Constructed wetlands for combined sewer overflow treatment in a Mediterranean country, Portugal

2013 ◽  
Vol 67 (12) ◽  
pp. 2739-2745 ◽  
Author(s):  
R. Amaral ◽  
F. Ferreira ◽  
A. Galvão ◽  
J. S. Matos
Keyword(s):  
Constructed Wetlands ◽  
Retention Time ◽  
Suspended Solids ◽  
Oxygen Demand ◽  
Total Suspended Solids ◽  
Mediterranean Country ◽  
Combined Sewer Overflow ◽  
Combined Sewer ◽  
Removal Efficiencies ◽  
Sewer Overflow

The use of constructed wetlands as a valuable and attractive method for combined sewer overflow (CSO) treatment has been demonstrated in several studies. In Portugal, a Mediterranean country having usually a long dry period, there are still no applications of this technology. The purpose of this research is to gather information and know-how required for the design and management of this type of infrastructure. A pilot-scale experimental setup for CSO treatment was installed and evaluated in situ, in terms of organic matter, total suspended solids and microorganism removal with emphasis on the results of the start-up. After 1 day of retention average removal efficiencies of 73–79% and 82–89% were obtained in terms of chemical oxygen demand (COD) and total suspended solids (TSS), respectively. During the remaining retention time a slower removal was observed. After 7 days, the COD removal efficiencies reached 86–91% and the TSS removal efficiencies reached 93–97%. On average, after 1 day, reductions of 1.2–2.0 log and 1.9–2.4 log, respectively, for total coliforms and Enterococcus were observed. For a retention time of 7 days these reductions attained 4.0–4.9 log and 4.4–5.3 log, respectively.

Flood reduction as an ecosystem service of constructed wetlands for combined sewer overflow

2018 ◽  
Vol 560 ◽  
pp. 150-159 ◽  
Author(s):  
A. Rizzo ◽  
R. Bresciani ◽  
F. Masi ◽  
F. Boano ◽  
R. Revelli ◽  
...  
Keyword(s):  
Constructed Wetlands ◽  
Ecosystem Service ◽  
Combined Sewer Overflow ◽  
Combined Sewer ◽  
Sewer Overflow

scholarly journals Performance comparison of uninsulated and insulated hybrid anaerobic baffled reactor (HABR) operating at warm temperature

2018 ◽  
Vol 78 (9) ◽  
pp. 1879-1892 ◽  
Author(s):  
Md Khalekuzzaman ◽  
Muhammed Alamgir ◽  
Mehedi Hasan ◽  
Md Nahid Hasan
Keyword(s):  
Removal Efficiency ◽  
Suspended Solids ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Total Suspended Solids ◽  
Performance Comparison ◽  
Warm Temperature ◽  
Anaerobic Baffled Reactor ◽  
Similar Chemical ◽  
Removal Efficiencies

Abstract In this research, a hybrid anaerobic baffled reactor (HABR) configuration was proposed consisting of a front sedimentation chamber and four regular baffled chambers followed by two floated filter media chambers for the treatment of domestic wastewater. Performance comparison of uninsulated and insulated HABRs was carried out operating at warm temperature (18.6–37.6 °C) under variable HRTs (30 h and 20 h). The study suggests that almost similar chemical oxygen demand (91% vs 88%), total suspended solids (90% vs 95%), turbidity (98% vs 97%), and volatile suspended solids (90% vs 93%) removal efficiencies were obtained for uninsulated and insulated HABRs. Higher removal of total nitrogen (TN) of 41%, NH4+-N of 44%, and NO3−-N of 91% were achieved by the insulated HABR compared to TN of 37%, NH4+-N of 36%, and NO3−-N of 84% by the uninsulated HABR, whereas lower PO43− removal efficiency of 17% was found in the insulated HABR compared to 24% in the uninsulated HABR. This indicated insulation increased nitrogen removal efficiencies by 4% for TN, 8% for NH4+-N and 7% for NO3−-N, but decreased PO43−removal efficiency by 7%.

