Comparison of maturation ponds and constructed wetlands as the final stage of an advanced pond system

2005 ◽  
Vol 51 (12) ◽  
pp. 307-314 ◽  
Author(s):  
C.C. Tanner ◽  
R.J. Craggs ◽  
J.P.S. Sukias ◽  
J.B.K. Park
Keyword(s):  
Constructed Wetlands ◽  
Algal Biomass ◽  
Suspended Solids ◽  
Geometric Mean ◽  
Open Water ◽  
Surface Flow ◽  
Effluent Quality ◽  
Treatment Performance ◽  
Pond System ◽  
Load Removal

The treatment performance of a maturation pond (MP), the typical final polishing stage of an Advanced Pond System (APS), is compared with that of a surface-flow constructed wetland (CW) over 19 months. Both received ∼67 mm d−1 of wastewater after passage through upstream stages of the APS. The MP, with greater sunlight exposure, had higher algal biomass (and associated suspended solids) than the CW, showed higher dissolved oxygen (DO) concentrations and greater diurnal variation in DO and pH. Neither polishing stages reduced nutrients markedly, with the CW exporting slightly more NH3-N and DRP, and less NO3-N than the MP. Disinfection was more efficient in the MP (geometric mean 1 log load removal, 12 MPN (100 ml)−1) compared to the CW (0.47 log load removal, 53 MPN (100 ml)−1). Incorporation of a final rock filter (28% of area) reduced median solids levels to <10 g m−3 in both the MP and CW. A hybrid between MPs and CWs with alternating zones of open-water (for enhanced disinfection and zooplankton grazing of algal solids) and wetland vegetation (promoting sedimentation and denitrification, and providing refugia for zooplankton) may provide more consistent effluent quality that either stage alone.

Performance assessment of pilot horizontal sub-surface flow constructed wetlands for removal of diesel from wastewater by Scirpus grossus

2013 ◽  
Vol 68 (10) ◽  
pp. 2271-2278 ◽  
Author(s):  
Israa Abdulwahab Al-Baldawi ◽  
Siti Rozaimah Sheikh Abdullah ◽  
Nurina Anuar ◽  
Fatihah Suja ◽  
Mushrifah Idris
Keyword(s):  
Constructed Wetlands ◽  
Suspended Solids ◽  
Flow System ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Surface Flow ◽  
Total Petroleum Hydrocarbon ◽  
Physical Parameters ◽  
Contaminated Water ◽  
Development Technology

One of the appropriate development technology options for the treatment of wastewater contaminated with diesel is constructed wetlands (CWs). Throughout 72 days of exposure, sampling was carried out for monitoring of physical parameters, plant growth and the efficiency of total petroleum hydrocarbon (TPH) removal, as an indication for diesel contamination, to assess the pilot-scale performance. Four pilot CWs with a horizontal sub-surface flow system were applied using the bulrush of Scirpus grossus. The CWs were loaded with different diesel concentrations of 0, 0.1, 0.2 and 0.25% (Vdiesel/Vwater). The TPH removal efficiencies were 82, 71, and 67% at the end of 72 days for diesel concentrations of 0.1, 0.2, and 0.25% respectively. In addition, the high removal efficiency of total suspended solids and chemical oxygen demand (COD) were 100 and 75.4% respectively, for a diesel concentration of 0.1%. It was concluded that S. grossus is a potential plant that can be used in a well-operated CW for restoring 0.1% diesel-contaminated water.

scholarly journals VERTICAL SUBSURFACE FLOW AND FREE SURFACE FLOW CONSTRUCTED WETLANDS FOR SUSTAINABLE POWER GENERATION AND REAL WASTEWATER SELECTIVE POLLUTANTS REMOVAL

2020 ◽  
Vol 24 (06) ◽  
pp. 91-102
Author(s):  
Zahraa S. Aswad ◽  
◽  
Ahmed H. Ali ◽  
Nadia M. Al-Mhana ◽  
◽  
...  
Keyword(s):  
Power Generation ◽  
Free Surface ◽  
Constructed Wetlands ◽  
Constructed Wetland ◽  
Suspended Solids ◽  
Subsurface Flow ◽  
Free Surface Flow ◽  
Surface Flow ◽  
Removal Efficiencies ◽  
Better Than

