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In this study, 130 surface soil samples were collected at an industrial pollution site in Beijing and the contents of As, Be, Cd, Cu, Cr, Hg, Ni, Pb, Sb, Ti, Zn, and 16 PAHs were determined. The positive matrix factorization (PMF) model was used to analyze the sources of heavy metals and PAHs, and the contributions of these sources to carcinogenic risk and hazard index in the study area were calculated. The results showed that the contents of Cd, Cu, Pb, Hg, As, Zn, and Cr in the soil exceeded the background values in different degrees; Cd, Hg, Pb, Zn, and Cu exceeded the background values by>50%. Low molecular weight PAHs (two and three rings) and high molecular weight PAHs (four to six rings) accounted for 39.6% and 60.4% of the total content of 16 PAHs. The PAH content at 77% of the sampling points at the target site was more than 1000 μg ·kg-1, which suggests severe PAH pollution at the site. Heavy metals Be, Ti, As, and Ni mainly originated from natural sources. There are three major sources of 7 heavy m the high levels of heavy metals and PAHs in the soil of the steel smelting sites that pose the most severe health risks. The results of this study can provide reference for soil remediation and process optimization at other heavily polluted industrial sites.To build a soil environmental quality monitoring network and collect the systematic soil geochemical data of heavy metals before and after the construction of Xiong’an New District(XND), long-term variations in soil heavy metal levels during the XND construction were monitored based on the land quality geochemical survey monitoring data and the geochemical distribution of heavy metals. Parameters such as sampling density, sampling quantity, and sampling period were estimated to construct the geochemical monitoring network, which provides a reference for the future long-term monitoring of soil heavy metal geochemistry in XND. The results indicate that variations in the amount of heavy metals As, Cd, Cu, Hg, and Pb are greater than 36%, while the nugget coefficients of Cd, Cu, and Pb are greater than 75% because of the superposition of manmade sources on the high natural background levels. At the 95% and 90% confidence levels, while the allowable error Δ of the sample mean value is 5%, 10%, and 15% and heavy metals as As, Cd, Cu, Hg,Ni, Pb and Zn is monitored in soil environmental quality monitoring network, the proper numbers in the study area are 1077, 270, 120 and 767, 192, 86, respectively. The minimum detectable change(MDC)of each heavy metal species is between 0.0025 and 2.54 mg ·kg-1. Soil heavy metal monitoring requires different revisit intervals under different annual change rates, but in the study area, revisit intervals of soil monitoring are approximately two years under the current conditions of constant annual change rates.A single-stage PN-ANAMMOX (PN/A) granular sludge cultured at room temperature was used to investigate the completely autotrophic nitrogen removal efficiency and microbial community structure of low-strength wastewater based on the completely autotrophic nitrogen removal over nitrite in granular sludge at a low temperature. The results showed that at the low temperature (15±1)℃, the ammonia nitrogen load was maintained at 1.29 kg ·(m3 ·d)-1, and the ammonia nitrogen concentration in the injection was gradually reduced from 70 mg ·L-1 to 40 mg ·L-1. DO/TAN was controlled at 0.22-0.25. The total nitrogen removal rate was maintained at (85±4)%, and the average TN concentration in the effluent was 8.9 mg ·L-1. There was no significant proliferation of nitrite-oxidizing bacteria (NOB) during the operation period, and the Nitrospira abundance was less than 1%. Elutriation of the floc sludge and the control of low DO/TAN values can be used as effective control strategies to inhibit NOB proliferation. Through completely autotrophic nitrogen removal over nitrite in granular sludge operated under low-temperature and low-substrate conditions, the particle size became smaller, and the color changed from brown red to brown yellow. The total amount of PS decreased slightly, and the ratio of PN/PS stabilized at 2.5-3.0. Planctomycetes and Proteobacteria dominated the community, and Candidatus_Kuenenia and Candidatus_Brocadia were two AMX bacteria in the sludge.The feasibility of the denitrifying phosphorus removal process in the ABR-MBR system with no sludge reflux and high concentration of seeding activated sludge (25 g ·L-1, in MLSS) in the ABR was investigated. The characteristics of the microbial community in the denitrifying phosphorus removal compartment were also evaluated. The denitrifying phosphorus removal function was achieved by gradually increasing the reflux ratio (R) from 0% to 200%. During the stable operation, the average removal rates of COD, PO43–P, and TN in the system were 88.28%, 54.45%, and 61.93%, respectively. When the influent loading rate, NO x –N reflux ratio, and hydraulic retention time (HRT) of ABR and MBR were 0.8 kg ·(m3 ·d)-1, 150%, and 9 h and 3.3 h, respectively, the average VFA concentration of 80.58 mg ·L-1, ρ(NO2–N)/ρ(NO3–N) reflux ratio of 1.68, and PO43–P and TN removal rates of 64.94% and 62.95% were obtained. The short-cut nitrification denitrifying phosphorus removal was achieved in the ABR-MBR system. Batch tests showed that denitrifying phosphorus removal bacteria (DPAOs) were the main functional bacteria in the ABR, with anaerobic phosphorus release and anoxic phosphorus uptake of 3.73 mg ·L-1 and 10.22 mg ·L-1, respectively. High throughput sequencing results showed that Proteobacteria and Bacteroidetes were the dominant phyla in the phosphorus removal compartment, accounting for 23.49%-53.66% and 16.55%-21.78% of the total phyla, respectively. Thauera, Thiothrix, Pseudomonas, norank_ f_Rhodocyclaceae, and unclassification_ f_Rhodocyclaceae in Proteobacteria, and Sphingobacteriales in Bacteroidetes were the potential denitrifying phosphorus removal microorganisms.Municipal wastewater methanogenesis is one of the ways to utilize municipal wastewater resources.In this study, a biofilter used to treat actual municipal wastewater was employed to investigate the methanogenesis in a pilot-scale reactor. The method of rapid start-up, the influence of temperature on the reactor performance, and the changes in the microbial structure were investigated in the pilot-scale study. The rapid start-up of the biofilter reactor was achieved by the combination of intermittent and continuous operations. check details The effluent concentration of SCOD was 60 mg ·L-1at the stable operation stage. The biofilter was operated steadily at a temperature higher than 14℃, the accumulation of volatile fatty acids (VFA) was low, and the effluent concentrations of SCOD and TCOD were 69 mg ·L-1and 90 mg ·L-1, respectively. In addition, the metabolism of hydrolysis and methanogenesis tended to balance off under such conditions. However, the abundance of microorganisms that can hydrolyze organic matter and produce methane decreased.