Lemmingantonsen5268

During wastewater treatment using a traditional biological denitrification process, the excessive concentration of nitrate nitrogen (NO3--N) in the effluent is the primary cause of excessive total nitrogen (TN) generation. By using an external carbon source to increase the carbon to nitrogen ratio (C/N), the denitrification process can be strengthened, which effectively addresses this problem. Using an integrated denitrification reactor developed based on the two-stage denitrification process principle with the addition of polybutylene succinate (PBS) in the second stage, the denitrification process was analyzed using a scanning electron microscope before and after characterization of PBS materials. Moreover, amplicon sequencing was used for in-depth exploration of changes in the microbial community structure in the second denitrification pool before and after the addition of PBS. The data of a continuous 120-day experiment showed that the COD removal rate dropped from 95.7% to 90.8%, the TN removal rate increased from 51.8% to 80%, the relative abundance of Proteobacteria phylum rose from 36.1% to 46.1%, and the relative abundance of Thermomonas rose from 6.47% to 13.48%. The results show that after the addition of PBS, PBS can not only provide carbon source for denitrification, but its surface can also serve as a carrier for microbial growth and attachment, play a good role in filming, and increase the abundance of denitrifying bacteria and strengthen denitrification. During the nitrification process, denitrification performance was significantly enhanced, effectively improving the TN removal rate of the system.A SMBBR was established to treat medium ammonium under room temperature. Results showed that TN load can reach 0.16 kg·(m3·d)-1, and the average TN removal efficiency was (51.58±6.80)% in the SMBBR with an influent ammonia concentration of 100 mg·L-1 and DO of 0.4-0.7 mg·L-1. AOB, ANAMMOX, and NOB activity reached (2253.21±502.10) mg·(m2·d)-1, (4847.46±332.89) mg·(m2·d)-1, and (1455.17±473.83) mg·(m2·d)-1, and ANAMMOX and AOB bacteria were found to develop a good collaborative relationship. Quantitative PCR results showed that the relative abundance of ANAMMOX, AOB and NOB were 11.57%, 1.01% and 0.94%, respectively. The stable operation of single stage partial nitritation-ANAMMOX process provide an alternative technology for medium ammonia wastewater.A petrochemical wastewater treatment plant (PWWTP) was selected to investigate the distribution and removal of antibiotic-resistant bacteria (ARB) and three forms of antibiotic resistance genes (ARGs), namely intracellular ARGs (iARGs), adsorbed-extracellular ARGs (aeARGs), and free extracellular ARGs (feARGs). Tetracycline, sulfanilamide, and ampicillin ARB were detected with the total absolute concentration of 8.45×102-2.38×105 CFU·mL-1; the absolute concentrations of three types of ARB decreased by 0.04 lg-0.21 lg through anaerobic treatment. The effect of aeration and precipitation treatment on ARB varies with its type, and the absolute concentration of ARB in effluent was 0.12 lg-0.63 lg higher than that in influent. The absolute abundance of aeARGs and iARGs in activated sludge was 1.96×107-3.02×1010 copies·g-1 and 5.22×107-4.15×1010 copies·g-1, respectively; the absolute abundance of feARGs in wastewater was 5.90×108-1.01×1012 copies·L-1. Anaerobic treatment can remove 0.13 lg-0.65 lg aeARGs and 0.04 lg-0.28 lg iARGs, while the removal efficiency of aeARGs and iARGs by aeration and precipitation process was affected by ARGs types and forms. The absolute abundance of feARGs in effluent is 0.06 lg-0.81 lg higher than that in influent. Redundancy analysis showed that the concentration of ARB was significantly positively correlated with chemical oxygen demand (COD), Cl-, and total nitrogen concentration (P less then 0.05). The abundance of aeARGs was positively correlated with COD and total nitrogen concentration (P less then 0.05), and both the abundance of iARGs and feARGs are positively correlated with heavy metals concentration (P less then 0.05). This study confirmed the enrichment risk of ARB and different forms of ARGs in PWWTPs, which provided references for the research and prevention of antibiotic resistance pollution in industrial wastewater.Wastewater treatment plants (WWTPs) are considered important reservoirs of antibiotic resistance genes (ARGs) and function as the main sources of ARGs in the environment. Membrane bioreactors (MBRs) have been recognized as effective tools for removing ARGs in WWTPs.There are a large number of pathogens and resistance genes in colloids, particulate matter, suspended matter, and microbial metabolites in intercepted wastewater by MBR. However, the distribution characteristics of resistance genes in membrane cleaning sludge remains unclear. In this study, resistance genes of membrane cleaning sludge were analyzed using a metagenomic technique. The results showed that there were 39 phyla in the membrane cleaning sludge. Proteobacteria, Nitrospirae, and Actinobacteria were the dominant phyla. The dominant genera were Nitrospira, Pseudomonas, and Bradyrhizobium. The pathogens accounted for 10.54% of all bacteria in the sample, among which Pseudomonas had the highest abundance, accounting for 3.94%. A total of 17 type cleaning sludge to provide guidance for selecting appropriate technologies for effectively removing ARGs, MRGs, and pathogens.Total heavy metal concentration, heavy metal nanoparticle concentration, particle size, and the removal effect of different treatment unit processes on heavy metals and heavy metal nanoparticles were analyzed in this study. https://www.selleckchem.com/products/bay-1217389.html Inductively coupled plasma mass spectrometry (ICP-MS) and single particle inductively coupled plasma mass spectrometry (SP-ICP-MS) were applied in nine treatment units performing continuous wastewater treatment processes in the Chengdu Shuangliu International Airport sewage treatment plant. Results showed that different treatment unit processes had different effects on the removal of different total heavy metal elements, with the effects on Fe being the most significant; Fe was mainly removed in the secondary sedimentation tank at a rate of 98.53%. The removal effects of different heavy metal nanoparticles varied in different treatment unit processes, with the effects of Ni, Pd, and Fe being the most significant. Heavy metal nanoparticles removal varied by treatment unit processes (aeration grit tank, secondary sedimentation tank, and high-efficiency sedimentation tank).