Total Nitrogen Removal Efficiency Research Articles

Biodegradable polylactic acid plastic can aid to achieve partial nitrification/denitrification for low carbon to nitrogen ratio wastewater treatment: Performance and microbial mechanism.

Biodegradable polylactic acid plastic can aid to achieve partial nitrification/denitrification for low carbon to nitrogen ratio wastewater treatment: Performance and microbial mechanism.

Denitrification efficiency and biofilm community succession in a bidirectional alternating influent biofilter.

Biofilters are widely used for nitrogen removal in wastewater treatment. This study developed a bidirectional alternating-influent biofilter to reduce clogging and enhance nitrogen removal. Alternating influent utilized biofilm on the media as a denitrification carbon source. With initial ammonium, nitrate, and total nitrogen concentrations of 8.49±0.30, 12.52±0.20, and 19.89±0.79 mg/L, the forward influent achieved ammonium, nitrate, and total nitrogen removal efficiencies of 81.6%, 66.8%, and 71.2%, increasing by 13.3%, 3.0%, and 4.8% at the effluent. Reverse influent further boosted nitrate and total nitrogen removal by 14.0% and 5.5%. The natural DO gradient under conventional influent conditions was simulated, and the nitrogen removal mechanism and treatment effect, mainly nitrification and denitrification, were discussed. Microbial analysis showed that endogenous carbon in the biofilm, derived from decaying cells and EPS, reduced clogging risk. Significant changes in bacterial count, EPS content, and microbial abundance were observed across influent directions, with Proteobacteria, Bacteroidetes, and Pseudomonas increasing under reverse flow. These results indicate that bidirectional alternating influent can significantly improve nitrogen removal and reduce clogging, offering an effective optimization for wastewater treatment.

Improving the operational performance of a wastewater treatment plant by using GPS-X simulations: a case study in northern Taiwan

Empirically optimizing the design of a wastewater treatment plant to achieve higher efficiencies of pollutant removal is an extremely time-consuming process. Digital model simulations serve as an effective solution to this problem. The current study used the GPS-X simulation software to simulate five scenarios for improving the oxidation ditch treatment process at the Guishan Wastewater Treatment Plant, which was selected as a case study. The simulation results of the five scenarios revealed that Scenario E, involving a simultaneous increase in flow velocity and aeration of oxidation ditch along with returned flow from the secondary sedimentation tank to the anoxic section of the oxidation ditch, resulted in the most significant improvement in the removal efficiencies for ammonia (36 to 95%) and total nitrogen (51 to 86%). Moreover, among the five scenarios, Scenario E had the lowest carbon emissions but achieved the same increases in removal efficiencies for biological oxygen demand, chemical oxygen demand, ammonia, and total nitrogen.

Efficient nitrogen removal and elemental sulfur recovery through sulfide-driven partial denitrification coupled with anammox: Strategies based on N/S ratio and HRT.

Efficient nitrogen removal and elemental sulfur recovery through sulfide-driven partial denitrification coupled with anammox: Strategies based on N/S ratio and HRT.

Deciphering intricate associations between vigorous development and novel metabolic preferences of partial denitrification/anammox granular consortia within mainstream municipal wastewater.

Deciphering intricate associations between vigorous development and novel metabolic preferences of partial denitrification/anammox granular consortia within mainstream municipal wastewater.

Optimization of an HRT-Fixed Plug-Flow Anaerobic-Oxic-Anoxic (AOA) Reactor: Changing the Specific Anaerobic/Oxic/Anoxic HRT Ratios

Anaerobic-Oxic-Anoxic (AOA) is a promising process that addresses the increasingly stringent requirements for advanced nitrogen (N) and phosphorus (P) removal in wastewater treatment plants (WWTPs). Plug-flow AOA systems have received much attention due to the similarity of their application scenarios to those of WWTPs; however, the understanding of the AOA process remains incomplete. In this study, a plug-flow AOA reactor was operated for 142 days under different A/O/A hydraulic retention time (HRT) ratios at a short HRT (13.3 h). Efficient nutrient removal performance was achieved at an A/O/A HRT ratio of 1:2:2, with total inorganic nitrogen (TIN), P, and chemical oxygen demand (COD) removal efficiencies of 78.3 ± 5.5%, 96.0 ± 3.7%, and 79.8 ± 4.9%, respectively. Predominant functional bacteria, including Candidatus_Competibacter (2.1%) and Defluviicoccus (8.0%), as typical glycogen accumulating organisms (GAOs) contributed to good endogenous denitrification (approximately 37% TIN removal). Additionally, the reasonable A/O/A HRT ratio ensured synergistic interactions among multiple functional bacteria, enabling the stable operation of the efficient and cost-effective AOA system.

