of the environment. This chapter discusses the role of a vast array of microorganisms used in the reclamation of wastewater containing metal pollutants through bioremediation and puts forward thoughts and opportunities for further research in the field.
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The quality of life on earth is completely dependent on the environment. The aquatic and terrestrial systems are the two major ecosystems on earth. In ancient times, our natural systems were efficient at absorbing and breaking down pollutants and maintaining the quality of our environment. But now, owing to population explosion, rapid industrialization, and urbanization, humans have produced and added a tremendous number of pollutants in enormous volumes to the environment. As a result, our environment has become polluted and unhealthy. There are various types of pollution, e.g., water, air, soil, noise, and thermal. The invention of modern technologies to exploit natural resources has also aggravated the rate of pollution. The problem of environmental pollution can be mitigated in many ways, but the most suitable methods are biological, in which green plants are used. These plants can absorb and degrade pollutants and act as both biomitigators and bioindicators. Aquatic plants can be used to treat water pollution, and terrestrial plants can be grown around industrial and urban areas to treat air pollution. The utilization of plants to treat pollution is known as phytoremediation. This treatment is considered an ecologically sustainable and cost-effective strategy to alleviate water and air pollution. In the present chapter, we discuss the role of higher plant species in mitigating pollution and the mechanisms they use.
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Bioremediation is an option to transform toxic heavy metals into a less harmful state using microbes or their enzymes and is an ecofriendly, cost-effective technique for revitalizing wastewater-polluted environments
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Indoor air pollution is a significant problem today because the release of various contaminants into the indoor air has created a major health threat for humans occupying indoors. Volatile Organic Compounds (VOCs) are pollutants released into the environment and persist in the atmosphere due to its low boiling point values. Various types of indoor activities, sources, and exposure to outdoor environments enhance indoor VOCs. This poor indoor air quality leads to adverse negative impacts on the people in the indoor environment. Many physical and chemical methods have been developed to remove or decompose these compounds from indoors. However, those methods are interrupted by many environmental and other factors in the indoor atmosphere, thus limit the applications. Therefore, there is a global need to develop an effective, promising, economical, and environmentally friendly alternatives to the problem. The use of the plant and associated microflora significantly impact reducing the environmental VOC gases, inorganic gases, particulate matter, and other pollutants contained in the air. Placing potted plants in indoor environments not only helps to remove indoor air pollutants but also to boost the mood, productivity, concentration, and creativity of the occupants and reduces stress, fatigue, sore throat, and cold. Plants normally uptake air pollutants through the roots and leaves, then metabolize, sequestrate, and excrete them. Plant-associated microorganisms help to degrade, detoxify, or sequestrate the pollutants, the air remediation, and promote plant growth. Further studies on the plant varieties and microorganisms help develop eco-friendly and environmentally friendly indoor air purifying sources.
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Air pollution by particulate matter (PM) and volatile organic compounds (VOCs) is a major global issue. Many technologies have been developed to address this problem. Phytoremediation is one possible technology to remediate these air pollutants, and a few studies have investigated the application of this technology to reduce PM and VOCs in a mixture of pollutants. This study aimed to screen plant species capable of PM and VOC phytoremediation and identify plant physiology factors to be used as criteria for plant selection for PM and VOC phytoremediation. Wrightia religiosa removed PM and VOCs. In addition, the relative water content in the plant and ethanol soluble wax showed positive relationships with PM and VOC phytoremediation, with a high correlation coefficient. For plant stress responses, several plant species maintained and/or increased the relative water content after short-term exposure to PM and VOCs. In addition, based on proteomic analysis, most of the proteins in W. religiosa leaves related to photosystems I and II were significantly reduced by PM2.5. When a high water content was achieved in W. religiosa (80% soil humidity), W. religiosa can effectively remove PM. The results suggested that PM can reduce plant photosynthesis. In addition, plants might require a high water supply to maintain their health under PM and VOC stress.
