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Constructed wetland-microbial fuel cell coupling system is a new type of bioelectrochemical system that couples constructed wetland and microbial fuel cell. The system plays an important role in biological power generation and sewage purification. The principle is that the bottom of the constructed wetland bed (low ORP) serves as the anode of the microbial fuel cell. The organic matter in the water is degraded under the action of the electricity-producing microorganisms and released during the degradation process. The electrons are transferred along the external circuit to the biocathode on the surface of the bed (higher ORP) to complete the redox reaction. This article summarizes the research progress of the microbial fuel cell-constructed wetland coupling system from two aspects: system structure and factors affecting system operation. The system structure includes electrode materials, substrates, wetland plants and microorganisms. The influencing factors include HRT, DO, organic matter concentration and wastewater composition, electrode structure. Finally, the problems and research directions of the microbial fuel cell-constructed wetland coupling system are summarized, and the research potential of the system is prospected.

In recent years, soil heavy metal pollution has caused serious harm to human beings and the environment. Phytoremediation has become the main means of soil remediation because of its advantages such as low cost, obvious effect and low secondary pollution. In this paper, the status quo and harm of soil cadmium pollution in China and the mechanism of phytoremediation of cadmium were summarized.

Nitrogen, as a common substance in water pollution, can easily cause eutrophication of water when it is excessive. Constructed wetland, as a water treatment method that combines the common actions of plants, microorganisms, and substrates, has positive significance for the removal of nitrogen. This article reviews the nitrogen removal mechanism of each component in constructed wetlands, and the effects of temperature, carbon-nitrogen ratio, dissolved oxygen, pH, and HRT on denitrification, and proposes existing problems and research directions in constructed wetlands.

Phytoremediation is a low cost and green remediation technology, which is widely used in remediation of soil polluted by heavy metals such as cadmium and manganese. However, with the extension and implementation of phytoremediation technology in soil remediation, the disposal of a large number of hyperaccumulator plant harvests has become a hot topic in the field of phytoremediation. These harvests generally contain high concentrations of heavy metals, which can cause secondary contamination if improperly disposed of. This paper reviews the traditional disposal techniques that can be processed by composting process, compaction landfill, Liquid phase extraction, incineration, Ashing and Pyrolysis as well as emerging resource disposal technologies such as phytomining and supercritical water technology and identifies current issues with phytoremediation plants disposal. The possible research directions in the future are also prospected.

Phytoremediation technology has become the frontier and hot research of soil heavy metal pollution areas of resource, environmental and biological sciences internationally. In view of current problems of phytoremediation technology, this paper summarizes research progress for phytoremediation technology of heavy metal contaminated soil, discussing physics, chemistry, biotechnology methods of increasing plant biomass and heavy metal accumulation. This paper focuses on the mechanism and application effects of genetic engineering technology, chelate induced technology and microbial combined phytoremediation and the future research direction of phytoremediation was also prospected.

Environmental pollution has long been a hot topic in the world, and soil heavy metal pollution is particularly prominent. In recent years, many scholars have found that the heavy metal antimony (Sb) has been widely found in the soil, which has shown many problems that cannot be ignored and has attracted widespread attention in the academic community. Article summarizes the related accumulator plant of Sb and the physical remediation technology, chemical remediation technology and phytoremediation technology of Sb contaminated soil. It is expected to provide reference for heavy metal soil remediation, and hope to find a hyperaccumulator plant that can efficiently absorb heavy metal antimony, to promote green with permanent governance effect, economical, and completely repair technology application and promotion.