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•This is the most detailed examination of heavy metals in Deception Bay since 1975.•XRF and various pollution indices were used to determine sediment quality.•There is ample evidence ...of lead contamination and enrichment of other heavy metals.•Multivariate data analysis gave insights into the underlying structure in the data.•The results have implications for pollution in complex marine environments.
Sediment samples from 13 sampling sites in Deception Bay, Australia were analysed for the presence of heavy metals. Enrichment factors, modified contamination indices and Nemerow pollution indices were calculated for each sampling site to determine sediment quality. The results indicate significant pollution of most sites by lead (average enrichment factor (EF) of 13), but there is also enrichment of arsenic (average EF 2.3), zinc (average EF 2.7) and other heavy metals. The modified degree of contamination indices (average 1.0) suggests that there is little contamination. By contrast, the Nemerow pollution index (average 5.8) suggests that Deception Bay is heavily contaminated. Cluster analysis was undertaken to identify groups of elements. Strong correlation between some elements and two distinct clusters of sampling sites based on sediment type was evident. These results have implications for pollution in complex marine environments where there is significant influx of sand and sediment into an estuarine environment.
The term heavy metals is used as a group name of toxic metals and metalloids (semimetals) causing contaminations and ecotoxicity. In strict chemical sense the density of heavy metals is higher than 5 ...g/cm3. From biological point of view as microelements they can be divided into two major groups. a. For their physiological function organisms and cells require essential microelements such as iron, chromium (III), cobalt, copper, manganese, molidenium, zinc. b. The other group of heavy metals is toxic to the health or environment. Of highest concern are the emissions of As, Cd, Co, Cu, Hg, Mn, Ni, Pb, Sn, Tl. The toxicity of heavy metals is well known at organizational level, while less attention has been paid to their cellular effects. This book describes the toxicity of heavy metals on microorganisms, yeast, plant and animal cells. Other chapters of the book deal with their genotoxic, mutagenic and carcinogenic effects. The toxicity of several metals touch upon the aspects of environmental hazard, ecosystems and human health. Among the cellular responses of heavy metals irregularities in cellular mechanisms such as gene expression, protein folding, stress signaling pathways are among the most important ones. The final chapters deal with biosensors and removal of heavy metals. As everybody is eating, drinking and exposed to heavy metals on a daily basis, the spirit of the book will attract a wide audience.
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.
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.
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.
•The concept and different approaches of bioaugmentation.•Actinobacteria as a potential for cleaning up contaminants.•Actinobacteria with pesticide degrading abilities and/or heavy metal resistance ...and removal capabilities.•Studies on bioaugmentation of soils contaminated with different pesticides and heavy metals by actinobacteria.
Over the past two decades, various eco-friendly approaches utilizing microbial species to clean up contaminated environments have surfaced. In this aspect, actinobacteria have demonstrated their potential in contaminant degradation. The members of actinobacteria phylum exhibits a cosmopolitan distribution, which means that they can be found widely in both aquatic and terrestrial ecosystems. Actinobacteria play important ecological roles in the environment, such as degrading complex polymers, recycling compounds, and producing bioactive molecules. Hence, using actinobacteria to clean up contaminants is an attractive method in the field of biotechnology. This can be achieved through the green technology of bioaugmentation, whereby the degradative capacity of contaminated areas can be greatly improved through the introduction of specific microorganisms. This review describes actinobacteria as an eco-friendly and a promising technology for the bioaugmentation of contaminants, with focus on pesticides and heavy metals.
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.
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.
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