Bacterial assembly and temporal dynamics in activated sludge of a full-scale municipal wastewater treatment plant.

Seasonal variation of antibiotic resistance genes in activated sludge of a full-scale municipal wastewater treatment plant: Contribution of activated sludge functional taxa and clinically relevant taxa

Phosphite (HPO3(2-), +3), a reduced P species in the P biogeochemical cycle, was monitored in a full-scale municipal wastewater treatment plant (MWTP) that uses an anaerobic/anoxic/aerobic-membrane bioreactor (A(2)/O-MBR) technology for treating mixed wastewater (56% industrial wastewater and 44% domestic wastewater) from June 2013 to May 2014. Wastewater samples were collected from influent after having gone through the fine grille, anaerobic tank, anoxic tank, and aerobics tank, respectively. The final stage yielded effluent. Results confirmed the presence of phosphite in the MWTP ranging from 4.62 ± 1.00 μg P L(-1) to 34.30 ± 3.49 μg P L(-1) in influent and from 1.15 ± 0.5 μg P L(-1) to 4.42 ± 0.9 μg P L(-1) in effluent. Phosphite accounted for approximately 0.15% to 2.27% of total soluble phosphorus (TSP). During the A(2)/O-MBR process, the average removal of phosphite was 82.41 ± 7.45%. The anaerobic biological treatment removed the most phosphite from wastewater in this study. Spatially, phosphite concentrations decreased gradually as the wastewater treatment process progressed. Seasonally, the phosphite concentrations in spring and winter were higher than those in summer and autumn. The phosphite concentration in effluent was of the same order of magnitude as that in nearby natural water, which suggested MWTP effluent may be an important phosphite contributor to the natural water.

Selective elimination of chromophoric and fluorescent dissolved organic matter in a full-scale municipal wastewater treatment plant

Quantify the contribution of anammox for enhanced nitrogen removal through metagenomic analysis and mass balance in an anoxic moving bed biofilm reactor

Different stochastic processes regulate bacterial and fungal community assembly in estuarine wetland soils

Start up of anoxic-oxic process in a full-scale municipal wastewater treatment plant at low temperature was studied in this paper. Bioaugmentation technology was used to accelerate the start up. Aeration rate and feed style of influent were also controlled as associated measure to reduce the negative effect of low temperature on start up. The results showed that the process was successfully started up in 15 days. The removal efficiencies of COD, TN and TP were 69%, 47% and 46%, respectively. Microscopic analysis showed that Suctorias, which were excellent indicators of good sludge, occurred in the biosolid in the last days of start up. As a conclusion, bioaugmentation seems to be a promising method to accelerate the start up of bioprocess in a full-scale municipal wastewater treatment plant at low temperature.

Nitrifying community structures and nitrification performance of full-scale municipal and swine wastewater treatment plants

A novel two-stage anoxic/oxic-moving bed biofilm reactor process for biological nitrogen removal in a full-scale municipal WWTP: Performance and bacterial community analysis

Spatial variation of pharmaceuticals in the unit processes of full-scale municipal wastewater treatment plants in Korea

Nitrifying communities in activated sludge play a crucial role in biological nitrogen removal processes in municipal wastewater treatment plants. While extensive research has been conducted in temperate regions, limited information is available on nitrifiers in tropical regions. The present study investigated all currently known nitrifying communities in two full-scale municipal wastewater treatment plants in Malaysia operated under low-dissolved oxygen (DO) (0.2–0.7‍ ‍mg‍ ‍DO‍ ‍L–1) or high-DO (2.0–5.5‍ ‍mg‍ ‍DO‍ ‍L–1) conditions at 30°C. The core nitrifiers in the municipal wastewater treatment plants were Nitrosomonas (ammonia-oxidizing bacteria, AOB), Nitrospira (nitrite-oxidizing or complete ammonia-oxidizing, comammox, bacteria), and ammonia-oxidizing archaea (AOA) as identified by a 16S rRNA gene amplicon sequencing ana­lysis and corroborated by 16S rRNA-targeted fluorescence in situ hybridization. A quantitative polymerase chain reaction (qPCR) targeting ammonia monooxygenase subunit A (amoA) genes revealed stable populations of comammox Nitrospira and AOB in both wastewater treatment plants. AOA were detected in only one of the plants and their population sizes fluctuated, with higher temporary abundance under high-DO conditions. These results provide important insights into the composition and dynamics of nitrifying communities in tropical municipal wastewater treatment plants.

Machine-learning insights into nitrate-reducing communities in a full-scale municipal wastewater treatment plant

Refractory wastewater shapes bacterial assembly and key taxa during long-term acclimatization

An integrated dynamic model for simulating a full-scale municipal wastewater treatment plant under fluctuating conditions

Functional relationship between ammonia-oxidizing bacteria and ammonia-oxidizing archaea populations in the secondary treatment system of a full-scale municipal wastewater treatment plant

This article reviews studies focusing on the removal performance of natural estrogens in municipal wastewater treatment plants (WWTPs). Key factors influencing removal include: sludge retention time (SRT), aeration, temperature, mixed liquor suspended solids (MLSS), and substrate concentration. Batch studies show that natural estrogens should biodegrade well; however, batch observations do not always agree with observations from full-scale municipal WWTPs. To explain this discrepancy, deconjugation kinetics of estrogen conjugates in lab-scale studies were examined and compared. Most estrogen conjugates with slow deconjugation rates are unlikely to be easily removed; others could be cleaved in WWTP settings. Nevertheless, some estrogens cleaved from their conjugates may be found in treated effluent, because deconjugation requires several hours or longer, and there is insufficient rest time for the biodegradation of the cleaved natural estrogens in the WWTP. Therefore, WWTP removals of natural estrogens are likely to be underestimated when estrogen conjugates are present in raw wastewater. This review suggests that biodeconjugation of estrogen conjugates should be enhanced to more effectively remove natural estrogens in WWTPs.