Risk management has reduced vulnerability to floods and droughts globally1,2, yet their impacts are still increasing³. An improved understanding of the causes of changing impacts is therefore needed, but has been hampered by a lack of empirical data4,5. On the basis of a global dataset of 45 pairs of events that occurred within the same area, we show that risk management generally reduces the impacts of floods and droughts but faces difficulties in reducing the impacts of unprecedented events of a magnitude not previously experienced. If the second event was much more hazardous than the first, its impact was almost always higher. This is because management was not designed to deal with such extreme events: for example, they exceeded the design levels of levees and reservoirs. In two success stories, the impact of the second, more hazardous, event was lower, as a result of improved risk management governance and high investment in integrated management. The observed difficulty of managing unprecedented events is alarming, given that more extreme hydrological events are projected owing to climate change³.
Coral geochemical tracers have been used in studies of the paleoclimatology and paleoceanography of the tropics and subtropics. We measured Sr/Ca and oxygen isotope ratios (δ18O) in a coral sample collected from the southern part of Lombok Strait, a significant outlet of the Indonesian Throughflow (ITF) to the Indian Ocean, to reconstruct the historical record of sea surface temperature (SST) and seawater δ18O. Seawater δ18O can be used to approximate sea surface salinity (SSS) because it reflects the balance of evaporation and precipitation. The resulting time series reconstructed SST and SSS, covering the period 1962–2012, shows no clear trend of global warming, although the record includes a large cooling event (~4°C) during 1996–1997. Although neither SST nor SSS shows a systematic relationship with El Niño–Southern Oscillation and Indian Ocean Dipole (IOD), weak but significant correlations are found partly. In addition, the coral data show signals of major IOD and El Niño events in 1994 and 1997, respectively, although climatic trends recorded in the coral are not consistent with those found along the Java-Sumatra coast. To evaluate other influences on the ITF in Lombok Strait, we compared our coral record with coral records from sites in the Java Sea, the southern part of Makassar Strait, and Ombai Strait. During the northwest monsoon (December–January–February), variations in SST and SSS at Lombok Strait site are similar to those at the Java Sea and southern Makassar sites for the period 1962–1995, which suggests that low-salinity water from the Java Sea is carried at least to the southern part of Makassar Strait where it suppresses the ITF upstream from Lombok Strait. However, the SST and SSS records differ at the three sites during the southeast monsoon (June–July–August), indicating that surface conditions in Lombok Strait vary separately from those in the Java Sea. In the longer term, although global warming has been widely identified in the Indonesian Seas, the coral record shows no clear warming trend in the southern part of Lombok Strait, where fluctuations in the ITF may be modulating the distribution of heat in the surface waters of the western Pacific and eastern Indian Ocean.
Most commercially available Surface Plasmon Resonance (SPR) devices are not equipped with convenient analysis software to be operated by the non-expert. We introduce a web-based application for SPR sample data analysis with Python’s Matplotlib and Bokeh as the primary tools. Users can directly upload and analyze the SPR data output, where the data are stored in the Firebase cloud storage. The web application is embedded with several features, including the graph label, tooltips, and interactive legend. With this application, SPR sample analysis only needs to be run within minutes, and the system is made portable by implementing Python virtual environment.
The study reported in this paper combines the electrocoagulation and photocatalysis for the simultaneous degradation of methylene blue dyes (MB)-antibiotic ciprofloxacin (CP) and production of hydrogen. The pollutant removal process was conducted by combining adsorption by electrocoagulation and degradation by photocatalysis. Meanwhile, H2 was produced by reducing the H⁺ on the cathode and the photocatalyst surface in a reactor made of acrylic equipped with aluminum as the anode, stainless steel 316 plates as a cathode, Fe-doped titania nanotube arrays (TiNTAs) as a photocatalyst, and a 250-W mercury lamp as the light source. TiNTAs were synthesized via anodization and followed by the successive ionic layer adsorption and reaction (SILAR) method to incorporate Fe as the dopant. In particular, the effects of Fe loading in the composite photocatalyst are investigated. XRD results showed that TiO2 nanotubes arrays comprise a 100% anatase phase. FESEM, EDX, TEM, and HRTEM analysis confirmed the formation of the nanotubular structure of TiO2 and the presence of Fe deposited on the surface. The UV–Vis DRS indicated that the bandgap of Fe-TiNTAs reduced with Fe introduction, as compared to that of the undoped TiNTAs. The results showed that accumulation of the produced hydrogen from the combination of electrocoagulation-photocatalytic system is greater than that which is obtained using individual electrocoagulation or photocatalytic system. The combined process exhibited an enhanced degradation ability of methylene blue and ciprofloxacin, as well as in the H2 production.
