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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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Environ Monit Assess
September 2025
College of Ecological and Environmental Engineering, Guizhou Minzu University, Guiyang, 550025, China.
The rapid development of industry and agriculture has led to a significant increase in the toxicity and pollution of cadmium (Cd) and lead (Pb) in soil. Consequently, soil remediation employing biochar or modified biochar has emerged as a cost-effective and environmentally sustainable approach to address the issue of heavy metal (HM) ion pollution. PEI-functionalization biochar (PBC) derived from corn straw (PBCC), wood straw (PBCW), and rice straw (PBCR) was synthesized to immobilize Cd and Pb in contaminated acidic yellow soil.
View Article and Find Full Text PDFSci Total Environ
September 2025
School of Civil Engineering, Sichuan Agricultural University, Chengdu, 611830, China; Sichuan Higher Education Engineering Research Center for Disaster Prevention and Mitigation of Village Construction, Sichuan Agricultural University, Chengdu, 611830, China.
Biochar has emerged as a promising soil amendment for improving soil quality and mitigating environmental impacts, such as nutrient leaching. This study evaluated the impacts of ball-milled bamboo nano-biochar on water infiltration dynamics, retention capacity, and nitrogen‑phosphorus leaching in sandy loam soil using controlled column experiments and leaching experiments with five application doses alongside bulk biochar and untreated controls. Experimental results demonstrated that nano-biochar application significantly enhanced soil water retention capacity compared to the raw soil.
View Article and Find Full Text PDFMar Pollut Bull
September 2025
Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung, 804, Taiwan. Electronic address:
This study investigates high-light-tolerant Nannochloropsis oceanica Rose Bengal mutants (RB2 and RB113) for bioremediation of shrimp aquaculture wastewater (SWW) under increased temperature and light, simulating future climate change. Cultivations were performed under 250 μmol photons m·s with flue gas CO₂ supply. At 18 °C, RB mutants and wild-type (WT) strain showed similar growth.
View Article and Find Full Text PDFMar Pollut Bull
September 2025
Ecological Risk Research Department, Korea Institute of Ocean Science & Technology, Geoje 53201, Republic of Korea; Department of Ocean Science, KIOST School, University of Science and Technology (UST), Daejeon 34113, Republic of Korea. Electronic address:
Eutrophication in semi-enclosed coastal systems remains a persistent concern due to restricted water circulation and continuous nutrient inputs. To better characterize nutrient-driven water quality degradation, we applied a threshold-based analysis to seasonal monitoring data collected from Masan Bay, South Korea, between 2010 and 2015. Eutrophication status was assessed using a composite Eutrophication Index (EI) integrating chemical oxygen demand (COD), dissolved inorganic nitrogen (DIN), and dissolved inorganic phosphorus (DIP).
View Article and Find Full Text PDFPhys Chem Chem Phys
September 2025
School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China.
To analyse the issues of high muzzle flame intensity and the easy migration of insensitive agents in conventional insensitive propellants, this study synthesizes modified nitrocellulose grafted with carboxymethyl potassium groups by a two-step process, starting from the molecular structure of nitrocellulose (NC), the principal component of propellants. First, the denitration reaction was performed to reduce part of the nitrate ester groups on the surface of NC to hydroxyl groups, followed by an etherification reaction to achieve directional grafting of carboxymethyl potassium groups. Compared with conventional flame retardant/insensitive systems based on nitrogen, phosphorus, or DBP (dibutyl phthalate), potassium-based functional groups exhibit superior thermal stability and environmental friendliness.
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