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Monitoring of air quality and the application of strategies for its improvement are perceived as key areas for reducing environmental pollution. The research on Nature Based Solutions for the mitigation of pollutant concentrations in the air has increasingly developed in the last twenty years. The purpose of this review is to evaluate whether the current knowledge about Nature-Based Solutions provides a quantitative answer of the real benefits of air phytoremediation. To address this question, the literature on air phytoremediation over the last twenty years was analyzed. Altogether, 52 variables were selected, grouped into six categories, to briefly characterize the contents, methodology and outcome of the peer-reviewed articles. Altogether, 413 plant species found in the analyzed studies were recorded. The results show the trends about the most studied pollutants and on the methodologies mostly applied, in relation to the study outcomes. The analysis demonstrated that particulate matter (PMx) was the most frequently examined pollutant, most studies on NBS are based on experiments with exposure chambers, and scaling up the results with models has been limited. Although effective reductions in pollutant concentrations have been shown in the majority of studies, there is a strong fragmentation of the approaches, most studies have looked at a single pollutant and detailed information for model parameterization is only available for a few species. Thus, the review highlights that studies of Nature Based Solutions in air phytoremediation require unification of methodologies, and should consider a broader range of pollutants and plant organisms useful for mitigating the impacts of air pollutants in indoor and outdoor human environments.
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ZZ (Zamioculcas zamiifolia), a member of the family Araceae, is emerging as an important foliage plant due to its aesthetic appearance, ability to tolerate low light and drought, and resistance to diseases and pests. However, little information is available regarding its propagation, production, and use. This report presents relevant botanical information and results of our four-year evaluation of this plant to the ornamental plant industry.
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We conducted laboratory tests with six species of plants to determine their ability to remove benzene, trichloroethylene (TCE) and toluene from air. The objective of this proof-of-principal study was to evaluate the idea that phytoremediation techniques might be used to lower the concentrations of indoor air pollutants, such as volatile or semi-volatile organic compounds. Plants were exposed to the pollutants singly or in mixtures in an airtight chamber, and concentrations of the pollutants in the chamber were monitored through time to assess plant effects on the pollutants. In several experiments, we measured air temperature and CO2, as well. Lower surfaces of leaves of several of the species we tested were also examined by scanning electron microscopy to determine stomate abundance and size, and to provide information about leaf-surface elemental composition (by X-ray emission spectroscopy). Several of the species demonstrated an extensive ability to remove benzene from air. Gas chromatography methods allowed a reasonably direct, continuous monitoring of the kinetics and overall efficiency of the pollutant-removal process. We found that pollutant removal efficiency varied in response to plant species and the pollutant. Of the pollutants tested, benzene was most efficiently removed from air by Pelargonium domesticum, Ficus elastica and Chlorophytum comosum. Kalanchoe blossfeldiana, a common ornamental plant, appeared to take up benzene selectively over toluene, and TCE was removed efficiently from the air by C. comosum. Pentane, sometimes used as an internal standard in GC/MS, was removed from air by at least four of the species. For C. comosum, TCE appeared to lower the removal rates of benzene and pentane. Low-vacuum scanning electron microscopy provided information on stomate size and density and permitted rapid initial elemental analysis of the plant-leaf surface by X-ray emission spectroscopy. Our results indicate that simple tests for pollutant uptake, morphological and chemical features of plants, and plant detoxification enzyme activity might be used in multivariate fashion to identify plant species capable of removing volatile or semi-volatile pollutants from air.
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Phytoremediation—using plants to remove toxins—is an attractive and cost effective way to improve indoor air quality. This study screened ornamental plants for their ability to remove volatile organic compounds from air by fumigating 73 plant species with 150 ppb benzene, an important indoor air pollutant that poses a risk to human health. The 10 species found to be most effective at removing benzene from air were fumigated for two more days (8 h per day) to quantify their benzene removal capacity. Crassula portulacea, Hydrangea macrophylla, Cymbidium Golden Elf., Ficus microcarpa var. fuyuensis, Dendranthema morifolium, Citrus medica var. sarcodactylis, Dieffenbachia amoena cv. Tropic Snow; Spathiphyllum Supreme; Nephrolepis exaltata cv. Bostoniensis; Dracaena deremensis cv. Variegata emerged as the species with the greatest capacity to remove benzene from indoor air.
