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

• Published in: Environmental science and pollution research international 2019-10, Vol.26 (30), p.31522-31536
• Main Authors: Türker, Onur Can, Yakar, Anıl, Türe, Cengiz, Saz, Çağdaş
• Format: Article
• Language: English
• Subjects: Agricultural practices; Aquatic plants; Aquatic Pollution; Araceae - drug effects; Araceae - physiology; Atmospheric Protection/Air Quality Control/Air Pollution; Biochemical fuel cells; Bioelectric Energy Sources; Bioelectricity; Biomass; Boron; Boron - analysis; Boron - metabolism; Chlorophyll; Clean technology; Duckweed; Earth and Environmental Science; Ecotoxicology; Electrodes; Environment; Environmental Chemistry; Environmental Health; Environmental science; Floating plants; Harvesting; Irrigation; Irrigation water; Lemna gibba; Magnesium; Microorganisms; Modules; Monoculture; Organic matter; Plant species; Polyculture; Purification; Research Article; Toxicity; Vegetation; Waste Disposal, Fluid - methods; Waste Water - chemistry; Waste Water Technology; Wastewater treatment; Water analysis; Water Management; Water Pollutants, Chemical - analysis; Water Pollutants, Chemical - metabolism; Water Pollution Control; Water purification; Water Purification - methods; Water sampling
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-019-06285-6

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/m 2 power density at a current density of 44.06 mA/m 2 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.