A hybrid constructed wetland combined with microbial fuel cell for boron (B) removal and bioelectric production

WOS: 000399623700044This study deals with performance assessment of a hybrid constructed wetland-microbial fuel cell (HCW-MFC) for boron (B) treatment and bioelectric production. Our innovative HCW-MFC is first literature report to testing for boron removal and bioelectric production at the same time in terms of an eco-technological perspective. The results indicated that 63.4% boron removal was achieved for wastewater containing an average 12.3 mg L-1 inflow of boron concentrations. Furthermore, HCW-MFC was able to remove 47.5% and 19.1% nitrate and nitrite from wastewater, respectively. The maximum power and current density were recorded as 78 mWatt/m(2) and 105 mA/m(2) for the last unit of the hybrid system, suggesting that the power and the current density were decreased with the increasing boron concentration. We found that some soil enzymes such as dehydrogenase and urease in wetland matrix strongly correlated with bioelectric production, thus these enzymes might play important roles in bioelectric production with HCW-MFC. (C) 2017 Elsevier B.V. All rights reserved

Bioaccumulation and toxicity assessment of irrigation water contaminated with boron (B) using duckweed (Lemna gibba L.) in a batch reactor system

WOS: 000390182600004PubMed: 27780623The present study assesses ability of Lemna gibba L. using a batch reactor approach to bioaccumulation boron (B) from irrigation waters which were collected from a stream in largest borax reserve all over the world. The important note that bioaccumulation of B from irrigation water was first analyzed for first time in a risk assessment study using a Lemna species exposed to various B concentrations. Boron toxicity was evaluated through plant growth and biomass production during phytoremediation process. The result from the present experiment indicated that L. gibba was capable of removing 19-63% B from irrigation water depending upon contaminated level or initial concentration. We also found that B was removed from aqueous solution following pseudo second order kinetic model and Langmuir isotherm model better fitted equilibrium obtained for B phytoremediation. Maximum B accumulation in L. gibba was determined as 2088 mg kg(-1) at average inflow B concentration 17.39 mg L-1 at the end of the experiment. Conversely, maximum bioconcentration factor obtained at lowest inflow B concentrations were 232 for L. gibba. The present study suggested that L. gibba was very useful B accumulator, and thus L. gibba-based techniques could be a reasonable phytoremediation option to remove B directly from water sources contaminated with B

The phytoremediation ability of a polyculture constructed wetland to treat boron from mine effluent

WOS: 000320288800017PubMed: 23500796This study focuses on describing the ability of a small-scale, subsurface-flow-polyculture-constructed wetland (PCW) to treat boron (B) mine effluent from the world's largest borax mine (Kirka, Turkey) under field conditions. This application is among the first effluent treatment methods of this type in both Turkey and the world. This study represents an important resource on how subsurface-flow-constructed wetlands could be used to treat B mine effluents in the field conditions. To this end, an experimental wetland was vegetated with common reed (Phragmites australis) and cattails (Typha latifolia), and mine effluent was moved through the wetland. The results of the present study show that B concentrations of the mine effluent decreased from 187 to 123 mg l(-1) (32% removal rate) on average. The T. latifolia individuals absorbed a total of 250 mg kg(-1) whereas P. australis in the PCW absorbed a total of 38 mg kg(-1) B during the research period. (c) 2013 Elsevier B.V. All rights reserved

Novel chitosan based smart cathode electrocatalysts for high power generation in plant based-sediment microbial fuel cells

Baran, Talat ( Aksaray, Yazar )Smart electrocatalysts are synthesized from chitosan polymer and magnetic particles to enhance power by plant based sediment microbial fuel cell (P-SMFC). Cross-linked procedure is performed gelatinous microspheres as supporting metals (Cu, Pd, Mn, Pt, and Ni) and magnetic particles which create a porous structure on smart catalysts for increase ORR activity. A high and quick OCV rising is achieved with addition of Mag-Pd-Ch in reactor, and OCV value immediately increase from 0.408 V to 0.819 V within 10 minutes. The highest power density is also obtained as 1298 mW m-2 for reactor with Mag-Pd-Ch, which was 15 times higher than control. Significant metal leaching is observed using plant growth for smart catalyst containing Cu. Consequently, high power production, good stabilization, easy separation from water environment due to magnetic property, and relatively low cost make use of Mag-Pd-Ch both economic and environment friendly tools to enhance power generation in P-SMF

Phyto-management of boron mine effluent using native macrophytes in mono-culture and poly-culture constructed wetlands

