scholarly journals Treatment of Piggery Wastewater by Three Grass Species Growing in a Constructed Wetland

2017 ◽  
pp. 75-83 ◽  
Author(s):  
Supaporn Pongthornpruek
Keyword(s):  
Wastewater Treatment ◽  
Constructed Wetland ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Oxygen Demand ◽  
Surface Flow ◽  
Grass Species ◽  
Vetiver Grass ◽  
Piggery Wastewater ◽  
Wastewater Quality

The study aimed to investigate the efficiency of piggery wastewater treatment by the surface flow constructed wetland with three different grass species; bulrush (Scirpus spp.), cattail (Typha angustifoliaL.), and vetiver grass (Vetiveria zizanioides L.). All pilot units were used for wastewater treatment by the flowing surface water system, giving a system carrying capacity of several 0.18 m3 d-1 of HLR with a 5 day hydraulic retention time (HRT). The results showed that the cattail pilot showed improvement in several wastewater quality indicators: biochemical oxygen demand (BOD), chemical oxygen demand (COD) and total kjeldahl nitrogen (TKN) with efficiencies of 80.59, 84.11 and 88.08 %, respectively. The vetiver grass was most efficient of the three grasses in treating total phosphorus (TP). The efficiency of constructed wetland treatment using bulrush and cattail for TP was not significantly different. The piggery wastewater treatment with a 5 day HRT was able to reduce the dirtiness in wastewater but ultimately was unable to meet the wastewater quality standard. Thus, the periods for hydraulic retention time should be increased to establish the optimal retention time for effective wastewater treatment.

scholarly journals Effect of hydraulic retention time on chemical oxygen demand and total nitrogen removal in intermittently aerated constructed wetlands

2020 ◽  
Vol 15 (3) ◽  
pp. 1 ◽  
Author(s):  
Isabela Pires da Silva ◽  
Gabriela Barbosa da Costa ◽  
João Gabriel Thomaz Queluz ◽  
Marcelo Loureiro Garcia
Keyword(s):  
Chemical Oxygen Demand ◽  
Constructed Wetlands ◽  
Total Nitrogen ◽  
Total Phosphorus ◽  
Constructed Wetland ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Subsurface Flow ◽  
Oxygen Demand ◽  
Intermittent Aeration

   This study evaluated the effect of hydraulic retention time on chemical oxygen demand (COD) and total nitrogen (TN) removal in an intermittently aerated constructed wetlands. Two horizontal subsurface-flow constructed wetlands were used: one without aeration and the other aerated intermittently (1 hour with aeration/7 hours without aeration). Both systems were evaluated treating domestic wastewater produced synthetically. The flow rate into the two CWs was 8.6 L day-1 having a hydraulic retention time of 3 days. The results show that the intermittently aerated constructed wetland were highly efficient in removing COD (98.25%), TN (83.60%) and total phosphorus (78.10%), while the non-aerated constructed wetland showed lower efficiencies in the removal of COD (93.89%), TN (48.60%) and total phosphorus (58.66). These results indicate, therefore, that intermittent aeration allows the simultaneous occurrence of nitrification and denitrification processes, improving the removal of TN in horizontal subsurface-flow constructed wetlands. In addition, the use of intermittent aeration also improves the performance of constructed wetlands in removing COD and total phosphorus.

Wastewater treatment performance efficiency of constructed wetlands in African countries: a review

2014 ◽  
Vol 71 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Andualem Mekonnen ◽  
Seyoum Leta ◽  
Karoli Nicholas Njau
Keyword(s):  
Wastewater Treatment ◽  
Constructed Wetland ◽  
Oxygen Demand ◽  
Surface Flow ◽  
Operational Parameters ◽  
Treatment Efficiency ◽  
African Countries ◽  
Wetland Type ◽  
Treatment Performance ◽  
Nutrient Removal Efficiency

In Africa, different studies have been conducted at different scales to evaluate wastewater treatment efficiency of constructed wetland. This paper aims to review the treatment performance efficiency of constructed wetland used in African countries. In the reviewed papers, the operational parameters, size and type of wetland used and the treatment efficiency are assessed. The results are organized and presented in six tables based on the type of wetland and wastewater used in the study. The results of the review papers indicated that most of the studies were conducted in Tanzania, Egypt and Kenya. In Kenya and Tanzania, different full-scale wetlands are widely used in treating wastewater. Among wetland type, horizontal subsurface flow wetlands were widely studied followed by surface flow and hybrid wetlands. Most of the reported hybrid wetlands were in Kenya. The results of the review papers indicated that wetlands are efficient in removing organic matter (biochemical oxygen demand and chemical oxygen demand) and suspended solids. On the other hand, nutrient removal efficiency appeared to be low.

