Sobia Ashraf’s research while affiliated with Government College University Faisalabad and other places

Soil heavy metal pollution is a major environmental issue in the world. With ever-increasing industrialization, it is the need of the hour to develop low-cost and eco-friendly heavy metal remediation procedures. Phytoremediation is a new approach to extracting heavy metals from contaminated soil for environmental sustainability. In the present study, Brassica juncea (L.) was tested to extract cadmium (Cd) from contaminated soil using Cd-tolerant plant growth-promoting rhizobacteria (PGPR) and acidified organic amendment. The PGPR were isolated, screened for Cd tolerance, and the best strain (CTB5; Pseudomonas aeruginosa) was selected for seed coating to be used in the pot experiment. To enhance the bioavailability of Cd, elemental sulfur (S°), molasses, and sulfur-oxidizing bacteria (SOB) were added to the cow dung for acidification. A pot experiment was conducted for 60 days under Cd-spiked and normal soil using Brassica juncea (L.) as test crop with six treatments (T1: Control; T2: 0.5% acidified organic amendment; T3: 1% acidified organic amendment; T4: PGPR-coated seeds of B. juncea; T5: 0.5% acidified organic amendment + PGPR-coated seeds of B. juncea; T6: 1% acidified organic amendment + PGPR-coated seeds of B. juncea). The results have shown that T6 treatment caused a maximum increase in the shoot and root Cd concentration of Brassica juncea (164% and 102%, respectively) over the respective untreated control. Bioconcentration and translocation factors also showed a similar trend. A significant decrease of 34, 52, 41, and 66% in malondialdehyde, peroxidase, superoxide dismutase, and catalase of Brassica juncea was observed due to T6 compared to respective untreated control under Cd-stressed soil. The results suggested that the combined application of PGPR and acidified organic amendment improved the antioxidative defense mechanism of Brassica juncea (L.) and could be employed for effective phytoremediation of Cd-contaminated soil.

Industrialization (industrial waste, paints, sewage discharge, and mining activities), agricultural practices (agricultural runoff, insecticides, and pesticides), and natural sources (soil erosion and weathering) are the main sources of heavy metal contamination of the environment and pose serious threat to the human health. Therefore, removal of heavy metals from the environment is very important to protect the surroundings we live. The traditional physio-chemical methods to phase out toxic metals from soil are not economical and environmentally sound. Indigenous and genetically engineered microorganisms can be used for the bioremediation of the hazardous metal-polluted sites for the stabilization of the ecosystem. Bacterial consortium can also be advantageous for effective bioremediation of toxic metal-contaminated sites. Furthermore, heavy-metal hyperaccumulator (HMH) plants have great potential to concentrate on heavy metals’ 100–1000-fold higher in their above-ground tissues in contrast to non-HMHs, thus can be good option to remove the contaminants from the environment.

Soil heavy metal contamination is increasing rapidly due to increased anthropogenic activities. Lead (Pb) is a well-known human carcinogen causing toxic effects on humans and the environment. Its accumulation in food crops is a serious hazard to food security. Developing environment-friendly and cost-efficient techniques is necessary for Pb immobilization in the soil. A pot experiment was executed to determine the role of biochar (BC), zero-valent iron nanoparticles (n-ZVI), and zero-valent iron nanoparticles biochar composite (n-ZVI-BC) in controlling the Pb mobility and bioaccumulation in wheat (Triticum aestivum L.). The results showed that BC and n-ZVI significantly enhanced the wheat growth by increasing their photosynthetic and enzymatic activities. Among all the applied treatments, the maximum significant (p ≤ 0.05) improvement in wheat biomass was with the n-ZVI-BC application (T3). Compared to the control, the biomass of wheat roots, shoots & grains increased by 92.5, 58.8, and 49.1%, respectively. Moreover, the soil addition of T3 amendment minimized the Pb distribution in wheat roots, shoots, and grains by 33.8, 26.8, and 16.2%, respectively. The outcomes of this experiment showed that in comparison to control treatment plants, soil amendment with n-ZVI-BC (T3) increased the catalase (CAT), superoxide dismutase (SOD) activity by 49.8 and 31.1%, respectively, ultimately declining electrolyte leakage (EL), malondialdehyde (MDA) and hydrogen peroxide (H2O2) content in wheat by 38.7, 33.3, and 38%respectively. In addition, applied amendments declined the Pb mobility in the soil by increasing the residual Pb fractions. Soil amendment with n-ZVI-BC also increased the soil catalase (CAT), urease (UR), and acid phosphatase (ACP) activities by 68, 59, and 74%, respectively. Our research results provided valuable insight for the remediation of Pb toxicity in wheat. Hence, we can infer from our findings that n-ZVI-BC can be considered a propitious, environment friendly and affordable technique for mitigating Pb toxicity in wheat crop and reclamation of Pb polluted soils.