The experiment on the artificial coral reef was conducted at BTIKK using ceramic body mass code BL1. This engineering was carried out in two steps, the first step was making the design of the growth media, and the second step was testing the mass of the ceramic body and making the growth media model. The hexagonal design was used beginning from the design concept that applies geometric shapes with many sides, making it easier to arrange the formation under the sea. Aesthetically, the hexagonal shape can represent a design concept. It resulted from integration in the design of coral reef planting media with natural marine ecosystems and can produce new experiences and impressions to attract people's attention to pay more attention to the preservation of coral reefs. The assessment of fired shrinkage, water absorption, and apparent porosity on body mass for making the growth medium model was tested on 15 test pieces. The average value of fired shrinkage on 900°C temperature fired test pieces is 1.3%, the average water absorption is 19.7%, and the apparent porosity is 32.9%. Their value could be used to make artificial coral reef growth media.
Rekayasa ulang dan pembuatan prototipe/purwarupa slurry ice machine yang selanjutnya disebut Mesin Pembuat Bubur Es (MPBE) metode scraped-surface telah dilakukan agar dapat beroperasi di wilayah laut tropis, khususnya Indonesia. Rekayasa ulang dan uji produksi slurry ice telah dilakukan terhadap unit contoh yang dibeli dari pasar komersial. Rekayasa ulang telah berhasil memproduksi slurry ice dengan fraksi kristal es antara 30-40% dan fraksi cairan 60-70%. Konstruksi prototipe MPBE telah didesain dan diproduksi berkapasitas 1 ton slurry ice/24 jam. Selanjutnya prototipe dites dan mampu memproduksi slurry ice sebesar 700 kg/24 jam, mesin cukup kokoh terhadap transportasi pick-up dari Depok, Jawa Barat ke Lampung, Tasikmalaya, Jawa Barat untuk mengolah air tambak di tambak udang, dan Tanjung Lesung, Banten untuk mengolah air laut di atas kapal nelayan 35 GT. Prototipe MPBE dapat mengolah air tambak insitu, air laut dan air laut tiruan 4% NaCl menjadi bubur es. Slurry ice yang diproduksi oleh prototipe MPBE efektif digunakan untuk mendinginkan dan mengawetkan kesegaran udang budidaya tambak dan bekerja lebih baik dibandingkan dengan menggunakan es cacah. Udang yang disimpan menggunakan es cacah pada hari kelima sudah terlihat bercak hitam, sementara dengan slurry ice pada hari ke 14 masih terlihat segar. Diharapkan nelayan dan pengusaha perikanan Indonesia mulai mengetahui dan termotivasi untuk menggunakan slurry ice dalam usaha meningkatkan kualitas dan produktivitas industri perikanannya.
Sargassum is undoubtedly one of the most predominant brown macroalgae, posing a significant disposal problem for coastal areas worldwide. The effective valorization of Sargassum sp. would be beneficial not only for environmental mitigation but also for producing high-value chemicals. However, the valorization of Sargassum sp. for bio-oil and biochar production via slow pyrolysis has not been well studied yet. Hence, this study aimed to conduct a comprehensive investigation into bio-oil and biochar production from Sargassum sp. via slow pyrolysis to provide valuable data for further valorization. A batch reactor was employed, and the pyrolysis of Sargassum sp. was conducted in a temperature range of 400-600 °C and with retention times of 10-50 min. The results showed significant compounds could be identified in bio-oil from Sargassum sp., including carboxylic acids, furan derivatives, aliphatic hydrocarbons, and N-aromatic compounds. Based on the ultimate analysis, the H/C and O/C atomic ratios of biochar were lower than the feedstock, reflecting the occurrence of dehydration and decarboxylation reactions throughout the pyrolysis. Biochar exhibited calorific values in the range of 23.12-25.89 MJ kg⁻¹, indicating it has more potential to be used as a solid fuel than low-ranked coals. Surface morphological analysis was performed by scanning electron microscopy (SEM) and showed a larger surface area in biochar than in the algal feedstock. Furthermore, a reaction model was deduced, and it was confirmed that the pyrolysis reaction obeyed the Arrhenius behaviour. Overall, the slow pyrolysis of Sargassum sp. provides an opportunity to obtain value-added chemicals and biochars, which could be further utilized for other applications.
