Purification Effect of Sequential Constructed Wetland for the Polluted Water in Urban River

Constructed wetlands can play an active role in improving the water quality of urban rivers. In this study, a sequential series system of the floating-bed constructed wetland (FBCW), horizontal subsurface flow constructed wetland (HSFCW), and surface flow constructed wetland (SFCW) were constructed for the urban river treatment in the cold regions of North China, which gave full play to the combined advantages. In the Yitong River, the designed capacity and the hydraulic loading of the system was 100 m3/d and 0.10 m3/m2d, respectively. The hydraulic retention time was approximately 72 h. The monitoring results, from April to October in 2016, showed the multiple wetland ecosystem could effectively remove chemical oxygen demand (COD), ammonia nitrogen (NH4+-N), total nitrogen (TN), total phosphate (TP), and suspended solids (SS) at average removal rates of 74.79%, 80.90%, 71.12%, 78.44%, and 91.90%, respectively. The removal rate of SS in floating-bed wetland was the largest among all the indicators (80.24%), which could prevent the block of sub-surface flow wetland effectively. The sub-surface flow wetland could remove the NH4-N, TN, and TP effectively, and the contribution rates were 79.20%, 64.64%, and 81.71%, respectively. The surface flow wetland could further purify the TN and the removal rate of TN could reach 23%. The total investment of this ecological engineering was $12,000. The construction cost and the operation cost were $120 and $0.02 per ton of polluted water, which was about 1/3 to 1/5 and 1/6 to 1/3 of the conventional sewage treatment, respectively. The results of this study provide a technical demonstration of the restoration of polluted water in urban rivers in northern China.

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Experimental study of a novel hybrid constructed wetland for water reuse and its application in Southern China

Water Science & Technology ◽

10.2166/wst.2011.790 ◽

2011 ◽

Vol 64 (11) ◽

pp. 2177-2184 ◽

Cited By ~ 23

Author(s):

J. Zhai ◽

H. W. Xiao ◽

K. Kujawa-Roeleveld ◽

Q. He ◽

S. M. Kerstens

Keyword(s):

Constructed Wetland ◽

Water Reuse ◽

Southern China ◽

Sewage Treatment ◽

Subsurface Flow ◽

Circulatory System ◽

Oxygen Demand ◽

Ammonia Nitrogen ◽

Municipal Sewage ◽

Horizontal Subsurface Flow

A new type of hybrid constructed wetland (CW), consisting of both vertical-baffled flow wetland (VBFW) and horizontal subsurface flow wetland (HSFW), has been deployed in Southern China to naturally accelerate the removal of organic matter and nitrogen. The hybrid CW system is characterised by a combination of continuous baffled flow vertical wetland and ‘S’ pattern horizontal subsurface flow wetland with natural aeration ditches to increase the concentration of dissolved oxygen in the HSFW bed. An internal circulatory system from the HSFW effluent back to the VBFW may optionally be operated to enhance the biological denitrification effect. Cyperus alternifolius is the main macrophyte in the wetland bed. The performance of the hybrid CW was studied with a pilot-scale system and three full-scale systems for municipal sewage treatment in Southern China. The results suggest that this new hybrid CW can achieve removal efficiencies of chemical oxygen demand, suspended solids, ammonia nitrogen, total nitrogen, and total phosphorus of better than 83.6, 95.0, 71.7, 64.5 and 68.1% respectively, with a specific wetland bed area of 0.70–0.93 m2 PE−1. The mean effluent concentrations of these parameters would meet the regulatory discharge limits for wastewater treatment systems (GB18918, 2002) and reuse in the context of agricultural irrigation solutions in China.

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COD and NH4-N Removal in Two-Stage Batch-Flow Constructed Wetland

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.448-453.604 ◽

2013 ◽

Vol 448-453 ◽

pp. 604-607 ◽

Cited By ~ 1

Author(s):

Hong Jie Sun ◽

Xin Nan Deng ◽

Rui Chen

Keyword(s):

