scholarly journals XỬ LÝ NƯỚC THẢI SINH HOẠT BẰNG ĐẤT NGẬP NƯỚC NHÂN TẠO NỀN XỈ THAN TỔ ONG KẾT HỢP TRỒNG CỎ VOI

2021 ◽  
Vol 5 (3) ◽  
pp. 2596-2605
Author(s):  
Kim Lavane ◽  
Nguyễn Thị Hoàng Hạnh ◽  
Phạm Văn Toàn
Keyword(s):  
Constructed Wetlands ◽  
Subsurface Flow ◽  
Domestic Wastewater ◽  
Pollutant Removal ◽  
Napier Grass ◽  
National Standard ◽  
Pennisetum Purpureum ◽  
Good Growth ◽  
Standard Type ◽  
Experimental Systems

Nghiên cứu này nhằm đánh giá hiệu suất của đất ngập nước (ĐNN) nhân tạo dòng chảy ngầm theo phương ngang (HSSF) và phương đứng (VF) có vật liệu nền là xỉ than tổ ong và trồng cỏ voi. Thí nghiệm được tiến hành trên mô hình phòng thí nghiệm với lưu lượng nạp của nước thải sinh họat là 85 lít/ngày. Tải lượng nạp BOD5, COD, TN, TP vào mô hình lần lượt là 7,47 g/m2.ngày, 3,17 g/m2.ngày, 1,43 g/m2.ngày, 0,12 g/m2.ngày. Kết quả nghiên cứu cho thấy nồng độ các chỉ tiêu ô nhiễm sau xử lý giảm đáng kể và đạt loại A theo QCVN 14:2008/BTNMT trong cả hai mô hình HSSFCW và VFCW. Hiệu suất xử lý của HSSFCW và VFCW đối với các chỉ tiêu lần lượt là SS: 88,7% và 92,4%; BOD5: 95,3% và 92,6%; COD: 94,3% và 92,6%; TN: 54,1% và 47,5%; N-NO3-: 38,4% và 33,6%; TP: 73,5% và 63,2%; P-PO43-: 87,6% và 59,7%. Nhìn chung, mô hình HSSFCW có hiệu suất loại bỏ các chất ô nhiễm tương đối cao hơn mô hình VFCW, ngoại trừ chỉ tiêu SS. Cỏ voi phát triển tốt và cho sinh khối cao trong thí nghiệm. Từ kết quả nghiên cứu cho thấy xỉ than tổ ong có thể tái sử dụng làm chất nền trong ĐNN nhân tạo dòng chảy ngầm. Bên cạnh đó, cỏ voi có thể trồng trong hệ thống ĐNN dòng chảy ngầm xử lý nước thải sinh hoạt. ABSTRACT This study aimed to evaluate the performances of horizontal subsurface flow (HSSF) and vertical flow (VF) constructed wetlands (CW) using combusted beehive charcoal residues as filtration bed media and planted with Napier grass (Pennisetum purpureum). The experimental systems were fed with a flow rate of 85 m3/day. The loading rates of BOD5, COD, TN, TP into the system were 7.47 g/m2.day, 3.17 g/m2.day, 1.43 g/m2.day, 0.12 g/m2.day, respectively. The results showed that the concentration of pollutants in effluents is significantly reduced and meet the national standard type A of QCVN 14:2008/BTNMT in both HSSFCW and VFCW models. The removal efficiencies in HSSFCW and SVFCW for SS: 88.7% and 92.4%; BOD5: 95.3% and 92.6%; COD: 94.3% and 92.6%; TN: 54.1% and 47.5%; N-NO3-: 38.4% and 33.6%; TP: 73.5% and 63.2%; P-PO43-: 87.6% and 59.7%, respectively. In general, the HSSFCW model has a relatively higher pollutant removal efficiency than the VFCW model, except for the SS. good growth and high biomass yield of Napier grass had been observed in the experimental systems. This study suggested that combusted beehive charcoal residues could be reused as bed substrate in constructed wetlands. Besides, Napier grass might also be a potential plant associated with subsurface flow constructed wetlands to treat domestic wastewater.

scholarly journals Analysis of potential of Napier grass, Vetiver and Equisetum plants for the treatment of domestic greywater using box-type constructed wetlands

2021 ◽  
Author(s):  
Sijimol MR ◽  
Mansa ML ◽  
Sabu Joseph
Keyword(s):  
Removal Efficiency ◽  
Constructed Wetlands ◽  
Human Activities ◽  
Pollutant Removal ◽  
Napier Grass ◽  
Pennisetum Purpureum ◽  
Vetiveria Zizanioides ◽  
Equisetum Hyemale ◽  
Global Concern ◽  
Pollutant Removal Efficiency

