Study on the Enhanced Operation of Self-Ventilation-Based Coupling System for Domestic Wastewater Treatment

In this study, a new coupling system of biological filter bed and subsurface-flow constructed wetland based on the self-ventilation network was proposed, and the comparative pollutant removal efficiency at low and high influent concentration of the pilot coupling system with different substrates configurations were investigated. The study found that: The comparison system (b) had better removal rates than that of the original system (a), and the removal rate when treating low influent concentration was 74.10%, 94.14%, 73.57% and 69.53%, while in high influent concentration case was 81.30%, 90.28%, 88.57% and 75.36% for CODCr , NH4+ -N, TN and TP, respectively. The removal of the above main water indexes of the comparison system (b) promoted by 11.00%, 11.55%, 2.69% and 8.09% respectively in low influent concentration case and 4.20%, 9.20%, 7.66% and 13.61% respectively in high influent concentration case when comparing to the original system (a), which showed that the optimized configuration of various kinds of substrates was significant and was more beneficial to the degradation and removal of pollutants. The adsorption and interception function of substrates in the constructed wetland was the main way of phosphorus removal. The function of self-ventilation ensured the amount of DO in the coupling system, making the phosphorus removal was less affected comparing to structure of traditional wetland.

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Study on the Application and Optimization of Domestic Sewage Treatment Demonstration Based on a Novel Biofilter-Constructed Wetland Coupling System

10.21203/rs.3.rs-569836/v1 ◽

2021 ◽

Author(s):

Xiaomin Wang ◽

Yunli Liu ◽

Yi Zhang ◽

Wenqing Shi ◽

Yifan Yang ◽

...

Keyword(s):

Big Data ◽

Data Analysis ◽

Constructed Wetland ◽

Sewage Treatment ◽

Original System ◽

Big Data Analysis ◽

Domestic Sewage ◽

Contrast Study ◽

System A ◽

Coupling System

Abstract A novel biofilter-constructed wetland coupling system has been applied more than 160 domestic sewage treatment projects in different cities of Zhejiang province, China. The performance of a randomly selected project (flux rate was 27.0 m3/d) based on the coupling system was evaluated in long-term, and the effluent monitoring by big data analysis showed a relatively stable and good water quality. The effluent concentrations of CODCr, NH4+-N and TP was 37.57 ± 11.17 mg/L, 5.64 ± 1.69 mg/L and 0.82 ± 0.16 mg/L, respectively, which met the first class of "Standards for Discharge of Water Pollutants from Rural Domestic Sewage Treatment Facilities" (DB33/973–2015). The concentrations of effluent TP showed a strong polynomial curve fitting with effluent NH4+-N concentrations (R2 = 0.9329) according to the big data analysis. Besides, the concentrations of effluent CODCr had a strong positive linear correlation with the concentrations of effluent NH4+-N (R2 = 0.9297), which increased with the increase of effluent TP concentrations (R2 = 0.6957). Results also showed C/N had stronger correlation with pH (R2 = 0.6441), while the concentration of effluent NH4+-N and effluent TP had weak correlation with pH (R2 = 0.3348 and R2 = 0.4834, respectively). The findings might have very important guiding significance for the future monitoring methods of water effluent quality of treatment facility and the cost reduction of monitoring management. Moreover, a demonstration and experiments were carried out for a contrast study of the enhanced system (b) and original system (a). The removal efficiency of CODCr, NH4+-N and TP of the enhanced system (b) was 81.33 %, 90.22 %, and 75.44 %, respectively, which increased by 4.33 %, 9.11 % and 13.77 % respectively compared to the original system (a).

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Gradient Boosting Machine for Phosphorus Removal Prediction in Multi-Soil-Layering (MSL) system operated in a rural area

10.5194/egusphere-egu21-5269 ◽

2021 ◽

Author(s):

Sofyan Sbahi ◽

Naaila Ouazzani ◽

Abderrahmane Lahrouni ◽

Abdessamed Hejjaj ◽

Laila Mandi

Keyword(s):

Rural Areas ◽

Phosphorus Removal ◽

Linear Models ◽

Removal Rate ◽

Pollutant Removal ◽

Validation Dataset ◽

Gradient Boosting ◽

Feature Selection Technique ◽

Gradient Boosting Machine ◽

Soil Layering

The quality of effluents from wastewater treatment plants still challenging especially in underprivileged rural areas where water resources are mostly affected by pollution, depletion and excessive exploitation. Thus, the prediction of phosphorus removal is one of the most important tasks in the management of wastewater effluent. Predictive model accuracy is crucial for safe reuse of treated water for public health and the environment. However, linear models that use a high dimensional dataset may be unable to build accurate and interpretable models. To address this complexity, the current study evaluates the effect of hydraulic retention time (HRT) on the removal of orthophosphates (PO4&#8211;P) and total phosphorus (TP) by the multi-soil-layering (MSL) eco-friendly technology. In addition, it attempts to predict this removal from domestic wastewater using a combined approach based on feature selection technique and gradient boosting machine algorithm (GBM). Sixteen physicochemical and bacterial indicators were monitored for a one-year period. The results show that the HRT impact significantly (p < 0.01) the removal of phosphorus content by the MSL system. The HRT, pH, PO4&#8211;P and TP were suggested relevant for predicting the removal of TP, while HRT and PO4&#8211;P were sufficient for predicting the removal rate of PO4&#8211;P. The analysis of accuracy using the validation dataset demonstrates that GBM models have high credibility as they achieve an R&#178; > 0.92, while the analysis of sensitivity reveals that the HRT was the most important factor affecting phosphorus removal in the MSL system. In addition, the modeling results show that the GBM model has proven to be useful for predicting pollutant removal in the MSL technology and investigating its behavior.&#160;

