Feasibility of using non-vegetated baffled submerged constructed wetland system for removal of heavy metals, COD and nutrients from hyper-saline hazardous landfill leachate

2017 ◽  
Vol 98 ◽  
pp. 254-265
Author(s):  
Naira Meky ◽  
Manabu Fujii ◽  
Chihiro Yoshimura ◽  
Ahmed Tawfik
Keyword(s):  
Heavy Metals ◽  
Constructed Wetland ◽  
Landfill Leachate ◽  
Removal Of Heavy Metals ◽  
Wetland System

scholarly journals Application of Electrocoagulation with a New Steel-Swarf-Based Electrode for the Removal of Heavy Metals and Total Coliforms from Sanitary Landfill Leachate

2021 ◽  
Vol 11 (11) ◽  
pp. 5009
Author(s):  
Mayk Teles de Oliveira ◽  
Ieda Maria Sapateiro Torres ◽  
Humberto Ruggeri ◽  
Paulo Scalize ◽  
Antonio Albuquerque ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Landfill Leachate ◽  
Lower Cost ◽  
Sanitary Landfill ◽  
Leachate Treatment ◽  
Removal Of Heavy Metals ◽  
Waste Characteristics ◽  
Electrode Passivation ◽  
Steel Swarf ◽  
Sanitary Landfill Leachate

Sanitary landfill leachate (LL) composition varies according to climate variables variation, solid waste characteristics and composition, and landfill age. Leachate treatment is essentially carried out trough biological and physicochemical processes, which have showed variability in efficiency and appear a costly solution for the management authorities. Electrocoagulation (EC) seems a suitable solution for leachate treatment taking into account the characteristics of the liquor. One of the problems of EC is the electrode passivation, which affects the longevity of the process. One solution to this problem could be the replacement of the electrode by one made of recyclable material, which would make it possible to change it frequently and at a lower cost. The objective of the present work was to evaluate the removal of heavy metals (As, Ba, Cd, Cr, Cu, Fe, Pb, Mn, Ni, Se and Zn) and coliforms from a LL by EC using electrodes made from steel swarf (SfE) up to 8 h. Removal efficiencies of detected heavy metals were 51%(Cr), 59%(As), 71%(Cd), 72%(Zn), 92%(Ba), 95%(Ni) and >99%(Pb). The microbial load of coliforms in leachate was reduced from 10.76 × 104 CFU/mL (raw leachate) to less than 1 CFU/mL (after treatment with SfE) (i.e., approximately 100% reduction). The use of SfE in EC of LL is very effective in removing heavy metals and coliforms and can be used as alternative treatment solution for such effluents.

Kinetics of Heavy Metals Adsorption on Gravels Derived From Subsurface Flow Constructed Wetland

2020 ◽  
pp. 193-213
Author(s):  
Celestin Defo ◽  
Ravinder Kaur
Keyword(s):  
Heavy Metals ◽  
Constructed Wetland ◽  
Contact Period ◽  
Batch Experiments ◽  
Removal Of Heavy Metals ◽  
Pseudo Second Order ◽  
Adsorption Rates ◽  
Kinetics Of ◽  
Best Fit ◽  
Concentration Levels

Adsorption kinetics of Ni, Cr, and Pb on gravels collected from constructed wetland was studied at varied metal concentrations and contact period for estimating the removal of heavy metals from wastewater. Batch experiments were conducted by shaking 120 ml of metal solutions having 5 concentration levels each of Ni (1.0, 2.0, 3.5, 5.0 and 6.0 mg l-1), Cr (1.0, 2.0, 3.0, 4.5 and 6.0 mg l-1), and Pb (1.0, 3.0, 6.0, 8.0 and 12.0 mg l-1) with 50 g of gravels for as function of time. Adsorption of Ni, Cr, and Pb on gravels ranged from 34.8 to 47.2, 42.7-54.9, and 47.5-56.9%, indicating their removal in the order: Pb > Cr > Ni. Freundlich model showed a good fit for Ni and Cr (R2>0.9) while Langmuir model fitted better for Pb (R2= 0.7). The pseudo-second-order model showed the best fit to simulate the adsorption rates of these metals on gravel.

scholarly journals Distribution of heavy metals in various compartments of the constructed wetland system in Przywidz

