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The enhancement of the toxic effect of microplastics (MPs) on heavy metals and its mechanism needs more in-depth and systematic research. In this study, the copper (Cu) accumulation, histological injury, and expression of genes involved in oxidative stress, inflammation, apoptosis, and autophagy of goldfish after single or combined exposure of MPs (1 mg/L) and Cu 2+ (0.1 mg/L) for 7 days were determined. The results demonstrated that MPs enhanced the Cu accumulation in hepatopancreas and intestine of goldfish and induced more severe oxidative stress in the hepatopancreas and intestine of goldfish. Additionally, combined exposure of MPs and Cu induced inflammation, excessive apoptosis and insufficient autophagy in the hepatopancreas. Contrary, the inflammation and apoptosis were depressed in the intestine after combined exposure of MPs and Cu, which still requires further exploration. Hence, these findings provide further evidence for the threat of MPs and its adsorbed heavy metals., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

The carbon and nitrogen stable isotope compositions of the sediment organic matter, fish feed and fish feces were measured to assess the impact of the aquaculture waste from the cage fish farm in Poyang Lake. The results provide evidence of the non-negligible effect of aquaculture waste on the sediment organic matter. The δ 13 C and δ 15 N of sediments varied from - 27.62 to - 25.66‰ and 4.83 to 6.92‰, respectively. The sediment organic matter had a mixed source of waste feed, fish feces and plankton. The average contribution ratio of waste feed and fish feces was 53.1% and 24.6%, respectively. The aquaculture derived organic matter ratio was high with ranging from 57.6 to 95.6%. The aquaculture waste seemed to disperse widely enough to influence the study site about 2.5 km distance from the cage. The dispersion and resuspension were the main two factors which can explain the great effect area found in this study.

Fate of 2,4,6-tribromophenol (TBP) in environmental matrices is obscure. We used 14 C-tracer to investigated mineralization, transformation, and non-extractable residue (NER)-formation of TBP in a soil under continuously oxic, continuously anoxic, and anoxic-oxic alteration conditions. In all cases, TBP rapidly dissipated, mineralized to CO 2 , and formed NERs in the soil. Considerable amounts of transformation products (2-12%) were detected during the incubation. Marked mineralization (13-26%) indicated that soil microorganisms used TBP as their energy source. About 62-70% of the initial radioactivity was transformed into NERs, being mainly attributed to binding to humic and fulvic acid fractions. TBP transformation was significantly faster under oxic conditions than under anoxic conditions, and was boosted when the soil redox changed from anoxic to oxic state. The results provide new insights into fate of TBP in soil and suggest the importance to evaluate the stability of NERs for risk assessment of TBP in soil.

Magnesite is the world's most important source material for magnesia refractory production, and Haicheng City in Liaoning Province, China has been called "the magnesium capital of the world." However, magnesite mining in these areas has caused serious environmental problems. Field investigations have shown that the soil profile of many sites in the mining region are contaminated by magnesium, and the magnesium-enriched crusts that have formed on the soil surface have affected ecologically important soil functions, particularly reduced water penetration rate. Laboratory experiment revealed that anionic polyacrylamide and calcium dihydrogen phosphate can be used to improve soil condition, and have positive effects on soil function. The findings of this study are of significance in the magnetite mining areas, providing clear options for the remediation of soils that should be carried out immediately.

Rotifers are one of the smallest metazoans. They serve as a model organism for ecotoxicological studies. More than 60% of the lakes in China are increasingly eutrophic and they are susceptible to blooms of Microcystis aeruginosa. We investigated the effects of M. aeruginosa on the survival and reproduction of Brachionus calyciflorus using the life table method at different temperatures. The findings showed that concentration of M. aeruginosa significantly affected the intrinsic rate of increase (r(m)), net reproductive rate (R(0)), average lifespan (L) and offspring number (p < 0.05). Temperature also significantly affected the generation time (T), average lifespan (L) and offspring number (p < 0.05). Moreover, the interaction between temperature and concentration had statistically significant effects on offspring number (p < 0.05). M. aeruginosa suppressed the survival and reproduction of B. calyciflorus, particularly at a concentration of 10(6) cells/mL. The r(m) values of the rotifers exposed at 10(6) cells/mL decreased more than 200% compared with those of the control group. However, at a lower concentration, 10(4) cells/mL, M. aeruginosa may supply appropriate nourishment to rotifers. In addition, at concentrations of 10(5) and 10(6) cells/mL, the inhibition of rotifers by M. aeruginosa heightened with increasing temperature.

The behavior of heavy metals in wood during its carbonization process was examined. Cadmium in wood samples was found to be volatile when the samples were carbonized at 600 degrees C or higher, which demonstrated that removal of cadmium was feasible. Meanwhile, lead was found to be barely volatile even if the wood samples were carbonized at 1,000 degrees C or higher, which demonstrated that lead was difficult to remove and recover. The possibility of removing/recovering lead contained in wood by energization was then examined. By examining the concentration of sulfuric acid used as an electrolyte as well as load voltage, approximately 10% of lead was found to be recoverable.