Nitrogen removal during the cold season by constructed floating wetlands planted with Oenanthe javanica

2018 ◽  
Vol 69 (5) ◽  
pp. 635 ◽  
Author(s):  
Penghe Wang ◽  
Nasreen Jeelani ◽  
Jie Zuo ◽  
Hui Zhang ◽  
Dehua Zhao ◽  
...  
Keyword(s):  
Waste Water ◽  
Nitrogen Removal ◽  
Nitrite Reductase ◽  
Waste Water Treatment ◽  
Microbial Community Composition ◽  
Cold Season ◽  
Anammox Bacteria ◽  
Ammonium Oxidation ◽  
Oenanthe Javanica ◽  
Floating Wetlands

Constructed floating wetlands (CFWs) are used to treat waste waters of various origins either alone or as part of waste water treatment trains. The aim of the present study was to determine the extent of nitrogen removal by CFWs planted with Oenanthe javanica (Blume) DC. at low temperatures (<10°C) and whether CFWs with vesuvianite as a substrate perform better than those without substrate. A batch model was used, with CFWs planted with O. javanica (Tc), CFWs without O. javanica (Ts), CFWs without substrate (Tp) and floating mats only (To) as a control. The average removal rates of NH4+-N, NO3–-N and total nitrogen were 78.3, 44.4 and 49.7% respectively in Tc; 72.0, 40.0 and 39.5% respectively in Ts; and 73.1, 33.7 and 44.0% respectively in Tp. In addition to a gradual increase in chemical oxygen demand during the experimental period, Tc had higher microbial richness and diversity, as well as a higher abundance of bacteria, archaea, anaerobic ammonium oxidation (Anammox) bacteria and key genes (ammonia mono-oxygenase, amoA, nitrous oxide reductase, nosZ, dissimilatory cd1-containing nitrite reductase, nirS, and dissimilatory copper-containing nitrite reductase, nirK) involved in nitrogen metabolism in the substrate than Ts. Further analysis of microbial community composition revealed a difference at multiple taxonomic levels among different systems. These results demonstrate the positive roles of O. javanica and vesuvianite in CFWs in nitrogen removal from waste water during the cold season (mean water temperature <10°C).

Elevated salinity inhibits nitrogen removal by changing the microbial community composition in constructed wetlands during the cold season

2018 ◽  
Vol 69 (5) ◽  
pp. 802
Author(s):  
Yajun Qiao ◽  
Penghe Wang ◽  
Wenjuan Zhang ◽  
Guangfang Sun ◽  
Dehua Zhao ◽  
...  
Keyword(s):  
Waste Water ◽  
Microbial Community ◽  
Community Composition ◽  
Constructed Wetlands ◽  
Nitrogen Removal ◽  
Bacterial Community Composition ◽  
Microbial Community Composition ◽  
Cold Season ◽  
Saline Waste ◽  
Elevated Salinity

In the present study we investigated whether subsurface flow constructed wetlands (SSF-CWs) can remove nitrogen from saline waste water and whether salinity affects nitrogen removal during the cold season (mean water temperature <10°C). Eight Iris pseudacorus-planted SSF-CWs were fed with normal (salinity 1.3–1.5‰; CWP) or saline (salinity 6.3–6.5‰; CWP+) waste water; similarly, eight unplanted SSF-CWs were fed with normal (CWU) or saline waste water (CWU+). The systems were run continuously at a hydraulic loading rate of 187.5mmday–1 and a hydraulic retention time of 4 days. Nitrogen removal efficiency, plant parameters and bacterial abundance and community composition were measured. In CWP, 80% of NH4+-N and 52% of total nitrogen (TN) were removed. In contrast, the removal rates of NH4+-N and TN in CWP+ were reduced by 27 and 37% respectively. In the presence of higher salinity, not only were there decreases in plant biomass (32.1%) and nitrogen uptake (50.1%), but the growth, activity and oxygen release of roots were also reduced (by 37.8, 68.0 and 62.9% respectively). Bacterial community composition also differed under conditions of elevated salinity. Elevated salinity is associated with lower nitrogen removal in SSF-CWs, which we speculate is a result of suppressed wetland macrophyte growth and activity, as well as changes in microbial community composition.

