scholarly journals Decentralized Domestic Sewage Treatment Using an Integrated Multi-Soil-Layering and Subsurface Wastewater Infiltration System

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 431
Author(s):  
Dan Li ◽  
Xinze Wang ◽  
Lina Chi ◽  
Zhiping Zhang ◽  
Yanping Liu ◽  
...  

In this study, an integrated multi-soil-layering and subsurface wastewater infiltration (MSL-SWI) system was developed for decentralized domestic sewage treatment under high hydraulic loading rates (HLRs). To improve sustainable nitrogen removal, the influence of intermittent operation and shunt distributing wastewater on the performance of MSL-SWI systems was investigated. The optimal performance—with removal efficiencies of 93.41% for chemical oxygen demand, 97.91% for total phosphorus, 74.02% for ammonia nitrogen, and 73.56% for total nitrogen—was achieved using both intermittent operation and shunt distributing wastewater under an HLR of 0.3 m3 m−2 d−1. The activity of microbial nitrogen functional genes (i.e., amoA, nirK, nirS, nosZ, and anammox 16S rRNA) and their relationships with nitrogen transformation rates were further analyzed in different layers of the system. The results imply that nitrification and anaerobic ammonium oxidation in the MSL section coupled with nitrification and denitrification in the SWI section contribute to main the mechanisms of sustainable nitrogen removal. In summary, MSL-SWI systems not only operate with high efficiency under high HLRs, but the contaminant removal is also stable and sustainable, which are promising properties for domestic sewage treatment in areas where land resources are limited.

Author(s):  
Yuan Wei ◽  
Yue Jin ◽  
Wenjie Zhang

A one-stage anaerobic ammonium oxidation (ANAMMOX) reactor can be quickly started within 40 days by mixing partial nitrifying sludge with ANAMMOX granular sludge with an average temperature of 30 °C. After 70 days of nitrogen load acclimation, Acinetobacter, including Candidatus Kuenenia, became the dominant strain of the system within the reactor, which exhibited high efficiency and a stable nitrogen removal performance. At an influent chemical oxygen demand (COD), NH4+-N content, total nitrogen (TN) content, hydraulic retention time (HRT), temperature, and reactor dissolved oxygen (DO) content of 100, 60, and 70 mg/L, 6 h, 30 ± 1 °C, and below 0.6 mg/L, respectively, the one-stage ANAMMOX reactor could effectively treat domestic sewage on campus. The removal rates of COD, NH4+-N, and TN were approximately 89%, 96.7%, and 70%, respectively.


2016 ◽  
Vol 74 (7) ◽  
pp. 1509-1517 ◽  
Author(s):  
Linan Zhu ◽  
Hailing He ◽  
Chunli Wang

The hybrid membrane bioreactor (HMBR) has been applied in ship domestic sewage treatment under high volumetric loading for ship space saving. The mechanism and influence factors on the efficiency, including hydraulic retention time (HRT), dissolved oxygen (DO) of chemical oxygen demand (COD) removal were investigated. The HMBR's average COD removal rate was up to 95.13% on volumetric loading of 2.4 kgCOD/(m3•d) and the COD concentration in the effluent was 48.5 mg/L, far below the International Maritime Organization (IMO) discharge standard of 125 mg/L. DO had a more remarkable effect on the COD removal efficiency than HRT. In addition, HMBR revealed an excellent capability of resisting organics loading impact. Within the range of volumetric loading of 0.72 to 4.8 kg COD/(m3•d), the effluent COD concentration satisfied the discharge requirement of IMO. It was found that the organics degradation in the aeration tank followed the first-order reaction, with obtained kinetic parameters of vmax (2.79 d−1) and Ks (395 mg/L). The original finding of this study had shown the effectiveness of HMBR in organic contaminant degradation at high substrate concentration, which can be used as guidance in the full scale of the design, operation and maintenance of ship domestic sewage treatment devices.


