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

2011 ◽  
Vol 64 (11) ◽  
pp. 2177-2184 ◽  
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.

scholarly journals Effect of HRT and seasons on the performance of pilot-scale horizontal subsurface flow constructed wetland to treat rural wastewater

2021 ◽  
Author(s):  
R. Shruthi ◽  
G. P. Shivashankara
Keyword(s):  
Removal Efficiency ◽  
Constructed Wetland ◽  
Subsurface Flow ◽  
Typha Latifolia ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Ammonia Nitrogen ◽  
Subsurface Flow Constructed Wetland ◽  
Horizontal Subsurface Flow ◽  
Rural Wastewater

Abstract To find the effect of Hydraulic Retention Time (HRT) and seasons on the performance of horizontal subsurface flow constructed wetland (HSSF CW) in treating rural wastewater, a pilot scale unit 2.5 m × 0.4 m × 0.3 m size bed planted with a Typha latifolia and Phragmites australis was operated for a 12-month duration. During the study 2, 4, 6, 8, and 10 days of HRT were maintained in winter, summer, and rainy seasons. The removal efficiency obtained was ranges from 62.09 to 87.23% for Chemical Oxygen Demand, 69.58% to 93.32% for Biochemical Oxygen Demand5 (BOD), 31.55% to 59.89% for Ammonia Nitrogen (NH4-N), 15.18% to 52.90% for Total Kjeldahl Nitrogen (TKN), 21.02% to 50.21% for Phosphate Phosphorus (PO43− P), 19.82% to 48.23% for, Total phosphorus (TP), 74.93% to 93.10% for Faecal Coliform (FC) and 69.93% to 90.23% Total Coliform (TC). Overall, results showed that the performance of the unit was good. For statistical analysis two way ANOVA test followed by the Tukey test was used with a 95% level of significance. It was observed that the removal efficiency of the pollutants were increased with an increase in HRT. HRT of 6 days found as adequate for significant removal of organic matter (COD and BOD). Seasonal removal efficiencies followed the order of summer > rainy > winter for all the parameters, but the difference was not statistically significant.

Performance of horizontal subsurface flow constructed wetland in the removal of tanninsA paper submitted to the Journal of Environmental Engineering and Science.

2010 ◽  
Vol 37 (3) ◽  
pp. 496-501 ◽  
Author(s):  
K.N. Njau ◽  
M. Renalda
Keyword(s):  
Removal Efficiency ◽  
Constructed Wetland ◽  
Control Cell ◽  
Subsurface Flow ◽  
Oxygen Demand ◽  
Cod Removal ◽  
Outlet Concentration ◽  
Cod Removal Efficiency ◽  
Subsurface Flow Constructed Wetland ◽  
Horizontal Subsurface Flow

A horizontal subsurface flow constructed wetland (HSSFCW) was employed to remove tannins from the effluent of a tannins extracting company. Two HSSFCW cells with hydraulic retention time (HRT) of 9 d and packed with limestone were used. One cell without macrophytes was used as a control, while the second cell was planted with Phragmites mauritianus . Results indicated that HSSFCW was capable of treating tannin wastewater that has been seeded with primary facultative pond sludge. Tannins and chemical oxygen demand (COD) removal efficiency of 95.9% and 90.6% with outlet concentration of 27 mg/L and 86 mg/L, respectively, were obtained in the planted cell; while the tannins and COD removal efficiency of 91.1% and 89.5% with outlet concentration of 57 mg/L and 96 mg/L, respectively, were obtained in the control cell.

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

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1054 ◽  
Author(s):  
Xueyuan Bai ◽  
Xianfang Zhu ◽  
Haibo Jiang ◽  
Zhongqiang Wang ◽  
Chunguang He ◽  
...  
Keyword(s):  
Constructed Wetland ◽  
Removal Rate ◽  
Sewage Treatment ◽  
Oxygen Demand ◽  
Ecological Engineering ◽  
Ammonia Nitrogen ◽  
Surface Flow ◽  
Urban River ◽  
Polluted Water ◽  
Urban Rivers

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.

A pilot study of a subsurface-flow constructed wetland treating membrane concentrate produced from reclaimed water

2015 ◽  
Vol 72 (2) ◽  
pp. 260-268 ◽  
Author(s):  
Rajat K. Chakraborti ◽  
James S. Bays ◽  
Thien Ng ◽  
Lou Balderrama ◽  
Terry Kirsch
Keyword(s):  
Pilot Study ◽  
Organic Carbon ◽  
Constructed Wetland ◽  
Water Reuse ◽  
Reclaimed Water ◽  
Subsurface Flow ◽  
Oxygen Demand ◽  
Water Volume ◽  
Mass Removal ◽  
Nitrate N

