title: Nitrogen removal and power generation from treated municipal wastewater by its circulated irrigation for resource-saving rice cultivation.
abstract: This study aims at improving the performance of the cultivating system of rice for animal feed with circulated irrigation of treated municipal wastewater by applying a larger amount of wastewater, as well as adding a microbial fuel cell (MFC) to the system. The results of bench-scale experiments indicate that this modification has increased the rice yield, achieving the target for the rice cultivar used in the experiment. In addition, an assessment of protein content of the harvested rice showed that the value of the rice as animal fodder has improved. Compared with normal one-way irrigation, circulated irrigation significantly enhanced the plant growth and rice production. The direction of the irrigation (bottom-to-top or top-to-bottom) in the soil layer had no significant effect. This modified system demonstrated >96% for nitrogen removal from the treated wastewater used for the irrigation, with approximately 40% of the nitrogen being used for rice plant growth. The MFC installed in the system facilitated power generation comparable with that reported for normal paddy fields. The power generation appeared to be enhanced by bottom-to-top irrigation, which could provide organic-rich treated wastewater directly to the bacterial community living on the anode of the MFC set in the soil layer.
authors.affiliation: Department of Food, Life, and Environmental Sciences, Faculty of Agriculture, Yamagata University, 1-23 Wakaba-machi, Tsuruoka, Yamagata 997-8555, Japan E-mail: to-ru@tds1.tr.yamagata-u.ac.jp.
authors.forename: Toru
authors.initials: T
authors.lastname: Watanabe
authors.affiliation: Department of Food, Life, and Environmental Sciences, Faculty of Agriculture, Yamagata University, 1-23 Wakaba-machi, Tsuruoka, Yamagata 997-8555, Japan E-mail: to-ru@tds1.tr.yamagata-u.ac.jp.
authors.forename: Takuma
authors.initials: T
authors.lastname: Mashiko
authors.affiliation: Faculty of Agricultural Technology, Gadjah Mada University, Jl. Sosio Yustisai, Bulaksumur, Yogyakarta 55281, Indonesia.
authors.forename: Rizki
authors.initials: R
authors.lastname: Maftukhah
authors.affiliation: Department of Food, Life, and Environmental Sciences, Faculty of Agriculture, Yamagata University, 1-23 Wakaba-machi, Tsuruoka, Yamagata 997-8555, Japan E-mail: to-ru@tds1.tr.yamagata-u.ac.jp.
authors.forename: Nobuo
authors.initials: N
authors.lastname: Kaku
authors.affiliation: The United Graduate School of Agricultural Sciences, Iwate University, 3-18-8 Ueda, Morioka, Iwate 020-8550, Japan.
authors.forename: Dong Duy
authors.initials: DD
authors.lastname: Pham
authors.affiliation: Department of Food, Life, and Environmental Sciences, Faculty of Agriculture, Yamagata University, 1-23 Wakaba-machi, Tsuruoka, Yamagata 997-8555, Japan E-mail: to-ru@tds1.tr.yamagata-u.ac.jp.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Ito
mesh_terms: D057914:Agricultural Irrigation; D000818:Animals; D001674:Bioelectric Energy Sources; D058440:Denitrification; D005240:Feasibility Studies; D009584:Nitrogen / Q000032:analysis*; D012275:Oryza / Q000254:growth & development*; D012987:Soil / Q000737:chemistry; D062065:Wastewater / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*
chemical_list: D009584:Nitrogen; D012987:Soil; D062065:Wastewater