Processes ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 109
Author(s):  
Yu Huang ◽  
Yongzhen Peng ◽  
Donghui Huang ◽  
Jiarui Fan ◽  
Rui Du

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.


2018 ◽  
Vol 78 (3) ◽  
pp. 545-555
Author(s):  
Xia Liu ◽  
Guohui Ning ◽  
Jianzhi Xie ◽  
Chunjing Liu ◽  
Ming Li

Abstract For achieving the economical and efficient configuration of constructed wetlands (CWs), a simulated device of vertical flow CWs was used to investigate the effects of different volume ratios of substrates to two cold-resistant plants on pollutant concentrations as well as their ratios in effluent under different inflow domestic sewage concentrations. The average removal rates (ARRs) of ammonia nitrogen, total nitrogen (TN) and total phosphorus were 82.7%, 84.9% and 80.6% respectively in the treatments with zeolite but no plants, which increased by 22.6%, 20.8% and 14.9% compared with those without zeolite and plants. However, in the treatments with zeolite and planted grasses, the ARRs of the three pollutants were over 90%, and those of chemical oxygen demand were lower. The removal rates of ammonia nitrogen, TN and total phosphorus had negative correlations with C:N and N:P ratios and positive correlations with the C:P ratios. Increasing the ratio of zeolite to soil from 1:1 to 2:1 had no significant effects in the removal efficiency. It was suggested that planting Lolium perenne or Poa annua on the substrate with a zeolite to soil volume ratio of 1:1 could be considered as the optimum combination to purify the domestic sewage in north rural areas of China.


2013 ◽  
Vol 726-731 ◽  
pp. 2931-2935
Author(s):  
Qi Bin Liang ◽  
Yun Gen Liu ◽  
Kun Tian

The study aimed at phosphorus and nitrogen removal by honeycomb cinder modified with Zinc chloride (ZnCl2). By bench-scale batch experiments, honeycomb cinders with different modification time and ZnCl2 dosage were modified and its adsorption capacities were evaluated by methylence blue as the adsorbate. Under the optimal modification conditions, large amount modified honeycomb cinders were prepared to remove the phosphorus and nitrogen from domestic sewage, which different operating conditions of honeycomb cinders dosage, and contact time were considered. The results show that removal efficiencies of total phosphate (TP), orthophosphate (PO43-P), total nitrogen (TN) and ammonia nitrogen (NH4+-N) could reach 89.9%, 96.7%, 18.9% and 23.3% under the optimal conditions, respectively. Modified honeycomb cinders might be an effective and low cost adsorbent for phosphorus removal.


2019 ◽  
Vol 80 (3) ◽  
pp. 597-606 ◽  
Author(s):  
Johannes Boog ◽  
Thomas Kalbacher ◽  
Jaime Nivala ◽  
Manfred van Afferden ◽  
Roland A. Müller

Abstract Despite recent developments in process-based modeling of treatment wetlands (TW), the dynamic response of horizontal flow (HF) aerated wetlands to interruptions of aeration has not yet been modeled. In this study, the dynamic response of organic carbon and nitrogen removal to interruptions of aeration in an HF aerated wetland was investigated using a recently-developed numerical process-based model. Model calibration and validation were achieved using previously obtained data from pilot-scale experiments. Setting initial concentrations for anaerobic bacteria to high values ( 35–70 mg L−1) and including ammonia sorption was important to simulate the treatment performance of the experimental wetland in transition phases when aeration was switched off and on again. Even though steady-state air flow rate impacted steady-state soluble chemical oxygen demand (CODs), ammonia nitrogen (NH4–N) and oxidized nitrogen (NOx–N) concentration length profiles, it did not substantially affect corresponding effluent concentrations during aeration interruption. When comparing simulated with experimental results, it is most likely that extending the model to include mass transfer through the biofilm will allow to better explain the underlying experiments and to increase simulation accuracy. This study provides insights into the dynamic behavior of HF aerated wetlands and discusses assumptions and limitations of the modeling approach.