Constructed Wetland ◽

Removal Rate ◽

Oxygen Demand ◽

Domestic Wastewater ◽

Pilot Scale ◽

Ammonia Nitrogen ◽

Two Stage ◽

Removal Rates ◽

N Removal ◽

Domestic Wastewater Treatment

Research was conducted on pilot-scale, two-stage batch-flow constructed wetland systems for domestic wastewater treatment. Synthetic domestic wastewater was treated in a pre-acidification reactor with a hydraulic retention time (HRT) of 3 hours and the average removal rate of chemical oxygen demand (COD) and ammonia-nitrogen (NH4-N) reached 30% and 13.6%, respectively. The first-stage constructed wetland operated with up-flow and batch feed and drain. One cycle was 12h, including 6h feed and 6h drain. With HRT of 3 days, the effluent COD concentrations fluctuated from 32.5 mg/L to 103.4 mg/L, removal rates varied from 60% to 88%; effluent NH4-N concentrations were in the range of 4.8 mg/L to 10.8 mg/L, removal rates varied from 50% to 70%. The second-stage constructed wetland operated with down-flow, which one cycle was 24h, including 12h feed and 12h drain. With HRT of 1 day, effluent COD concentrations varied from 15.7 mg/L to 48.7 mg/L, removal averaged 53.2%; effluent NH4-N concentrations ranged from 0 mg/L to 0.4 mg/L, average removal exceeded 99%. The spatial variation of COD and NH4-N in the first-stage constructed wetland demonstrated that entrainment of air during draining of constructed wetland could strengthen the removal of COD and NH4-N. Temperature had no significant effect on COD degradation while obviously affected the removal of NH4-N.

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Nutrients Removal from Secondary Effluent by Using Different Constructed Wetland Systems

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.518-523.2155 ◽

2012 ◽

Vol 518-523 ◽

pp. 2155-2160

Author(s):

Xue Min Xiang ◽

Xiao Bai Zhou ◽

Xiao Kun Wang ◽

Ji Ti Zhou ◽

Ren Wang

Keyword(s):

Constructed Wetland ◽

Removal Rate ◽

Feeding Strategy ◽

Oxygen Demand ◽

Ammonia Nitrogen ◽

Control Treatment ◽

Feeding Strategies ◽

Secondary Effluent ◽

Intermittent Feeding ◽

Multi Stage

Constructed wetland was recognized as an economic and ecological-friendly technique to reduce excess nitrogen (N) and phosphorus (P) in secondary effluent from sewage treatment plants. In this study, the removal capacity of non-planted control treatment, one stage constructed wetland with different feeding strategies, and multi-stage constructed wetland on chemical oxygen demand (COD), total nitrogen (TN), ammonia nitrogen (NH4+-N) and total phosphorus (TP)were evaluated. The results showed that all the planted treatments displayed superior removal efficiency for COD and nutrients in compare with the non-planted control treatment. The feeding strategy could influence COD andN removal rate that the averageremoval rate of the COD, TN, and NH4+-N in intermittent feeding treatment (61.3%, 52.6% and 88.7%) was much higher than continuous feeding treatment (46.8%, 20.6% and 73.9%). Higher TN and TP removal rate was observed in multi-stage constructed wetland (74.1% and 98.1%) than the single-stage constructed wetland (20.6% and 96.9%). This implied that intermittent feeding strategy and the multi-stage constructed wetland may have a good potential for removing nutrients from secondary effluent.

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Study on the Operation Effect of Constructed Wetland Project for Tailwater Treatment—An Example from a Sewage Plant in Zhejiang Province

E3S Web of Conferences ◽

10.1051/e3sconf/202019404030 ◽

2020 ◽

Vol 194 ◽

pp. 04030

Author(s):

Mengyin Chen ◽

Weifeng Zeng ◽

Guan Wang ◽

Fangchun Lu ◽

Jinjuan Zhang ◽

...

Keyword(s):

Constructed Wetland ◽

Removal Rate ◽

Sewage Treatment ◽

Sewage Treatment Plant ◽

Treatment Plant ◽

Oxygen Demand ◽

Design Parameters ◽

Class Iii ◽

Urban Sewage ◽

Sewage Plant

The constructed wetland project of tailwater from an urban sewage plant in central Zhejiang was selected to collect water samples in different seasons, and the samples were tested for chemical oxygen demand (COD), total phosphorus (TP), total nitrogen (TN) and other indicators. The results showed that the operation effect of the constructed wetland project is good when the effluent from the sewage treatment plant meets the Class A discharge standard. Among them, the removal effect of TP was the best, with an average removal rate of 61.52%, reaching the standards of surface water class III and class IV in some tests. Besides, the removal effect of TP was stable and varies little with seasons. The removal rates of COD and TN were relatively low and varied greatly with seasons, which were higher in spring and summer than in autumn and winter, with a negative removal rate of TN in winter. This research provides practical data for optimizing the engineering design parameters and improving the operation management to promote the operation efficiency of the constructed wetland.