A vertical subsurface flow constructed wetland (VSSFCW) and a free surface flow constructed wetland (FSFCW) were set for the objective of comparison the performance of two systems in order to make a decision of the better one for future installation of wastewater treatment system and power generation. Both of the constructed wetlands were planted with Cyperus Alternifolius. During the observation period (19 days or 456 hours), environmental conditions such as pH, temperature, total chemical oxygen demand (COD), phosphate (PO4), nitrate (NO3) ,total suspended solids (TSS), total dissolved solids (TDS), Pb, Cu, and Cd removal efficiencies of the systems were determined. According to the results, final removal efficiencies for the VSSF and FWSF, respectively, were: COD (94.3% and 94.3%),PO4 (84.3% and 75.3%), NO3 (100% and 100%), TSS (96.8% and 85.6%), Pb (65.8% and 81.4%), Cu (more than 94.7% and 89.4%), Cd (85.7% and 88%). The treatment performances of the VSSF were better than that of the FWSF with regard to the removal of suspended solids and nutrients. In FWSF systems, electricity generation performed better than VSSF of 31.4 mV especially with batch system during one wastewater feed is loaded among all of the nineteen days with maximum voltage of 33.7 mV and decreased gradually as oxygen depletion in cathode chamber and less metabolism processes has occurred.

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>

An assessment of mosquito breeding and control in four surface flow wetlands in tropical-subtropical Australia

2003 ◽  
Vol 48 (5) ◽  
pp. 249-256 ◽  
Author(s):  
M. Greenway ◽  
P. Dale ◽  
H. Chapman
Keyword(s):  
Constructed Wetlands ◽  
Open Water ◽  
Surface Flow ◽  
Mosquito Larvae ◽  
Subtropical Climate ◽  
Macroinvertebrate Communities ◽  
Breeding Sites ◽  
Climatic Regions ◽  
Invertebrate Biodiversity ◽  
And Control

In Queensland, Australia, the tropical-subtropical climate is ideal to promote macrophyte growth in surface flow wetlands; however, there have been concerns that constructed wetlands are potential breeding sites for disease-bearing mosquitoes. The aim of this study was to assess whether mosquitoes were breeding in these constructed wetlands, and if so, where they breed, and what parameters might influence breeding: e.g. water quality, vegetation, or macroinvertebrate communities. A study of four surface flow constructed wetlands located in different climatic regions was undertaken. Mosquito larvae were sampled using 240 ml dippers and macroinvertebrates using dip nets. The wetland with the greatest biodiversity of macrophytes and macroinvertebrates had the least number of mosquito larvae (< 1% of all dips). Samples with most mosquito larvae occurred amongst dense mats of Paspalum grass or dead Typha. Despite the presence of larvae in some parts of these wetlands very few late instars or pupae were found i.e. completion of the mosquito life cycle to adult mosquitoes was unsuccessful. This study has shown that the presence of mosquito larvae can be minimised by increasing macro-invertebrate biodiversity, by planting a variety of macrophyte types and species, excluding aggressive plant species, and maintaining at least 30% open water. Macroinvertebrates are probably a crucial factor in the control of mosquito larvae ensuring that predation of the early instars prevents or limits the development of pupae and the emergence of adults.

scholarly journals PARAMETERS EVALUATION OF MUNICIPAL WASTE WATER AFTER TREATMENT USING SUB SURFACE FLOW CONSTRUCTED WETLAND IN EKANT PARK BHOPAL

2016 ◽  
Vol 4 (12) ◽  
pp. 24-30
Author(s):  
Shalini Saxena
Keyword(s):  
Constructed Wetlands ◽  
Constructed Wetland ◽  
Suspended Solids ◽  
Removal Rate ◽  
Surface Flow ◽  
Chemical Parameters ◽  
Nitrogen And Phosphorus ◽  
Public Park ◽  
Physico Chemical ◽  
Natural Wetlands

Land areas which are wet during part or all of the year are referred as wetlands. Constructed wetlands are manmade systems that mimic the functions of natural wetlands and applied for wastewater treatment. Aim of the present study is to investigate the feasibility of using a Tracheophyte, Phragmiteskarka in constructed wetland for treatment of wastewater in an public park. The daily inlet and outlet wastewater physico-chemical parameters were analysed during the period of two months. The parameters studied were pH, BOD, COD, DO, Total Suspended Solids, Total Dissolved Solids, Nitrogen and Phosphorus. The percentage removal of the parameters were analysed and studied until the percent removal rate gets stabilized. The study showed that the subsurface flow constructed wetlands are best alternative among modern treatments.

