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Reclaimed water plays an important role in alleviating the shortage of urban water resources; however, the trace pollutants and pathogens in reclaimed water have an effect on the plankton community in the receiving water. This study investigated the spatial variation mechanism of microbial community diversity in the Beijing-Tianjin-Hebei reach of the Nordkanal River based on the OTUs and phylum level fragment number and fragment abundance data matrix. The results showed that the physical and chemical disturbance caused by the frequent inflow of reclaimed water changed the hydrology and water quality of the water body, and the plankton community could be divided into two different groups along the geographical scale:the medium and upstream clustering (MUC) and the downstream clustering (DC). The analysis of diversity index based on the OTUs data matrix showed that the species diversity of the DC group was significantly higher than that of the MUC group, and the abundance distribution and evenness showed the opposite trend. The species richness was mainly determined by the fragment diversity of the occasional microflora; the evenness was mainly determined by the variation of the abundance of the dominant microflora; the sensitivity of the subcommunity structure with different abundance levels to spatial change was in the order of non-dominant microflora > occasional microflora > dominant microflora. The diversity analysis of the data matrix based on phylum level also showed that the species diversity of the DC group was significantly higher than that of the MUC group, and the change trend of abundance was the opposite; the most sensitive microflora group was the non-dominant phyla, followed by the occasional phyla, and the dominant phyla group was the least sensitive. The data matrix based on the number of level segments of the gate was more sensitive to environmental changes than the multi-degree data matrix based on the level of the gate. The environmental factors significantly related to microbial community were turbidity; permanganate index; oxidation-reduction potential (ORP); macrolide (MLs); tetracycline antibiotic (TCs); and regional response factors of salt ions, carbon, and inorganic nitrogen. In the aspect of abundance and diversity, these phylas that the DC group was significantly more than the MUC group were more significantly negatively correlated with MLs, whereas they were positively correlated with TCs, and these phylas that the MUC group was significantly more than the DC group was more significantly positively correlated with MLs. The research results can provide a theoretical basis and technical guidance for the ecological rehabilitation of urban river courses with reclaimed water as their main water supply source.

Due to the limitations of the treatment process of urban sewage treatment plants and the complexity of water sources, the rich inorganic nitrogen and trace persistent organic matter in the reclaimed water cause potential human health risks through lateral leakage or bioaccumulation during the replenishment process of rivers and lakes. Exploring the distribution law of different types of reclaimed water characteristic water quality factors and their formation in reclaimed water replenishment river channels is of great significance to river and lake management. This study takes the Beijing-Tianjin-Hebei section of the North Canal as the research area and explores the spatial variation characteristics of conventional physical parameters, full index, inorganic nitrogen, and salinity hydronium antibiotics in river water quality with the help of clustering, discrimination, principal components, and variance decomposition. The results showed that, although the spatial distribution patterns of different types of water quality factors were consistent, they all showed significant mid-upstream and downstream distribution; however, there were big differences in the degree of variation and the mechanism of variation. The spatial variation of inorganic nitrogen and antibiotics was the most obvious, whereas the variation in conventional physical parameters and the full index was the weakest, and the salinity hydronium showed moderate variation. The spatial variation mechanism of conventional physical parameters was mainly reflected in microbial degradation. The full index was the result of the combined effect of microorganisms, diffusion, the synergy of the two, and a certain degree of source-sink homogeneity. Diffusion was the main mechanism affecting the spatial variation in salinity hydronium. The spatial variation mechanism of inorganic nitrogen was mainly reflected in the source-sink homogenization and microbial degradation; as a secondary mechanism of the spatial variation of inorganic nitrogen, diffusion had a synergistic mode with microbial degradation. Antibiotics, which have great differences in chemical structural stability and biodegradability, showed high spatial variability and had the highest diffusion and microbial synergy mechanism. This research provides a quantitative analysis of the spatial variability mechanism of water quality based on variance decomposition, which has practical guiding significance for the causes of the spatial variability of river pollutants and river management.

