Mitigative Effect of La on Glycine max seedlings under Pb-Cd Compound Pollution

Mitigative effect of La on Glycine max seedlings under combined Pb and Cd pollution was studied through pot culture experiment. The results show that the growth and metabolism of Glycine max seedlings are inhibited by the solution with 500 mg.L-1 Pb + 100 mg.L-1 Cd. When 30 mg. L-1 LaCl3 is used to spray Glycine max seedlings once, the injury effect of combined Pb and Cd pollution is reduced. The experiment proves that the effect is related to La which can raise photosynthetic rate, chlorophyll content and activity of nitrate reductase, and reduce cell membrane permeability, content of Pb and Cd, and keep TTC reduction ability of Glycine max seedling.

Compound pollution of Cd,Pb,Cu,Zn,As in plant-soil system and its prevention

By means of both pot and field tests,this paper studied the contents of Cd,Pb,Cu,Zn and As and their ecological effects on plant-soil system.in tissues of crops and soil microorganisms.It was found that there exist synergistic effect among these five elements,especially for Cd in combination.The reclaniation of soil polluted by these elements in combination is rather difficult to be carried out.The distinctive ecological and chemical behaviors between Cd and As make various reclamation measures less applicable,and thus,further research measures are necessary.

Studies on Heavy Metal Pollution in Soil-Plant System:A Review

Heavy metal pollution in soil-plant system is of major environmental concern on a world scale and in China in particular with the rapid development of industry. The heavy metal pollution status in soil-plant system in China, the research progress on the bioavailability of heavy metals (affecting factors, extraction methods, free-ion activity model, adsorption model, multivariate regression model, Q-I relationship, and compound pollution), and soil remediation are reviewed in the paper. Future research and monitoring is also discussed.

Review on the Effects of Combined Pollution of Lead and Chromium on Soil Microorganisms and Treatment Methods

Heavy metals—Pb and Cr are important causes of environmental pollution, and they often coexist in nature. At present, the effects of Pb and Cr toxicity on soil microorganisms have been less studied, in soil environment which is extremely complex. Simulating soil environment and studying microbial reaction under various heavy metal conditions are of great significance for revealing microbial tolerance to heavy metals. In this paper, firstly, the related concepts of soil rechecking pollution are discussed, and the physical and chemical properties and forms of lead and chromium are introduced accordingly. Secondly, the effects of combined pollution of lead and chromium on soil microbial biomass, soil microbial community structure and soil microbial activity were discussed. Finally, the relevant treatment methods of heavy metal contaminated soil were put forward.

Effect of Polyethylene (LDPE) Microplastic on Remediation of Cadmium Contaminated Soil by <i>Solanum nigrum</i>L.

Solanum nigrum L. has a delightful prospect as a hyperaccumulation plant for cadmium pollution remediation, and microplastic is a new type of pollution that has received wide attention. In this study, the effects of polyethylene microplastics (LDPE) (0.135, 0.27, 0.81 and 1.35 mg·kg-1) and cadmium (20 mg·kg-1) on the growth indexes and soil physical and chemical properties of Solanum nigrum L. were investigated in a 17-day microcosm experiment. The results showed that single LDPE contamination showed a trend of low concentration promotion and medium-high concentration inhibited the growth index of Solanum nigrum L. and soil physicochemical index, and single Cd contamination was more stressful to plants than single LDPE contamination, while low concentration of LDPE could reduce the effect of Cd on soil physical and chemical properties and promote plant growth and uptake of soil nutrients. These findings suggest that high concentrations of microplastics can inhibit the growth of Solanum nigrum L. alone or in combination with Cd, rather than reducing the toxicity of Cd.

Effects of pH on photochemical decomposition of perfluorooctanoic acid in different atmospheres by 185 nm vacuum ultraviolet

Perfluorooctanoic acid （PFOA）, a persistent organic pollutant, receives increasing concerns due to its worldwide occurrence and resistance to most conventional treatment processes. The photochemical decomposition by 185 nm vacuum ultraviolet （VUV） is one of the efficient methods for PFOA decomposition. The effects of pH on PFOA decomposition in nitrogen atmosphere or oxygen atmosphere were investigated. At its original pH （4.5） of PFOA aqueous solution, PFOA decomposed efficiently both in nitrogen and in oxygen atmosphere. However, when the pH increased to 12.0, PFOA decomposition was greatly inhibited in oxygen atmosphere, while it was greatly accelerated in nitrogen atmosphere with a very short half-life time （9 rain）. Furthermore, fluorine atoms originally contained in PFOA molecules were almost completely transformed into fluoride ions. Two decomposi- tion pathways have been proposed to explain the PFOA decomposition under different conditions. In acidic and neutral solutions, PFOA predominantly decomposes via the direct photolysis in both atmospheres; while in the alkaline solution and in the absence of oxygen, the decomposition of PFOA is mainly induced by hydrated electrons.