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COD removal efficiency and mechanism of HMBR in high volumetric loading for ship domestic sewage treatment

Water Science & Technology ◽

10.2166/wst.2016.271 ◽

2016 ◽

Vol 74 (7) ◽

pp. 1509-1517 ◽

Cited By ~ 4

Author(s):

Linan Zhu ◽

Hailing He ◽

Chunli Wang

Keyword(s):

Removal Efficiency ◽

Removal Rate ◽

Sewage Treatment ◽

Oxygen Demand ◽

Domestic Sewage ◽

Cod Removal ◽

Aeration Tank ◽

Remarkable Effect ◽

Cod Removal Efficiency ◽

Volumetric Loading

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.

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Assessment of the Effects of Ornamental Wetland Polyculture Combinations on Urban Sewage Treatment

10.21203/rs.3.rs-179927/v1 ◽

2021 ◽

Author(s):

Min Wang ◽

Yujue Zhou ◽

Lin Xiang ◽

Xiaoyang Ke ◽

Hui Zhang ◽

...

Keyword(s):

Plant Diversity ◽

Municipal Wastewater ◽

Plant Biomass ◽

Removal Rate ◽

Sewage Treatment ◽

Oxygen Demand ◽

Wetland Plant ◽

Urban Sewage ◽

Thalia Dealbata ◽

Cyperus Alternifolius

Abstract Previous studies have shown that wetland plants can treat wastewater in a cost-effective and sustainable way, however, the studies on the performance of ornamental wetland plant diversity in treating urban sewage were scarce. Therefore, this study was conducted to assess and select wetland polyculture combination that was effective in urban sewage treatment in subtropical areas. We formed five combinations out of six ornamental wetland plant species including Thalia dealbata, Cyperus alternifolius, Iris pseudacorus, Lythrum sastlicaria, Nymphaea tetragona, and Zantedeschia aethiopica. The growth state and removal effects of each plant combination were systematically measured and assessed. The results indicated all the combinations exhibited remarkable total nitrogen (TN), total phosphorus (TP), ammonium nitrogen (NH4+-N), and chemical oxygen demand chromium (CODcr) removal rate of 70.75%-77.67%, 63.86%-73.71%, 69.73%-76.85%, and 57.28%-75.69%, respectively. Additionally, pH was reduced to 7.54-8.00 in the sewage. The purification effect reached the best during 30-36th day. The comprehensive assessment showed the mixture of Thalia dealbata + Cyperus alternifolius, closely followed by Thalia dealbata + Cyperus alternifolius+ Lythrum sastlicaria, was highly effective at extracting various pollutants, and both of them could be used as favorable combinations to convert eutrophication and purify municipal wastewater. Linear regression showed that TP, TP, NH4+-N, and CODcr. were significantly related to plant biomass, indicating that plant biomass essential indicator for screening purification plants. Our study highlighted the importance of plant diversity in biological wastewater treatment, however the competition between plants was suggested to take into consideration in future studies.

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In Situ Nutrient Removal from Rural Runoff by A New Type Aerobic/Anaerobic/Aerobic Water Spinach Wetlands

Water ◽

10.3390/w11051100 ◽

2019 ◽

Vol 11 (5) ◽

pp. 1100 ◽

Cited By ~ 1

Author(s):

Ya-Wen Wang ◽

Hua Li ◽

You Wu ◽

Yun Cai ◽

Hai-Liang Song ◽

...

Keyword(s):

Nitrogen Removal ◽

Constructed Wetland ◽

Removal Rate ◽

Oxygen Demand ◽

Ammonium Nitrogen ◽

Water Spinach ◽

Nitrogen And Phosphorus ◽

The Matrix ◽

New Type ◽

Nitrification And Denitrification

Rural runoff with abundant nutrients has become a great threat to aquatic environment. Hence, more and more attention has been focused on nutrients removal. In this study, an improved aerobic/anaerobic/aerobic three-stage water spinach constructed wetland (O-A-O-CW) was used to improve the removal of nitrogen and phosphorus of rural runoff. The removal rate of the target pollutants in O-A-O-CW was compared with the common matrix flow wetland as well as the no-plant wetland. The results showed that the O-A-O-CW significantly increased the chemical oxygen demand, total phosphorus, ammonium-nitrogen, nitrate, and total nitrogen removal rate, and the corresponding removal rate was 55.85%, 81.70%, 76.64%, 89.78%, and 67.68%, respectively. Moreover, the best hydraulic condition of the wetland, including hydraulic retention time and hydraulic loading, was determined, which were 2 days and 0.45 m3·m−2·day−1, respectively. Furthermore, the removal mechanism of the constructed wetland was thoroughly studied, which included the adsorption of nitrogen and phosphorus by the matrix and water spinach, and the nitrification and denitrification by the bacteria. The results demonstrated that the mechanisms of nitrogen removal in the new type wetland were principally by the nitrification and denitrification process. Additionally, adsorption and precipitation by the matrix are mainly responsible for phosphorus removal. These results suggested that the new O-A-O-CW can efficiently removal nutrients and enhance the water quality of the rural runoff.