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Reversing Clogging in Vertical-Flow Constructed Wetlands by Backwashing Treatment

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.129-131.1064 ◽

2010 ◽

Vol 129-131 ◽

pp. 1064-1068

Author(s):

Fei Ma ◽

Li Jiang ◽

Ting Zeng

Keyword(s):

Waste Water ◽

Hydraulic Conductivity ◽

Constructed Wetlands ◽

Constructed Wetland ◽

Removal Rate ◽

Pollutant Removal ◽

Vertical Flow ◽

Vertical Flow Constructed Wetlands ◽

The World ◽

Design Guidance

More and more constructed wetland CW) were used to treat waste water in the world for its advantage on cheaper and efficiency. CW would clog for improper design or imperfect management, so application for it was limited. The purpose of this paper is that using backwashing method resolve filter media clogging problem which is an intractable matter in constructed wetlands project. The effects of the backwashing treatment on pollutant removal, as well as the influence on characteristics of hydraulics of wetlands, were studied. The experimental results indicate that CW hydraulic conductivity, hydraulic resistance time and removal rate of COD increased after backwashing. This paper confirmed that backwashing method can reverse clogging in vertical-flow constructed wetlands, and provided design guidance for applying backwashing method to treat clogging vertical-flow constructed wetlands.

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Removal of organic and nitrogen in a novel anoxic fixed-bed / aerobic fluidized-moving bed integrated with a constructed wetland bio-reactor (A/O-FMCW)

E3S Web of Conferences ◽

10.1051/e3sconf/202016701001 ◽

2020 ◽

Vol 167 ◽

pp. 01001

Author(s):

Changmiao Lai ◽

Yu Sun ◽

Yong Guo ◽

Qin Cai ◽

Ping Yang

Keyword(s):

Wastewater Treatment ◽

Removal Efficiency ◽

Constructed Wetland ◽

Removal Rate ◽

Fixed Bed ◽

Oxygen Demand ◽

Integrated System ◽

Nitrification Rate ◽

Moving Bed ◽

Influent Concentration

An innovative hybrid process was designed using an integrated bio-reactor based on an anoxic / aerobic process that combined a fixed bed and a fluidized-moving bed with a constructed wetland (A/OFMCW) to enhance the removal of organic material and nitrogen. The goal was to achieve stringent discharge standards for rural domestic wastewater treatment. A preliminary lab-scale investigation of about 130 days obtained an average COD (Chemical Oxygen Demand) removal rate as high as 92.2% at an average influent concentration of 319.5 mg/L. The average TN (Total Nitrogen) removal efficiency positively correlated with the attached-growth biofilm as observed by SEM (Scanning Electron Microscope), and declined from 79.1% to 53.2%. The was accompanied by a gradual increase in the average influent concentration from 16.73 to 52.01 mg/L despite the relative nitrification rate fluctuating between 92.5% and 97.9%. The entire integrated system improved the COD removal efficiency by nearly 36% and the TN by 14–28%. Classical autotrophic nitrification and heterotrophic denitrification were the main mechanisms responsible for the elimination of pollutants, and the latter was determined to be the limiting step. Overall, this study provides an effective and less expensive alternative method to apply or upgrade DWWT (Decentralized Wastewater Treatment).

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Effect on Treating Urban Wastewater Process by Constructed Wetland Method

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.726-731.1778 ◽

2013 ◽

Vol 726-731 ◽

pp. 1778-1781

Author(s):

Jian She Yang ◽

Xiao Dan Ke

Keyword(s):

Water Quality ◽

Constructed Wetland ◽

Removal Rate ◽

Domestic Sewage ◽

Urban Wastewater ◽

System A ◽

Wetland System ◽

Contact Oxidation ◽

Engineered Wetland ◽

Quality Indexes

Constructed wetland conduct technology is a kind of artificialgovernable and engineered wetland system. A multiplied technology combination of "Hydrolysis precipitation, Contact oxidation and Constructed wetland" has been applied to conduct the domestic sewage of the towns, and the combination of that, the treatment effect and the working cost have been discussed here. The testing results of outlet water quality indexes showed as following, the removal rate of the CODCr was reach to 77.8%, the removal rate of the BOD5 was reach to 83.3%, the removal rate of the T-P was reach to 87%, the removal rate of the SS was reach 80% and the removal rate of the NH3-N was reach 67%.

