Gravel Media Filtration as a Constructed Wetland Component for the Reduction of Suspended Solids from Maturation Pond Effluent

1994 ◽  
Vol 29 (4) ◽  
pp. 55-66 ◽  
Author(s):  
D. P. Sapkota ◽  
H. J. Bavor

Experiments were carried out in a horizontal gravel media filter (GMF) with media size ranging from 5-40 mm. Such gravel-based, sub-surface flow units have been used in both planted and unplanted formats in a range of constructed wetland systems. This GMF was subjected to various hydraulic application rates ranging from 1 m3/(m2.d) to 36 m3/(m2.d) over a twc-year period. The range of suspended solids (SS) concentration was 2-36 mg/l and that of turbidity (NTU) was 3-44 during the experimental period. The average removal of suspended solids varied from 30-86%. It was observed that SS was reduced by a maximum of 86% at an application rate of 13m3/(m2.d), within the above noted SS range. An additional laboratory scale experiment was carried out with artificially grown algae in a vertical perspex tube of 190 mm inner diameter (I.D.) in upward flow condition. Results from the laboratory scale and pilot scale experiments are presented and discussed. The study demonstrates that a constructed wetland format with a subsurface flow and horizontal gravel media component could be used as an alternative method for reducing suspended solids from maturation pond effluent

2011 ◽  
Vol 63 (10) ◽  
pp. 2360-2366 ◽  
Author(s):  
S. Ç. Ayaz ◽  
N. Findik ◽  
L. Akça ◽  
N. Erdoğan ◽  
C. Kınacı

This research project aimed to determine the technologically feasible and applicable wastewater treatment systems which will be constructed to solve environmental problems caused by small communities in Turkey. Pilot-scale treatment of a small community's wastewater was performed over a period of more than 2 years in order to show applicability of these systems. The present study involves removal of organic matter and suspended solids in serially operated horizontal (HFCW) and vertical (VFCW) sub-surface flow constructed wetlands. The pilot-scale wetland was constructed downstream of anaerobic reactors at the campus of TUBITAK-MRC. Anaerobically pretreated wastewater was introduced into this hybrid two-stage sub-surface flow wetland system (TSCW). Wastewater was first introduced into the horizontal sub-surface flow system and then the vertical flow system before being discharged. Recirculation of the effluent was tested in the system. When the recirculation ratio was 100%, average removal efficiencies for TSCW were 91 ± 4% for COD, 83 ± 10% for BOD and 96 ± 3% for suspended solids with average effluent concentrations of 9 ± 5 mg/L COD, 6 ± 3 mg/L BOD and 1 mg/L for suspended solids. Comparing non-recirculation and recirculation periods, the lowest effluent concentrations were obtained with a 100% recirculation ratio. The effluent concentrations met the Turkish regulations for discharge limits of COD, BOD and TSS in each case. The study showed that a hybrid constructed wetland system with recirculation is a very effective method of obtaining very low effluent organic matter and suspended solids concentrations downstream of anaerobic pretreatment of domestic wastewaters in small communities.


2015 ◽  
Vol 16 (1) ◽  
pp. 69-82 ◽  
Author(s):  
Anita Jakubaszek ◽  
Zofia Sadecka

Abstract This paper presents the results of the research work related to the removal efficiency from wastewater organic pollutants and suspended solids at HSSF (horizontal subsurface flow) constructed wetland. The average effectiveness defined as loss of value COD in wastewater has reached 77%, for BOD5 - 80% and TOC - 82%. The effect of seasonal temperature changes and the period of plant vegetation and rest on the effectiveness of wastewater treatment were also analyzed. The results of the presented research showed a decrease in the efficiency of removing organic pollutants from wastewater and suspended solids in the autumn and winter. During the vegetation the object in Małyszyn has been characterized by the effectiveness of wastewater treatment at the level of 78% for COD, 82% for BOD5, and in the non-vegetation period the effectiveness has decreased up to 75% for COD and 74% for BOD5. During the plants growth the total suspension was removed in 88%, whereas during the plants rest efficiency of removing lowered to 69%.


2013 ◽  
Vol 68 (10) ◽  
pp. 2271-2278 ◽  
Author(s):  
Israa Abdulwahab Al-Baldawi ◽  
Siti Rozaimah Sheikh Abdullah ◽  
Nurina Anuar ◽  
Fatihah Suja ◽  
Mushrifah Idris

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.