WOS: 000381636400009Due to the high solubility of boron (B) compounds in mine effluent and its potential to cause teratogenic effects in the ecological components, the boron mine effluent pollution issues have aroused more and more global attentions, especially drinking waters source where flow through boron-enriched areas. In this study, mono-culture and poly-culture constructed wetlands (CWs) planted with native macrophytes, Typha angustifolia, Juncus gerardii, and Phragmites australis, were tested to phyto-management option of boron mine effluent under the natural climatic conditions in largest boron mine reserve area over the world. According to present results, higher bioconcentration factor (BCF) values were found as 2.095 and 2.828 for Typha angustifolia and J. gerardii growing in CWs during the experiment period. Therefore, T. angustifolia and J. gerardii seem to be the suitable species for phytoremediation of boron mine effluent. Among the native macrophytes, we found that J. gerardii in the mono-culture CW uptake higher than 1000 mg kg(-1) B from mine effluent during the study period. In this respect, J. could be a reasonable bio-filter option to control boron pollution directly from mining effluent outlets in boron mine reserve areas all over the world. (C) 2016 Elsevier B.V. All rights reserved.Scientific and Technological Research Council of Turkey [113Y335]; Scientific Research Funds of Anadolu University, Turkey [1403F098]This work was financially supported by the Scientific and Technological Research Council of Turkey (Project Number: 113Y335) and Scientific Research Funds of Anadolu University, Turkey (Project Number: 1403F098). We thank to Dr. Beth Middleton in USGS (United States Geological Survey, National Wetland Research Center), Dr. Jan Vymazal (Department of Applied Ecology, Faculty of Environmental Science, Prague, Czech Republic) and Dr. Yi Chen (Department of Applied Ecology, Faculty of Environmental Science, Prague, Czech Republic) for their comments on of the manuscript and language improvement

Effect of vegetation type on treatment performance and bioelectric production of constructed wetland modules combined with microbial fuel cell (CW-MFC) treating synthetic wastewater

WOS: 000427592100058PubMed: 29327193An operation of microcosm-constructed wetland modules combined with microbial fuel cell device (CW-MFC) was assessed for wastewater treatment and bioelectric generation. One of the crucial aims of the present experiment is also to determine effect of vegetation on wastewater treatment process and bioelectric production in wetland matrix with microbial fuel cell. Accordingly, CW-MFC modules with vegetation had higher treatment efficiency compared to unplanted wetland module, and average COD, NH4 (+), and TP removal efficiency in vegetated wetland modules were ranged from 85 to 88%, 95 to 97%, and 95 to 97%, respectively. However, the highest NO3 (-) removal (63%) was achieved by unplanted control module during the experiment period. The maximum average output voltage, power density, and Coulombic efficiency were obtained in wetland module vegetated with Typha angustifolia for 1.01 +/- 0.14 V, 7.47 +/- 13.7 mWatt/m(2), and 8.28 +/- 10.4%, respectively. The results suggest that the presence of Typha angustifolia vegetation in the CW-MFC matrix provides the benefits for treatment efficiency and bioelectric production; thus, it increases microbial activities which are responsible for biodegradation of organic compounds and catalyzed to electron flow from anode to cathode. Consequently, we suggest that engineers can use vegetated wetland matrix with Typha angustifolia in CW-MFC module in order to maximize treatment efficiency and bioelectric production

Constructed wetlands as green tools for management of boron mine wastewater

WOS: 000325787600001PubMed: 24912241Constructed wetlands are of increasing interest worldwide given that they represent an eco-technological solution to many environmental problems such as wastewater treatment. Turkey possesses approximately 70% of the world's total boron (B) reserves, and B contamination occurs in both natural and cultivated sites throughout Turkey, particularly in the north-west of the country. This study analyzes B removal and plant uptake of B in pilot plots of subsurface horizontal-flow constructed wetlands. Constructed wetlands were vegetated with Typha latifolia (referred to as CW1) and Phragmites australis (referred to as CW2) to treat wastewater from a borax reserve in Turkey-the largest of its type in the world and were assessed under field conditions. The B concentrations of water inflows to the systems were determined to be 10.2, 28.2, 84.6, 232.3, 716.4, and 2019.1mg l(-1). The T. latifolia in the CW(1)treatment group absorbed a total of 1300mg kg(-1) B, whereas P. australis absorbed 839mg kg(-1). As a result, CW(1)had an average removal efficiency of 40.7%, while that of CW(2)was 27.2%. Our results suggest that constructed wetlands are an effective, economic and eco-friendly solution to treating B mine wastewater and controlling the adverse environmental effects of B mining

Cost-effectiveness of boron (B) removal from irrigation water: an economic water treatment model (EWTM) for farmers to prevent boron toxicity