Abstract The management of wastewater generated as a byproduct of various human activities from agricultural, industrial, and domestic sectors is a matter of global concern today. Greywater is a class of wastewater generated from the domestic sector. Greywater management can be done effectively by treating greywater at the source itself. In this context, constructed wetlands (CWs) come handy with low-tech, environmental, and economic-friendly options. In the present study, box-type horizontal subsurface flow constructed wetlands were designed and the efficiency of Napier grass (Pennisetum purpureum), Vetiver (Vetiveria zizanioides), and Equisetum (Equisetum hyemale) were assessed in treating domestic greywater. There was a drastic significant increase in DO with 47.0% in Vetiver, 92.5% in Napier grass, and 97.2% in Equisetum. The average percent pollutant removal of some major parameters was 92.4% for turbidity, 92.7% for acidity, 81.3% for BOD, 91.0% for COD with Napier grass. In the case of Vetiver, the removal percent was 82.5% turbidity, 87.9% acidity, 81.8% BOD, and 92.9% COD. For Equisetum, the average pollutant removal efficiency varied with 94.6% turbidity, 91.4% acidity, 80.0% BOD, and 88.1%COD. The study thus proves the efficiency of all the three plants to be used in box-type constructed wetlands.

scholarly journals Efficiency of horizontal subsurface flow-constructed wetlands considering different support materials and the cultivation positions of plant species

2020 ◽  
Vol 15 (2) ◽  
pp. 1 ◽  
Author(s):  
Suymara Toledo Miranda ◽  
Antonio Teixeira de Matos ◽  
Mateus Pimentel Matos ◽  
Claudéty Saraiva
Keyword(s):  
Plant Species ◽  
Constructed Wetlands ◽  
Subsurface Flow ◽  
Pollutant Removal ◽  
Pennisetum Purpureum ◽  
Pet Bottles ◽  
Removal Efficiencies ◽  
Horizontal Subsurface Flow ◽  
Subsurface Flow Constructed Wetlands ◽  
One Year

 The present work evaluated the influence of filling substrate material (crushed PET bottles or fine gravel) on the efficiency of pollutant removal in horizontal subsurface flow constructed wetlands (HSSF-CWs). They were cultivated with a consortium of elephant grass cv. Napier (Pennisetum purpureum Schum) and Tifton 85 (Cynodon spp.) to treat wastewater from a common milk cooling tank (WWMT). For this, six HSSF-CWs were used which had dimensions of 0.6 m tall x 1.0 m wide x 2.5 m long. In order to investigate possible efficiency loss in the removal of pollutants from the system, operation was divided into two periods: Period I (from April to December 2015) and Period II (April to December 2016). Thus, the removal efficiencies of BOD5, solids and total nitrogen (TN), total phosphorus (TP), potassium (K) and sodium (Na) from WWMT were statistically compared. Results indicated that the efficiency of the HSSF-CWs for removing pollutants increased or remained similar after one year and nine months of their operation; and PET bottles were a viable alternative substrate in HSSF-CWs based on the efficient removal of pollutants from WWMT during the one year and nine months of monitoring. Crushed PET bottles constitute a viable substrate for filling HSSF-CWs. Altering the cultivation positions of the plant species did not change pollutant removal efficiencies, but indicates the importance of species arrangement to maximize system performance.

Field-Scale Studies of Subsurface Flow Constructed Wetlands for Stormwater Quality Enhancement

1997 ◽  
Vol 32 (1) ◽  
pp. 101-118 ◽  
Author(s):  
Q.J. ROCHFORT ◽  
W.E. Watt ◽  
J. Marsalek ◽  
B.C. Anderson ◽  
A.A. Crowder
Keyword(s):  
Organic Carbon ◽  
Constructed Wetlands ◽  
Suspended Solids ◽  
Nutrient Loading ◽  
Subsurface Flow ◽  
Reaction Rates ◽  
Pollutant Removal ◽  
Order Kinetic ◽  
Dissolved Metals ◽  
Subsurface Flow Constructed Wetlands

