title: Effects of four different phosphorus-locking materials on sediment and water quality in Xi'an moat.
abstract: To lower phosphorus concentration in Xi'an moat, four different phosphorus-locking materials, namely, calcium nitrate, sponge-iron, fly ash, and silica alumina clay, were selected in this experiment to study their effects on water quality and sediment. Results of the continuous 68-day experiment showed that calcium nitrate was the most effective for controlling phosphorus concentration in overlying and interstitial water, where the efficiency of locking phosphorus was >97 and 90 %, respectively. Meanwhile, the addition of calcium nitrate caused Fe/Al-bound phosphorus (Fe/Al-P) content in sediment declining but Ca-bound phosphorus (Ca-P) and organic phosphorus (OP) content ascending. The phosphorus-locking efficiency of sponge-iron in overlying and interstitial water was >72 and 66 %, respectively. Meanwhile, the total phosphorus (TP), OP, Fe/Al-P, and Ca-P content in sediment increased by 33.8, 7.7, 23.1, and 23.1 %, respectively, implying that under the action of sponge-iron, the locked phosphorus in sediment was mainly inorganic form and the phosphorus-locking efficiency of sponge-iron could be stable and persistent. In addition, the phosphorus-locking efficiency of fly ash was transient and limited, let alone silica alumina clay had almost no capacity for phosphorus-locking efficiency. Therefore, calcium nitrate and sponge-iron were excellent phosphorus-locking agents to repair the seriously polluted water derived from an internal source.
authors.affiliation: School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, China.
authors.forename: Guanbai
authors.initials: G
authors.lastname: Wang
authors.affiliation: School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, China. wangyi1003@sina.com.
authors.forename: Yi
authors.initials: Y
authors.lastname: Wang
authors.affiliation: School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Guo
authors.affiliation: School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, China.
authors.forename: Dangcong
authors.initials: D
authors.lastname: Peng
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry; D017610:Calcium Compounds / Q000737:chemistry; D002681:China; D060729:Coal Ash / Q000737:chemistry; D004784:Environmental Monitoring / Q000379:methods; D052918:Environmental Restoration and Remediation / Q000379:methods*; D005618:Fresh Water / Q000737:chemistry*; D019015:Geologic Sediments / Q000737:chemistry*; D007501:Iron / Q000737:chemistry; D009566:Nitrates / Q000737:chemistry; D010758:Phosphorus / Q000032:analysis* / Q000737:chemistry; D014507:Urbanization; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry; D060753:Water Quality
chemical_list: D000538:Aluminum Silicates; D017610:Calcium Compounds; D060729:Coal Ash; D009566:Nitrates; D014874:Water Pollutants, Chemical; D010758:Phosphorus; D007501:Iron; C059948:calcium nitrate
keywords: Calcium nitrate; Heavy pollution; Internal phosphorus; Phosphorus control; Sponge-iron; Urban landscape water