In order to investigate the effect of compound antibiotics on anaerobic digestion of chicken manure, the inhibitory effect of three different combinations of oxytetracycline (OTC), sulfamethoxazole (SMZ), and enrofloxacin (ENR) on anaerobic digestion of chicken manure was studied by the sequencing batch method. Under the condition of adding three different combinations of antibiotics, the experiment was run for 50 days. The concentrations of soluble chemical oxygen demand (SCOD), total ammonia nitrogen (TAN), VFAs, and methane production in the reactor were measured, and the microbial diversity affecting the stability of the system was analyzed. The results showed that OTC and SMZ inhibited methane production, while SMZ and ENR promoted methane production, and the cumulative methane production was R4>R3>R1>R2. After the 25th day, the SCOD concentration in the R2 and R4 groups decreased, which was due to the existence of SMZ and ENR promoting the degradation of SCOD. TAN concentrations in the four groups were kept between 1,190 and 2,100 mg/L. The results of 16S rRNA sequencing showed that the mixed antibiotics had different effects on the bacterial community, which was mainly composed of Firmicutes, Bacteroidota, unidentified bacteria, Cloacimonadota, Proteobacteria, and Spirochaetota. Bacteroidota was superior in the whole reaction process under the influence of OTC and SMZ because it stimulated the microbial flora and made its activity higher. The study provides relevant data for the proper management of livestock manure.

Nanofiltration concentrated leachate (NFCL) is a high-concentration organic wastewater produced from landfill leachate during the process of membrane advanced treatment, which is more difficult to treat than landfill leachate. In this study, the effect and cost of treating NFCL by flocculation combined with a multistage ozone/bioreactor process based on a field scale are discussed. The results show that the process has a good effect on the removal of organic matter and nitrogen pollutants in NFCL, with removal efficiencies of chemical oxygen demand, ammonia nitrogen, nitrate, and total nitrogen being 96.6%, 90.1%, 38.2%, and 75.8%, respectively. The effluent can meet the discharge standard of China’s standard with a direct operating cost of approximately USD 18.48–20.82/m3. This study proved the effectiveness, structural rationality, and economic benefit of the process in a practical engineering application, and provided a certain theoretical basis and engineering reference for the wide application of the process in the treatment of leachate membrane concentrate.

To investigate the effects of different structural parameters in the degradation of o-Dichlorobenzene (o-DCB) by dielectric barrier discharge nonthermal plasma (DBD-NTP) and to explore the optimal reactor structural parameters, experimental investigations were carried out using plasma reactors of different structures. The effects of single and double dielectric, different high-voltage electrode positions, different dielectric thicknesses, different discharge gaps and different discharge lengths on the degradation efficiency, carbon monoxide and carbon dioxide selectivity, carbon balance, and ozone of o-DCB were investigated in the reactor. The results show that single dielectric, external high-voltage electrode and lower dielectric thickness, discharge gap, and longer discharge length favor ozone control and improve o-DCB degradation and carbon monoxide CO2 selectivity as well as carbon balance.

Computational fluid dynamics (CFD) is a branch of fluid mechanics that uses numerical analysis and data structures to calculate, analyze, and visualize fluid (liquids, gases, and dissolved gases) flows. This document provides general introductions to best practices for CFD modeling in water infrastructure for practitioners, particularly those new to CFD modeling, which is becoming a widely used tool in the design and retrofitting of water, wastewater, and stormwater infrastructure. The method serves as an alternative, or complement, to physical modeling. In recent years, CFD has often been used in evaluating and troubleshooting existing water systems as well as improving future designs. As with the applications in other fields, the popularity of CFD in the water industry has been propelled by a multitude of factors including, but not limited to, the maturity achieved by CFD techniques, the development of stable and reliable numerical schemes, and the ever-improving computer-aided design (CAD) and meshing technologies for real-world complex geometries. This has been accompanied by many commercial and open-source CFD packages that can be run on increasingly more powerful computing hardware. Despite the visible progress in the application of CFD in water infrastructure projects achieved to date, there are still many challenges that hinder the widespread use of CFD techniques in water treatment design. Perhaps more important is that many of these challenges may result in misuse of the tool with dire consequences. It is imperative that CFD practitioners appropriately apply this tool without overpromising capability or accuracy and that reviewers of CFD model results know what to look for in ensuring proper methods have been applied and that results are representative of reality.

