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A laboratory study was conducted to observe the release of nitrogen and phosphorus from the sedimentsrrrrrrrrrnunder both anaerobic and aerobic conditions. The samples used were five creek sediments and a fish-pondrrrrrrrrrnsediment (as a comparison) obtained from suburban Shanghai. High loads of nitrogen and phosphorusrrrrrrrrrnwere found in the creek sediments. Total nitrogen of the sediments ranged from 1.17 to 5.95 g kg-1; totalrrrrrrrrrnphosphorus from 608.63 to 2 033.95 mg kg-1. Making up more than 90% of the total nitrogen, organicrrrrrrrrrnnitrogen was the dominant nitrogen fraction in the sediments; whereas inorganic phosphorus was the dominantrrrrrrrrrnphosphorus fraction, which made up more than 85 percent of the total phosphorus. Cabound phosphorusrrrrrrrrrnfraction dominated inorganic phosphorus, which occupied more than 50% of the total.rrrrrrrrrnA large amount of ammonium was released from the sediments under both aerobic and anaerobic con-rrrrrrrrrnditions, and the anaerobic releases were slightly greater than the aerobic. In addition, ammonium contents
A laboratory study was conducted to observe the release of nitrogen and phosphorus from the sediments r r r r r r r r nunder both anaerobic and aerobic conditions. The samples used were five creek sediments and a fish-pond r r r r r r r r n nsediment (as a comparison) obtained from suburban Shanghai. High loads of nitrogen and phosphorus r r r r r r r r r nwere found in the creek sediments. Total nitrogen of the sediments ranged from 1.17 to 5.95 g kg-1; total r r r r r r r r nphosphorus from 608.63 to 2 033.95 mg kg-1. Making up more than 90% of the total nitrogen, organic r r r r r r r r r nnitrogen was the dominant nitrogen fraction in the sediments; while inorganic phosphorus was the dominant r r r r r r r r rphosphorus fraction, which made up more than 85 percent of the total phosphorus. Cabound phosphorus r r r r r r r r r nfraction dominated inorganic phosphorus, which has more than 50% of the total. r r r r r r r r n a large amount of ammonium was released from th e sediments under both aerobic and anaerobic con- r r r r r r r r r r r r r nditions, and the anaerobic releases were slightly greater than the aerobic.