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Performance of hybrid subsurface constructed wetland system for piggery wastewater treatment

Water Science & Technology ◽

10.2166/wst.2015.457 ◽

2015 ◽

Vol 73 (1) ◽

pp. 13-20 ◽

Cited By ~ 11

Author(s):

X. Zhang ◽

T. Inoue ◽

K. Kato ◽

J. Harada ◽

H. Izumoto ◽

...

Keyword(s):

Wastewater Treatment ◽

Constructed Wetland ◽

Removal Rate ◽

Oxygen Demand ◽

Total Coliform ◽

Organic Content ◽

Pollutant Removal ◽

Total Carbon ◽

Piggery Wastewater ◽

Ammonium N

The objective of this study was to evaluate performance of a hybrid constructed wetland (CW) built for high organic content piggery wastewater treatment in a cold region. The system consists of four vertical and one horizontal flow subsurface CWs. The wetland was built in 2009 and water quality was monitored from the outset. Average purification efficiency of this system was 95 ± 5, 91 ± 7, 89 ± 8, 70 ± 10, 84 ± 15, 90 ± 6, 99 ± 2, and 93 ± 16% for biochemical oxygen demand (BOD5), chemical oxygen demand (COD), total carbon (TC), total nitrogen (TN), ammonium-N (NH4-N), total phosphorus (TP), total coliform (T. Coliform), and suspended solids (SS), respectively during August 2010–December 2013. Pollutant removal rate was 15 ± 18 g m−2 d−1, 49 ± 52 g m−2 d−1, 6 ± 4 g m−2 d−1, 7 ± 5 g m−2 d−1, and 1 ± 1 g m−2 d−1 for BOD5, COD, TN, NH4-N, and TP, respectively. The removal efficiency of BOD5, COD, NH4-N, and SS improved yearly since the start of operation. With respect to removal of TN and TP, efficiency improved in the first three years but slightly declined in the fourth year. The system performed well during both warm and cold periods, but was more efficient in the warm period. The nitrate increase may be attributed to a low C/N ratio, due to limited availability of carbon required for denitrification.

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Municipal wastewater treatment with pond–constructed wetland system: a case study

Water Science & Technology ◽

10.2166/wst.2005.0491 ◽

2005 ◽

Vol 51 (12) ◽

pp. 325-329 ◽

Cited By ~ 18

Author(s):

X. Wang ◽

X. Bai ◽

J. Qiu ◽

B. Wang

Keyword(s):

Constructed Wetland ◽

Municipal Wastewater ◽

Municipal Wastewater Treatment ◽

Oxidation Pond ◽

System A ◽

Treated Effluent ◽

Wetland System ◽

Oxidation Ponds ◽

Better Than

The performance of a pond–constructed wetland system in the treatment of municipal wastewater in Kiaochow city was studied; and comparison with oxidation ponds system was conducted. In the post-constructed wetland, the removal of COD, TN and TP is 24%, 58.5% and 24.8% respectively. The treated effluent from the constructed wetland can meet the Chinese National Agricultural and Irrigation Standard. The comparison between pond–constructed wetland system and oxidation pond system shows that total nitrogen removal in a constructed wetland is better than that in an oxidation pond and the TP removal is inferior. A possible reason is the low dissolved oxygen concentration in the wetland. Constructed wetlands can restrain the growth of algae effectively, and can produce obvious ecological and economical benefits.

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Treatment of Combined Dairy and Domestic Wastewater with Constructed Wetland System in Sicily (Italy). Pollutant Removal Efficiency and Effect of Vegetation

Water ◽

10.3390/w13081086 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1086

Author(s):

Mario Licata ◽

Roberto Ruggeri ◽

Nicolò Iacuzzi ◽

Giuseppe Virga ◽

Davide Farruggia ◽

...

Keyword(s):

Plant Growth ◽

Organic Compounds ◽

Removal Efficiency ◽

Constructed Wetland ◽

Organic Pollutant ◽

Dairy Farm ◽

Domestic Wastewater ◽

Pollutant Removal ◽

Dairy Wastewater ◽

Giant Reed

Dairy wastewater (DWW) contains large amounts of mineral and organic compounds, which can accumulate in soil and water causing serious environmental pollution. A constructed wetland (CW) is a sustainable technology for the treatment of DWW in small-medium sized farms. This paper reports a two-year study on the performance of a pilot-scale horizontal subsurface flow system for DWW treatment in Sicily (Italy). The CW system covered a total surface area of 100 m2 and treated approximately 6 m3 per day of wastewater produced by a small dairy farm, subsequent to biological treatment. Removal efficiency (RE) of the system was calculated. The biomass production of two emergent macrophytes was determined and the effect of plant growth on organic pollutant RE was recorded. All DWW parameters showed significant differences between inlet and outlet. For BOD5 and COD, RE values were 76.00% and 62.00%, respectively. RE for total nitrogen (50.70%) was lower than that of organic compounds. RE levels of microbiological parameters were found to be higher than 80.00%. Giant reed produced greater biomass than umbrella sedge. A seasonal variation in RE of organic pollutants was recorded due to plant growth rate Our findings highlight the efficient use of a CW system for DWW treatment in dairy-cattle farms.

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