In order to improve adsorption of macromolecular contaminants and promote the growth of microorganisms, active carbon for biological wastewater treatment or follow-up processing requires abundant mesopore and good biophile ability. In this experiment, biophile mesopore active carbon is produced in one-step activation with orange peel as raw material, and zinc chloride as activator, and the adsorption characteristics of orange peel active carbon is studied by static adsorption method. BET specific surface area and pore volume reached 1477 m²/g and 2.090 m³/g, respectively. The surface functional groups were examined by Fourier transform infrared spectroscopy (FT-IR). The surface of the as-prepared activated carbon contained hydroxyl group, carbonyl group, and methoxy group. The analysis based on X-ray diffraction spectrogram (XRD) and three-dimensional fluorescence spectrum indicated that the as-prepared activated carbon, with smaller microcrystalline diameter and microcrystalline thickness and enhanced reactivity, exhibited enhanced adsorption performance. This research has a deep influence in effectively controlling water pollution, improving area water quality, easing orange peel waste pollution, and promoting coordinated development among society, economy, and environment.

The primary objective of this paper was to synthesize a porous calcium silicate hydrate (CSH) with enhanced phosphate recovery property using polyethyleneglycol (PEG) as pore-generation agent. The formation mechanism of porous CSH was proposed. PEG molecules were inserted into the void region of oxygen–silicon tetrahedron chains and the layers of CSH. A steric hindrance layer was generated to prevent the aggregation of solid particles. A porous structure was formed due to the residual space caused by the removal of PEG through incineration. This porous CSH exhibited highly enhanced solubility of Ca²⁺ and OH⁻ due to the decreased particle size, declined crystalline, and increased specific surface area (S_BET) and pore volume. Supersaturation was increased in the wastewater with the enhanced solubility, which was beneficial to the formation of hydroxyapatite (HAP) crystallization. Thus, phosphate can be recovered from wastewater by producing HAP using porous CSH as crystal seed. In addition, the regenerated phosphate-containing products (HAP) can be reused to achieve sustainable utilization of phosphate. The present research could provide an effective approach for the synthesis of porous CSH and the enhancement of phosphate recovery properties for environmental applications.

Microplastics are characterized with universality, persistence and toxicity to aquatic organisms, the pollution of microplastics has attracted worldwide attention. At present, studies on microplastic pollution were mainly focused on the composition, abundance and species of microplastics in water bodies and sediments, and few studies were focused on the source and influence characteristics of microplastics in surface water bodies. Starting from the sources of microplastic pollution in surface water of this paper, the pollution status of agricultural microplastics was analyzed, and the importance and urgency of studying microplastic pollution in agricultural non-point sources were put forward. Therefore, it was intended to provide effective scientific basis and technical support for the control of microplastics non-point source pollution in river basins.

Water pollution due to heavy metals has become a universal environmental problem. Ni(II) is a common heavy metal ion in polluted wastewater, which has high toxicity and carcinogenicity. In this study, the structure of a calcium-iron layered double hydroxide (Ca-Fe-LDHs) was synthesized and characterized by FTIR, XRD, SEM and XPS. Then, Ni(II) ion was effectively removed by Ca-Fe-LDHs and its mechanism for this materials was described. The maximum adsorption capacity of Ni(II) for Ca-Fe-LDHs was 418.9 mg‧g⁻¹ when the initial concentration of Ni(II) was 1 g/L. The adsorption and removal of Ni(II) by Ca-Fe-LDHs was attributed to the action of hydroxyl groups on the hydrotalcite, generating surface capture. Ni(OH)₂)0.75(H₂O)0.16(NiCO₃)0.09, Ni(OH)₂, NiO, NiSO₄ and other precipitates were generated on its surface. And a small amount of Ni-Fe-LDHs was generated through isomorphic transition before hydrolysis. Therefore, surface capture and isomorphic transition enhanced the removal efficiency of Ni(II) with Ca-Fe-LDHs, making Ca-Fe-LDHs as a potential material for effective removal of Ni(II).

In order to investigate the cause of accumulation of the inorganic suspended solid (ISS) in biochemical tank for wastewater treatment plant (WWTP) in recent years, the influent quality of one WWTP in Chongqing was monitored in one year, and the removal efficiency of ISS during the pretreatment process was studied. Results showed that the low removal efficiency of ISS (<7%) was ascribed to the weak removal efficiency of sand in the grit chamber. The primary sedimentation tank showed a good removal efficiency of ISS up to 69% and also had a good removal efficiency of COD up to 70%. The annual variation rule of MLVSS/MLSS for mixed liquor varied in contrast to the influent quality, ranging from 0.24 to 0.57, much lower than the normal value of 0.7. In order to maintain the normal function of activated sludge, it is necessary to retain the primary sedimentation tank to remove ISS.

Air pollutants cause severe problems in urban areas, specifically in terms of toxicological impacts on human health. Therefore, it is urgent to develop an effective, safe, and inexpensive technique to remove these air pollutants. In this study, the MoS₂/OMC heterojunction photocatalyst was successfully synthesized by a hydrothermal process and used for improving photocatalytic oxidation performance for removing VOCs. Formaldehyde was used as a model VOC in the gas phase and was removed at room temperature under visible light irradiation. For my research, the microstructure and morphology of the photocatalyst were deeply characterized, and the results indicated that MoS₂ were successfully coupled into OMC materials to prepare MoS₂/OMC heterojunction photocatalysts. The trend of photocatalytic efficiency for formaldehyde decomposition was MoS₂/OMC > MoS₂ > OMC. Besides, the MoS₂/OMC heterojunction photocatalyst showed an excellent regeneration performance after several recycles, indicating the potential of MoS₂/OMC composite as a promising photocatalyst for VOC removal. These results indicated that the photocatalytic reactor containing MoS₂/OMC photocatalysts was highly active and stable.