Abstract Two subsurface flow constructed wetlands were tested for pollutant removal performance in conjunction with an on-line stormwater detention pond, in Kingston Township, Ontario. The 4.9 m2 wetland cells were filled with 9 mm limestone gravel, and planted with cattail, common reed and spike rush. Changes in nutrient (total organic carbon, PO43- and NH4+), suspended solids and metal (Cu, Pb, Zn) concentrations were used to assess performance. Contaminant removal occurred through a combination of physical, chemical and biological means. As with any biological system, variation in performance of stormwater wetlands can be expected to occur as a result of fluctuations in contaminant loading, contact time and ambient environmental conditions. Storm pond effluent was delivered in continuous flow through the wetlands (during baseflow and event conditions), with a detention time of 1 to 3 days. The wetlands were able to maintain removal rates of up to 39% for orthophosphate even during the more severe conditions of fall dieback. Average removal of suspended solids (46%) and dissolved metals (Cu 50%) remained similar throughout all tests. Organic carbon was reduced by less than 10% during these tests. Low nutrient levels in the pond effluent were supplemented by spiking with sources of carbon, nitrogen and phosphorus during pulsed loading conditions. Daily sampling produced a time series, which illustrated the rates of decline in concentration of nutrients. First order kinetic assimilation rates ranged from 1.7 d-1 for NH4002B to 0.12 d-1 for organic carbon, which were noticeably lower when compared with municipal and industrial wastewater treatment rates. Three methods of sizing stormwater wetlands (impervious surface area, volumetric load and kinetic reaction rates) were compared using the same design storm and data from this study. From this comparison it was seen that the kinetic sizing approach proved to be the most versatile, and allowed for adaptation to northern climatic conditions and anticipated nutrient loading.

Mass transfer approach and the designing of horizontal subsurface flow constructed wetland systems treating waste stabilisation pond effluent

2018 ◽  
Vol 78 (12) ◽  
pp. 2639-2646 ◽  
Author(s):  
Anita M. Rugaika ◽  
Damian Kajunguri ◽  
Rob Van Deun ◽  
Bart Van der Bruggen ◽  
Karoli N. Njau
Keyword(s):  
Mass Transfer ◽  
Constructed Wetlands ◽  
Rate Constants ◽  
Removal Rate ◽  
Subsurface Flow ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Organic Load ◽  
Mass Transfer Effect ◽  
Horizontal Subsurface Flow

Abstract Pilot-scale constructed wetlands (CWs) that allowed wastewater to flow with high interstitial velocities in a controlled environment were used to evaluate the possibility of using mass transfer approach to design horizontal subsurface flow constructed wetlands (HSSF-CWs) treating waste stabilisation ponds (WSPs) effluent. Since CW design considers temperature which is irrelevant in tropics, mass transfer approach could improve the design. HSSF-CWs were operated in batch recycle mode as continuous stirred tank reactors (CSTR) at different interstitial velocities. The overall removal rate constants of chemical oxygen demand (COD) at various interstitial velocities were evaluated in mesocosms that received pretreated domestic wastewater. The mean overall removal rate constants were 0.43, 0.69, 0.74 and 0.73 d−1 corresponding to interstitial velocities of 15.43, 36, 56.57 and 72 md−1, respectively. Results showed that the interstitial velocities up to 36 md−1 represented a range where mass transfer effect was significant and, above it, insignificant to the COD removal process. Since WSPs effluent has high flow rates and low organic load, it is possible to induce high interstitial velocities in a HSSF-CW treating this effluent, without clogging and overflow. The performance of these HSSF for tertiary treatment in tropical areas could be improved by considering flow velocity when designing.

Reciprocating constructed wetlands for treating industrial, municipal and agricultural wastewater

2001 ◽  
Vol 44 (11-12) ◽  
pp. 399-405 ◽  
Author(s):  
L. Behrends ◽  
L. Houke ◽  
E. Bailey ◽  
P. Jansen ◽  
D. Brown
Keyword(s):  
Wastewater Treatment ◽  
Constructed Wetlands ◽  
Environmental Protection Agency ◽  
Subsurface Flow ◽  
Domestic Wastewater ◽  
High Strength ◽  
Time Frequency ◽  
Operating Technique ◽  
Tennessee Valley ◽  
Subsurface Flow Constructed Wetlands

Scientists at the Tennessee Valley Authority (TVA), and in collaboration with the U.S. Environmental Protection Agency (EPA), are continuing to develop and refine an innovative wastewater treatment system referred to as reciprocating subsurface-flow constructed wetlands. Reciprocation relates to patented improvements in the design and operation of paired subsurface-flow constructed wetlands, such that contiguous cells are filled and drained on a frequent and recurrent basis. This operating technique turns the entire wetland system into a fixed-film biological reactor, in which it is possible to control redox potential in alternating aerobic and anaerobic zones. Reciprocating systems enable manipulation of wastewater treatment functions by controlling such parameters as hydraulic retention time, frequency of reciprocation, reciprocation cycle time, depth of reciprocation, and size and composition of substrate. These improved wetland technologies have been used for treating municipal/domestic wastewater, high strength animal wastewater, and mixed wastewater streams containing acids, recalcitrant compounds, solvents, antifreeze compounds, heavy metals, explosives, and fertilizer nutrients. Results from selected treatability studies and field demonstrations will be summarized with respect to conceptual design and treatment efficacy.

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