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In order to solve the problem of difficult treatment of high-concentration chromium-containing wastewater, sulfate-reducing bacteria (SRB) with a high tolerance of hexavalent chromium and a strong ability to reduce the compound were isolated from sludge from a sedimentation tank in a leather industrial park and was identified as Desulfovibrio by morphological observation, routine physiological and biochemical determination, 16S rDNA sequencing and phylogenetic tree construction. After ethanol acclimation, a strain of SRB that could reduce chromium (CR-1) was selected as the research object. The optimum growth conditions for hexavalent chromium removal by the strain were determined by single-factor analysis. The chromium removal mechanism of the strain was analyzed, and a kinetic model of the reduction process was established. The chromium-reducing ability of the strain was 500 mg/L, the optimum pH value was 7, the optimum temperature was 35 °C, the optimum cultivation time was 24 h, and the optimum ratio of bacteria to waste (volume ratio of bacterial solution dosage and chromium-containing wastewater) was 1:5. The mechanism of treatment of Cr(VI) by this strain is mainly based on the reduction of Cr(VI) by H2S accumulated in the cultured bacterial solution and the small amount of H2S generated by bacterial reductase, bacterial growth and SO42− reduction in the waste liquid.

Heavy metal pollution is a serious threat to human health. Because of the development of nanotechnology, removal of heavy metal is more convenient and effective. Nano zero valent iron (Fe 0 ) particles have high activity and specific surface area. At present, Fe 0 nanoparticles have been used in the processing of refractory organics, heavy metals, inorganic salts, soil restoration, and other areas of the environment. But the dispersion and stability of the Fe 0 nanoparticles are poor. We can improve physical and chemical properties of Fe 0 by adding carrier materials to make iron nanoparticles have better stability, dispersion and the treatment effect. This paper mainly introduced the situation of removing heavy metals by the Fe 0 nanoparticles and hybridized Fe 0 particles. Hybridized Fe 0 has good performance and high removal efficiency to heavy metals. We also discussed what are inadequate and need to be further researched.

With nitrite or nitrate nitrogen as electron acceptor in the high salt conditons, halophilic denitrifying bacteria can transfer nitrite or nitrate to nitrogen, thereby purifying the high-salt wastewater. Halophilic denitrifying bacteria play an important role in the carbon and nitrogen removal of saline wastewater, such as petroleum, chemical industry, seafood processing and seafood farming. This article dissussed halophilic denitrifying bacteria screening, the main types and the corresponding morphological characteristics, then we focused on the research progress of main factors of halophilic denitrifying bacteria’s growth and nitrogen removal. Finally put forward the current problems of the research and development trend of halophilic denitrifying bacteria.

Complex microbial inoculants are highly effective compound bacteria which are widely used in the removal of pollutants, such as organic matter, nitrogen and phosphorus in the paper, printing and dyeing, petroleum and high-salt wastewater. The development of complex microbial inoculants was introduced in this paper, especially their application and influence factors in wastewater treatment. Finally we put forward current problems and development prospects of complex microbial inoculants.

The spatial location of zerovalent iron nanoparticles hybridized with montmorillonite was identified with easily accessible X-ray diffraction, transmission electron microscopy, and element analyses. These hybridized nanoparticles are not intercalated into the interlayer space of clay whereas mainly located on the external surface of clay. This result would be of great importance for the sorption-based applications of these heterostructures.

It was of great significance to study the damage evolution mechanism of geomaterial/soil interfaces in landfill seepage control systems to evaluate the slope instability of landfill sites with high dam and large storage capacity. In this paper, the interfacial shear behaviors of geomaterial/soil were studied by drawing test. At the same time, the interface meso-test was used to analyze the change characteristics of geomaterial/soil interfaces during the drawing process. The results showed that under the synergistic action of the interface friction of geotextile/geomembrane and the reinforced shear band at the interface of geotextile/soil, the shear strength and interface stability of the composite geomaterial/soil interface not only increased but also improved. In order to describe the shear deformation and softening characteristics of the geomaterial/soil interfaces, a constitutive model of the interface was established based on the statistical damage theory to study the damage evolution mechanism of the interface under the action of drawing. The fitting results showed that the fitting correlation between the interface constitutive model established in this paper and the shear strength–drawing displacement curves obtained from the tests was greater than 0.97, which indicated that the constitutive model could better describe the shear deformation characteristics of the interface.