Treatment of Domestic Strength Wastewater with Anaerobic Hybrid Reactors

1987 ◽  
Vol 22 (3) ◽  
pp. 474-490 ◽  
Author(s):  
R.L. Droste ◽  
S.R. Guiot ◽  
S.S. Gorur ◽  
K.J. Kennedy
Keyword(s):  
Retention Time ◽  
Suspended Solids ◽  
Hydraulic Retention Time ◽  
Oxygen Demand ◽  
Anaerobic Treatment ◽  
Synthetic Wastewater ◽  
Solids Retention Time ◽  
Solids Retention ◽  
Removal Efficiencies ◽  
Hybrid Reactors

Abstract Anaerobic treatment of dilute synthetic wastewater (300-1,000 mg chemical oxygen demand/L using laboratory upflow sludge blanket filter reactors with and without effluent recycle is described. Treatment of dilute synthetic wastewater at hydraulic retention times less than 1 and 2 h in reactors without and with recycle, respectively, resulted in biomass washout as the solids retention time decreased to less than 12 d. Reseeding would be required to operate at these critical hydraulic retention times for extended periods. Treatment of dilute synthetic wastewater at hydraulic retention times between 3-12 h resulted in soluble COD removal efficiencies between 84-95% treating 300 mg COD/L. At a 3 h hydraulic retention time, solids retention time of 80 d and stable reactor biomass concentrations of 25 g volatile suspended solids/L were maintained.

The improvement of water quality indicators in constructed wetland treatment systems in Latvia

2020 ◽  
Author(s):  
Linda Grinberga ◽  
Ainis Lagzdins
Keyword(s):  
Water Quality ◽  
Constructed Wetlands ◽  
Constructed Wetland ◽  
Catchment Area ◽  
Suspended Solids ◽  
Subsurface Flow ◽  
Oxygen Demand ◽  
Total Suspended Solids ◽  
Surface Flow ◽  
Subsurface Flow Constructed Wetland

<p>This study includes water quality monitoring data obtained since June, 2014 at the farm located in the middle part of Latvia. The water treatment system with two separate constructed wetlands was established to improve water quality in agricultural area. A surface flow constructed wetland received drainage runoff from the agricultural catchment basin. A subsurface flow constructed wetland was implemented to retain nutrients from the surface runoff collected in the area of impermeable pavements of the farmyard. As there are no other specific calculations recommended for the designing of constructed wetlands in Latvia, both wetlands were calculated basing on the surface area of the constructed wetland/catchment area ratio. The surface area of the subsurface flow constructed wetland was deigned by 1.2% of the catchment area and the ratio was 0.5 % for the surface flow constructed wetland.</p><p>Water samples were collected manually by grab sampling method once or twice per month basing on a flowrate. Water quality parameters such as total suspended solids (TSS), nitrate-nitrogen (NO3-N), ammonium-nitrogen (NH4-N), total nitrogen (TN), orthophosphate-phosphorus (PO4-P), and total phosphorus (TP), biochemical oxygen demand (BOD) and chemical oxygen demand (COD) were analysed to monitor the performance of both wetlands. The concentrations at the inlet and outlet were compared to evaluate the efficiency of the water treatment.</p><p>The concentrations of NO3-N, NH4-N and TN were reduced on average by 21 %, 35 % and 20 %, respectively for the surface flow constructed wetland. PO4-P and TP concentrations were reduced on average by 31 % and 45 %, respectively for the surface flow constructed wetland. Total suspended solids were reduced by 17% at the outlet of the surface flow constructed wetland. However, in some cases, an increase in nutrient concentrations in water leaving the wetland was observed. The study showed the constant reduction of the PO4-P and TP concentrations 82 % and 83 %, respectively in the subsurface flow constructed wetland. The concentrations of NO3-N, NH4-N and TN were reduced on average by 14 %, 66 % and 53 %, respectively for the subsurface flow constructed wetland. BOD and COD reduction on average by 93 % and 83 %, respectively in for the subsurface flow constructed wetland indicated the ability of the treatment system to be adapted for wastewater treatment with high content of organic matter under the given climate conditions. This study outlined that the farmyards should receive a special attention regarding surface runoff management.</p>

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