The ability of simultaneous biological phosphorus and nitrogen removal was investigated in a lab-scale continuous-flow two-sludge system. Alternating anaerobic and anoxic conditions were combined with contact oxidation stage for treating raw municipal wastewater. Long-term experiments showed that the contradiction of competing for the organic substrate between denitrifying bacteria and PAOs (phosphorus accumulating organisms) in traditional phosphorus and nitrogen removal system has been resolved. The system can adapt to low influent COD/TN ratio (C/N). Furthermore the SRT (sludge retention time) of nitrifying sludge and denitrifying phosphorus removal sludge can be controlled at optimal conditions respectively. The removal efficiency of COD, TP, TN, and NH4-N was 81.78%, 92.51%,75.75%, and 84.47% respectively. It was also found that the appropriate influent C/N should be controlled at the range of 3.8-6, while the optimal C/N to the system ranged between 4-5, and the BFR (bypass sludge flow rate) should be controlled at 0.35 around.
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J Environ Manage
January 2025
71 Smith Ave., Bureau of Water Supply, New York City Department of Environmental Protection, Kingston, NY, 12401, USA.
The paired watershed monitoring approach is widely used to investigate hydrologic processes and water quality, providing streamflow and water quality records for long-term trend analysis, as well as data for developing and testing hydrologic models. In this study we use 20 years of streamflow and water quality data, along with a watershed model, to examine sources of stream nutrients and their changes over time in two small streams within the New York City water supply system. We compare sources and trends in stream nitrate and dissolved phosphorus in the urbanized Amawalk watershed with those of the predominantly forested Boyd Corners watershed in the Croton system of reservoirs.
View Article and Find Full Text PDFAppl Biochem Biotechnol
January 2025
CSIR-National Environmental Engineering Research Institute (CSIR-NEERI), Nehru Marg, Nagpur, 440020, Maharashtra, India.
The present study investigated the genomic and functional potential of Burkholderia contaminans PB_AQ24, a bacterial strain isolated from the municipal solid waste dumpsite, for boosting the growth of Dendrocalamus strictus (Male bamboo) seedlings. The isolated strain exhibited high potency for metal solubilization and ACC (1-Aminocyclopropane-1-carboxylate) deaminase activity. Its genome harbored diverse genes responsible for nitrogen and phosphorus utilization (trpABCDES, iaaH, acdS, pstABCS, phoAUD, pqqABCDE, kdpABC, gln, and nirBD) and also an abundance of heavy metal tolerant genes (ftsH, hptX, iscX-fdx-hscAB-iscAUR, mgtA, corA, and copC).
View Article and Find Full Text PDFOecologia
January 2025
Plant Evolutionary Ecology, Institute of Ecology, Evolution and Diversity, Faculty of Biological Sciences, Goethe University Frankfurt, Max-Von-Laue-Str. 13, 60438, Frankfurt am Main, Germany.
Rapid environmental changes across Europe include warmer and increasingly variable temperatures, changes in soil nutrient availability, and pollinator decline. These abiotic and biotic changes can affect natural plant populations and force them to optimize resource use against competitors. To date, the evolution of competitive ability in the context of changes in nutrient availability remains understudied.
View Article and Find Full Text PDFSci Rep
January 2025
Environmental Geochemistry group, Department of Geosciences and Geography, University of Helsinki, Helsinki, Finland.
The two-stage channel (TSC) design with a vegetated man-made floodplain has been recommended as an alternative to conventional re-dredging for managing suspended sediment (SS) and nutrient loads in agricultural streams. However, there are currently uncertainties surrounding the efficiency of TSCs, since mass balances covering the whole annual hydrograph and including different periods of the channel life cycle are lacking. This paper aims to improve understanding of the medium-term morphological development and sedimentary nutrient retention when a dredged, trapezoidal-shaped channel is converted into a TSC, using a mass balance estimate of nutrient and carbon retention from immediately after excavation until the establishment of approximate biogeochemical equilibrium retention.
View Article and Find Full Text PDFSci Total Environ
January 2025
School of Earth System Science, Tianjin University, Tianjin 300072, China.
The hydrodynamics, water temperature, and water quality model for the Dan River and Renzhuang Reservoir continuum were developed using field monitoring data and the Environmental Fluid Dynamics Code (EFDC). An in-situ water discharge experiment enabled the calculation of water propagation time using a simulated flood progression method and the hydrodynamics module of EFDC. Based on these model results, degradation coefficients for chemical oxygen demand, biochemical oxygen demand, nitrogen (N), phosphorus (P), fluoride, arsenic were determined, revealing significantly higher values when the wetland barrage was opening.
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