In this study, the influence of coconut shell biochar addition (CSB) on heavy metals (Cu and Zn) resistance bacterial fate and there correlation with physicochemical parameters were evaluated during ...poultry manure composting. High-throughput sequencing was carried out on five treatments, namely T1−T5, where T2 to T5 were supplemented with 2.5%, 5%, 7.5% and 10% CSB, while T1 was used as control for the comparison. The results of HMRB indicated that the relative abundance of major potential bacterial host altered were Firmicutes (52.88–14.32%), Actinobacteria (35.20–4.99%), Bacteroidetes (0.05–15.07%) and Proteobacteria (0.01–20.28%) with elevated biochar concentration (0%−10%). Beta and alpha diversity as well as network analysis illustrated composting micro-environmental ecology with exogenous additive biochar to remarkably affect the dominant resistant bacterial community distribution by adjusting the interacting between driving environmental parameters with potential host bacterial in composting. Ultimately, the amendment of 7.5% CSB into poultry manure composting was able to significantly reduce the HMRB abundance, improve the composting efficiency and end product quality.
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•Bacterial diversity was reduced (88.10%−57.70%) with increasing biochar concentration.•The superior bacterial were Firmicutes (52.88–14.32%) and Actinobacteria (35.20–4.99%).•The 7.5% biochar can be efficiently altered the Cu and Zn resistant bacterial viability.•Biochar remarkably affect composting environment.
Environmental pollution by heavy metals resulting from rapid economic development is a major concern. Soil, water, wheat, and rice samples were collected from the Lihe River Watershed in the Taihu ...Region (east China). In this study area, many types of industrial plants, including ceramics factories, plants working with refractory materials, and chemical plants are densely distributed and cause serious heavy metal pollution. In addition, well-developed transportation and agricultural activities are also important sources of heavy metals. Thus, the concentrations of selected heavy metals including cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn) in the samples were analyzed to evaluate their potential integral risk (IR) to the health of the local population. Accordingly, the spatial distribution pattern of the IR values was determined in the study. The soil in the study area showed heavy Cd pollution, whereas the pollution by other elements was relatively slight. When the proportions of grain samples in which the concentrations exceeded the tolerance limits were examined, the grains were primarily contaminated with Pb, Ni, Cd, and Zn; and less contaminated with Cu and Cr. The drinking water of the local inhabitants was safe. The average IR value was 3.53 for adults and 3.91 for children, indicating that both adults and children may experience adverse health effects. The spatial distribution pattern of the IR values among the exposed populations in the study area showed high values in the eastern and middle parts, with maximum values >5, and low values in the western part, with minimum values <2. This is consistent with the distributions of the industries and the population. The study may provide a basis for comparison to other regions both in China and worldwide.
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•Elevated concentrations of heavy metals were observed in the soil and crop locally.•Risk assessment of heavy metal contamination was significant for local inhabitants.•IR via ingesting rice, wheat, water and soil was high, especially for children.•Consumption of rice and wheat was the major contribution to risk.•The spatial distribution pattern of IR was predicted using geostatistical analysis.
Soil contamination with persistent and potentially (eco)toxic heavy metal(loid)s is ubiquitous around the globe. Concentration of these heavy metal(loid)s in soil has increased drastically over the ...last three decades, thus posing risk to the environment and human health. Some technologies have long been in use to remediate the hazardous heavy metal(loid)s. Conventional remediation methods for heavy metal(loid)s are generally based on physical, chemical and biological approaches, which may be used in combination with one another to clean-up heavy metal(loid) contaminated soils to an acceptable and safe level. This review summarizes the soil contamination by heavy metal(loid)s at a global scale, accumulation of heavy metal(loid)s in vegetables to toxic levels and their regulatory guidelines in soil. In this review, we also elucidate and compare the pool of available technologies that are currently being applied for remediation of heavy metal(loid) contaminated soils, as well as the economic aspect of soil remediation for different techniques. This review article includes an assessment of the contemporary status of technology deployment and recommendations for future remediation research. Finally, the molecular and genetic basis of heavy metal(loid) (hyper)accumulation and tolerance in microbes and plants is also discussed. It is proposed that for effective and economic remediation of soil, a better understanding of remediation procedures and the various options available at the different stages of remediation is highly necessary.
