环境工程学报2023，Vol.17Issue(12)：3943-3952,10.DOI:10.12030/j.cjee.202309103
土工管袋法固结底泥氮磷转化特征及释放风险
Nitrogen and Phosphorus transformation characteristics and release risks in the soil consolidated by geopipe bag method
摘要
Abstract
In this study,the geotechnical pipe bag method of dewatering consolidated sediment was used as the object to analyse the nitrogen and phosphorus morphology and release characteristics of the sediment in the pipe bag before and after the consolidation of dredged sediment in Chaohu Lake.The impact of geopipe bag consolidation on nitrogen and phosphorus transformation of dredged sediments and the risk of release was studied.The results showed that,compared with the original sediment of the lake,the organic matter and total nitrogen content of the solidified sediment decreased(organic matter decreased by 10.87％,total nitrogen content decreased by 3.50％),but the total phosphorus increased significantly(increased by about 18.89％).Meanwhile the maximum adsorption capacity(Qm)of solidified sediment increased about 1.35 times compared with uncured sediment,which was 0.89 mg·g-1.The isothermal equilibrium concentration(EPC0)of the cured substrate was about 1.58 times lower than that of the substrate before curing,indicating that the risk of phosphorus release was reduced after the substrate was cured.Nitrogen and phosphorus patterns showed that ammonia nitrogen content decreased after curing of the pipe bags,but nitrate nitrogen content did not change significantly.Fe-P and Al-P in the cured substrate increased by about 1.20 and 1.49 times,respectively,compared with the unsolidified substrate,while the Org-P content decreased by about 71.60％compared with that of the pre-solidified sediment.The results of static release showed that the nitrogen release from the cured sediments increased with the increase of temperature,in which the ammonia nitrogen release rate from the cured sediments at 30℃ was 3.31 mg·(m2·d)-1,which was about 10％of the uncured sediments in the lake body.However,cured substrate phosphorus was in the uptake state,with the maximum phosphate uptake rate of 2.74 mg·(m2·d)-1 at 30℃.The above results showed that the total amount of nitrogen and phosphorus in the cured substrate,the active state and its release fluxes was all reduced,with low risk of re-release.关键词
巢湖/土工管袋/固结底泥/释放/氮磷形态Key words
Chaohu Lake/geotube bags/solidified sediment/release/nitrogen and phosphorus forms分类
资源环境引用本文复制引用
李发建,关宇,李延勋,曾勋才,赵琼,尹洪斌..土工管袋法固结底泥氮磷转化特征及释放风险[J].环境工程学报,2023,17(12):3943-3952,10.基金项目
中国科学院基础前沿科学研究计划项目(ZDBS-LY-DQC018) （ZDBS-LY-DQC018）
