Three floating treatment wetlands (FTWs), which consist of emergent macrophytes, were constructed and planted to investigate the influence of seasonal change on contaminant removal and harvesting strategy. The investigation was carried out by treating simulated urban stormwater runoff sewage through selected aquatic plants in Jiaxing, Yangtze River Delta, China. Samples collected from the influent and effluent water of three FTWs planted with Canna indica, Thalia dealbata, and Lythrum salicaria, respectively, were analyzed for contaminant concentration in different batches. Results demonstrated that T. dealbata outperformed C. indica and L. salicaria in nutrient removal. The FTWs of T. dealbata achieved average removal efficiencies (AREs) of 71.17% ± 2.01% for chemical oxygen demand (COD), 69.96% ± 2.11% for total nitrogen (TN), and 82.40% ± 2.34% for total phosphorus (TP) in nine stages. The COD and TN concentrations in effluent water were under 20 and 1.5 mg L −1 for 20 weeks. Based on the analyses of accumulated nutrient removal in vegetation over time, the strategy of harvesting the aboveground tissues of T. dealbata and C. indica in late October or early November is recommended. However, L. salicaria aboveground tissues should be harvested in September. In Jiaxing, the constructed FTWs of T. dealbata exhibited the best seasonal applicability.

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In recent years, the widespread of antibiotic resistance genes (ARGs) has brought tremendous risk to the biological safety of drinking water. With the increasing demand for drinking water quality, ARGs have been regarded as a new pollutant that may cause serious public health problems. A large number of studies showed that the disinfection process of drinking water treatment plants can remove ARGs. However, the effects of traditional disinfection methods on ARGs have their own disadvantages. Tea polyphenols have attracted more and more researchers’ attention as a green, efficient and non-disinfection by-products disinfectant. The effect of the ozone–tea polyphenols disinfection process on ARGs in filtered effluent of waterworks was analyzed by using the metagenomic sequencing. The result shows that the ozone–tea polyphenols disinfection process is suitable for specific raw water containing more tetracycline, sulfonamide, β-lactam, and aminoglycoside resistance genes, and the removal rate of total resistance genes in water is higher than the traditional disinfection process. The effect of the ozone–tea polyphenols disinfection process on ARGs is to reduce the transfer of ARGs by destroying ARGs molecules and inhibiting the proliferation of ARGs host cells. As an assistant disinfectant, tea polyphenols have significance for the ability to remove ARGs during traditional disinfection.

Taking the public building domestic wastewater as an example, the combination of the MBR (membrane bioreactor) process and the traditional A2/O (anaerobic-anoxic-oxic) process was established and analyzed in terms of the removal effect of the pollutants, the impact of the microbial community changes on the process, the MBR membrane fouling, the cleaning methods, and the cleaning performance. The results indicated that the effluent water quality of the domestic wastewater treated with the A2/O-MBR process was stable and met the emission requirement to the natural water body. There was good microbial diversity in raw water, the anaerobic tank, the anoxic tank, the aerobic MBR tank and the disinfection tank, and the aerobic MBR tank has a wide variety of aerobic microorganisms, which elevates the removal of organics and the nitrification of ammonia nitrogen and ensures the qualification of nitrogen and phosphorus indexes of the system effluent water. For the fouled membrane, the surface of the contaminated membrane was covered by macromolecular contaminants, causing the membrane flux to drop, and after different cleaning methods to the membrane were compared, it was discovered that the combined use of cleaning agents had better effects than the single ones, and the cleaning method of sodium hydroxide followed by hydrochloric acid showed the best effect, achieving a membrane flux restoration ratio above 80% after cleaning.