Enhanced removal of nutrients and heavy metals from domestic-industrial wastewater in an academic campus of Hanoi using modified hybrid constructed wetlands

Abstract Vietnam, like many developing countries, is facing serious water quality issues due to discharging wastewaters without treatment or with improper treatment, which can constitute a potential risk for aquatic ecosystems, food safety and human health. Hybrid constructed wetlands with four substrate layers (HCW) and modified hybrid constructed wetland (MHCW-1 and MHCW-2) with seven substrate layers were designed to evaluate the enhanced treatment capacity for wastewaters. To this end, we carried out an outdoor experiment at the Vietnam Academy of Science and Technology, Vietnam to treat its wastewaters from April to August 2019. All constructed wetland units were planted with reed Phragmites australis and cyperus Cyperus alternifolius; and specifically wetland MHCW-2 was cultured with earthworm Perionys excavates. Results indicated that MHCW-1 and MHCW-2 with seven substrate layers had higher removal efficiencies of -N, TKN and TP than HCW system. More substrate layers in MHCW-1 and MHCW-2 also resulted in increase of Cu and Pb removal efficiencies, with 73.5%, 79.4%, 71.5% and 67.8%, respectively. Particularly, earthworm addition in MHCW-2 was more efficient in decreasing the concentrations of biochemical oxygen demand (BOD5), with removal efficiency over 70%.

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Combined Industrial Wastewater Treatment in Anaerobic Bioreactor Posttreated in Constructed Wetland

BioMed Research International ◽

10.1155/2013/957853 ◽

2013 ◽

Vol 2013 ◽

pp. 1-8 ◽

Cited By ~ 7

Author(s):

Bibi Saima Zeb ◽

Qaisar Mahmood ◽

Saima Jadoon ◽

Arshid Pervez ◽

Muhammad Irshad ◽

...

Keyword(s):

Heavy Metals ◽

Water Quality ◽

Constructed Wetland ◽

Industrial Wastewater ◽

Industrial Effluents ◽

Quality Standards ◽

Water Quality Standards ◽

Anaerobic Bioreactor ◽

Treated Effluent ◽

Removal Efficiencies

Constructed wetland (CW) with monoculture ofArundo donaxL. was investigated for the posttreatment of anaerobic bioreactor (ABR) treating combined industrial wastewater. Different dilutions of combined industrial wastewater (20, 40, 60, and 80) and original wastewater were fed into the ABR and then posttreated by the laboratory scale CW. The respective removal efficiencies of COD, BOD, TSS, nitrates, and ammonia were 80%, 78–82%, 91.7%, 88–92%, and 100% for original industrial wastewater treated in ABR. ABR was efficient in the removal of Ni, Pb, and Cd with removal efficiencies in the order of Cd (2.7%) > Ni (79%) > Pb (85%). Posttreatment of the ABR treated effluent was carried out in lab scale CW containingA. donaxL. CW was effective in the removal of COD and various heavy metals present in ABR effluents. The posttreatment in CW resulted in reducing the metal concentrations to 1.95 mg/L, 0 mg/L, and 0.004 mg/L for Ni, Pb, and Cd which were within the permissible water quality standards for industrial effluents. The treatment strategy was effective and sustainable for the treatment of combined industrial wastewater.

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Constructed wetland for water quality improvement: a case study from Taiwan

Water Science & Technology ◽

10.2166/wst.2010.492 ◽

2010 ◽

Vol 62 (10) ◽

pp. 2408-2418 ◽

Cited By ~ 9

Author(s):

C. Y. Wu ◽

J. K. Liu ◽

S. H. Cheng ◽

D. E. Surampalli ◽

C. W. Chen ◽

...