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•Soil heavy metal contamination is ubiquitous around the globe.•Bioremediation is more economical & eco-friendly than physical & chemical methods.•Combined remediation is the most effective and economical at large scale.•Microbial assisted genetically modified plants have high future perspectives.
In recent years, soil pollution is a major global concern drawing worldwide attention. Earthworms can resist high concentrations of soil pollutants and play a vital role in removing them effectively. ...Vermiremediation, using earthworms to remove contaminants from soil or help to degrade non-recyclable chemicals, is proved to be an alternative, low-cost technology for treating contaminated soil. However, knowledge about the mechanisms and framework of the vermiremediation various organic and inorganic contaminants is still limited. Therefore, we reviewed the research progress of effects of soil contaminants on earthworms and potential of earthworm used for remediation soil contaminated with heavy metals, polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), polycyclic aromatic hydrocarbons (PAHs), pesticides, as well as crude oil. Especially, the possible processes, mechanisms, advantages and limitations, and how to boost the efficiency of vermiremediation are well addressed in this review. Finally, future prospects of vermiremediation soil contamination are listed to promote further studies and application of vermiremediation in contaminated soils.
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•Earthworms are useful for the removal of heavy metals and organic contaminants from soil.•Vermiremediation consist of accumulation, transformation, and degradation of the contaminants.•Remediation can be boosted by the addition of surfactants, biochar and co-application with phytoremediation.
Water contamination by toxic heavy metal ions and dyes remains a serious public health problem for humans, so attention on specific methods and technologies to remove heavy metal ions and dyes from ...wastewaters/aqueous solutions are desired. Numerous adsorbents have been reported for the removal of heavy metal ions/dyes from wastewaters/aqueous solutions. Polyaniline (PANI) and its derivatives, as conducting polymers, are good adsorbents to remove various kinds of heavy metal ions and dyes from wastewaters/aqueous solutions. The nanoadsorbents based on PANI and its derivatives have received much consideration, and are extensively reported in literature. This review focuses on the PANI and its derivatives based on nanoadsorbents for water purification. Various types of these nanoadsorbents used for the removal of heavy metal ions/dyes from wastewaters/aqueous solutions are also briefly compared in this review.
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•Nanoadsorbents based on conductive polymers can remove heavy metal ions/dye.•Contact time, pH, adsorbent dosage and temperature are effective adsorption factors.•Chemical structures of nanoadsorbents play an important role in adsorption.•Adsorption of metal ions on PANI based nanocomposites is of physical type.
The reasonable disposal of plant biomass containing heavy metals (HMs) is a difficult problem for the phytoremediation technology. This review summarizes current literature that introduces various ...disposal and utilization methods (heat treatment, extraction treatment, microbial treatment, compression landfill, and synthesis of nanomaterials) for phytoremediation plants with HMs. The operation process and technical parameters of each disposal method are different. HMs can migrate and transform in different disposal processes. Some disposal and utilization methods can get some by-products. The main purpose of this paper is to provide reference for technical parameters and characteristics of various disposal and utilization methods, so as to choose and use the appropriate method for the treatment of plant biomass containing HMs after phytoremediation.
•There are various methods for the treatment of plant biomass with heavy metals.•Heavy metals can migrate and transform in different disposal processes.•The operation process and technical parameters of each disposal method are different.•Many factors should be considered in choosing a reasonable disposal method.•The combination of multiple disposal methods can be considered.
Mercuric ion (Hgsup.2+) in aqueous media is extremely toxic to the environment and organisms. Therefore, the ultra-trace electrochemical determination of Hgsup.2+ in the environment is of critical ...importance. In this work, a new electrochemical Hgsup.2+ sensing platform based on porous activated carbon (BC/Cusub.2O) modified with cuprous oxide was developed using a simple impregnation pyrolysis method. Differential pulse anodic stripping voltammetry (DPASV) was used to investigate the sensing capability of the BC/Cusub.2O electrode towards Hgsup.2+. Due to the excellent conductivity and large specific surface area of BC, and the excellent catalytic activity of Cusub.2O nanoparticles, the prepared BC/Cusub.2O electrode exhibited excellent electrochemical activity. The high sensitivity of the proposed system resulted in a low detection limit of 0.3 ng·Lsup.−1 and a wide linear response in the ranges from 1.0 ng·Lsup.−1 to 1.0 mg·Lsup.−1. In addition, this sensor was found to have good accuracy, acceptable precision, and reproducibility. All of these results show that the BC/Cusub.2O composite is a promising material for Hgsup.2+ electrochemical detection.
