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 Post-treatment of tannery wastewater using pilot scale horizontal subsurface flow constructed wetlands (polishing)

2017 ◽  
Vol 77 (4) ◽  
pp. 988-998 ◽  
Author(s):  
Tadesse Alemu ◽  
Andualem Mekonnen ◽  
Seyoum Leta
Keyword(s):  
Removal Efficiency ◽  
Batch Reactor ◽  
Subsurface Flow ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Surface Flow ◽  
Tannery Wastewater ◽  
Treated Effluent ◽  
Horizontal Subsurface Flow ◽  
Pollutants Removal

Abstract In the present study, a pilot scale horizontal subsurface flow constructed wetland (CW) system planted with Phragmites karka; longitudinal profile was studied. The wetland was fed with tannery wastewater, pretreated in a two-stage anaerobic digester followed by a sequence batch reactor. Samples from each CW were taken and analyzed using standard methods. The removal efficiency of the CW system in terms of biological oxygen demand (BOD), chemical oxygen demand (COD), Cr and total coliforms were 91.3%, 90%, 97.3% and 99%, respectively. The removal efficiency for TN, NO3− and NH4+-N were 77.7%, 66.3% and 67.7%, respectively. Similarly, the removal efficiency of SO42−, S2− and total suspended solids (TSS) were 71.8%, 88.7% and 81.2%, respectively. The concentration of COD, BOD, TN, NO3−N, NH4+-N, SO42 and S2− in the final treated effluent were 113.2 ± 52, 56 ± 18, 49.3 ± 13, 22.75 ± 20, 17.1 ± 6.75, 88 ± 120 and 0.4 ± 0.44 mg/L, respectively. Pollutants removal was decreased in the first 12 m and increased along the CW cells. P. karka development in the first cell of CW was poor, small in size and experiencing chlorosis, but clogging was higher in this area due to high organic matter settling, causing a partial surface flow. The performance of the pilot CW as a tertiary treatment showed that the effluent meets the permissible discharge standards.

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 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.

The effect of a vertical flow filter bed on a hybrid constructed wetland system

2005 ◽  
Vol 51 (9) ◽  
pp. 137-144 ◽  
Author(s):  
A. Noorvee ◽  
E. Põldvere ◽  
Ü. Mander
Keyword(s):  
Constructed Wetland ◽  
Flow System ◽  
Subsurface Flow ◽  
Oxygen Demand ◽  
Vertical Flow ◽  
Efficient Removal ◽  
Loading Rates ◽  
Purification Efficiency ◽  
Wetland System ◽  
Filter Bed

Data from 18 sampling wells in Kodijärve horizontal subsurface flow (HSSF) constructed wetland (CW) (South Estonia) is presented and differences in purification efficiencies inside the HSSF CW are calculated. Temporarily anaerobic conditions in the Kodijärve HSSF system did not allow efficient removal of BOD7, NH4-N, Ntot and Ptot. In 2002 a vertical subsurface flow filter was constructed to enhance aeration. The design of the system was based simply on the oxygen demand of the wastewater and on the aeration potential of vertical flow wetlands. The vertical flow system has shown satisfactory results. The purification efficiency of BOD7 in the Kodijärve CW has improved significantly and there has been a slight increase in purification efficiencies of NH4-N and Ntot. On the ohther hand, the removal efficiency of Ptot has decreased significantly. Although, the mass loading rates have increased, mass removal rates of all four parameters have improved significantly. Nevertheless, optimization of the constructed wetland system is essential in order to meet effluent standards during wintertime.

Removal efficiency of the constructed wetland wastewater treatment system at Bainikeng, Shenzhen

1995 ◽  
Vol 32 (3) ◽  
pp. 31-40 ◽  
Author(s):  
Yang Yang ◽  
Zhencheng Xu ◽  
Kangping Hu ◽  
Junsan Wang ◽  
Guizhi Wang
Keyword(s):  
Wastewater Treatment ◽  
Removal Efficiency ◽  
Constructed Wetland ◽  
Suspended Solids ◽  
Oxygen Demand ◽  
Design Flow ◽  
Treatment System ◽  
Wastewater Treatment System ◽  
Tennessee Valley ◽  
Wetland System

In this paper, three years study on a constructed wetland wastewater treatment system at Bainikeng, Shenzhen, is reviewed and summarized. The wetland system under study occupies an area of 8400m2, with a design flow of 3100 m3 per day. The study was conducted to understand removal efficiencies of constructed wetland systems for municipal wastewaters from small or medium scale towns in the sub-tropics. Such parameters as biological oxygen demand, chemical oxygen demand, suspended solids, total nitrogen, and total phosphorus in the influent and effluent of the wetland system are examined, and their removal rates are determined. It is shown that the system is very effective in removing organic pollutants and suspended solids and its removal efficiency is much similar to those of the constructed wetlands at Tennessee Valley Authority (TVA) (Choate et al., 1990) while better than those of conventional secondary biochemical treatments.

Performance Evaluation of the Horizontal Subsurface Flow Constructed Wetland with Ipomoea Aquatica Plant for Rural Domestic Wastewater Treatment

2014 ◽  
Vol 1073-1076 ◽  
pp. 965-969 ◽  
Author(s):  
Ahmed Mohammed Osman ◽  
Xi Wu Lu
Keyword(s):  
Removal Efficiency ◽  
Constructed Wetland ◽  
Growth Parameters ◽  
Subsurface Flow ◽  
Operation Time ◽  
Domestic Wastewater ◽  
System Operation ◽  
Ipomoea Aquatica ◽  
Subsurface Flow Constructed Wetland ◽  
Horizontal Subsurface Flow

In this study, the performance treatment of horizontal subsurface flow constructed wetland (HSFCW) was evaluated. The HSFCW built as a tertiary treatment process after the biological reactors to improve the effluent quality. The HSFCW system was operated with different hydraulic loading rates (HLRs) ranged from 0.15 to 0.333 m3/ (m2.d) to assess their influence on removal efficiency. During the system operation time, the average temperature was ranged of 22.3 to 31.2 °C and pH ranges was 7.3 – 8.1. The Ipomoea aquatica (Chinese spinach) planted into HSFCW system and the growth parameters during the experimental operation observed. The Ipomoea aquatica growth parameters such as the plant height, a fresh and dry weights were monitored and measured. The influent and effluent of chemical oxygen demand (COD), ammonium nitrogen (NH4-N), total nitrogen (TN) and total phosphorus (TP) were examined. The removal efficiency for all parameters showed decreased with an increase in HLR from 0.15 to 0.333 m3/ (m2.day). The results demonstrated that the average removal efficiency of the COD, NH4-N, TN and TP during system operation is 52.9%, 64.6%, 58.2% and 72.8% respectively. These results confirm that the HSFCW has a good efficient in treatment and can be used for the nutrients and organic matter removal from the domestic wastewater.

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