Ulva Lactuca is a fast-growing algae that can be utilized as a bioenergy source. However, the direct utilization of U. lactuca for energy applications still remains challenging due to its high moisture and inorganics content. Therefore, thermochemical processing such as slow pyrolysis to produce valuable added products, namely bio-oil and biochar, is needed. This study aims to conduct a thorough investigation of bio-oil and biochar production from U. lactuca to provide valuable data for its further valorization. A slow pyrolysis of U. lactuca was conducted in a batch-type reactor at a temperature range of 400–600 °C and times of 10–50 min. The results showed that significant compounds obtained in U. lactuca’s bio-oil are carboxylic acids (22.63–35.28%), phenolics (9.73–31.89%), amines/amides (15.33–23.31%), and N-aromatic compounds (14.04–15.68%). The ultimate analysis revealed that biochar’s H/C and O/C atomic ratios were lower than feedstock, confirming that dehydration and decarboxylation reactions occurred throughout the pyrolysis. Additionally, biochar exhibited calorific values in the range of 19.94–21.61 MJ kg−1, which is potential to be used as a solid renewable fuel. The surface morphological analysis by scanning electron microscope (SEM) showed a larger surface area in U. lactuca’s biochar than in the algal feedstock. Overall, this finding provides insight on the valorization of U. lactuca for value-added chemicals, i.e., biofuels and biochar, which can be further utilized for other applications.
Water available for livestock in the tropical lowland region is generally high in acidity. This study determined the effects of the acid water on nutrient intake, water balance, and the growth of goats in the tropical environment. A total of nine Kacang goats were stratified based on body weight (BW) and assigned to three treatment groups which were offered drinking water at varying pH levels, namely 6.9, 5.2, and 3.8. All goats were offered ad libitum Asystasia gangetica hay and dried cassava chips at 1% of BW (dry matter (DM) basis) following a crossover design with three treatments tested in three periods. At the 5.2 pH level, drinking water intake (DWI) tended to be lower (P = 0.09) while total DM intake (%BW) was decreased (P < 0.05). Ruminal pH was significantly difference (P < 0.01); 6.98, 6.94, and 6.58 at the 6.9, 5.2, and 3.8 pH levels, respectively. Metabolizable energy and daily gain tended to be higher at the 6.9 and 3.8 pH levels compared to those at the 5.2 level (P = 0.08). There were no significant adverse effects of acid water on nutrient intake, utilization, and growth of Kacang goats. Moreover, the increase in temperature-humidity index was followed by the elevated DWI (P < 0.01) at 6.9 pH level, but no such significant relationship was found at other pH levels that indicated a better capability of thermoregulation response under heat stress exposure.
The use of petroleum-based plastics has raised environmental issues as more plastic waste enters and accumulates in the environment. It has led to the development of biodegradable plastics. Starch is one of the potential materials to make biodegradable plastic, but starch-based plastic has poor mechanical strength. Blending starch with poly(vinyl alcohol) (PVA) and lignin is expected to improve the mechanical properties of the plastic. Biodegradable plastic films from PVA/starch/lignin blends with glycerol as a plasticizer were prepared using an internal mixer for compounding and a hot press molding machine for film making. The percentage of lignin (2-10%), glycerol (25-65%), and mixing temperature (190-230 oC) were varied according to the three levels of the Box-Behnken design. The ANOVA evaluation revealed that glycerol had the most significant effect on the mechanical properties of the film. Then, three models for the estimation of tensile strength, elongation at break, and tear resistance were developed. As expected, the models satisfactorily predict the effect of all input variables on the response variables. The optimum conditions for preparing the film were acquired from the equations, namely 197.6 oC for the temperature, 10% for lignin, and 45.1% for glycerol. The biodegradable plastic prepared using the optimum conditions possessed a tensile strength of 8.46 ± 1.08 MPa, an elongation at break of 139.00 ± 8.59%, and a tear resistance of 69.50 ± 2.50 N/mm. These values are in good agreement with the predicted values. Doi: 10.28991/ESJ-2022-06-02-03 Full Text: PDF
The aim of this study was to evaluate the effect of supplementation of organic acid and probiotic derived from grass silage on the egg quality of duck. Seventy-two Pegagan laying ducks (average age: 24 weeks) were randomly allocated to six treatment groups: basal diet, basal diet + organic acid, basal diet + probiotic, basal diet + tetracycline, basal diet + probiotic + organic acid, and basal diet + organic acid + tetracycline. The result showed that the feeding diets containing probiotics and organic acid significantly (P < 0.05) reduced yolk fat and yolk cholesterol and increased eggshell weight, egg index, yolk color score, Haugh unit, and protein content. However, egg weight, albumen weight, yolk weight, albumen index, yolk index, and water content were not significantly (P > 0.05) different. It is concluded that dietary supplementation of organic acid and probiotic derived from grass silage improved egg quality in terms of yolk color score, fat, and cholesterol content.