A pilot study was conducted for 7 months for the City of Oxnard, California, on the use of constructed wetlands to treat concentrate produced by microfiltration and reverse osmosis (RO) of reclaimed wastewater. The treatment performance of a transportable subsurface-flow wetland was investigated by monitoring various forms of nitrogen, orthophosphate, oxygen demand, organic carbon, and selenium. Significant mass removal of constituents was measured under two hydraulic residence times (HRTs) (2.5 and 5 days). Inflow and outflow concentrations of nitrate-N and ammonia-N were significantly different for both HRTs, whereas nitrite-N and total organic carbon (TOC) were significantly different during HRT2. Mass removal by the constructed wetland averaged 61% of nitrate-N, 32% of nitrite-N, 42% of ammonia-N, 43% of biochemical oxygen demand, 19% of orthophosphate as P, 18% of TOC and 61% of selenium. Mass removal exceeded concentration reductions through water volume loss through evapotranspiration. Calibrated first-order area-based removal rates were consistent with literature ranges, and were greater during HRT1 consistent with greater mass loads, higher hydraulic loading and shorter HRTs. The rate constants may provide a basis for sizing a full-scale wetland receiving a similar quality of water. The results indicated that engineered wetlands can be useful in the management of RO membrane concentrate for reclaimed water reuse.

scholarly journals Evaluation of Tannery Wastewater Treatment by Integrating Vesicular Basalt With Local Plant Species in a Constructed Wetland System

2021 ◽  
Vol 9 ◽  
Author(s):  
Agegnehu Alemu ◽  
Nigus Gabbiye ◽  
Brook Lemma
Keyword(s):  
Plant Species ◽  
Removal Efficiency ◽  
Constructed Wetland ◽  
Subsurface Flow ◽  
Oxygen Demand ◽  
Tannery Wastewater ◽  
Local Plant ◽  
Vesicular Basalt ◽  
Wetland System ◽  
Horizontal Subsurface Flow

Tannery wastewater is composed of a complex mixture of organic and inorganic components from various processes that can critically pollute the environment, especially water bodies if discharged without treatment. In this study, integrated vesicular basalt rock and local plant species were used to establish a horizontal subsurface flow constructed wetland system and to investigate the treatment efficiency of tannery wastewater. Four pilot units were vegetated with P. purpureum, T. domingensis, C. latifolius, and E. pyramidalis, and a fifth unit was left unvegetated (control). The constructed wetland units in horizontal subsurface flow systems were effective in removing total chromium (Cr), chemical oxygen demand (COD), and 5-day biological oxygen demand (BOD5) from the inflow tannery wastewater. The removal efficiency reached up to 99.38, 84.03, and 80.32% for total Cr, COD, and BOD5, respectively, in 6 days of hydraulic retention time (HRT). The removal efficiency of total suspended solid (TSS), total phosphorus (TP), and nitrate (NO3−) of the constructed wetland units reached a maximum of 70.59, 62.32, and 71.23%, respectively. This integrated system was effective for treating tannery wastewater, which is below the Ethiopian surface water standard discharge limit set to BOD5 (200 mg L−1), COD (500 mg L−1), total Cr (2 mg L−1), NO3− (20 mg L−1), TSS (50 mg L−1), and TP (10 mg L−1).

scholarly journals USING HORIZONTAL SUBSURFACE FLOW CONSTRUCTED WETLAND SYSTEM IN THE TREATMENT OF MUNICIPAL WASTEWATER FOR AGRICULTURE PURPOSES

2019 ◽  
Vol 50 (4) ◽  
Author(s):  
Rahi & Faisal
Keyword(s):  
Constructed Wetland ◽  
Municipal Wastewater ◽  
Subsurface Flow ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Treated Wastewater ◽  
Subsurface Flow Constructed Wetland ◽  
Real Wastewater ◽  
Horizontal Subsurface Flow ◽  
Reuse Of Treated Wastewater

 Reuse of treated wastewater for irrigation purpose can reduce high pressure on freshwater resources. A horizontal subsurface flow constructed wetland (HSSF CW) system filled with gravel and planted with Phragmites Australia was used to treat the real wastewater at Al-Rustumia wastewater treatment plant. Some characteristics of wastewater such as biochemical oxygen demand, phosphate and total suspended solids have been monitored from 15 January until 8 July 2018. The results proved that HSSF unit has a good efficacy in the reduction of previous parameters with removal of 84.2, 55.4 and 72.7% while sulphate and total dissolved solids were less removal efficiency with 3.3 and  0.99 % respectively. The measured values of these parameters were within the permissible limits suitable for irrigation purposes.

Performance evaluation of wastewater treatment using horizontal subsurface flow constructed wetlands optimized by micro-aeration and substrate selection

2015 ◽  
Vol 71 (9) ◽  
pp. 1317-1324 ◽  
Author(s):  
Fei Zhong ◽  
Juan Wu ◽  
Yanran Dai ◽  
Dongfang Xiang ◽  
Shuiping Cheng ◽  
...  
Keyword(s):  
Constructed Wetlands ◽  
Sewage Treatment ◽  
Subsurface Flow ◽  
Oxygen Demand ◽  
Ammonium Nitrogen ◽  
Domestic Sewage ◽  
Substrate Selection ◽  
N Removal ◽  
Horizontal Subsurface Flow ◽  
The Individual