Sediment bacteria have attracted much attention because of their important roles in energy flow and pollutant cycle transformation. The changes in the spatial distribution pattern of bacteria are the basis for research on the biodiversity generation and maintenance mechanisms. However, there are few studies on the spatial variation in benthic microorganisms and its biogeographic models. The highly artificial North Canal River across the Beijing-Tianjin-Hebei area was chosen as the research area in this study. The spatial variation in the different classification levels of the Kingdom, Phylum, Class, Order, Family, Genus, Species, and operational taxonomic units and their diversity formation mechanisms were analyzed. The results showed that the samples at different classification levels had a more homogeneous distribution pattern. There were clearer distribution boundaries at the low classification levels than at the high classification levels. The significance of the bacterial community variation increased as the classification level of the bacterial community decreased. Furthermore, the difference between groups increased and the similarities within groups decreased as the classification level of the bacterial community decreased. The typical rhizosphere microorganisms represented by Frankiales and Rhodobacterales showed significant enrichment in the upstream samples, followed by the midstream samples and a significant decrease in the downstream samples. Microorganisms related to the carbon, nitrogen, and sulfur cycles represented by Anaerolineales and Desulfobacterales showed significant enrichment in the midstream, followed by the downstream and a significant reduction in the upstream. The genus Phenylobacterium was significantly enriched in the upstream followed by the midstream, and was significantly reduced in the downstream. The pathogenic bacteria represented by Clostridium_gasigenes and Moraxella_osloensis showed a significant enrichment pattern in the midstream. The contents of Ca 2+ , SO 4 2- , and total organic carbon (TOC) in the downstream samples were significantly higher than those in the upstream and midstream samples. The discharge of untreated wastewater downstream increased the salt and TOC contents in the sediment. The ecological restoration project in the sediment of the riparian zone decreased the salt and TOC contents in the upstream and midstream samples. Environmental selection was the main driving factor of the pattern of spatial variation in the bacterial communities in the sediments of the North Canal River.

Objective: To investigate the clinical efficacy and short-term and long-term adverse reactions for different antiviral regiments for coronavirus disease 2019 (COVID-19) in Ningxia Hui Autonomous Region during hospitalization and follow-up in 3 months., Methods: A single-center retrospective study was conducted to enroll the COVID-19 patients in isolation ward of the only designated hospital to receive COVID-19 patients (the Fourth People's Hospital of Ningxia Hui Autonomous Region) when the authors were assigned by the Ningxia Health Commission as experts from January 20, 2020 to March 15, 2020. According to the antiviral regimen, the patients were divided into conventional antiviral group and unconventional antiviral group. The conventional antiviral group received α-interferon combined with Lopinavir/Ritonavir (LPV/R). The unconventional antiviral group was given α-interferon combined with LPV/R and Abidor or Ribavirin or Chloroquine. The patients were divided into mild (13 cases), ordinary (45 cases), severe (14 cases) and critical (1 case) types. The clinical data, length of hospital stay, the first 2019 novel coronavirus (2019-nCoV) nucleic acid negative recovery time, cost of hospitalization, 2019-nCoV nucleic acid positive reversal after 14 days of discharge, and the combination of hormones and antibiotics were collected. The differences in blood routine, liver function, blood lipid level and adverse reactions of antiviral drugs during hospitalization were compared between the two groups at 1, 3 and 7 days after admission and 1 and 3 months after discharge., Results: (1) General information: a total of 75 patients with confirmed COVID-19 were admitted, and 73 patients were eventually enrolled, including 47 cases in the conventional antiviral group and 26 cases in the unconventional antiviral group. Patients with different clinical classification were analyzed, the higher the clinical classification and the patients' age, the higher the proportion of primary diseases and the cost of treatment, and the longer the length of hospital stay. Compared with conventional antiviral group, in unconventional antiviral group the percentage of severe and critical patients were higher [34.6% (9/26) vs. 10.6% (5/47), 3.8% (1/26) vs. 0 (0/47)], the length of hospital stay (days: 16.1±5.6 vs. 11.6±3.3), first nucleic acid negative recovery time (days: 12.4±4.5 vs. 10.0±3.5) were longer, and hospitalization cost was higher [Yuan: 11 984.2 (9 000.6, 24 424.7) vs. 8 140.4 (6 715.7,9 707.7)], with statistically significant differences (all P < 0.05). There were no significant differences in gender, age, proportion of patients with primary diseases and nucleic acid positive reversal rate after 14 days of discharge between the unconventional and conventional antiviral groups (all P > 0.05). (2) Laboratory tests: during the hospitalization, white blood cell count (WBC), platelet count (PLT), total bilirubin (TBil) and three acyl glycerin (TG) levels were first increased and then reduced, lymphocyte count (LYM) was first decreased and then increased in two groups. In the unconventional antiviral group, WBC [(6.53±2.78)×10 9 /L], PLT [(250.77±96.12)×10 9 /L], and TG [(1.94±0.96) μmol/L] all reached their peak values at 7 days after admission. TBil peaked at 3 days after admission, which was (23.69±12.14) μmol/L, and LYM reached the peak 1 month after discharge, which was (1.82±0.50)×10 9 /L; however, there was no statistical significance among the above indicators between two groups. There were no statistically significant differences in alanine aminotransferase (ALT), aspartate aminotransferase (AST) and total cholesterol (TC) between the two groups at each time point. (3) The ratio of combined use of hormones in the non-antiviral group was significantly higher than that in the conventional antiviral group [26.9% (7/26) vs. 4.3% (2/47), P < 0.05]., Conclusions: Age and associated primary diseases are related to the severity of COVID-19 patients. Unconventional antiviral treatment regimens are mostly used for severe COVID-19 patients whose ucleic acid did not turn negative for a long time. Individual antiviral therapy can be used based on the patients' response and tolerance to drugs.