Optimizing Nitrogen Removal Through Coupled Simultaneous Nitrification-Denitrification and Sulfur Autotrophic Denitrification: Microbial Community Dynamics and Functional Pathways in Mariculture Tailwater Treatment

This study investigates the nitrogen removal pathways and microbial community dynamics in a novel system coupling simultaneous nitrification and denitrification (SND) with sulfur autotrophic denitrification (SAD) for the treatment of mariculture tailwater. High-throughput sequencing and predictive functional analysis were employed to examine microbial compositions and their functional roles across varying carbon-to-nitrogen (C/N) ratios. The results revealed that SND occurred in the aerobic stage, with Nitrosomonas and Nitrospira facilitating nitrification, while Denitromonas and Paracoccus drove denitrification. In the anaerobic stage, SAD was the primary nitrogen removal process, with sulfur metabolism supported by Thiobacillus and Desulfobacteria. Increasing C/N ratios enriched denitrifying bacteria, enhancing nitrogen removal performance, but reduced nitrifying activity. Functional gene analysis demonstrated the upregulation of denitrification genes (napAB, nirS, norBC, nosZ) with higher carbon inputs, while sulfur metabolism genes (sqr, soxB, dsrAB) confirmed the critical role of sulfur cycling in SAD. The integration of SND and SAD pathways, supported by carbon addition, achieved efficient nitrogen removal, while promoting sulfur bioavailability. Under C/N ratios of 1.2, the nitrate nitrogen (NO3−-N) removal efficiencies reached 93.48%, respectively, while the total nitrogen (TN) removal efficiencies were 95.06%. Ammonia nitrogen (NH4+-N) removal efficiency consistently exceeded 95%, stabilizing at 99.00% in the steady-state operation. This research provides a comprehensive understanding of the microbial and functional mechanisms underlying SND–SAD systems, offering an innovative solution for sustainable mariculture tailwater management.

Monitoring the stability of aerobic granular sludge under increasing fractions of slowly biodegradable substrate using quantitative image analysis.

Monitoring the stability of aerobic granular sludge under increasing fractions of slowly biodegradable substrate using quantitative image analysis.

Optimizing Wastewater Treatment Using Endophytic Fungi Isolated from Acacia saligna L. Bark

Endophytic fungi’s application in biological wastewater treatment is a cost, clean, and eco-friendly. This study aimed to assess the efficiency of three Aspergillus species in the mycoremediation of industrial (I) and agricultural (A) wastewater. These species were Aspergillus flavipes, Aspergillus niger, and Aspergillus flavus isolated from the bark of a medicinal plant (A0cacia saligna). Aspergillus species were subculture on potato dextrose broth at 28 °C for 7 days on a rotatory shaker at 180 rpm until fungal pellets were formed. Before and after treatment with fungi, all wastewater samples were examined for pH, TDS, salinity, EC, COD, BOD, TP, TN, and turbidity. According to the results, Aspergillus flavipes has a good removal efficiency of total phosphorus, removing 78% of it from sample (I) after 25 days, and turbidity removing 91% after 20 days in (A) sample. Aspergillus niger has a high chemical oxygen demand removal efficiency of 99% and 99.8% in (I and A) samples after the 15th and 10th day, respectively, in addition to total nitrogen removal efficiency of 99% in (A) sample after the 25th day; and turbidity removal efficiency of 99.7% in the same sample. Also, Aspergillus flavus recorded high removal of biological oxygen demand by 76% and 66% in (I and A) samples after the 10th day of each, respectively; total nitrogen by 69% after the 10th day in (I) sample; total phosphorus by 23% after 10th day in (A) sample; electrical conductivity by 10.7% after 10th day in (I) sample; and total dissolved salts by 1.3% after 5th day in (I) sample. The results explained that Aspergillus niger and Aspergillus flavus were the most efficient in the removal of chemical oxygen demand and biological oxygen demand which represented indicators of pollution in wastewater. The obtained results will be useful for optimal management of agricultural and industrial wastewater.

Assessment of reactor configurations and key factors for enhanced anammox-based nitrogen removal.

Assessment of reactor configurations and key factors for enhanced anammox-based nitrogen removal.

Simultaneous removal of organic matter and inorganic nitrogen in Baijiu wastewater by methanotrophic denitrification.

Simultaneous removal of organic matter and inorganic nitrogen in Baijiu wastewater by methanotrophic denitrification.