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Zamioculcas zamiifolia (Araceae), a terrestrial East African aroid, with two defining attributes of crassulacean acid metabolism (CAM) (net CO(2) uptake in the dark and diel fluctuations of titratable acidity) is the only CAM plant described within the Araceae, a mainly tropical taxon that contains the second largest number of epiphytes of any vascular plant family. Within the Alismatales, the order to which the Araceae belong, Z. zamiifolia is the only documented nonaquatic CAM species. Zamioculcas zamiifolia has weak CAM that is upregulated in response to water stress. In well-watered plants, day-night fluctuations in titratable acidity were 2.5 μmol H(+)·(g fresh mass)(-1), and net CO(2) uptake in the dark contributed less than 1% to daily carbon gain. Following 10 d of water stress, net CO(2) uptake in the light fell 94% and net CO(2) uptake in the dark increased 7.5-fold, such that its contribution increased to 19% of daily carbon gain. Following rewatering, dark CO(2) uptake returned to within 5% of prestressed levels. We postulate that CAM assists survival of Z. zamiifolia by reducing water loss and maintaining carbon gain during seasonal droughts characteristic of its natural habitat.
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The effect of water stress on respiration and mitochondrial electron transport has been studied in soybean (Glycine max) leaves, using the oxygen-isotope-fractionation technique. Treatments with three levels of water stress were applied by irrigation to replace 100%, 50%, and 0% of daily water use by transpiration. The levels of water stress were characterized in terms of light-saturated stomatal conductance (g(s)): well irrigated (g(s) > 0.2 mol H(2)O m(-2) s(-1)), mildly water stressed (g(s) between 0.1 and 0.2 mol H(2)O m(-2) s(-1)), and severely water stressed (g(s) < 0.1 mol H(2)O m(-2) s(-1)). Although net photosynthesis decreased by 40% and 70% under mild and severe water stress, respectively, the total respiratory oxygen uptake (V(t)) was not significantly different at any water-stress level. However, severe water stress caused a significant shift of electrons from the cytochrome to the alternative pathway. The electron partitioning through the alternative pathway increased from 10% to 12% under well-watered or mild water-stress conditions to near 40% under severe water stress. Consequently, the calculated rate of mitochondrial ATP synthesis decreased by 32% under severe water stress. Unlike many other stresses, water stress did not affect the levels of mitochondrial alternative oxidase protein. This suggests a biochemical regulation (other than protein synthesis) that causes this mitochondrial electron shift.
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There is nowadays no single fully satisfactory method for VOC removal from indoor air due to the difficulties linked to the very low concentration (microg m(-3) range), diversity, and variability at which VOCs are typically found in the indoor environment. Although biological methods have shown a certain potential for this purpose, the specific characteristic of indoor air and the indoor air environment brings numerous challenges. In particular, new methods must be developed to inoculate, express, and maintain a suitable and diverse catabolic ability under conditions of trace substrate concentration which might not sustain microbial growth. In addition, the biological treatment of indoor air must be able to purify large amounts of air in confined environments with minimal nuisances and release of microorganisms. This requires technical innovations, the development of specific testing protocols and a deep understanding of microbial activities and the mechanisms of substrate uptake at trace concentrations.
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From screening 8 ornamental plants, it was found that Dracaena sanderiana had the highest benzene removal efficiency. In a long-term study, 4 cycles of benzene were studied under both 24 h dark and 24 h light conditions. From the 2nd to 4th cycle, benzene uptake by plants under 24 h light condition had higher intensity than under 24 h dark conditions, and the close of D. sanderiana stomata was found only in 24 h dark condition. At the final cycle, D. sanderiana still survived, and benzene uptake continued. From the calculation, 46% of benzene was taken up by D. sanderiana crude wax, while 54% was predicted to be taken up by the stomata by 72 h.
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Three factors influencing foliar uptake of monocyclic aromatic hydrocarbons (MAHs; benzene, toluene, ethylbenzene, xylenes) in situ were investigated. The first factor, the plant species, was found to determine absorption pattern and concentrations. Secondly, time variation studies showed that response of leaf concentrations to small changes in air concentrations only occurs after several days or weeks, whereas adaptation to a much higher level of air pollution takes several months. Thirdly, MAH leaf concentrations were observed to be dependent on mean air pollution at the sampling site. Bioconcentration factors BCFvs (g m−3 of wet leaf/g m−3 of air) for MAHs in Pseudotsuga menziesii (Mirb.) Franco leaves were determined to range from 2.7 × 104 to 4.7 × 105.