Keyword(s):

Water Quality ◽

Wastewater Treatment ◽

Constructed Wetlands ◽

Constructed Wetland ◽

Water Reuse ◽

Oxygen Demand ◽

Sediment Oxygen Demand ◽

Nucleotide Sequence Analysis ◽

Sediment Samples ◽

Wetland System

In Taiwan, more than 20% of the major rivers are mildly to heavily polluted by domestic, industrial, and agricultural wastewaters due to the low percentage of sewers connected to wastewater treatment plants. Thus, constructed or engineered wetlands have been adopted as the major alternatives to clean up polluted rivers. Constructed wetlands are also applied as the tertiary wastewater treatment systems for the wastewater polishment to meet water reuse standards with lower operational costs. The studied Kaoping River Rail Bridge Constructed Wetland (KRRBCW) is the largest constructed wetland in Taiwan. It is a multi-function wetland and is used for polluted creek water purification and secondary wastewater polishment before it is discharged into the Kaoping River. Although constructed wetlands are feasible for contaminated water treatment, wetland sediments are usually the sinks for organics and metals. In this study, water and sediment samples were collected from the major wetland basins in KRRBCW. The investigation results show that more than 97% of total coliforms (TC), 55% of biochemical oxygen demand (BOD), and 30% of nutrients [e.g. total nitrogen (TN), total phosphorus (TP)] were removed via the constructed wetland system. However, results from the sediment analyses show that wetland sediments contained high concentrations of metals (e.g. Cu, Fe, Zn, Cr, and Mn), organic contents (sediment oxygen demand = 1.7 to 7.6 g O2/m2 d), and nutrients (up to 18.7 g/kg of TN and 1.22 g/kg of TN). Thus, sediments should be excavated periodically to prevent the release the pollutants into the wetland system and causing the deterioration of wetland water quality. Results of polymerase chain reaction (PCR), denaturing gradient gel electrophoresis (DGGE), and nucleotide sequence analysis reveal that a variation in microbial diversity in the wetland systems was observed. Results from the DGGE analysis indicate that all sediment samples contained significant amounts of microbial ribospecies, which might contribute to the carbon degradation and nitrogen removal. Gradual disappearance of E. coli was also observed along the flow courses through natural attenuation mechanisms.

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

10.5194/egusphere-egu2020-12678 ◽

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

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.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.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.

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Utilization of zeolite industrial wastewater for removal of copper and zinc from copper-brass pipe industrial wastewaterA paper submitted to the Journal of Environmental Engineering and Science.

Canadian Journal of Civil Engineering ◽

10.1139/l09-008 ◽

2009 ◽

Vol 36 (4) ◽

pp. 709-719 ◽

Cited By ~ 3

Author(s):

Siranee Sreesai ◽

Suthipong Sthiannopkao

Keyword(s):

Heavy Metals ◽

Industrial Wastewater ◽

Ph Value ◽

Oxygen Demand ◽

Sorption Isotherms ◽

Freundlich Equation ◽

Metals Removal ◽

Removal Efficiencies ◽

The Relationship ◽

Cu And Zn

Utilization of zeolite industrial wastewater as a sorbent and (or) precipitant to remove Cu and Zn from copper-brass pipe industrial wastewater was conducted. These wastewaters were sampled and values for pH, temperature, biochemical oxygen demand (BOD5), chemical oxygen demand (COD), total solids (TS), total dissolved solids (TDS), total suspended solids (TSS), and heavy metals were determined. In addition, the sorption isotherms of Cu and Zn in copper-brass pipe industrial wastewater onto solids of zeolite industrial wastewater at various dilutions of copper-brass pipe industrial wastewater were explored. The relationship between Cu and Zn concentrations and their removal efficiencies under different conditions of wastewater pH, contact times, and ratios between copper-brass pipe industrial wastewater and zeolite industrial wastewater was examined. Zeolite industrial wastewater contained various carbonate compounds that contributed to high pH and TDS values, and low heavy metals contamination whereas copper-brass pipe industrial wastewater had a low pH value and was contaminated with heavy metals, especially Cu and Zn. Application of zeolite industrial wastewater significantly increased the pH of copper-brass pipe industrial wastewater and consequently removed Cu and Zn. The increase in pH of the wastewater mixture significantly enhanced the heavy metals removal. The Langmuir equation described sorption isotherms of Cu and Zn onto solids of zeolite industrial wastewater at neutral pH (6–7) while the Freundlich equation fitted well at pH > 12. The maximum Cu (97%–98%) and Zn (92%–96%) removal efficiencies occurred at the original pH 12.8 of zeolite industrial wastewater, at the ratio of copper-brass pipe industrial wastewater to zeolite industrial wastewater 3:1 (vol.:vol.) and at 30 min contact time.

