The release behavior of inorganic nitrogen and phosphorus in sediment during disturbance

Sediments and surface water were sampled in a tide flat in the Huiquan Bay, Qingdao, China in January 2004 to simulate the exchange of NH4-N/NO3-N/PO43- between sediments and surface water. A working system was designed with which samples were shaken at 60, 120 and 150 revolutions per minute (r/min). Experiment results show that NH4-N concentration in water at shaking rate of 60 r/min decreased gradually, while at 120 r/min increased gradually. In resuspension, fine-grained sediments contributed most NH4-N to the seawater, followed by medium-grained and coarse-grained sediments. The NO3-N concentration in water had a negative relation, with the shaking rate; the medium-grained sediments contributed more NO3-N to seawater than the coarse- and fine-grained sediments. The PO43- concentration is positively related with the shaking rate, the fine-grained sediments were the main N and P contributor to the seawater, followed by medium- and coarse-grained sediments.

Sediments and surface water were sampled in a tide flat in the Huiquan Bay, Qingdao, China in January 2004 to simulate the exchange of NH(4)-N/NO(3)-N/PO(4)(3-) between sediments and surface water. A working system was designed with which samples were shaken at 60, 120 and 150 revolutions per minute (r/min). Experiment results show that NH(4)-N concentration in water at shaking rate of 60 r/min decreased gradually, while at 120 r/min increased gradually. In resuspension, fine-grained sediments contributed most NH(4)-N to the seawater, followed by medium-grained and coarse-grained sediments. The NO(3)-N concentration in water had a negative relation, with the shaking rate; the medium-grained sediments contributed more NO(3)-N to seawater than the coarse- and fine-grained sediments. The PO(4)(3-) concentration is positively related with the shaking rate, the fine-grained sediments were the main N and P contributor to the seawater, followed by medium- and coarse-grained sediments.