Insight into enhanced enrichment and nitrogen removal performance of Anammox bacteria with novel biochar/tourmaline polyurethane sponge modified biocarrier

Insight into enhanced enrichment and nitrogen removal performance of Anammox bacteria with novel biochar/tourmaline polyurethane sponge modified biocarrier

Enhancing biological nitrogen removal of slaughterhouse and meat processing wastewater in three-stage AO process by influent allocation: From lab-scale to full-scale investigation

Enhancing biological nitrogen removal of slaughterhouse and meat processing wastewater in three-stage AO process by influent allocation: From lab-scale to full-scale investigation

The start-up of red blood cell-like anammox granular sludge based on substrate volume flux

The start-up of red blood cell-like anammox granular sludge based on substrate volume flux

Molecular ecological insights into the synergistic response mechanism of nitrogen transformation, electron flow and antibiotic resistance genes in aerobic activated sludge systems driven by sulfamethoxazole and/or trimethoprim stresses

Molecular ecological insights into the synergistic response mechanism of nitrogen transformation, electron flow and antibiotic resistance genes in aerobic activated sludge systems driven by sulfamethoxazole and/or trimethoprim stresses

Stratified biofilm structure of MABR enabling efficient ammonia removal from aquaculture medicated bath wastewater.

Stratified biofilm structure of MABR enabling efficient ammonia removal from aquaculture medicated bath wastewater.

Coupling Thiosulfate-Driven denitrification and anammox to remove nitrogen from actual wastewater.

Coupling Thiosulfate-Driven denitrification and anammox to remove nitrogen from actual wastewater.

Activated carbon and anthraquinone-2,6-disulfonate as electron shuttles for enhancing carbon and nitrogen removal from simultaneous methanogenesis, Feammox and denitrification system.

Activated carbon and anthraquinone-2,6-disulfonate as electron shuttles for enhancing carbon and nitrogen removal from simultaneous methanogenesis, Feammox and denitrification system.

Utility of integrated papyrus-bivalve for bioremediation of aquaculture wastewater.

Aquaculture generates substantial amount of residual feeds and faecal matter that accumulate in the culture environment and pollute effluent-receiving water, diminishing its ecological functioning. To devise means of treating nutrient-rich aquaculture wastewater, the efficiency of integrated papyrus-bivalve mesocosms in removing nutrients was evaluated. The mesocosms were fed on water (6600 L) from one brood-stock pond and allowed to settle for 2weeks. Physico-chemical parameters, including nutrient level in influent and effluent of mesocosms, were analysed fortnightly using standard methods. The integrated papyrus-bivalve mesocosms had the highest removal of 69.5, 52.9, and 70.5% for total nitrogen (TN), total phosphorus (TP), and total dissolved solids (TDS), respectively, from the aquaculture wastewater. The removal efficiency of TN and TDS by the mesocosms followed the order: integrated papyrus-bivalve ˃ papyrus ˃ bivalves ˃ control, and removal efficiency for TP followed a similar trend, albeit integrated papyrus-bivalve≈papyrus. The nutrient retention (g/DMm2) in papyrus biomass was 24.09 and 2.93 in integrated papyrus-bivalve mesocosm and 20.77 and 3.81 in papyrus mesocosms for nitrogen and phosphorus, respectively. Meanwhile, the nutrient retention in bivalve biomass was 3.06 and 0.44 in integrated papyrus-bivalve and 1.95 and 0.34 in bivalve mesocosm, for nitrogen and phosphorus, respectively. The study confirms the synergistic functionality of papyrus and bivalves in treating aquaculture wastewater. Papyrus and bivalves in the mesocosms contributed to the bioremediation of wastewater through physical and biochemical processes, including filtration, nutrient uptake, and attachment surfaces for microorganisms. Therefore, we recommend integrated papyrus-bivalve bioremediation technology to fish farmers and policy makers.

Purification Effect and Microbial Community Analysis of Aquaculture Wastewater Using High-Efficiency and Stable Biochemical System

An adaptable, low-cost, and easy-to-operate biological treatment system for pollutant abatement in aquaculture water at the field pond scale needs to be developed. In this study, the pollutant removal capacity of a stable bioreactor for aquaculture wastewater was assessed, and the related mechanism was elucidated via an analysis of the microbial community’s characteristics and functions. The average removal efficiencies of chemical oxygen demand, suspended solids, total nitrogen, and total phosphorus were 40%, 86.22%, 38.62%, and 53.74%, respectively. The effluent quality meets the Requirement for Water Discharge from Freshwater Aquaculture Pond, SC/T9101-2007. The results indicate that the fillers under anaerobic conditions could attract Denitratisoma and unclassified_Rhodocyclaceae, promoting the denitrification reaction. This aligns with the characteristic that total nitrogen in aquaculture sewage mainly exists in the form of nitrate nitrogen. An anaerobic atmosphere helps degrade organic contaminants at liquid interfaces and remove nitrogen in the solid phase. The fillers under anaerobic conditions could attract Bacteroidota and promote the production of polysaccharides to form biofilms, which may be associated with phosphorus removal. The results indicate that the anaerobic stage can promote the formation of biofilm on the fillers to remove pollutants, thus achieving higher aquaculture sewage treatment efficiency.