This paper reports a novel method for the rapid determination of ammonia nitrogen in sewage by headspace gas chromatography (HS-GC) through a chemical reaction. During the experiment, formaldehyde, initially in excess, was reacted with NH 4 + in a headspace bottle to produce a strong acid with equal molarity. Thereafter, NaHCO 3 was reacted with the newly generated acid to produce CO 2 . In the final step, the released CO 2 was determined using a gas chromatograph equipped with a thermal conductivity detector. Good linear correlation between the ammonia nitrogen content and the gas chromatographic signals was achieved. The observed correlation coefficient was 0.999, and the limit of quantification (LOQ) was 0.786 mg/L (measured based on the mass concentration of N). The relative standard deviation of reproducibility was less than 2%, and the standard recovery was between 95% and 105%. Compared with Nassar's reagent method, the relative deviation of this method is within ±5%. This method has high detection efficiency and is suitable for the rapid batch detection of ammonia nitrogen in sewage.

Using Cu-MOF (HKUST-1) as a template, copper oxide was prepared by heat treatment under different temperatures in this study. The effect of treatment temperature on the composition and morphology of the products were studied. The catalytic abilities of the copper oxide products were tested through a series of experiments of activating peroxymonosulfate (PMS) to degrade RhB under different conditions. The results of XRD, SEM, and XPS show that the product is gradually transformed from a Cu 2 O/CuO mixture into pure CuO with the increase of heat treatment temperature. The original octahedron structure of HKUST-1 was collapsed. Under neutral pH conditions, when the dosage of PMS and CuO-650 was 1.00 mmol·L -1 and 0.20 g·L -1 , respectively, the total degradation of RhB (concentration of 0.10 mmol·L -1 ) could be completed within 90 min. In addition, CuO-650 also has many advantages, such as it can be applied within a wide range of pH values. In addition, the copper ion dissolution rate was low (1.309 mg·L -1 at pH=3 and 0.987 mg·L -1 at pH=7), and it has great recyclability and stability. These characteristics further proved that CuO-650 can be used as a promising catalyst for PMS activation.

MIL-88A@MIP was fabricated for the first time in this experiment with a metal-organic framework of MIL-88A as the precursor based on the molecular imprinting method. It was characterized by X-ray diffraction (XRD), scanning electronic microscopy (SEM), energy dispersive spectrometer (EDS), and N 2 adsorption. The catalytic performance of MIL-88A@MIP was tested to activate persulfate (PS) to generate SO 4 -· for the degradation of dibutyl phthalate (DBP), which was used as a target pollutant. Compared with the precursor MIL-88A, the catalytic activity of MIL-88A@MIP was improved effectively through targeted modification, and the DBP removal rate increased 80.4% after reacting for 480 min. An experiment determining the influencing factors showed that the optimum activation condition of the catalyst was PS:DBP=600:1, MIL-88A@MIP dosage of 0.5 g·L -1 ,and pH=3.26. Furthermore, MIL-88A@MIP shows a high capability of removing different phthalic acid ester (PAE) contaminants that reflect its targeting selectivity.