Türker, Onur Can ( Aksaray, Yazar )Protection of water sources which are used for irrigation has raised great interest in the last years among the environmental strategists due to potential water scarcity worldwide. Excessive boron (B) in irrigation water poses crucial environmental problems in the agricultural zones and it leads to toxicity symptoms in crops, as well as human beings. In the present research, economic water treatment models consist of dried common wetland plants (Lemna gibba, Phragmites australis, and Typha latifolia) and Lemna gibba accumulation was tested and assessed to create a simple, cost-effective, and eco-friendly method for B removal from irrigation water. Significant amount of B was removed from irrigation water samples by EWTMs and B concentrations decreased below < 1 mg L−1 when the components were exposed to 4 and 8 mg L−1 initial B concentrations. Moreover, the results from batch adsorption study demonstrated that dried L. gibba had a higher B loading capacity compare to other dried plants, and B sorption capacity of dried L. gibba was found as 2.23 mg/g. The optimum pH value for sorption modules was found as neutral pH (pH = 7) in the batch adsorption experiment. Boron sorption from irrigation water samples fitted the Langmuir model, mostly B removed from irrigation water during the first 2 h of contact time. Techno-economic analysis indicated that EWTM is a promising method that appears to be both economically and ecologically feasible, and it can also provide a sustainable and practical strategy for farmers to prevent B toxicity in their agricultural zones...

Boron (B) removal and bioelectricity captured from irrigation water using engineered duckweed-microbial fuel cell: effect of plant species and vegetation structure

*Türker, Onur Can ( Aksaray, Yazar )Boron (B) in the irrigation water can be hazardous to human beings and other aquatic or terrestrial organisms when B concentration exceeds a certain level. More importantly, B removal from irrigation water is relatively difficult using conventional processes. In the present experiment, an innovative treatment model based on monoculture and polyculture duckweed wastewater treatment modules was tested for B-rich irrigation water purification and bioelectricity harvesting. Different modules were designed using Lemna gibba L., Lemna minor L., and their combination in order to determine the most optimal duckweed species and vegetation structure for B removal process and bioelectricity generation in a module. In this respect, the module with a monoculture of Lemna gibba achieved the highest net B removal efficiency (71%) when it was exposed to 4 mg/L B (initial concentration). However, B removal efficiencies from all modules decreased when the initial B concentrations reached up to 4 mg/L in the irrigation water. The highest bioelectricity production was measured as 1.04 V with 17783 mWatt/m2 power density at a current density of 44.06 mA/m2 for module with Lemna gibba in monoculture through sacrificial magnesium anode. Specifically, both monocultures and polyculture removed considerable amounts of organic matter from irrigation water. However, biomass production and total chlorophyll (a + b) concentrations of duckweeds significantly decreased when they were exposed to 32 mg/L B in the irrigation water samples. Consequently, our modules present a holistic perspective to the prevention B toxicity problems in agricultural zones, and are a sustainable strategy for farmers or agricultural experts to produce bioelectricity by a cost-effective and eco-technological method...

Role of plants and vegetation structure on boron (B) removal process in constructed wetlands

WOS: 000369691900014In this study, we investigated the direct role of plants and vegetation composition on B removal pathways, as well as the effect of the presence of plants on physicochemical parameter of wastewater in the constructed wetlands (CWs) under natural climate conditions in the largest B reserve area all over the world. The results indicated that the maximum B removal was achieved by a monoculture CW planted with T. latifolia with average removal efficiency of 64%, while the lowest B removal efficiency (38.1% removal rate) was obtained by unplanted system in the experimental period. Therefore, we emphasized that the presence of plants in CWs can offer a positive effect on improving the quality of the wastewater due to direct uptake of B in tissues and influence filtering capacity, leading to higher levels of sorption or adsorption around the rhizosphere and sediment. The results also suggested that the cumulative effect of plants or vegetation on physicochemical parameter of wastewater (pH, EC, and DO) related to B removal cannot be significant. Furthermore, we found that the main B removal pathway in CW was sediment storage through a mass balance model, and plant has minor contribution to the overall removal of B in CWs.Scientific and Technological Research Council of Turkey [113Y335]; Scientific Research Funds of Anadolu University, Turkey [1403F098]This work was financially supported by the Scientific and Technological Research Council of Turkey (Project Number: 113Y335) and Scientific Research Funds of Anadolu University, Turkey (Project Number: 1403F098). We thank to Dr. Jan Vymazal in Czech University of Life Sciences (Department of Applied Ecology, Faculty of Environmental Science, Prague, Czech Republic) and Dr. Beth Middleton in USGS (United States Geological Survey, National Wet-land Research Center) for their comments on earlier versions of the manuscript and language improvement