Oil palm empty fruit bunches (OPEFB) are the lignocellulosic complex organic waste material from palm oil mills that is cheap, environmentally friendly, and abundant in Indonesia. Slow degradation of OPEFB becomes a problem for oil palm plantations. OPEFB which has decayed naturally for 6 months, 1 year, and 2 years were obtained from the Oil Palm Plantation, PTPN VIII Cikasungka, Bogor, Indonesia. In this study, fungal and bacterial diversity in naturally decaying OPEFB in plantations was identified using Illumina MiSeq sequencing of the ITS2 for fungal, the V3 region of the 16S rRNA gene, and the V4 region of the 18S rRNA gene for bacterial. Bacterial diversity in decaying OPEFB was dominated by the phylum Planctomycetes (40-60%), whereas most of the fungal sequences taken belonged to Ascomycota (60-90%). Biodiversity profile resulting from metagenomic analysis is useful for increasing knowledge about microbial composition in the natural degradation process of OPEFB. The resulting data can be used to compare the diversity of bacteria at different weathering times and depths. In-depth observation of the diversity of lignin-degrading microbes from the natural decomposition of OPEFB has the potential to discover novel enzymes and ligninolytic activities that are useful for the fast degradation of OPEFB, production of biofuels based on enzymatic technology, and the development of high value-added biomass products.
Precipitate in B20 fuel stored in storage tanks can accumulate at the bottom level of the tank and affect the fuel filter, clogging in the fuel distribution and engine system. This study examines the precipitate formation prediction in B20 fuel based on the monoglyceride content in biodiesel. This research used a modified CSFT method of ASTM D7501 for the precipitation test. Monopalmitin was added to biodiesel with a variation of monoglyceride content. Each biodiesel sample was then blended with petroleum diesel fuel to produce two groups of samples. Each sample was separately soaked in the cooling chamber at constant and room temperature for 21 days. The bottom layer of each B20 fuel sample stored in the measuring cylinder was then pipetted and filtered, washed with petro-ether, vacuum-dried, and weighed for a constant amount of precipitate retained on the filter. The simulation results show that the ratios between the amount of collected precipitate at the bottom layer of the 2-liter measuring cylinder and the total amount of collected precipitate for the 2-liter measuring cylinder increased with the monoglyceride content biodiesel. This ratio was used to predict the amount of accumulated sludge for a given volume of B20 fuel loaded into the storage tank. This study shows the effect of monoglyceride content on the precipitation behaviour in the storage tank concerning general tank storage dimension parameters and B20 loading frequency. This approach can be applied to estimate the sludge removal frequency for biodiesel storage.
Due to population growth and economic development, the world is experiencing a global challenge in managing high energy demand. Sustainable energy development should include three aspects: promotion of renewable energy, reduced environmental risk, and high process optimization. However, the biomass feedstock is not suitable for end-users' direct use as a source of primary energy. They can use various conversion technologies to produce secondary energy forms or energy carriers such as biofuels, heat, or electricity. This situation has sparked a lot of interest in secondary energy carriers like hydrogen, potentially helping renewable energy in different forms. Unfortunately, due to its low volumetric density and proneness to leakage, hydrogen poses a major storage challenge. In order to address this issue, efficient hydrogen storage and transportation methods are being actively developed, including compression, liquefaction, hydrate binding, and conversion to other materials (ammonia, methanol). This chapter discusses advanced production systems for ammonia from empty fruit bunch. In addition, liquid hydrogen, methylcyclohexane, and ammonia are considered potential hydrogen storage among several alternatives and are also discussed briefly at the beginning of this chapter.
This chapter will focus on how readily available biomass waste from agricultural activities can be used as a cost-effective alternative fuel. Agricultural waste is no longer openly burned or left to rot on the ground, as it has been for a long time, contaminating the atmosphere and emitting greenhouse gases. Several biomass-utilization technologies, including agricultural waste, have been developed over time. Both biochemical (fermentation) and thermochemical (pyrolysis, gasification) methods may produce liquid and/or gaseous fuels. These fuels may be used as energy sources directly or converted into chemicals and products that are useful. Physical processes such as briquetting and compaction can also be utilized to make solid fuels. However, since microbes struggle to break down the highly crystalline cellulose embedded in the lignin matrix, biochemical conversion is not recommended for lignocellulosic biomass breakdown. Although a high-intensity heat source is needed, the thermochemical process is still considered an effective technology for converting lignocellulosic biomass into bioenergy. Integrated systems using rice waste and palm oil residue (empty fruit bunch) have been proposed and evaluated in this chapter. The aim is to achieve high total energy efficiency by minimizing exergy destruction in the integrated system.
