Phosphorus removal by the multipond system sediments receiving agricultural drainage in a headstream watershed.
Wetland systems in headstream watersheds are important to control the nonpoint source pollutant phosphorus. Experiments were conducted using intact sediment-water columns obtained from the multipond system in Liuchahe watershed of Chaohu Lake to determine its capacity to retain P. It was found that pond sediments had strong P retention ability. For the Hill pond, Village pond and Rice pond, their retention coefficient(A) were 288.3, 279.2 and 260.8 L/m2, respectively. The equilibrium P concentration (EPCw) were 0.016, 0.028 and 0.018 mg/L, respectively. The Hill pond indicated the highest P retention ability. P retained in the pond sediments indicated high stable degree. P removal from the overlying water column into the pond sediments followed a first-order kinetic model. Under the experimental hydrological conditions, the retention time had a positive correlation with the P loading. The multipond system could provide enough retention time to retain P in drainage runoffs. At the P levels evaluated, the sediments of the multipond system are effective sinks to retain P from nonpoint source runoffs.
Fu
Qiang
Q
State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy Sciences, Beijing 100085, China. fuqiang75@126.com
Yin
Cheng-Qing
CQ
Ma
Yun
Y
D002681:China; D005618:Fresh Water; D019015:Geologic Sediments / Q000032:analysis*; D006207:Half-Life; D007700:Kinetics; D010758:Phosphorus / Q000032:analysis*; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification / Q000379:methods*
D014874:Water Pollutants, Chemical; D010758:Phosphorus