In this study, two combined processes of coagulation sedimentation-NaClO disinfection and coagulation sedimentation-ultrafiltration (UF)-NaClO disinfection are used as advanced treatment processes to explore the removal effect and mechanism of the combined processes on Legionella, Pseudomonas aeruginosa, Mycobacterium avium, and Escherichia coli in the secondary effluent. In addition, reclaimed water was reused in the landscape as an evaluation scenario, Monte Carlo simulation of the health risk of opportunistic pathogens in process effluent was carried out, and the microbiological safety of the two processes was evaluated. The results showed that the combined process of coagulation sedimentation-UF-NaClO has a good removal effect on Legionella, Pseudomonas aeruginosa, Mycobacterium avium, and Escherichia coli, and the removal rates are 99.8%, 98.6%, 99.4%, and 99.1%, respectively. There is a significant positive correlation between the concentration of Escherichia coli in the secondary effluent and the three opportunistic pathogens, but the correlation between the concentration of Escherichia coli in the effluent and the three opportunistic pathogens is no longer significant after the two combination processes. The three opportunistic pathogens has the lowest single-exposure infection probability after secondary effluent coagulation sedimentation-UF-NaClO disinfection and reuse for urban landscape leisure activities. The safety rate for human health may range from 70.9% to 100%.

The development of industry has caused metal pollution of aquatic ecosystems and water deterioration worldwide. Therefore, environmentally friendly strategies for industrial wastewater treatment are needed. In this study, constructed wetlands (CWs) were planted with Schoenoplectus californicus in a culture medium with different concentrations of Cu, Pb, and Zn. The aims of this work were to evaluate the ability of S. californicus to accumulate Cu, Pb, and Zn and its physiological response to metal exposure, and assess the wastewater treatment performance of the CW systems. The accumulation of Cu, Pb, and Zn in the shoot and root of the emergent aquatic plant depended on the metal concentration during the 28 days of exposure, except for Pb in shoots. The bioconcentration factors of Cu (46.7±10.8) and Zn (896±317) were highest in the treatment with moderate levels of metals (T-2), whereas for Pb (57.4±15.9), the maximum bioconcentration factor was recorded in the treatment with the highest metal levels (T-3). Metal translocation from root to shoot reached values greater than 1 for Cu, but were lower for Pb and Zn because accumulation occurred predominantly in the root. In general, the removal efficiency of the CW systems was higher than 90% for Pb and Zn, and higher than 80% for Cu. Furthermore, Cu, Pb, and Zn bioaccumulation in S. californicus did not reflect toxicological damage to physiological parameters, such as the formation of products of lipid membrane peroxidation. The results showed that the exposure to relatively high metal concentrations in the CWs did not affect the survival of the species. Considering the capacity of S. californicus to tolerate and accumulate Pb, Zn, and Cu, this species can be used as a phytoextractor in wastewater treatment in CW systems.

With the increase in the chemical oxygen demand (COD) of the influent and the organic/hydraulic loading rate (OLR/HLR), the treatment efficiency of the vermifiltration (VF) process decreases. Also, the treatment performance of the VF process varies with the type of wastewater, even if all the other operating conditions remain the same. To date, the inhibitory effects of wastewater, e.g., its composition, concentration, and OLR/HLR, on earthworms (EWs) and VF’s treatment efficacy have been completely overlooked. Herein, such inhibitory effects on the survival, growth, and reproduction of the EWs have been investigated using real brewery, dairy, domestic, and diluted brewery wastewater. The acute and chronic tests were performed in vertical subsurface flow reactors in accordance with the guidelines with some modifications. Results showed that 50% mortality of EWs occurred within 11–21, 16–33, 21–41, and 24–48 days for brewery, diluted brewery, dairy, and domestic wastewater, respectively, at the HLR of 8–4 m3 m−2day−1. For each wastewater, the maximum growth of EWs was observed at the lowest tested HLR (4 m3 m−2day−1). Domestic sewage ensured the highest number of juvenile (20–38 nos. EW−1) and cocoon production (10–15 nos. EW−1), followed by dairy (juveniles: 7–21; cocoons: 5–10), diluted brewery (juveniles: 4–15; cocoons: 2–9), and brewery wastewater (juveniles: 2–12; cocoons: 2–7), with the HLR and OLR having a negative impact on the same. Therefore, brewery wastewater had the highest biological inhibition on survival and biological activities of the EWs, whereas domestic sewage had the least. The dilution given to brewery wastewater reduced the extent of the inhibitory effects imposed on the survival, growth, and reproduction of EWs. Results of this study indicated that the VF technology is more suitable for treating domestic sewage, can treat dairy wastewater substantially, and can treat brewery wastewater, but appropriate pretreatment (such as bioaugmentation or dilution) may be necessary.