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Integrated constructed wetlands treating industrial wastewater from seed production

Water Practice & Technology ◽

10.2166/wpt.2021.008 ◽

2021 ◽

Author(s):

Elizabeth Kiflay ◽

Juma Selemani ◽

Karoli Njau

Keyword(s):

Seed Production ◽

Constructed Wetland ◽

Industrial Wastewater ◽

Oxygen Demand ◽

Pollutant Removal ◽

Organic Loading Rate ◽

Vetiveria Zizanioides ◽

Wastewater Samples ◽

Cyperus Alternifolius ◽

Raw Wastewater

Abstract The performance of an integrated wastewater treatment system composed of horizontal subsurface flow constructed wetland (HSSFCW), floating constructed wetland (FCW), and anaerobic baffled reactor (ABR) was studied for pollutant removal from seed production wastewater. Cyperus alternifolius (Umbrella Papyrus) plants were used in the HSSFCW, and Vetiveria zizanioides (Vetiver grass) in the FCW. The ABR was fed with 25 m3/d wastewater from its equalization tank. The average raw wastewater organic loading rate was 0.208 kg-COD/d. Grab wastewater samples were collected twice weekly for three months from each unit's inlet and outlet. The system's performance in removing biochemical oxygen demand (BOD5), chemical oxygen demand (COD), total suspended solids (TSS), turbidity, nitrate, phosphate, and ammonium was studied. The average removal efficiencies obtained were 95.5% BOD5, 94.6% COD, 86.2% TSS, 76.6% turbidity, 82.4% nitrate, 76% phosphate, and 32.9% ammonium. The results show that integrating ABR, HSSFCW, and FCW improves pollutant removal from seed production wastewater, and the treated water can be used for agricultural purposes.

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Constructed Wetland-Microbial Fuel Cells for Sustainable Greywater Treatment

Water ◽

10.3390/w10070940 ◽

2018 ◽

Vol 10 (7) ◽

pp. 940 ◽

Cited By ~ 9

Author(s):

Ignacio Araneda ◽

Natalia Tapia ◽

Katherine Lizama Allende ◽

Ignacio Vargas

Keyword(s):

Fuel Cells ◽

Constructed Wetlands ◽

Constructed Wetland ◽

Microbial Fuel Cells ◽

Energy Recovery ◽

Low Cost ◽

Nitrate Removal ◽

Oxygen Demand ◽

Phosphate Removal ◽

Removal Efficiencies

Greywater reuse through decentralized and low-cost treatment systems emerges as an opportunity to tackle the existing demand for water. In recent years, constructed wetlands (CW) systems and microbial fuel cells (MFCs) have emerged as attractive technologies for sustainable wastewater treatment. In this study, constructed wetland microbial fuel cells (CW-MFCs) planted with Phragmites australis were tested to evaluate the potential of combining these two systems for synthetic greywater treatment and energy recovery. Open (CW) and closed circuit (CW-MFCs) reactors were operated for 152 days to evaluate the effect of energy recovery on the removal of soluble chemical oxygen demand (sCOD), nutrients and total suspended solids (TSS). Results indicate no significant differences for sCOD and phosphate removal efficiencies. CW-MFCs and CW reactors presented sCOD removal efficiency of 91.7 ± 5.1% and 90 ± 10% and phosphate removal efficiencies of 56.3 ± 4.4% and 61.5 ± 3.5%, respectively. Nitrate removal efficiencies were higher in CW: 99.5 ± 1% versus 86.5 ± 7.1% in CW-MFCs, respectively. Energy generation reached a maximum power density of 33.52 ± 7.87 mW m−3 and 719.57 ± 67.67 mW m−3 at a poised anode potential of −150 mV vs. Ag/AgCl. Thus, our results suggest that the incorporation of MFC systems into constructed wetlands does allow energy recovery while providing effective greywater treatment.

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Artificial floating islands for water quality improvement

Environmental Reviews ◽

10.1139/er-2016-0038 ◽

2017 ◽

Vol 25 (3) ◽

pp. 350-357 ◽

Cited By ~ 13

Author(s):

Yueya Chang ◽

He Cui ◽

Minsheng Huang ◽

Yan He

Keyword(s):

Water Quality ◽

Quality Improvement ◽

Constructed Wetlands ◽

Oxygen Demand ◽

Key Factors ◽

Water Quality Improvement ◽

Factors Influencing ◽

Wetland Treatment ◽

Improve Water Quality

Artificial floating islands (AFIs) are a variation of wetland treatment systems for water quality improvement. This paper provides a review concerning AFIs in terms of their development, classification, and applications in the removal of nutrients, heavy metals, and chemical oxygen demand on waterways. The role of microorganisms, aquatic plants, and aquatic animals in AFIs for water decontamination and purification was also discussed. Additionally, some key factors influencing the AFIs’ performances were discussed and comparisons between AFIs and constructed wetlands were reviewed. Finally, further perspectives of artificial floating islands were identified to possibly improve their performances. The understanding of the mechanisms in AFIs that drive removal of various contaminants to improve water quality is crucial, and is also highlighted in this paper.