Program on Treatment of the Landfill Leachate by Onland Planting Reed (Phragmites)

2011 ◽  
Vol 71-78 ◽  
pp. 2852-2855
Author(s):  
Kun Shi ◽  
Ming Zou
Keyword(s):  
Removal Efficiency ◽  
Constructed Wetland ◽  
Landfill Leachate ◽  
Retention Time ◽  
Suspended Solids ◽  
Preferential Flow ◽  
Hydraulic Retention Time ◽  
Oxygen Demand ◽  
Surface Loading ◽  
Waste Landfill

The microcosm tests were done to estimated the HRT (Hydraulic Retention Time) and removal efficiency of reflowing treatment of the landfill leachate collected from Dalian Maoyingzi Municipal Solid Waste Landfill, which contained high levels of COD (Chemical Oxygen Demand, 38400 mg/L) and SS (Suspended Solids, 650 mg/L) by the reed constructed wetland located in the south area of Dalian Jiaotong University. The results showed that: (1) The HRT in nature soil cuboids were significant shorter than those in sieved soil cuboids (P<0.01); (2) The removal efficiency among the output water with the trend as follows: Preferential flow (53.9%)<Percolating water (59.2%)<Reflowing water (63.3%); (3) The COD and SS were decreased from 38400 and 650 mg/L to 14080 and 213 mg/L by the way of reflowing with the HSL (Hydraulic Surface Loading) of 0.16 m3/(m2·d) by reflowing (Removal efficiency: COD: 63.3%; SS: 67.3%).

Domestic wastewater treatment by a constructed wetland system planted with rice

2011 ◽  
Vol 64 (12) ◽  
pp. 2376-2380 ◽  
Author(s):  
Suwasa Kantawanichkul ◽  
Wanida Duangjaisak
Keyword(s):  
Wastewater Treatment ◽  
Chemical Oxygen Demand ◽  
Constructed Wetland ◽  
Retention Time ◽  
Paddy Field ◽  
Suspended Solids ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Biological Oxygen Demand ◽  
Removal Efficiencies

The experiments were conducted in four concrete laboratory scale free water surface constructed wetland units 1 m wide, 1.5 m long and 0.8 m deep. Paddy field soil was added to a depth of 0.4 m and rice seedlings (Oryza sativa L.) were transplanted into the units at a density of 25 plants/m2. Domestic wastewater collected from Chiang Mai University was applied into each unit via two different modes to evaluate suitable conditions for wastewater treatment and rice yield. In the first experiment, the wastewater was fed intermittently (7 h/day) with a hydraulic loading rate of 2, 4, 6 and 8 cm/day. The maximum removal efficiencies for chemical oxygen demand, biological oxygen demand, total kjedahl nitrogen and suspended solids were only 49.1, 58.7, 64.0 and 59.4%, respectively, due to the short hydraulic retention time for the biodegradation of organic substances. In the second experiment, the wastewater in each unit was inundated to a depth of 15 cm for 10, 15, 20 and 25 days in each unit and then drained and re-flooded. Removal efficiencies of chemical oxygen demand, biological oxygen demand, total kjedahl nitrogen and suspended solids were greater than in the first experiment especially at the 25 day retention time and except for suspended solids met the Thai national effluent standard. The study revealed that apart from wastewater treatment, wastewater can replace natural water to grow rice in the dry season or throughout the year. Moreover, nutrients in wastewater can be a substitute for chemical fertilizers. Rice grain production was 4,700 kg/ha and only 6% less than the production from the conventional paddy field.

scholarly journals ANALYSIS OF A WETLAND SYSTEM IN THE POST-TREATMENT OF WASTEWATER

2014 ◽  
Vol 3 (1) ◽  
Author(s):  
Carlos Eduardo Zacarkim ◽  
Luciano Caetano De Oliveira ◽  
Nayara Symanski ◽  
Fernando Rodolfo Espinoza Quinõnes ◽  
Soraya Moreno Palácio ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Retention Time ◽  
Treatment Process ◽  
Hydraulic Retention Time ◽  
Low Cost ◽  
Surface Flow ◽  
Wastewater Treatment Process ◽  
Wetland System ◽  
Simple Technology ◽  
Conventional Systems