2019 ◽  
pp. 297-305
Author(s):  
Hanna Obarska-Pempkowiak ◽  
Katarzyna Klimkowska
Keyword(s):  
Heavy Metals ◽  
Constructed Wetland ◽  
Treatment Plant ◽  
Domestic Sewage ◽  
Point Of View ◽  
Filling Material ◽  
Toxic Heavy Metals ◽  
Wetland System ◽  
Cascade Filter ◽  
The Hill

In the last decade constructed wetlands have become a very popular technology for removal of contaminants from domestic sewage. They are also assesed from the point of view of their capacity for removal of toxic heavy metals and organic substances resistant to degradation. Constructed wetland in Przywidz localized about 60 km from Gdansk is a pilot wastewater treatment plant (WWTP) designed for 150 PE (person equivalent). The system consists of two sections: vegetated submerged bed (VSB) with horizontal flow of sewage and a cascade filter situated on a slope of a hill. Domestic sewage after a conventional pretreatment ( consists of an Imhoff tank and a trickling filter) is pumped to the VSB filter located on slope of the hill. Total area of constructed wetland is about 870 m2. In the period 1995-98 the measurments of several heavy metals (Cd, Cu, Pb) were carried out. These measurments were carried out in inflowing and outflowing sewage and as well in samples collected from each section of constructed wetland system. In particular analysis of sediment collected in ditches of the cascade filter, filling material of the dykes, VSB filter and plants were carried out. It was found out that content of heavy metals in suspended soil decreased along the course of treatment, starting from VSB filter, through the first ditch to the last ditch. Measurable concentration of dissolved heavy metals were found in sewage collected from several subsequent ditches. The main mechanism of removal on particular matter in subsequent ditches was sorption.

scholarly journals Simultaneous Removal of Heavy Metals And Bioelectricity Generation In Microbial Fuel Cell Coupled With Constructed Wetland: An Optimization Study On Substrate And Plant Types

2021 ◽  
Author(s):  
Lu Wang ◽  
Dayong Xu ◽  
Qingyun Zhang ◽  
Tingting Liu ◽  
Zhengkai Tao
Keyword(s):  
Heavy Metals ◽  
Fuel Cell ◽  
Microbial Fuel Cell ◽  
Constructed Wetland ◽  
Water Hyacinth ◽  
Plant Roots ◽  
Optimization Study ◽  
Removal Of Heavy Metals ◽  
Metal Treatment ◽  
Optimal Construction

Abstract A microbial fuel cell coupled with constructed wetland (CW-MFC) was built to remove heavy metals (Zn and Ni) from sludge. The performance for the effects of substrates (granular activated carbon (GAC), ceramsite) and plants (Iris pseudacorus, Water hyacinth) towards the heavy metal treatment as well as electricity generation were systematically investigated. The CW-MFC systems possessed higher Zn and Ni removal efficiencies as compared to CW. The maximal removal rates of Zn (76.88%) and Ni (66.02%) were obtained in system CW-MFC based on GAC and Water hyacinth (GAC- and WH-CW-MFC). Correspondingly, the system produced the maximum voltage of 534.30 mV and power density of 70.86 mW·m-3, respectively. Plant roots and electrodes contributed supremely to the removal of heavy metals, especially for GAC- and WH-CW-MFC systems. The coincident enrichment rates of Zn and Ni reached 21.10% and 26.04% for plant roots, 14.48% and 16.50% for electrodes, respectively. A majority of the heavy metals on the sludge surface were confirmed as Zn and Ni. Furthermore, the high-valence Zn and Ni were effectively reduced to low-valence or elemental metals. This study provides a theoretical guidance for the optimal construction of CW-MFC and the resource utilization of sludge containing heavy metals.

