Coal mining and related industry can increase heavy metals (HMs) concentrations in soil, atmosphere and wheat, thereby posing metal-associated human health risk via food ingestion.  In this study, 58 samples of soil, wheat, and dust were collected from Xuzhou coal mine eastern China, six kinds of HMs Pb, Cd, Cu, Zn, As and Cr were studied for their spatial distribution in wheat, enrichment in different wheat organs (roots, stem leaf, glumes, and grains), pollution level and potential human health risks. Results show that the spatial distribution of HMs in wheat grains were likely to coal while dissimilar to soil.  Most of heavy metals enrichment in wheat organs retained in glume and stem leaf after roots, and followed by grains, indicating that HMs was accumulated more from atmospheric dust as compared to other sources. Meanwhile, 71% of wheat grains were contaminated by HMs comprehensively in Xuzhou coal mine area. The potential health risk indicated that ingestion of food was the main exposure route causing non-carcinogenic and carcinogenic risk for inhabitants. This study provides basic information to control HMs enrichment from atmospheric dust and human health risk management policies in the mining area.

The present investigation has been conducted to assess the status of physico-chemical parameters as well as the concentrations of some selected heavy metals to understand the present scenario of water quality at Perak River basin, Malaysia. The temperature, turbidity, pH, EC and DO values of all the examined samples have been within the range of 25.0 to 30.5 0C, 39.5 to 168.00 NTU, 6.8 to 7.33, 30.3 to 113.8 μs/cm and 3.62 to 7.01 mg/L, respectively. The concentrations of trace metallic constituents have been determined by means of Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES), giving the following ranges: Cr: 0.01 to 0.052 mg/L; Pb: 0.01 to 0.03 mg/L; Zn: 0.11 to 0.92 mg/L; Fe: 1.38 to 5.55 mg/L; Mn: 0.10 to 0.25 mg/L and Ca: 2.55-23.23 mg/L, respectively. The concentrations of heavy metals at downstream of Perak River water were higher than the concentrations of upstream. The order of heavy metallic constituents in the water samples was Fe > Zn > Mn > Cr > Pb. R mode Cluster Analysis (CA) suggests that multiple anthropogenic activities like urban runoff, agricultural runoff, discharges of vehicles washing and workshops, land use changes, unplanned settlements, domestic effluents, wastewater of livestock husbandry farms etc., are influencing the physico-chemical parameters and heavy metals concentrations of Perak River water. The present study is highly significant for providing baseline information of potential hazardous level of heavy metals to human health, environment, and sustainable water resources management for economically and environment friendly uses of Perak River.

Nickel and cadmium usually enter the environment and water resources through wastewater, released by various industries, and may have adverse effects. The current study employs α–Fe2O3 nanoparticles of 20-40 nm in order to remove nickel and cadmium from the wastewater of Saba Battery Company. Also, it investigates the influence of effective parameters on adsorption process, including pH, contact time, and the adsorbent rate so that it can optimize the adsorption process. The maximum adsorption rate of nickel and cadmium can be observed in pH ranges of 5 to 9. In addition, adsorption rates for nickel (at pH = 7) and for cadmium (at pH = 5) have been 92.98% and 93.97%, respectively. By increasing the adsorbent rate, the adsorption grows, due to the increase in absorbate surface area, and an optimum adsorbent rates of 0.15 g and 0.2 g are obtained for cadmium and nickel, respectively. The maximum nickel and cadmium adsorption rates occur during the first 60 min of contact with nanoparticles. In this study, adsorption kinetics and isotherms have also been investigated and it has been found that the adsorption kinetics of both nickel and cadmium ions follow the pseudo-second-order model, while adsorption isotherms of nickel and cadmium follow the Freundlich model.