Heavy metal contamination of soil is an alarming environmental dilemma all over the world. With increasing industrialization, timely development of low-cost and eco-friendly remedial techniques for heavy metal-contaminated soil is needed. Phytoremediation is an emerging technique to remove heavy metals from contaminated soil for environmental sustainability. In the present study, ryegrass was used for phytoextraction of lead and cadmium from contaminated soil in a pot experiment. To enhance the bioavailability of heavy metals, cow dung was acidified by amending with elemental sulfur and molasses and also bioaugmented with an SS-16 sulfur-oxidizing strain to boost biological sulfur oxidation and, hence, four chemically different organic products were prepared. The pot experiment was conducted for a period of 60 days under Pb- and Cd-spiked soil for growing ryegrass with the application of a 10% slurry of each acidified organic product. A significant increase in root and shoot fresh mass as well as Pb and Cd accumulation in the root and shoot of the ryegrass was recorded. As compared to the control and the acidified organic product, P4 was the most effective product overall. Bioconcentration and translocation factors of ryegrass for Pb and Cd were also calculated. At the same time, acidified cow dung slurry (10%) also improved the antioxidative defense mechanism of ryegrass. The results suggest that acidified organic products could be effective for phytoextraction of lead and cadmium from contaminated soil, and in the future acidified cow dung slurry can be used to restore heavy metal-polluted soils in an environmentally sustainable way.

The rapid increase in population growth due to industrialization and urbanization has resulted in air quality deterioration in Pakistan. Consequently, a considerable increase has been seen in the types of sources of air pollutants. However, the air quality of the country has deteriorated in the absence of management capabilities against air quality. Evidence from numerous governmental organizations and international bodies has specified that the environment, health, and quality of life are at high risk due to air pollution. Although the government of Pakistan established the Pakistan Clean Air Program, along with continuous monitoring stations to manage the quality of ambient air, air quality values have not yet been achieved. The present investigations were made in the city of Faisalabad in selected locations. Sampling of a 24 h average was done for selected sites. The air quality parameters such as NO2, SO2, COx, O2, noise level, and suspended particulate matter (SPM) were measured at two locations, i.e., Khurrianwala and Liaqatabad in the Faisalabad District. The measured values of air quality parameters were compared with national environmental quality standards (NEQS). Air pollutants such as SPM, SO2, and noise levels were found to be significantly higher than the 24-h standards of NEQS, which poses harmful effects on the quality of air and health, whereas the O2 concentration was found to be lower than the normal values, and NO2 and COx values were normal. The SO2, CO2, noise level, SPM, and O2 values ranged from 418–652 and 423–661 µg/m3, 3.03–3.44 and 3.08–3.51 mg/m3, 68–73 and 69–75 dB, 555–667 and 581–682 µg/m3, and 19.5–20 and 19.5–20.3 % for summer and winter season, respectively, as compared to standard values (150 µg/m3, 10 mg/m3, 65 dB, 550 µg/m3 and 21%). After the complete analysis of the selected locations, it was concluded that the ambient air quality of this area is severely degraded due to industrial as well as other commercial activities. These significant variations in air quality parameters suggest that there is a need to check the air quality regularly to take appropriate measures for reducing ambient air pollutants, especially in industrial areas as well as commercial areas.

Reduced germination and early crop maturity due to soil compaction, nutrients stress, and low moisture are major constraints to achieve optimum crop yield, ultimately resulting in significant economic damages and food shortages. Biochar, having the potential to improve physical and chemical properties of soil, can also improve nutrients and moisture access to plants. In the present study, a growth room experiment was conducted to assess biochar influence on maize seed germination, early growth of seedlings, and its physiological attributes. Corn cob biochar (CCB) was mixed with soil at different rates (0.5%, 1%, 1.5%, 2%, 2.5%, and 3% w/w) before seed sowing. Results obtained showed that increasing CCB application rate have neutral to positive effects on seed germination and seedling growth of maize. Biochar addition at the rate of 1.5% (w/w) significantly increased shoot dry biomass (40%), root dry biomass (32%), total chlorophyll content (a and b) (55%), germination percentage (13%), seedling vigor (85%), and relative water content (RWC) (68%), in comparison to un-amended control treatment. In addition to this, it also improved germination rate (GR) by 3% as compared to control treatment, while causing a reduction in mean emergence time (MET). Moreover, application of biochar (3%) also resulted in enhancement of antioxidant enzyme activity, particularly superoxide dismutase (SOD) and catalase (CAT) by 13% and 17%, respectively. Conclusively, biochar application is an attractive approach to improve the initial phase of plant growth and provide better crop stand and essential sustainable high yields.

Soil pollution with heavy metal is a serious problem across the globe and is on the rise due to the current intensification of chemical industry. The leather industry is one of them, discharging chromium (Cr) in huge quantities during the process of leather tanning and polluting the nearby land and water resources, resulting in deterioration of plant growth. In this study, the effects of biochar application at the rate of 3% were studied on four maize cultivars, namely NK-8441, P-1543, NK-8711, and FH-985, grown in two different tannery polluted Kasur (K) and Sialkot (S) soils. Maize plants were harvested at vegetative growth and results showed that Cr toxicity adversely not only affected their growth, physiology, and biochemistry, but also accumulated in their tissues. However , the level of Cr toxicity, accumulation, and its influence on maize cultivars varied greatly in both soils. In this pot experiment, biochar application played a crucial role in lessening the Cr toxicity level, resulting in significant increase in plant height, biomass (fresh and dry), leaf area, chlorophyll pigments, photosynthesis, and relative water content (RWC) over treatment set as a control. However, applied biochar significantly decreased the electrolyte leakage (EL), antioxidant enzymes, lipid peroxidation, proline content, soluble sugars, and available fraction of Cr in soil as well as Cr (VI and III) concentration in root and shoot tissues of maize plant. In addition to this, maize cultivar differences were also found in relation to their tolerance to Cr toxicity and cultivar P-1543 performed better over other cultivars in both soils. In conclusion, biochar application in tannery polluted soils could be an efficient ecofriendly approach to reduce the Cr toxicity and to promote plant health and growth.