Analysis of performances of pilot-scale in-situ aeration remediation for endogenous nutrients in malodorous river sediments

In this research, the performance of in-situ aeration for the removal of endogenous nutrients was investigated in the field in an approximately 50 meter long segment of an industrial river in Shanghai. The results obtained could provide technical references for an aerating engineering application to treat a malodorous river. The results showed that in-situ aeration was an effective method for the controlled release of the endogenous nitrogen and phosphorus in the sediment. The reduction efficiency of the dissolved total nitrogen (DTN) was (48.4±6.0)%, and the DTN concentration dropped from 13.4 mg·L^-1 to 8.7 mg·L^-1 in the overlying water. The removal rate of NH₄⁺-N was (46.3±16.7)%, and the concentrations were lower than 7.6 mg·L^-1 in the overlying water. The nitrification and denitrification rates at the sediment-water interface reached 46.3% and 46.3%, respectively. The reduction rate of the dissolved total phosphorus (DTP) was (35.4±2.9)% in the overlying water. The actual performances were deemed superior to those observed, because the demonstration area had not been isolated from the other areas. Additionally, the static economic evaluation showed that the environmental and economic efficiency of in-situ aeration remediation were superior in comparison with sediment dredging technologies for remediating malodorous river sediments.