Pre-Precipitation Facilitates Nitrogen Removal without Tank Expansion

1990 ◽  
Vol 22 (7-8) ◽  
pp. 85-92 ◽  
Author(s):  
Ingemar Karlsson ◽  
Gunnar Smith
Keyword(s):  
Waste Water ◽  
Organic Matter ◽  
Water Treatment ◽  
Carbon Source ◽  
Nitrogen Removal ◽  
Waste Water Treatment ◽  
Chemical Precipitation ◽  
Sewage Water ◽  
Laboratory Studies ◽  
Denitrification Process

Chemically coagulated sewage water gives an effluent low in both suspended matter and organics. To use chemical precipitation as the first step in waste water treatment improves nitrification in the following biological stage. The precipitated sludge contains 75% of the organic matter in the sewage and can by hydrolysis be converted to readily degradable organic matter, which presents a valuable carbon source for the denitrification process. This paper will review experiences from full-scale applications as well as pilot-plant and laboratory studies.

scholarly journals Enhanced Nitrogen Removal from Domestic Wastewater by Partial-Denitrification/Anammox in an Anoxic/Oxic Biofilm Reactor

Processes ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 109
Author(s):  
Yu Huang ◽  
Yongzhen Peng ◽  
Donghui Huang ◽  
Jiarui Fan ◽  
Rui Du
Keyword(s):  
Nitrogen Removal ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Biofilm Reactor ◽  
Anammox Bacteria ◽  
Stable Operation ◽  
Ammonium Oxidation ◽  
N Accumulation ◽  
Carbon Demand ◽  
Oxidation Efficiency

A partial-denitrification coupling with anaerobic ammonium oxidation (anammox) process (PD/A) in a continuous-flow anoxic/oxic (A/O) biofilm reactor was developed to treat carbon-limited domestic wastewater (ammonia (NH4+-N) of 55 mg/L and chemical oxygen demand (COD) of 148 mg/L in average) for about 200 days operation. Satisfactory NH4+-N oxidation efficiency above 95% was achieved with rapid biofilm formation in the aerobic zone. Notably, nitrite (NO2−-N) accumulation was observed in the anoxic zone, mainly due to the insufficient electron donor for complete nitrate (NO3−-N) reduction. The nitrate-to-nitrite transformation ratio (NTR) achieved was as high as 64.4%. After the inoculation of anammox-enriched sludge to anoxic zones, total nitrogen (TN) removal was significantly improved from 37.3% to 78.0%. Anammox bacteria were effectively retained in anoxic biofilm utilizing NO2−-N produced via the PD approach and NH4+-N in domestic wastewater, with the relative abundance of 5.83% for stable operation. Anammox pathway contributed to TN removal by a high level of 38%. Overall, this study provided a promising method for mainstream nitrogen removal with low energy consumption and organic carbon demand.

scholarly journals Recovery of Phosphorus from Waste Water Profiting from Biological Nitrogen Treatment: Upstream, Concomitant or Downstream Precipitation Alternatives

Agronomy ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1039
Author(s):  
Albert Magrí ◽  
Mar Carreras-Sempere ◽  
Carmen Biel ◽  
Jesús Colprim
Keyword(s):  
Waste Water ◽  
Water Treatment ◽  
Waste Water Treatment ◽  
N Recovery ◽  
Ammonium Oxidation ◽  
Chemically Induced ◽  
Wide Range ◽  
N Treatment ◽  
Phosphate Salts ◽  
Biological Nitrogen