The removal of pathogens in surface-flow constructed wetlands and its implications for water reuse

2007 ◽  
Vol 56 (3) ◽  
pp. 207-216 ◽  
Author(s):  
A. Ghermandi ◽  
D. Bixio ◽  
P. Traverso ◽  
I. Cersosimo ◽  
C. Thoeye
Keyword(s):  
Constructed Wetlands ◽  
Water Reuse ◽  
Microbiological Quality ◽  
Surface Flow ◽  
Treated Wastewater ◽  
Coliform Bacteria ◽  
Effluent Quality ◽  
Open Questions ◽  
Surface Flow Constructed Wetlands

Microbiological quality represents the biggest concern to the reuse of treated wastewater. This paper reports and discusses the results of an international survey on the removal of indicators of microbiological contamination in surface-flow constructed wetlands. Constructed wetlands consistently provide a reduction of 90–99% (1–2 log-removal) in the concentration of indicators such as coliform bacteria and faecal streptococci. This removal is found in wetlands treating water from different types of pretreatment (primary sedimentation, activated sludge, trickling filter, maturation ponds). On the other hand, when the influent is of high microbiological quality, wetlands act as sources of pathogenic contamination. The final water quality, however, is still compatible with medium to no-contact recreational activities and other final water uses. High variability in the effluent quality and seasonality might limit the opportunities for reuse. The role of constructed wetlands in different treatment schemes and the remaining open questions concerning removal mechanisms and reference pathogens are discussed.

Diel changes in iron concentrations in surface-flow constructed wetlands

2001 ◽  
Vol 44 (11-12) ◽  
pp. 421-426 ◽  
Author(s):  
R.R. Goulet ◽  
F.R. Pick
Keyword(s):  
Constructed Wetlands ◽  
Littoral Zone ◽  
Surface Flow ◽  
Diel Variation ◽  
Diel Changes ◽  
Treatment Performance ◽  
Late Fall ◽  
Surface Flow Constructed Wetlands ◽  
Iron Concentrations

Diel changes in Fe concentrations were examined from spring to late fall at two surface-flow wetlands. The highest concentrations of ferrous, dissolved and total Fe were measured at night in the littoral zone, when oxygen and pH were low. The lowest Fe concentrations were measured during the day when oxygen and pH were highest. The amplitude of change over the day-night cycle was greatest in July and lowest in May and October. These diel changes were also observed at the outlet of both wetlands. Overall, O2 and pH explained 60% of the observed seasonal and diel variation in water Fe (R2=0.60, p=0.004). The treatment performance of wetlands can be overestimated when based on samples collected during the day.

Variability of treatment performance in constructed wetlands

1995 ◽  
Vol 32 (3) ◽  
pp. 241-250 ◽  
Author(s):  
E. Kuehn ◽  
James A. Moore
Keyword(s):  
Constructed Wetlands ◽  
Suspended Solids ◽  
Vegetation Type ◽  
Oxygen Demand ◽  
Pulp Mill ◽  
Total Suspended Solids ◽  
Matched Pairs ◽  
Vegetation Types ◽  
Treatment Performance ◽  
Over Time

Eight constructed wetland ponds treating pulp mill effluent were monitored for removal of biochemical oxygen demand (BOD) and total suspended solids (TSS). Matched pairs of ponds differed by retention times and vegetation types. Analysis showed that variations over time between pairs of similar ponds were small. Performance of similarly designed constructed wetlands should be similar. TSS effluent concentrations varied by vegetation type, while BOD effluent concentrations varied with season.

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