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Photosystem II plays an especially important role in the response of photosynthesis in higher plants to environmental perturbations and stresses. The relationship between photosystem II and photosynthetic CO2 assimilation is examined and factors identified that may modulate photosystem II activity in vivo. Particular attention is given to non-photochemical quenching of excitation energy, photoinhibition, state transitions, protein phosphorylation and biogenesis of photosystem II.
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An experimental method is described to measure foliar uptake and translocation of volatile organic compounds in plants. A flow-through exposure chamber was designed to determine phytoxicity of volatile organic compounds; an air-tight chamber was used for exposure of whole plants to radiolabeled test compound. 14C-toluene uptake by soybean (Glycine max) foliage was measured as an example of the experimental approach. Leaf tissue concentrations of 14C-toluene were measured over a 55.5-hr exposure period during light and dark periods. Photosynthetic rate was not affected by chronic atmospheric exposure to 27 μmole cm−3 hr toluene. During a 55.5-hr exposure to 7.2 μmoles cm−3 hr 14C-toluene (1.94 Bq cm−3), deposition velocities were greatest in the light phases and showed a marked decrease during the dark phases of exposure, suggesting that stomatal uptake as well as surface deposition contributed to toluene uptake. 14C was translocated from foliage to the roots. These data indicate that deposition of volatile organic compounds to vegetation may constitute a mechanism leading to herbivore exposure to volatile hazardous organics at waste sites. The experimental method described can be used to measure foliar uptake and translocation of volatile organic compounds to whole plants under laboratory conditions.
Article
A simple model is proposed to account for observed emissions of volatile organic compounds (VOCs) from new carpets. The model assumes that the VOCs originate predominantly in a uniform slab of polymer backing material. Parameters for the model (the initial concentration of a VOC in the polymer, a diffusion coefficient and an equilibrium polymer/air partition coefficient) are obtained from experimental data produced by a previous chamber study. The diffusion coefficients generally decrease as the molecular weight of the VOCs increase, while the partition coefficients generally increase as the vapor pressure of the compounds decreases. In addition, for two of the study carpets that have a styrene-butadiene rubber (SBR) backing, the diffusion and partition coefficients are similar to independently reported values for SBR. The results suggest that prediction of VOC emissions from new carpets may be possible based solely on a knowledge of the physical properties of the relevant compounds and the carpet backing material. However, a more rigorous validation of the model is desirable.
Article
An experimental method for the determination of the internal diffusion coefficient (D) and partition coefficient (ke) of volatile organic compounds (VOCs) is developed for dry building materials (such as carpet, vinyl flooring, plywood, etc.). The method is used to determine D and ke for four VOCs (toluene, nonane, decane, and undecane ) through the backing material of a carpet specimen, for four VOCs (ethylbenzene, nonane, decane, and undecane) through a floor tile specimen, and three VOCs (cyclohexene, ethylbenzene, and decane) through a plywood specimen. It was found that the values of diffusion coefficients for a given material are inversely proportional to the molecular weights of the VOCs, whereas the value of the partition coefficients are proportional to the vapour pressures of the VOCs. The measured diffusion and partition coefficients are useful for predicting the emission rates of VOCs from building materials.