Over the past 50 years, the emergence of plastic waste as one of the most urgent environmental problems in the world has given rise to several proposals to address the rising levels of contaminants ...associated with plastic debris. Worldwide plastic production has increased significantly over the last 70 years, reaching a record high of 359 million tonnes in 2020. China is currently the world's largest plastic producer, with a share of 17.5%. Of the total marine waste, microplastics account for 75%, while land-based pollution accounts for responsible for 80–90%, and ocean-based pollution 10–20% only in overall pollution problems. Even at small dosages (10 μg/mL), microplastics have been found to cause toxic effects on human and animal health. This review examines the sources of microplastic contamination, the prevalent reaches of microplastics, their impacts, and the remediation methods for microplastic contamination. This review explains the relationship between the community composition and the presence of microplastic particulate matter in aquatic ecosystems. The interaction between microplastics and emerging pollutants, including heavy metals, has been linked to enhanced toxicity. The review article provided a comprehensive overview of microplastic, including its fate, environmental toxicity, and possible remediation strategies. The results of our study are of great value as they illustrate a current perspective and provide an in-depth analysis of the current status of microplastics in development, their test requirements, and remediation technologies suitable for various environments.
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•Microplastics are emerging global contaminants in the environment.•Aspects related to sources, distribution, categorization, and characterization are discussed.•Higher toxicity may be induced by the interaction of MPs'.•Technologies for remediation and microplastic detection were discussed.•The mechanism, benefits, and key challenges of MPs removal technology are proposed.
Terrestrial surface ecosystems are important sinks for antibiotic resistance genes (ARGs) due to the continuous discharge of contaminants from human-impacted ecosystems. However, the abundance and ...resistance types of ARGs and their influencing factors in terrestrial subsurface soils are not well known. In this study, we investigated the abundance and diversity of ARGs, and their correlations with metal resistance genes (MRGs), mobile genetic elements (MGEs), bacteria, and heavy metals in subsurface soils using high throughput quantitative PCR and metagenomic sequencing approaches. Abundant and diverse ARGs were detected with high spatial heterogeneity among sampling sites. Vertically, there was no significant difference in ARG profiles between the aquifer and non-aquifer soils. Heavy metals were key factors shaping ARG profiles in soils with high heavy metal contents, while they showed no significant effect in low contents. Moreover, heavy metals could trigger the proliferation of antibiotic resistance by increasing MGE abundance or influencing bacterial communities. Metagenomic analysis also revealed the widespread co-occurrence of ARGs and MRGs, with heavy metals possibly enhancing the co-selection of ARGs and MRGs in soils with high heavy metal contents. This study highlighted the heavy metal-driven co-selection of ARGs and revealed the occurrence of ARG pollution in terrestrial subsurface soils.
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•Heavy metal contaminations could drive co-selection of ARGs and MRGs.•The key driver shaping ARG profiles was heavy metals in metal polluted soils.•Heavy metals could induce ARG proliferation by impacting MGEs or bacterial communities.•Heavy metal-driven co-selection of ARGs made terrestrial subsurface soils an ARG sink.
Lead toxicity: a review Wani, Ab Latif; Ara, Anjum; Usmani, Jawed Ahmad
Interdisciplinary toxicology,
6/2015, Volume:
8, Issue:
2
Journal Article
Peer reviewed
Open access
Lead toxicity is an important environmental disease and its effects on the human body are devastating. There is almost no function in the human body which is not affected by lead toxicity. Though in ...countries like US and Canada the use of lead has been controlled up to a certain extent, it is still used vehemently in the developing countries. This is primarily because lead bears unique physical and chemical properties that make it suitable for a large number of applications for which humans have exploited its benefits from historical times and thus it has become a common environmental pollutant. Lead is highly persistent in the environment and because of its continuous use its levels rise in almost every country, posing serious threats. This article reviews the works listed in the literature with recent updates regarding the toxicity of lead. Focus is also on toxic effects of lead on the renal, reproductive and nervous system. Finally the techniques available for treating lead toxicity are presented with some recent updates.
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