Landfill leachate treatment by an experimental subsurface flow constructed wetland in tropical climate countries

2005 ◽  
Vol 52 (12) ◽  
pp. 243-250 ◽  
Author(s):  
Z. Ujang ◽  
E. Soedjono ◽  
M.R. Salim ◽  
R.B. Shutes
Keyword(s):  
Heavy Metals ◽  
Constructed Wetlands ◽  
Constructed Wetland ◽  
Landfill Leachate ◽  
Subsurface Flow ◽  
Experimental Unit ◽  
Leachate Treatment ◽  
Emergent Plants ◽  
Subsurface Flow Constructed Wetland ◽  
Better Than

Municipal leachate was treated in an experimental unit of constructed wetlands of subsurface flow type. The parameters studied were organics (BOD and COD), solids and heavy metals (Zn, Ni, Cu, Cr and Pb). Using two types of emergent plants of Scirpus globulosus and Eriocaulon sexangulare, more than 80% removal was achieved for all the parameters. E. sexangulare removed organics and heavy metals better than Scirpus globulosus. A higher concentration of heavy metals in the influent did not change the removal efficiency.

Retention and distribution of Cu, Pb, Cr, and Zn in a full-scale hybrid constructed wetland receiving municipal sewage

2013 ◽  
Vol 67 (10) ◽  
pp. 2257-2264
Author(s):  
Haiwen Xiao ◽  
Shengli Zhang ◽  
Jun Zhai ◽  
Qiang He ◽  
Adriaan Mels ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Constructed Wetland ◽  
Manganese Oxides ◽  
Free Water ◽  
Municipal Sewage ◽  
Plant Tissues ◽  
Water Stream ◽  
Wastewater Treatment Process ◽  
Metal Concentrations ◽  
Removal Of Heavy Metals

This study was conducted to investigate the retention and distribution of Cu, Pb, Cr, and Zn in a hybrid constructed wetland (CW) that consists of both vertical baffled flow wetlands (VBFWs) and horizontal subsurface flow wetlands (HSSFs) with unique flow regimes and oxygen distribution. The heavy metal concentrations in water, sediments, and plant tissues in the hybrid CW were analysed. The removal of heavy metals from the water stream in the monitoring period was not statistically significant. Metal concentrations in the sediments generally decreased along the wastewater treatment process. The reductive anaerobic condition in the VBFW may promote the sulphate reduction and form highly insoluble Cu, Pb, and Zn sulphides, resulting in the higher concentration of the bivalent cations in the VBFW sediments than the corresponding values in the HSSF; however, the aerobic and anoxic environments in the HSSF enhanced the removal of Cr with the co-precipitation of iron and manganese oxides, and their hydroxides. Metal concentrations in plant tissues were not significantly influenced by the concentrations in sediments, while roots contained statistically higher metal concentrations than stems and leaves. The sediments stored 94.01, 86.31, 95.85, and 89.51% of the total Cu, Pb, Cr, and Zn retained in the hybrid CW system, respectively, while only small fractions (<10%) were accumulated in the harvestable macrophyte tissues. It is important to clean not only the accessible sediments in free water surface tank and ponds but also the embedded sediments in vegetated beds for the sustainable removal of heavy metals.

Zero-discharge of nutrients and water in a willow dominated constructed wetland

2001 ◽  
Vol 44 (11-12) ◽  
pp. 407-412 ◽  
Author(s):  
P. Gregersen ◽  
H. Brix
Keyword(s):  
Heavy Metals ◽  
Constructed Wetland ◽  
High Density Polyethylene ◽  
Salix Viminalis ◽  
Annual Rainfall ◽  
Soil Infiltration ◽  
Annual Basis ◽  
Zero Discharge ◽  
Wetland System

A novel constructed wetland system has been developed to treat sewage, evaporate water and recycle nutrients from single households at sites where effluent standards are stringent and soil infiltration is not possible. Main attributes of the willow wastewater cleaning facilities are that the systems have zero discharge, the willows evapotranspire the water, and nutrients can be recycled via the willow biomass produced in the system. The willow wastewater cleaning facilities generally consist of c. 1.5 m deep high-density polyethylene-lined basins filled with soil and planted with clones of willow (Salix viminalis L.). The surface area of the systems depends on the amount and quality of the sewage to be treated and the local annual rainfall. For a single household the area needed typically is between 200-300 m2. Settled sewage is dispersed underground into the bed under pressure. When correctly dimensioned, the willow will - on an annual basis - evapotranspire all water from the sewage and rain falling onto the system, and take up all nutrients and heavy metals from the sewage. The stems of the willows are harvested on a regular basis to remove nutrients and heavy metals and to stimulate the growth of the willows. Initial experiences from full-scale systems in Denmark show promising results.

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