Mined phosphate rock is the largest source of phosphorus (P) for use in agriculture and agro-industry, but it also is a finite resource irregularly distributed around the world. Alternatively, waste water is a renewable source of P, available at the local scale. In waste water treatment, biological nitrogen (N) removal is applied according to a wide range of variants targeting the abatement of the ammonium content. Ammonium oxidation to nitrate can also be considered to mitigate ammonia emission, while enabling N recovery. This review focuses on the analysis of alternatives for coupling biological N treatment and phosphate precipitation when treating waste water in view of producing P-rich materials easily usable as fertilisers. Phosphate precipitation can be applied before (upstream configuration), together with (concomitant configuration), and after (downstream configuration) N treatment; i.e., chemically induced as a conditioning pre-treatment, biologically induced inside the reactor, and chemically induced as a refining post-treatment. Characteristics of the recovered products differ significantly depending on the case studied. Currently, precipitated phosphate salts are not typified in the European fertiliser regulation, and this fact limits marketability. Nonetheless, this topic is in progress. The potential requirements to be complied by these materials to be covered by the regulation are overviewed. The insights given will help in identifying enhanced integrated approaches for waste water treatment, pointing out significant needs for subsequent agronomic valorisation of the recovered phosphate salts, according to the paradigms of the circular economy, sustainability, and environmental protection.

scholarly journals Achieving fast start-up of anammox process by promoting the growth of anammox bacteria with FeS addition

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Chunzhen Zou ◽  
Beibei Guo ◽  
Xuming Zhuang ◽  
Liying Ren ◽  
Shou-Qing Ni ◽  
...  
Keyword(s):  
Microbial Community ◽  
Nitrogen Removal ◽  
Nitrite Reductase ◽  
Removal Rate ◽  
Anammox Bacteria ◽  
Gene Encoding ◽  
Start Up ◽  
Fast Start ◽  
The Difference ◽  
Anammox Process

Abstract The effects of FeS on nitrogen removal performance and microbial community of anammox process were studied. During the start-up period, the removal efficiencies of nitrite and total nitrogen were significantly improved by FeS. The addition of FeS increased the content of iron ions in the reactor and promoted the synthesis of heme c, which was involved in the formation of various enzymes. Compared with the control, the abundance of anammox bacteria in the FeS reactor was increased by 29%, and the expression level of the nirS gene (encoding cd1 type nitrite reductase containing heme) was nearly doubled. The content of nitrite reductase (ammonia-forming) in the community was increased by 26.4%. The difference in functional bacteria and enzyme contents in the microbial community resulted in a difference in nitrogen removal rate (NRR) between the two reactors. High-throughput results indicated that FeS increased the richness and diversity of microbial community and enhanced the metabolic function of the microbial community. The addition of FeS did not change the dominant position of Ca. Kuenenia in both reactors. But the relative abundance of heterotrophic denitrifying bacteria was reduced with FeS, which may be related to the inhibition effect of S2− produced by FeS.

Anaerobic ammonium oxidation in polyvinyl alcohol and sodium alginate immobilized biomass system: a potential tool to maintain anammox biomass in application

2013 ◽  
Vol 69 (4) ◽  
pp. 718-726 ◽  
Author(s):  
Gang-Li Zhu ◽  
Jia Yan ◽  
Yong-You Hu
Keyword(s):  
Polyvinyl Alcohol ◽  
Sodium Alginate ◽  
Nitrogen Removal ◽  
Enrichment Culture ◽  
Batch Reactor ◽  
Anaerobic Ammonium Oxidation ◽  
Anammox Bacteria ◽  
Ammonium Oxidation ◽  
Gel Beads ◽  
Key Factor

Anaerobic ammonium oxidation (anammox) has been proved to be a promising nitrogen removal method for treating ammonium-rich wastewater. However, because of the low-growth rate of anammox bacteria, maintenance of a sufficient amount of anammox biomass in reactor became a key factor in application. Gel immobilization is an efficient method to prevent biomass from being washed out and to promote hyper-concentrated cultures. This study focused on a nitrogen removal process by anammox enrichment culture immobilized in polyvinyl alcohol and sodium alginate (PVA-SA) gel beads. The rapid startup of reactor demonstrated that gel entrapment was supposed to be a highly effective technique for immobilizing anammox bacteria. The anammox bacteria present in the enrichment were identified to be Jettenia-like species (&gt;98%). Moreover, the effect of hydraulic retention time (HRT), pH, and temperature on immobilized anammox processes were investigated. The effect of pH and temperature on the anammox process was evidently weakened in PVA-SA immobilized gel beads, however, the effect of HRT on the anammox reaction was enhanced. Therefore, a stable operated reactor could be obtained in an anaerobic sequencing batch reactor, which proved gel immobilization was an excellent method to maintain the biomass in anammox reactor for application.