This chapter is prepared to understand basic thermodynamic concepts and adopt them in practical applications. Understanding thermodynamics concepts will help us to apply them in a targeted system to improve its efficiency. Some essential engineering thermodynamics backgrounds will be explained first before discussing the exergy concept, pinch analysis, and enhanced process integration. Exergy efficiency is an important tool to evaluate system performance. Analysis based on exergy efficiency can make more sense than counting energy efficiency since it would give efficiencies close to 100%. Thus, exergy analysis has a significant role in investigating and improving various technologies and systems' performances. It also becomes a useful tool for engineers and scientists as well as policymakers in many fields. However, ingenuity and creativity are often required to implement the efficiency improvement. Also, by understanding the causes, locations, and magnitudes of the losses, efficiency-improvement efforts can be more focused. Using these approaches, we want to achieve the enhanced process integration based on straightforward thermodynamics and practically use it for the biomass-based system.
This chapter proposes stand-alone recovery from black liquor (BL). Ideally, in the modern pulp mill industry, a factory system can independently provide internal energy demands for continuous process. Traditionally, energy recovery is conducted by combusting BL after water removal via multiple-effect evaporation (MEE). Firstly, the conventional methods for the production of electricity and H2 from BL are discussed. The performance of these systems is evaluated by comparing lower heating value (LHV)-based efficiency. Furthermore, several integrated systems are proposed based on the concept of exergy recovery and process integration to minimize exergy loss. Thermodynamic modeling of proposed integrated systems is also investigated to show the performance of BL recovery. The proper BL utilization can significantly improve the economic benefit and minimize the impacts on the environment. The appropriate waste recovery can also satisfy the internal energy demand before the surplus energy can be exported.
The main biomass-to-energy conversion pathways can be classified into thermochemical and biochemical conversion. The former involves heat and chemical processes to obtain primary products from biomass waste. Among thermochemical methods are combustion, gasification, pyrolysis, liquefaction, and thermochemical cycle. Biochemical conversion involves microorganisms to decompose and convert biomass into gaseous or liquid fuels such as anaerobic digestion, fermentation, and photobiological hydrogen production. In this chapter, biomass upgrading, several possible routes, and key conversion technologies of “biomass waste to energy” are reviewed. Recent progress related to biochemical and thermochemical conversion technologies and their main products is described. Also, several challenges regarding the conversion and utilization of biomass and waste are discussed.
The massive use of fossil fuels in today's global energy has caused environmental problems by releasing greenhouse gases (carbon dioxide and nitrous oxide) to the environment and contributing to various health problems. Also, energy consumption is expected to grow rapidly due to population and global economic growth. Humans consume energy for transportation, heating/cooling, or electricity in their daily activities. Reducing fossil fuels requires alternative energy sources that offer a sustainable supply with lower environmental impacts. This chapter discusses a brief introduction to an overview of biomass waste utilization. It starts with a discussion of current energy and environmental problems in including the opportunity to utilize biomass waste as an energy source. The global energy situation is also presented to understand the escalating increase in energy demand, continued dependence on fossil-based fuels for generation, and the rise in renewable energy use in many countries. Classification of biomass, including general properties, and its potential in the world are also reviewed in this chapter.
The high performance of the proposed integrated systems should be feasible technically, economically, and environmentally. Exergoeconomic analysis can be used in thermal systems as a modern tool for integrating exergy and economic analysis to investigate biomass-based energy conversion processes. As a complement, the exergoenvironmental analysis can be adopted to assign environmental impacts within each process component for both energy and material flows as well as thermodynamic inefficiencies. Though some researchers employ exergoeconomic analysis and exergoenvironmental analysis in design energy systems, they mostly focus on only one of the two aspects (either exergoeconomic analysis or exergoenvironmental analysis). However, the systems operating under optimized exergoeconomic conditions might not agree with the best exergoenvironmental requirements. Furthermore, this book's main conclusions are: (1) Exergy analysis is a useful tool to evaluate a system's performance. (2) There are two engineering design problems in integrated processes. The first is the problem of unit operation design and the second is designing entire systems. This book mostly addresses the second issue. (3) Ingenuity and creativity are required to design a process and implement efficiency improvement. (4) However, comprehensive evaluations are needed considering the interrelations among exergy efficiency itself, economy, and environment for a sustainable system.
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