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In order to investigate the explosion process of calcium carbide (CaC

Fly ash from municipal solid waste incineration is considered as a hazardous waste, which would raise great threats on environmental safety due to the inherent toxic heavy metals and organic pollutants. In this study, we applied the life cycle assessment to evaluate the thermal plasma vitrification process for stabilization of fly ash from municipal solid waste incineration. We established four scenarios: (i) plasma vitrification, including centralized and off-site plasma treatment, (ii) fuel-based vitrification, (iii) water-washing treatment followed by a rotary kiln, and (iv) conventional solidification and landfill. We found that the environmental impacts, especially toxicity to ecosystem quality and human health, could be significantly reduced by deploying plasma vitrification technology. We also found that centralized plasma vitrification facilities possessing larger treatment capabilities with clean electricity could further reduce the environmental impacts. In contrast, the water-washing treatment exhibited the highest environmental impacts due to the emissions of vaporized heavy metals. Based on the LCA and sensitivity analysis, we confirmed that the thermal plasma vitrification should be considered as an environmentally-friendly solution to sustainable treatment of fly ash from municipal solid waste incineration. Lastly, we provided several perspectives and prospects of plasma vitrification for realizing the sustainable materials management.

For decades, pesticides have been widely used for controlling pests and protecting crops around the world, and the food safety issues caused by these compounds have raised widespread concern. However, the different enantioselective behaviors and biological activities of chiral pesticide enantiomers are often ignored. In this work, a novel method was put forward to investigate the enantioselective effects and potential risks of two paclobutrazol enantiomers during cucumber pickling process. The degradation kinetics indicated that when paclobutrazol reside in cucumber and was introduced into the pickling process, the half-time of paclobutrazol isomers were significantly different (9.24 d and 16.6 d), and the conversion phenomenon between the two enantiomers could also be observed. In addition, results from 16S rRNA and ITS sequencing shown that (2R, 3R)-paclobutrazol and (2S, 3S)-paclobutrazol have an obviously enantiomeric effects on microbial community of pickling system and the degradation of paclobutrazol was probably attributed to the presence of Pseudomonas and Serratia. Finally, the microorganisms functions were found to be disrupted under the exposure of (2R, 3R)-paclobutrazol and metabolic function of microorganisms to xenobiotic was inhibited, which might cause potential risks to the quality of preserved foods. In summary, we have devised a method and provided a novel insight into the potential risks of chiral pesticide residues on food safety and human health.

Metalloids such as boron and silicon are key elements for plant growth and crop productivity. However, toxic metalloids such as arsenic are increasing in the environment due to inputs from natural sources and human activities. These hazardous metalloids can cause serious health risks to humans and animals if they enter the food chain. Plants have developed highly regulated mechanisms to alleviate the toxicity of metalloids during their 500 million years of evolution. A better understanding the molecular mechanisms underlying the transport and detoxification of toxic metalloids in plants will shed light on developing mitigation strategies. Key transporters and regulatory proteins responsive to toxic metalloids have been identified through evolutionary and molecular analyses. Moreover, knowledge of the regulatory proteins and their pathways can be used in the breeding of crops with lower accumulation of metalloids. These findings can also assist phytoremediation by the exploration of plants such as fern species that hyperaccumulate metalloids from soils and water, and can be used to engineer plants with elevated uptake and storage capacity of toxic metalloids. In summary, there are solutions to remediate contamination due to toxic metalloids by combining the research advances and industrial technologies with agricultural and environmental practices.

A Gram-negative chlorate-reducing bacterial strain XM-1 was isolated. The 16S rRNA gene sequence identified the isolate as Ochrobactrum anthropi XM-1, which was the first strain of genus Ochrobactrum reported having the ability to reduce chlorate. The optimum growth temperature and pH for strain XM-1 to reduce chlorate was found to be 30 °C and 5.0–7.5, respectively, under anaerobic condition. Strain XM-1 could tolerate high chlorate concentration (200 mM), and utilize a variety of carbohydrates (glucose, L-arabinose, D-fructose, sucrose), glycerin and sodium citrate as electron donors. In addition, oxygen and nitrate could be used as electron acceptors, but perchlorate could not be reduced. Enzyme activities related to chlorate reducing were characterized in cell extracts. Activities of chlorate reductase and chlorite dismutase could be detected in XM-1 cells grown under both aerobic and anaerobic conditions, implying the two enzymes were constitutively expressed. This work suggests a high potential of applying Ochrobactrum anthropi XM-1 for remediation of chlorate contamination.

Aluminum (Al) stress in acid soils is one of the major factors limiting crop productivity. ATP binding cassette (ABC) transporters have numerous roles in plants, but the link between ABCB protein subfamily and plant Al tolerance is still elusive. Here, we identified and characterized a novel tonoplast HvABCB25 in barley root cells. HvABCB25 was up-regulated in the transcriptome of Al-tolerant wild barley XZ16 under Al treatment and was highly Al-inducible in root tips. ABCB25 is originated from Streptophyte algae and evolutionarily conserved in land plants. Moreover, silencing HvABCB25 in Al-tolerant XZ16 led to significant suppression of Al tolerance as indicated by significantly reduced root growth and enhanced Al accumulation in root cells. Conversely, HvABCB25-overexpressed plants and Golden Promise showed similar Al content in whole roots and in cell sap, but the overexpression lines exhibited significantly higher Al-induced relative root growth and dry weight. Al florescence in cytosol of root cells were significantly less in overexpression lines than that in GP. These results indicated that overexpressing HvABCB25 may be responsible for Al detoxification via vacuolar Al sequestration in barley roots, providing useful insight into the genetic basis for a new Al detoxification mechanism towards plant Al tolerance in acid soils.

In the present study, the degradation mechanisms of beta-cypermethrin and its metabolites in soil were explored through the quantitative response relationships between the degradation rates and related functional genes. We found that the degradation rate of beta-cypermethrin was rapid in unsterilized soil but not in sterilized soil, which indicated that the degradation process is microbially based. Moreover, three metabolites (3-phenoxybenzoic acid, phenol and protocatechuic acid) were detected during the degradation process and used to identify the degradation pathway and functional genes related to the degradation process. The key rate-limiting functional genes were pytH and pobA, and the relative contributions of these genes to the degradation process were examined with a path analysis. The path analysis revealed that the genes pobA and pytH had the greatest direct effects on the degradation of beta-cypermethrin (pobA), alpha-cypermethrin (pobA), theta-cypermethrin (pytH) and 3-phenoxybenzoic acid (pytH).