Heavy Metal Contamination in an Industrially Affected River Catchment Basin: Assessment, Effects, and Mitigation

Heavy metals in meat products from Shandong, China and risk assessment

In this study 13 heavy metals were analysed in representative livestock meat, poultry meat, livestock offal and poultry offal samples (20 per category) from marketplaces and retail stores in 16 cities in Shandong province, China. The investigated heavy metals were Cu, Cr, V, Ni, As, Se, Sn, Cd, Pb, Sb, Mn, Ba and Hg. Results revealed mean levels of total heavy metals in meat and offal of 1.56 mg/kg and 39.8 mg/kg, respectively. Cu, Cr, Mn, Ni, Se, Ba and Pb were found in all samples (100%), followed by Hg (95.0%), V (91.3%), Sn (73.8%), Cd (51.3%), As (21.3%) and Sb (11.3%). Hazard Quotient (HQ) and Hazard Index (HI) values showed that high meat intake can cause potential health risks. Thus, continuous monitoring of health risks and trends of heavy metals in meat products is needed, both for food safety and consumer's health.

Preparation of basic magnesium carbonate nanosheets modified pumice and its adsorption of heavy metals

Heavy metal pollution in wastewater poses a grave danger to the environment and the human body. Pumice is a mineral with abundant reserves and low prices, and its prospect of heavy metal adsorbent is very broad. In this work, we modified pumice with basic magnesium carbonate nanosheets by a convenient hydrothermal synthesis. The adsorption capacity of heavy metals is greatly improved. The effects of different pH and adsorption dosages are investigated. All the optimum pH values for Cu2+, Pb2+, and Cd2+ are 5. The adsorption of three kinds of ions conforms to the quasi-second-order adsorption kinetics model. The theoretical adsorption capacities of Cu2+, Pb2+, and Cd2+, which are calculated by the Langmuir model, are 235.29 mg/L, 595.24 mg/L, and 370.34 mg/L, respectively. The adsorption of Cu2+ and Cd2+ fit the Langmuir model better. The Freundlich model is fitted well with the adsorption of Pb2+. In the experiment simulating real wastewater, the adsorption capacity of heavy metals is not affected. It also shows good reusability in three regeneration cycles. And Mg5(CO3)4(OH)2·4H2O@pumice adsorption column showed the good removal efficiency of three heavy metals at different concentrations and different spatial velocities in the column experiment. Thus, it is believed that the Mg5(CO3)4(OH)2·4H2O@pumice is a promising adsorbent for the efficient removal of heavy metals.

Ecological Characterization and Bio-Mitigation Potential of Heavy Metal Contamination in Metallurgically Affected Soil

Heavy metals (HMs) remain persistent in soil for a long time and thus present a long-term threat of environmental pollution. In this study, the concentrations of some HMs (As, Cu, Zn, Pb, and Mo) in soil, potentially affected by the ex-operation of a metallurgical plant—specifically, a copper smelter in Alaverdi Town, northeastern Armenia—were measured, based on which, the HM contamination and its ecological, biological, and health effects were assessed. Concentrations of HMs (Cu, Zn, and Pb) were also measured in different plant (leaves) and invertebrate species that occur in the soil over the metallurgical factory site in order to assess the potential for the bioremoval of HMs from the soil. The results showed that the ex-operation of the metallurgical facility created such contamination in the soil that it caused a noticeable loss of invertebrate biomass in the soil and posed ecological, non-carcinogenic (for children), and carcinogenic health hazards. The investigated plant and invertebrate species were characterized by different capacities for the accumulation of HMs from the soil, based on which the plant species Fraxinus excelsior, Acer platanoides, Robinia pseudoacacia, and Aesculus hippocastanum and the invertebrate species Deroceras caucasicum, Limax flavus, and Eisenia rosea are recommended to be used for the selective removal of HMs (Cu, Zn, and Pb) from the soil.