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Experiment Research of Solar Energy Ozonizer Used in Sewage Treatment

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.263-266.510 ◽

2012 ◽

Vol 263-266 ◽

pp. 510-515

Author(s):

Li Mei Dong ◽

Ying Chang Zhou ◽

Ze Chi Han ◽

Fei Wang ◽

Yong Qing Wang ◽

...

Keyword(s):

Solar Energy ◽

Fecal Coliform ◽

Removal Rate ◽

Sewage Treatment ◽

Oxygen Demand ◽

Ozone Production ◽

Second Phase ◽

Rainy Weather ◽

Solar Battery ◽

The City

The device is composed of solar battery, power automatic switching, high pressure booster inverter, dielectric-barrier discharge type ozonizer, air compressor and microporous aerator components, whicn is powered by the double power suppl y modes including the solar battery and the city electricity. In the conditions of insufficient illumination or rainy weather, power can switch to the city electricity automatically. The article introduces the composition and working principle of solar ozonizer. The experiment is respectively done in the sample of the second phase of water from BaoDingYingdingzhuang sewage plant, the urban river water and the dyeing effluent with 1500 ml.The power of the solar energy ozonizer is 18W and ozone production is 25 mg/min. The experiment results show that the removal rate of Fecal coliform, Chroma and Chemical Oxygen Demand (COD) are obviously improved. Especially, the removal effect of Fecal coliform and Chroma is very significant. The experiment indicates that the content of NH3-N has increased with the growth of ozone contact time.

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Tech-IA floating system introduced in urban wastewater treatment plants in the Veneto region – Italy

Water Science & Technology ◽

10.2166/wst.2013.357 ◽

2013 ◽

Vol 68 (5) ◽

pp. 1144-1150 ◽

Cited By ~ 17

Author(s):

Anna Mietto ◽

Maurizio Borin ◽

Michela Salvato ◽

Paolo Ronco ◽

Nicola Tadiello

Keyword(s):

Wastewater Treatment Plants ◽

Oxygen Demand ◽

Domestic Wastewater ◽

Alnus Glutinosa ◽

Primary Treatment ◽

Ammonia Nitrogen ◽

Surface Flow ◽

Treatment Wetland ◽

N Removal ◽

Floating System

The performance of three integrated wetland treatment plants (horizontal sub-surface flow (h-SSF) and floating treatment wetland (FTW) with differentiated primary treatments) designed for treating domestic wastewater was investigated, monitoring total (TN), nitrate (NO3-N), nitrite (NO2-N) and ammonia nitrogen (NH4-N), total (TP) and phosphate phosphorus (PO4-P), chemical (COD) and biological oxygen demand (BOD5), and dissolved oxygen (DO) at the inlet and outlet of each wetland section from February 2011 to June 2012. Sediments settled in the FTW were collected and analyzed. The growth of plants in each system was also monitored, observing their general conditions. The chemical–physical characteristics of the pretreated domestic wastewater depended on the primary treatment installed. During the monitoring period we observed different reduction performance of the wetland sector in the three sites. In general, the wetland systems demonstrated the capacity to reduce TN, COD, BOD5 and Escherichia coli, whereas NO3-N and NH4-N removal was strictly influenced by the chemical conditions, in particular DO concentration, in the h-SSF and FTW. Vegetation (Phragmites australis, Alnus glutinosa and Salix eleagnos) was well established in the h-SSF as well as in the floating elements (Iris pseudacorus), although there were some signs of predation. FTW is a relatively novel wetland system, so the results obtained from this study can pave the way for the application of this technology.

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Performance of a pilot-scale constructed wetland for stormwater runoff and domestic sewage treatment on the banks of a polluted urban river

Water Science & Technology ◽

10.2166/wst.2014.027 ◽

2014 ◽

Vol 69 (7) ◽

pp. 1410-1418 ◽

Cited By ~ 12

Author(s):

Weijie Guo ◽

Zhu Li ◽

Shuiping Cheng ◽

Wei Liang ◽

Feng He ◽

...

Keyword(s):

Constructed Wetland ◽

Sewage Treatment ◽

Stormwater Runoff ◽

Oxygen Demand ◽

Pilot Scale ◽

Domestic Sewage ◽

Nitrogen And Phosphorus ◽

Effective Technique ◽

Integrated Constructed Wetland ◽

One Year

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.

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