The study was based on a surface flow wetland system, using the macrophyte Eicchornia crassipes. The use of wetlands as an alternative in the wastewater treatment process has been employed due to the handling and simple technology, addition to the low cost compared to conventional systems. Three hydraulic retention times, they are 4, 6 and 8 days were analyzed. In general the system showed significant results in relation to removals of nutrients for all TRH reviews, where the hydraulic retention time of 6 days achieved the best performance. The proposed system achieved 79.91% reductions for COD, 83.51% of Total Phosphorus, Total Nitrogen 67.93%, 87.7% chromium and 52% Sulfur.

scholarly journals Assessing the factors influencing the performance of constructed wetland–microbial fuel cell integration

2020 ◽  
Vol 81 (4) ◽  
pp. 631-643 ◽  
Author(s):  
Huang Jingyu ◽  
Nicholas Miwornunyuie ◽  
David Ewusi-Mensah ◽  
Desmond Ato Koomson
Keyword(s):  
Wastewater Treatment ◽  
Fuel Cell ◽  
Microbial Fuel Cell ◽  
Constructed Wetland ◽  
Retention Time ◽  
Electricity Generation ◽  
Electrode Materials ◽  
Hydraulic Retention Time ◽  
Wetland Plants ◽  
Wide Range

Abstract Constructed wetland coupled microbial fuel cell (CW-MFC) systems integrate an aerobic zone and an anaerobic zone to treat wastewater and to generate bioenergy. The concept evolves based on the principles of constructed wetlands and plant MFC (one form of photosynthetic MFC) technologies, of which all contain plants. CW-MFC have been used in a wide range of application since their introduction in 2012 for wastewater treatment and electricity generation. However, there are few reports on the individual components and their performance on CW-MFC efficiency. The performance and efficiency of this technology are significantly influenced by several factors such as the organic load and sewage composition, hydraulic retention time, cathode dissolved oxygen, electrode materials and wetland plants. This paper reviews the influence of the macrophyte (wetland plants) component, substrate material, microorganisms, electrode material and hydraulic retention time (HRT) on CW-MFC performance in wastewater treatment and electricity generation. The study assesses the relationship between these parameters and discusses progress in the development of this integrated system to date.

Performance of hybrid subsurface constructed wetland system for piggery wastewater treatment

2015 ◽  
Vol 73 (1) ◽  
pp. 13-20 ◽  
Author(s):  
X. Zhang ◽  
T. Inoue ◽  
K. Kato ◽  
J. Harada ◽  
H. Izumoto ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Constructed Wetland ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Total Coliform ◽  
Organic Content ◽  
Pollutant Removal ◽  
Total Carbon ◽  
Piggery Wastewater ◽  
Ammonium N

The objective of this study was to evaluate performance of a hybrid constructed wetland (CW) built for high organic content piggery wastewater treatment in a cold region. The system consists of four vertical and one horizontal flow subsurface CWs. The wetland was built in 2009 and water quality was monitored from the outset. Average purification efficiency of this system was 95 ± 5, 91 ± 7, 89 ± 8, 70 ± 10, 84 ± 15, 90 ± 6, 99 ± 2, and 93 ± 16% for biochemical oxygen demand (BOD5), chemical oxygen demand (COD), total carbon (TC), total nitrogen (TN), ammonium-N (NH4-N), total phosphorus (TP), total coliform (T. Coliform), and suspended solids (SS), respectively during August 2010–December 2013. Pollutant removal rate was 15 ± 18 g m−2 d−1, 49 ± 52 g m−2 d−1, 6 ± 4 g m−2 d−1, 7 ± 5 g m−2 d−1, and 1 ± 1 g m−2 d−1 for BOD5, COD, TN, NH4-N, and TP, respectively. The removal efficiency of BOD5, COD, NH4-N, and SS improved yearly since the start of operation. With respect to removal of TN and TP, efficiency improved in the first three years but slightly declined in the fourth year. The system performed well during both warm and cold periods, but was more efficient in the warm period. The nitrate increase may be attributed to a low C/N ratio, due to limited availability of carbon required for denitrification.

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