The leachate collection system (LCS) and leak detection system (LDS) flow rate data from 240 cells (or a combination of cells) at 54 municipal solid-waste landfills (located in seven US states) with double-liner systems were analyzed to assess the performance of the primary liner system. The average LCS leachate collection rates for the study sites ranged from 380 L ha^-1 day^-1 (40.7 gal. acre^-1 day^-1) to 22,400 L ha^-1 day^-1 (2,390 gal. acre^-1 day^-1) on a sitewide basis, and the average LDS leachate collection rates ranged from 1.8 L ha^-1 day^-1 (0.2 gal. acre^-1 day^-1) to 577 L ha^-1 day^-1 (61.7 gal. acre^-1 day^-1) on a sitewide basis. Assuming all leachate generated is collected either by the LCS or LDS, the data suggest that the primary liner systems' aggregated efficiency is over 98%. The collection efficiency at sites that used a composite liner (geomembrane underlain by a geosynthetic clay liner or a compacted clay liner) system was not statistically different from the sites that used only a geomembrane as the primary liner (geomembrane underlain by a permeable layer) (median of 99% for both types). Leakage rates were compared with those estimated from the equations used by the hydrologic evaluation of landfill performance (HELP) model. The comparison suggests that the equations used by the HELP model to estimate leakage through the liner overestimate the leakage rate through geomembrane primary liners but underestimate the leakage rate through composite primary liners based on the HELP-model-default defect size and suggested defect frequency. It is also possible that groundwater intrusion could contribute to a portion of the leachate collected from the LDS because leachate quality data collected from a few sites indicated the LCS leachate had a higher concentration of most constituents than the leachate collected from LDS.

In this study, silver nanoparticles (AgNs) were prepared using new methodology, and carbon quantum dots (CQDs) were prepared from waste plastics. For nitenpyram analysis, modified electrodes based on CQDs/AgNs/ sodium dodecyl sulfate (SDS) have been developed. There was no reduction peak observed on bare glassy carbon electrode (GCE), whereas nitenpyram underwent reduction at −450 mV on the CQDs/AgNs/SDS-modified electrode, which is much lower compared with previous reports. Further, its improved electrocatalytic activity is demonstrated by a higher sensing current. The detection limit was found to be 0.1 nM [signal to noise ratio (S/N=3)], which is much lower than other reports to date. Because the film remains intact and can detect nitenpyram for many days without losing sensitivity, it is suitable for long-term use. Standard and commercial pesticide recovery rates were evaluated in tomatoes and paddy food samples. Validation of electrochemical results has been achieved by comparing them with high-pressure liquid chromatography (HPLC) results. There was good agreement between the results and those obtained by HPLC. This proposed method was also used to verify the purity of the commercial nitenpyram sample, which agrees well with HPLC results. The proposed sensor opens up new possibilities for sensing of nitenpyram in environmental samples.

Phosphorus (P) and nitrogen (N) can be simultaneously recovered by struvite (MgNH4PO4·6H2O) crystallization, and this has attracted more and more attention. However, the cost of producing struvite from wastewater is high due to the chemical inputs, which makes the struvite process unattractive in terms of economic benefits. Thus, it is important to develop a new struvite technology with low cost and simple operation. In this work, the antigorite was activated by a ball-milling process. The crystal form of the antigorite was destroyed by the mechanical forces, leading an increase in the dissolution of Mg2+ and OH− in the structure. The concentration of Mg2+ dissolved into water increases with the milling time, as well as the pH. Additionally, the dissolution of the activated antigorite depends on the concentration of phosphate-ammonium. The responsive dissolution makes the activated antigorite adaptively adjust the dissolution of Mg2+ and OH− and maintain a stable recovery of nitrogen and phosphorus from wastewater. The performance of P and N recovery was investigated by moderating variables, including the molar ratio of N/P, activation time, reaction time, and dosage. The results showed that the activated antigorite in the wastewater can be automatically converted into struvite. Actual swine wastewater was treated by the activated antigorite process, and a recovery rate of 98% was achieved by adding 1.2 g/L activated antigorite. The economic evaluation shows that the cost of the activated antigorite process is only 36% of an ordinary chemical process (MgSO4 and NaOH).