Article
BTEX is the commonly used term for a group of toxic compounds (benzene, toluene, ethyl benzene, ortho-xylene and meta- and para-xylene), some of which, most notably benzene, are known carcinogens. The aim of this study is to measure the BTEX levels both inside and outside the homes of 352 one-year old children from the Valencia cohort of the INMA study (Spain) and to analyze the determinants of these levels. Passive samplers were used to measure BTEX levels during a 15day period and a questionnaire was administered to gather information on potentially associated factors (sociodemographics, residential conditions, and lifestyle). The average concentrations of benzene, toluene, ethyl benzene, ortho-xylene, and meta- and para-xylene were 0.9, 3.6, 0.6, 0.6, and 1.0μg/m(3), respectively. On average, the indoor levels of all the compounds were approximately 2.5 times higher than those observed outdoors. Factors associated with higher BTEX concentrations inside the home were being the child of a mother of non-Spanish origin, living in a house that had been painted within the last year, living in an apartment, and not having air conditioning. Higher outdoor concentrations of BTEX depend on the residence being situated in a more urban zone, being located within the city limits, having living in a building with more than one story, residing in an area with a greater frequency of traffic, and the season of the year in which the sample was taken. The data thus obtained provide helpful information not only for implementing measures to reduce exposure to these pollutants, but also for evaluating the relation between such exposure and possible health risks for the children in the cohort.
Article
Recent discoveries in the phytoremediation of volatile organic compounds (VOCs) show that vapor-phase transport into roots leads to VOC removal from the vadose zone and diffusion and volatilization out of plants is an important fate following uptake. Volatilization to the atmosphere constitutes one fundamental terminal fate processes for VOCs that have been translocated from contaminated soil or groundwater, and diffusion constitutes the mass transfer mechanism to the plant-atmosphere interface. Therefore, VOC diffusion through woody plant tissues, that is, xylem, has a direct impact on contaminant fate in numerous vegetation-VOC interactions, including the phytoremediation of soil vapors and dissolved aqueous-phase contaminants. The diffusion of VOCs through freshly excised tree tissue was directly measured for common groundwater contaminants, chlorinated compounds such as trichloroethylene, perchloroethene, and tetrachloroethane and aromatic hydrocarbons such as benzene, toluene, and methyl tert-butyl ether. All compounds tested are currently being treated at full scale with tree-based phytoremediation. Diffusivities were determined by modeling the diffusive transport data with a one-dimensional diffusive flux model, developed to mimic the experimental arrangement. Wood-water partition coefficients were also determined as needed for the model application. Diffusivities in xylem tissues were found to be inversely related to molecular weight, and values determined herein were compared to previous modeling on the basis of a tortuous diffusion path in woody tissues. The comparison validates the predictive model for the first time and allows prediction for other compounds on the basis of chemical molecular weight and specific plant properties such as water, lignin, and gas contents. This research provides new insight into phytoremediation efforts and into potential fruit contamination for fruit-bearing trees, specifically establishing diffusion rates from the transpiration stream and modeling volatilization along the transpiration path, including the trunk and branches. This work also has importance in other plant-VOC interactions, such as potential uptake from the atmosphere for hydrophobic compounds and also uptake from vapor-phase soil contaminants.
Article
During the transition from a centrally planned economy to a market economy, many countries seem to have experienced some degree of macroeconomic instability. This paper attempts to provide a theoretical explanation of this phenomenon. The paper develops a simple monetary model and shows how macroeconomic stability can be achieved in a rigid centrally planned economy, despite the inherent structural imbalances and irrational price system. On the other hand, the study shows that without hardening enterprise budget constraints, wage and price decontrol tends to destablize the economy and may lead to persistent budget deficits and inflation. The paper also provides a rigorous analysis of household savings and money demand in a shortage economy, and clarifies the somewhat confusing concept of "monetary overhang" in the literature.
How to grow fresh air
  • B C Wolverton
Wolverton B.C. (1996). How to grow fresh air. New York: Penguin Book.
Some application of chlorophyll fluorescence kinetics to plant stress physiology, phytoecology and agricultural modernization
  • S Q Lin
  • C H Xu
  • Q D Zhang
  • L Xu
  • D Z Mao
  • T Y Kuang
  • SQ Lin
Lin, S. Q., Xu, C. H., Zhang, Q. D., Xu, L., Mao, D. Z., & Kuang, T. Y. (1992). Some application of chlorophyll fluorescence kinetics to plant stress physiology, phytoecology and agricul-tural modernization. Chinese Bulletin of Botany, 9, 1–16.
Gaseous deposition of 14C-toluene to soybean (Glycine max) foliage
  • M S Jen
  • M A Hoylman
  • T N Edwards
  • T B Walton
  • MS Jen