The effects of micro-aeration and substrate selection on domestic sewage treatment performance were explored using three pairs (with or without micro-aeration) of horizontal subsurface flow (HSSF) constructed wetlands (CWs) filled with zeolite, ceramsite or quartz granules. The individual and combined effects of micro-aeration and substrate selection on the purification performance of the experimental-scale HSSF CWs were evaluated. The results showed that micro-aeration significantly increased the treatment efficiencies for chemical oxygen demand, total nitrogen, total phosphorus (TP), ortho-phosphate (PO43−-P) and ammonium nitrogen (NH4+-N) using HSSF CWs, while the substrate selection significantly affected the TP, PO43−-P and NH4+-N removal efficiencies (p < 0.05). A two-way analysis of variance (ANOVA) indicated that there was a significant interaction term (i.e. micro-aeration × substrate selection) for NH4+-N removal (p < 0.05). Among the three substrates, ceramsite was the best substrate for the treatment of domestic sewage using HSSF CWs. Therefore, the results of this study suggest that a ceramsite-filled HSSF CW with micro-aeration could be the optimal configuration for decentralized domestic sewage treatment.

scholarly journals Investigation on the performance evaluation of vertical subsurface flow constructed wetland for the treatment of rural wastewater

2021 ◽  
Author(s):  
R. Shruthi ◽  
G. P. Shivashankara
Keyword(s):  
Removal Efficiency ◽  
Constructed Wetland ◽  
Retention Time ◽  
Subsurface Flow ◽  
Oxygen Demand ◽  
Ammonia Nitrogen ◽  
Treatment Unit ◽  
Entire Study ◽  
Subsurface Flow Constructed Wetland ◽  
Rural Wastewater

Abstract In rural country like India, low cost and decentralized treatment unit like vertical subsurface flow constructed wetland (VSSF CW) can be reflected as a novel wastewater system. In this concern a pilot-scale VSSF CW unit of size 0.92 m × 0.92 m × 0.85 m bed planted with a Typha latifolia and Phragmites australis was operated for a 12-month duration to treat the simulated rural wastewater. During the operation, a constant head arrangement was done to maintain a continuous flow to achieve 5 different Hydraulic Retention Time (HRT) of 2, 4, 6, 8 and 10 days in each seasons such as winter, summer and rainy to investigate the performance of unit under different retention time. Reactor showed optimum removal efficiency at 6 days HRT at 12.5 cm/day Hydraulic Loading Rate (HLR) for organic matter removal. Both macrophytes and microbial biomass of filter media were effectively treated the rural wastewater. Average removal efficiency of the reactor during entire study were 64.73%–88.80% for Chemical Oxygen Demand, 74.96%–95.34% for Biochemical Oxygen Demand, 40.13%–79.45% for Ammonia Nitrogen, 25.36%–65.65% for Total Kjeldahl Nitrogen, 22.86%–58.48% for Phosphate phosphorus, 23.50%–55.45% for Total phosphorous, 74.91%–98.59% for Faecal Coliforms and 71.14%–95.31% for Total Coliforms respectively. Two-way ANOVA followed by post hoc Tukey's test showed that HRT had a significant impact on removal efficiency but not the season. Overall performance of the unit was good and study suggested that VSSF CW can be an smart alternative technology to treat rural wastewater before the final disposal.

scholarly journals Effect of Aeration Modes and COD/N Ratios on Organic Matter and Nitrogen Removal in Horizontal Subsurface Flow Constructed Wetland Mesocosms

Water ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1530 ◽  
Author(s):  
Xin Chen ◽  
Hui Zhu ◽  
Yingying Xu ◽  
Brian Shutes ◽  
Baixing Yan ◽  
...  
Keyword(s):  
Nitrogen Removal ◽  
Subsurface Flow ◽  
Oxygen Demand ◽  
Ammonia Nitrogen ◽  
Pollutant Removal ◽  
Artificial Aeration ◽  
Influent Water ◽  
Horizontal Subsurface Flow ◽  
Aerobic And Anaerobic ◽  
Wetland Mesocosms

A series of mesocosm-scale horizontal subsurface flow constructed wetlands (HSSF-CWs) were established. In Experiment 1, four artificial aeration (AA) modes, including pre-aeration at 24 h before the input of influent water (PA), aeration at 6 h (6AA) and 12 h (12AA) after the input of influent water and non-aeration (NA), were tested to obtain an optimal aeration mode for chemical oxygen demand (CODCr) and nitrogen removal. The results showed that aeration after the input of influent water could improve the removal efficiencies of CODCr and ammonia-nitrogen (NH4⁺-N), but lead to an accumulation of nitrate-nitrogen (NO3−-N). The above observation demonstrated that a single aeration cannot create an ideal alternation of aerobic and anaerobic conditions for simultaneous nitrification and denitrification. Therefore, HSSF-CWs with intermittent aeration (IA), after the input of influent water and NA were established to evaluate the combined effects of IA and influent COD/N ratios on pollutant removal in Experiment 2. The HSSF-CW with IA exhibited a better performance in CODCr and nitrogen removal compared to HSSF-CW with NA. The highest removal percentages of CODCr (90.1%), NH4+-N (99.8%) and total nitrogen (TN, 99.5%) were achieved at a COD/N ratio of 9.3 in HSSF-CW with IA.

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