2003 ◽  
Vol 48 (5) ◽  
pp. 143-148 ◽  
Author(s):  
J. Vymazal ◽  
M. Masa

A constructed wetland with horizontal sub-surface flow at Dolni Mesto (Czech Republic) was put into operation in 1999 and treats municipal wastewater from 522 PE. The total area of vegetated beds of 2,646 m2 is divided into two parallel sections of equal size, each with two beds in series. Between two periods of water discharge there is no outflow from the bed. During the period of September 1999-September 2000 one bed was operated with a pulsing water level while the other one was not pulsing, i.e., was operated as regular sub-surface flow in order to evaluate the effect of pulsing on treatment efficiency, especially on removal of NH4-N. Between September 1999 and February 2000 the pulse was 8 cm, for the rest of the experimental period the pulse was 15 cm. The results indicate a positive effect of pulsing on removal of BOD5 (annual average of 53%), COD (30%) and NH4-N (27%) as compared to non-pulsing beds. For SS, a decrease in removal effect by 30% was observed. This is probably due to the higher outflow velocity of discharged water from pulsing beds which can flush out settled particles. The results also indicate that a pulsing level of 15 cm was more efficient than 8 cm.


2021 ◽  
Vol 13 (22) ◽  
pp. 12456
Author(s):  
Tao Wang ◽  
Liping Xiao ◽  
Hongbin Lu ◽  
Shaoyong Lu ◽  
Xiaoliang Zhao ◽  
...  

The quality of micropolluted water is unstable and its substrate concentration fluctuates greatly. The goal is to predict the concentration effect on the treatment of nitrogen in a river with an actual low C/N ratio for the proposed full-scale Xiaoyi River estuary wetland, so that the wetland project can operate stably and perform the water purification function effectively in the long term. Two pilot-scale multistage constructed wetland–pond (MCWP) systems (S1 and S2, respectively) based on actual engineering with the same “front ecological oxidation ponds, two-stage horizontal subsurface flow constructed wetlands and surface flow constructed wetlands (SFCWs) as the core and postsubmerged plant ponds” as the planned process were constructed to investigate the effect of different influent permanganate indexes (CODMn) and total nitrogen (TN) contents on nitrogen removal from micropolluted river water with a fixed C/N ratio from summer to winter in the field. The results indicate that the TN removal rate in the S1 and S2 systems was significant (19.56% and 34.84%, respectively). During the process of treating this micropolluted water with a fixed C/N ratio, the influent of S2 with a higher CODMn concentration was conducive to the removal of TN. The TN removal rate in S2 was significantly affected by the daily highest temperature. There was significant nitrogen removal efficiency in the SFCWs. The C/N ratio was a major determinant influencing the nitrogen removal rate in the SFCWs. The organic matter release phenomenon in SFCWs with high-density planting played an essential role in alleviating the lack of carbon sources in the influent. This research strongly supports the rule that there is seasonal nitrogen removal in the MCWPs under different influent substrate concentrations, which is of guiding significance for practical engineering.


2020 ◽  
Vol 24 (06) ◽  
pp. 91-102
Author(s):  
Zahraa S. Aswad ◽  
◽  
Ahmed H. Ali ◽  
Nadia M. Al-Mhana ◽  
◽  
...  

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.


2020 ◽  
Author(s):  
Linda Grinberga ◽  
Ainis Lagzdins

<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>


Minerals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 379 ◽  
Author(s):  
Ha Nguyen ◽  
Bien Nguyen ◽  
Thuy Duong ◽  
Anh Bui ◽  
Hang Nguyen ◽  
...  

This study was conducted to assess the removal of arsenic (As) and heavy metals from mining wastewater by the combination of adsorption, using modified iron-ore drainage sludge, and horizontal-subsurface-flow constructed wetland with common reed (Phragmites australis). The pilot-scale experiment with a constant flow rate of 5 m3/day was operated for four months using real wastewater from a Pb–Zn mine in northern Vietnam. Atomic absorption spectroscopy was used for elemental analysis in wastewater and plant. X-ray diffraction (XRD), surface charge measurements (by a particle charge detector (PCD)), Fourier-transform infrared (FTIR), and surface area Brunauer–Emmet–Teller (BET) measurements were performed to determine the characteristics of the adsorbent. The results showed that the average removals of As, Mn, Cd, Zn, and Pb by the combined system with limestone substrate during four months were 80.3%, 96.9%, 79.6%, 52.9%, and 38.7%, respectively. The use of another constructed wetland substrate, laterite, demonstrated better removal efficiency of As than limestone. The concentrations of As and heavy metals in the effluent were lower than the limits established by the QCVN 40:2011/BTNMT for industrial wastewater, which indicated the feasibility of combining adsorption and constructed wetland for the treatment of mining wastewater.


Author(s):  
Shalini Saxena

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.


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