Greenhouse experiment was conducted for four months using Leucaena leucocephala and Pleurotus tuber-regium to determine their bioremediation potentials. Leucaena leucocephala, Pleurotus tuber-regium and Leucaena leucocephala combined with Pleurotus tuber-regium were tested for their ability to improve nutrient (N, P, K, total organic carbon) and reduce heavy metals (Zn, Ni, Pb, Cu) of soil polluted with spent engine oil [5% (w/v)] and soil without spent engine oil was used as control. Bioaccumulation of nutrients and heavy metals in Leucaena leucocephala and Pleurotus tuber-regium were also determined. The highest reduction in Zn, Ni, Pb and Cu (41%, 48.39%, 61.60 and 52.72% respectively) were recorded in soil remediated with Leucaena leucocephala alone, reduction of 30.40%, 26.53%, 48.07% and 39.60% respectively were recorded in soil remediated with Pleurotus tuber-regium alone while in soil remediated with combined Pleurotus tuber-regium and Leucaena leucocephala, reductions of 32.7%, 33.43%, 88.41% and 46.22% respectively were recorded. Bioaccumulation of Zn, Ni, Pb and Cu in Leucaena leucocephala increased by 73.41%, 85.46%, 3366.04% and 125.53% respectively, similarly in Pleurotus tuber-regium by 30.16%, 21.67%, 71.11% and 53.21% respectively. These studies have shown that Pleurotus tuber-regium and Leucaena leucocephala are capable of bioremediating spent engine oil polluted soil although, treatment with Leucaena leucocephala alone tends to be most effective of these treatments.

The present study was carried out to investigate the adsorption and leaching behavior of Cu2+, Zn2+ and Pb2+ by sediments collected from the western banks of three different sectors along River Nile at Aswan governorate, Egypt. The feasibility of sediments for the removal of Cu2+, Zn2+ and Pb2+ from aqueous solutions was tested under the effect of three conditions (pH, initial metal concentration and contact time). By increasing pH, the adsorption of Cu2+ and Pb2+ by sediments decreased while that of Zn2+ increased. The optimum pH values for Cu2+, Zn2+ and Pb2+ removal were determined as 5, 8.5 and 5, respectively. The adsorption capacities of sediments for metal ions were in the order of Pb2+ > Cu2+ > Zn2+. The maximum uptake for Cu2+, Zn2+ and Pb2+ by sediments occurred at contact times of 48 h, 24 h and 72 h, respectively. Adsorption data were fitted well by Freundlich, Dubinin–Radushkevich and Temkin isotherms. The experimental results obtained were analyzed using two adsorption kinetic models, pseudo-first-order and pseudo-second-order, in which pseudo-second-order equation described the data more than pseudo-first-order one. The average leaching percentages of Cu2+, Zn2+ and Pb2+ from sediments were 0.77%, 2.72% and 0.38%, respectively, with respect to pH, 0.83%, 2.49% and 0.38%, respectively , with respect to temperature, and also 0.79%, 2.34% and 0.38%, respectively with respect to contact time. The leaching percentages of metal ions from sediments were in the order of Zn2+ > Cu2+ > Pb2+.

The ever increasing pile-up of electronic waste in dumping sites, especially in developing countries such as China, Pakistan, India and several African countries, might have caused a significant alteration in the microbial community of the contaminated sites. This change in the microbial population may have significant impact to the soil ecology function. The major pollutants of electronic waste are heavy metals like cadmium, lead, nickel, mercury, hexavalent chromium, arsenic and persistent organic pollutants like polychlorinated biphenyls and polybrominated diphenyl ethers. In general, the toxic pollutants reduce the normal soil microbial biota but give rise to increase in the heavy metal resistant and organic pollutants remediating microbes. With the development of culture- independent approach as a tool for studying microbial diversity, the microbial community structures in toxic waste contaminated sites have been revealed gradually. Studies on the microbial community structure of electronic waste contaminated sites show that there are significant differences between the contaminated and the non-contaminated sites. Soil pH in the e-waste contaminated sites of various regions has been reported in a wide range varying from pH 4 to pH 12. However, the predominant phyla so far identified in the electronic waste contaminated sites, based on studies through culture independent approach, are Firmicutes, Proteobacteria, Actinobacteria, Acidobacteria, Chloroflexi, Crenarchaeota and Bacteroidetes accounting for more than 80% of the total sequence reads on an average. The genera like Pseudomonas, Bacillus, Clostridium, Rhodococcus, Achromobacter and many unclassified bacteria are the common types in the contaminated sites.