2014 ◽  
Vol 69 (7) ◽  
pp. 1410-1418 ◽  
Author(s):  
Weijie Guo ◽  
Zhu Li ◽  
Shuiping Cheng ◽  
Wei Liang ◽  
Feng He ◽  
...  

To examine the performance of a constructed wetland system on stormwater runoff and domestic sewage (SRS) treatment in central east China, two parallel pilot-scale integrated constructed wetland (ICW) systems were operated for one year. Each ICW consisted of a down-flow bed, an up-flow bed and a horizontal subsurface flow bed. The average removal rates of chemical oxygen demand (CODCr), total suspended solids (TSS), ammonia (NH4+-N), total nitrogen (TN) and total phosphorus (TP) were 63.6, 91.9, 38.7, 43.0 and 70.0%, respectively, and the corresponding amounts of pollutant retention were approximately 368.3, 284.9, 23.2, 44.6 and 5.9 g m−2 yr−1, respectively. High hydraulic loading rate (HLR) of 200 mm/d and low water temperatures (<15 °C) resulted in significant decrease in removals for TP and NH4+-N, but had no significant effects on removals of COD and TSS. These results indicated that the operation of this ICW at higher HLR (200 mm/d) might be effective and feasible for TSS and COD removal, but for acceptable removal efficiencies of nitrogen and phosphorus it should be operated at lower HLR (100 mm/d). This kind of ICW could be employed as an effective technique for SRS treatment.


2012 ◽  
Vol 518-523 ◽  
pp. 214-217
Author(s):  
Tao Hong Liao ◽  
Kang Huai Liu ◽  
Jia Chun Yang ◽  
Kenji Furukawa

This experiment aimed to explore the effect of high- concentration nitrogen removal by Anaerobic ammonium oxidation process. The mixed liquor suspended solid(MLSS)was 510 mg/L. In the beginning of the experiment, the inflow concentration rate of ammonia nitrogen and nitrite nitrogen was about 1:1.3 and the total nitrogen concentration was low. When the reactor reached the ideal treatment effect then gradually increased the total nitrogen concentration, until reaching the maximum nitrogen load rate(NLR) of the reactor. In the temperature of 34.4 °C, PH was 7.23, the inflow concentration of ammonia nitrogen was 223.3 mg. N/L, the inflow concentration nitrite nitrogen was 289.7 mg. N/L, the dissolved oxygen (DO) was 2.3 mg. N/L, the nitrogen load rate (NLR) was 6.08 kg. N / (m3. d), the nitrogen removal rate (NRR) was 5.60 kg. N / (m3. d), the total nitrogen (TN) removal rate was 92.2%, under this conditions, the reactor achieved the best effect.


2016 ◽  
Vol 73 (11) ◽  
pp. 2662-2669 ◽  
Author(s):  
Siyu Song ◽  
Jing Pan ◽  
Shiwei Wu ◽  
Yijing Guo ◽  
Jingxiao Yu ◽  
...  

The matrix oxidation reduction potential level, organic pollutants and nitrogen removal performances of eight subsurface wastewater infiltration systems (SWISs) (four with intermittent aeration, four without intermittent aeration) fed with influent chemical oxygen demand (COD)/N ratio of 3, 6, 12 and 18 were investigated. Nitrification of non-aerated SWISs was poor due to oxygen deficiency while higher COD/N ratios further led to lower COD and nitrogen removal rate. Intermittent aeration achieved almost complete nitrification, which successfully created aerobic conditions in the depth of 50 cm and did not change anoxic or anaerobic conditions in the depth of 80 and 110 cm. The sufficient carbon source in high COD/N ratio influent greatly promoted denitrification in SWISs with intermittent aeration. High average removal rates of COD (95.68%), ammonia nitrogen (NH4+-N) (99.32%) and total nitrogen (TN) (89.65%) were obtained with influent COD/N ratio of 12 in aerated SWISs. The results suggest that intermittent aeration was a reliable option to achieve high nitrogen removal in SWISs, especially with high COD/N ratio wastewater.


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