title: Development of natural treatment system consisting of black soil and Kentucky bluegrass for the post-treatment of anaerobically digested strong wastewater.
abstract: To develop a sound post-treatment process for anaerobically-digested strong wastewater, a novel natural treatment system comprising two units is put forward. The first unit, a trickling filter, provides for further reduction of biochemical oxygen demand and adjustable nitrification. The subsequent soil-plant unit aims at removing and recovering the nutrients nitrogen (N), phosphorus (P) and potassium (K). As a lab-scale feasibility study, a soil column test was conducted, in which black soil and valuable Kentucky bluegrass were integrated to treat artificial nutrient-enriched wastewater. After a long-term operation, the nitrification function was well established in the top layers, despite the need for an improved denitrification process prior to discharge. P and K were retained by the soil through distinct mechanisms. Since they either partially or totally remained in plant-available forms in the soil, indirect nutrient reuse could be achieved. As for Kentucky bluegrass, it displayed better growth status when receiving wastewater, with direct recovery of 8%, 6% and 14% of input N, P and K, respectively. Furthermore, the indispensable role of Kentucky bluegrass for better treatment performance was proved, as it enhanced the cell-specific nitrification potential of the soil nitrifying microorganisms inhabiting the rhizosphere. After further upgrade, the proposed system is expected to become a new solution for strong wastewater pollution.
authors.affiliation: Department of Urban Engineering, The University of Tokyo, Tokyo 113-8656, Japan. Electronic address: chenxiaochen1984@gmail.com.
authors.forename: Xiaochen
authors.initials: X
authors.lastname: Chen
authors.affiliation: Integrated Research System for Sustainability Science, The University of Tokyo, Tokyo 113-8654, Japan.
authors.forename: Kensuke
authors.initials: K
authors.lastname: Fukushi
mesh_terms: D058465:Nitrification; D010865:Pilot Projects; D031785:Poa / Q000737:chemistry*; D012987:Soil / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D012987:Soil; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Black soil; Kentucky bluegrass; Natural treatment system; Soil column test; Strong wastewater