scholarly journals Recovery profile of anaerobic ammonium oxidation (anammox) bacteria inhibited by ZnO nanoparticles

2021 ◽  
Author(s):  
Safiye Can ◽  
Tugba Sari ◽  
Deniz Akgul
Keyword(s):  
Nitrogen Removal ◽  
Extracellular Polymeric Substances ◽  
Recovery Period ◽  
Industrial Applications ◽  
Anammox Bacteria ◽  
Ammonium Oxidation ◽  
Zno Nps ◽  
Treatment Processes ◽  
Recovery Profile ◽  
Different Doses

Abstract The potential effects of nanoparticles (NPs) on biological treatment processes have become significant due to their increasing industrial applications. The purpose of this research was to investigate the self-recovery ability of anammox bacteria following to acute ZnO NPs toxicity. In this context, a 2-liter lab-scale anammox reactor was operated for 550 days to enrich the biomass required to the batch exposure tests. Anammox culture was firstly exposed to four different doses of ZnO NPs (50, 75, 100 and 200 mg/L) for 24 h. Then, the ZnO NPs were removed and self-recovery performance of the anammox bacteria was assessed by evaluating the nitrogen removal capacities for 72 h. Besides the nitrogen removal performance, extracellular polymeric substances (EPS) production was also detected to deeply understand the response of the enriched anammox culture against ZnO NPs exposure. The results revealed that, sudden and high load of ZnO NPs (100 and 200 mg/L) resulted in persistent impairment on the nitrogen removal performance of the enriched anammox culture. However, relatively lower doses (50 and 75 mg/L) caused deceleration of the nitrogen removal performance during the recovery period. In addition, EPS content in the reactor decreased along with escalating load of ZnO NPs.

scholarly journals Effects of Oenanthe javanica on Nitrogen Removal in Free-Water Surface Constructed Wetlands under Low-Temperature Conditions

2019 ◽  
Vol 16 (8) ◽  
pp. 1420 ◽  
Author(s):  
Song ◽  
Wang ◽  
Liu ◽  
Zhao ◽  
An
Keyword(s):  
Constructed Wetlands ◽  
Nitrogen Removal ◽  
Nitrite Reductase ◽  
Water Surface ◽  
Eastern China ◽  
Free Water ◽  
Free Water Surface ◽  
Nitrite Reductase Gene ◽  
Reductase Gene ◽  
Oenanthe Javanica

To investigate the role and microorganism-related mechanisms of macrophytes and assess the feasibility of Oenanthe javanica (Blume) DC. in promoting nitrogen removal in free-water surface constructed wetlands (FWS-CWS) under low temperatures (<10 °C), pilot-scale FWS-CWS, planted with O. javanica, were set up and run for batch wastewater treatment in eastern China during winter. The presence of macrophytes observably improved the removal rates of ammonia nitrogen (65%–71%) and total nitrogen (41%–48%) (p < 0.05), with a sharp increase in chemical oxygen demand concentrations (about 3–4 times). Compared to the unplanted systems, the planted systems not only exhibited higher richness and diversity of microorganisms, but also significantly higher abundances of bacteria, ammonia monooxygenase gene (amoA), nitrous oxide reductase gene (nosZ), dissimilatory cd1-containing nitrite reductase gene (nirS), and dissimilatory copper-containing nitrite reductase gene (nirK) in the substrate. Meanwhile, the analysis of the microbial community composition further revealed significant differences. The results indicate that enhanced abundances of microorganisms, and the key functional genes involved with nitrogen metabolism in the planted systems played critical roles in nitrogen removal from wastewater in FWS-CWS. Furthermore, abundant carbon release from the wetland macrophytes could potentially aid nitrogen removal in FWS-CWS during winter.

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