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An Overview of River Side Pollutants and their Effects on Physico-Chemical Changes in Water Quality of River Halda, Bangladesh

Asian Journal of Chemistry ◽

10.14233/ajchem.2020.22347 ◽

2020 ◽

Vol 32 (4) ◽

pp. 827-834

Author(s):

Muhammad Towhid Moula ◽

Ranjit K. Nath ◽

Mh. Mosfeka Chowdhury ◽

Md. Abu Bakar Siddique

Keyword(s):

Heavy Metals ◽

Water Quality ◽

Anthropogenic Activities ◽

Oxygen Demand ◽

Aquatic Organisms ◽

Total Suspended Solid ◽

Total Solid ◽

Suspended Solid ◽

Total Alkalinity ◽

Physico Chemical

Halda is an important river of Bangladesh, is now polluted in different ways through industrial, agricultural, domestic and sewage disposal. Increased anthropogenic activities have increased the potential pollution of the river and excessive pollutants may be toxic to humans and aquatic fauna. Presence of heavy metals in the river water causes perilous impact on the aquatic organisms. Hence, regular monitoring of pollution levels in the river is indispensable. In this study, we discuss about physico-chemical assessments of water quality parameters viz. pH, dissolve oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total solid (TS), total suspended solid (TSS), total dissolved substance (TDS), total alkalinity, turbidity, salinity, electrical conductivity (EC), hardness, chloride and heavy metals in the water of Halda river during rainy and winter seasons, at different points; sources of pollutants in water and their effects given starting from the early research until the current research.

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

Ambiente e Agua - An Interdisciplinary Journal of Applied Science ◽

10.4136/ambi-agua.2504 ◽

2020 ◽

Vol 15 (3) ◽

pp. 1 ◽

Cited By ~ 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.

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The Improvement of Pollutant Removal in the Ferric-Carbon Micro-Electrolysis Constructed Wetland by Partial Aeration

Water ◽

10.3390/w12020389 ◽

2020 ◽

Vol 12 (2) ◽

pp. 389 ◽

Cited By ~ 4

Author(s):

Cheng Dong ◽

Mengting Li ◽

Lin-Lan Zhuang ◽

Jian Zhang ◽

Youhao Shen ◽

...

Keyword(s):

Water Quality ◽

Wastewater Treatment ◽

Constructed Wetland ◽

Sewage Treatment ◽

Pollutant Removal ◽

Functional Genes ◽

Subsurface Flow Constructed Wetland ◽

Removal Efficiencies ◽

Oxidation Efficiency ◽

Denitrification Process

Subsurface flow constructed wetland (SSFCW) has been applied for wastewater treatment for several decades. In recent years, the combination of ferric-carbon micro-electrolysis (Fe/C-M/E) and SSFCW was proven to be an effective method of multifarious sewage treatment. However, Ferric substrate created a relatively reductive condition, decreased the oxidation efficiency of NH4+-N, and blocked the following denitrification process, which led to the low removal efficiencies of NH4+-N and total nitrogen (TN). In this study, partial aeration was introduced into the ferric-carbon micro-electrolysis SSFCW (Fe/C-M/E CW) system to solve the problem above. The water quality and nitrogen-related functional genes of bacteria on the surface of substrate were measured for mechanism exploration. The results showed that, the removal efficiencies of NH4+-N and total phosphorus (TP) in an aerated Fe/C-M/E CW system were 96.97% ± 6.06% and 84.62% ± 8.47%, much higher than 43.33% ± 11.27% and 60.16% ± 2.95% in the unaerated Fe/C-M/E CW systems. However, the TN removal in Fe/C-M/E CW system was not enhanced by aeration, which could be optimized by extending more anoxic section for denitrification.

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