基于水稻秸秆资源化的底泥固化材料配比优化研究OA

In order to reduce the cost of solidifying river and lake sediments while achieving resource utilization of agricultural waste,this study focused on four common materials:rice straw,cement,fly ash,and Bacillus compound.Through a four-factor and three-level orthogonal experiment(rice straw 1%～3%,cement 0～10 g/kg,fly ash 0～10 g/kg and Bacillus compound 0.01～1 g/L)to investigate how different material ratios affect sediment solidification efficiency and the overlying water environment.Results indicated that the solidification materials significantly influenced both the overlying water environment and sediment properties,with the solidification materials increased the concentrations of COD,TN,and TP in the overlying water by 17.03%～404.89%,2.16%～53.04%and 23.48%～758.70%,respectively,while reduced endogenous DOM input and humification levels in the overlying water;high cement addition elevated CDOM concentration.Solidification materials increased sediment particle size and strength,with compaction increasing by 91.12%～210.77%compared to CK,while moisture content decreased by 29.96%～68.30;the addition of cement significantly increased the median particle size,compaction,and compressive strength of the sediment(p<0.01),while the addition of straw significantly reduced the sediment moisture content(p<0.05).Scanning electron microscopy revealed that the solidified material enhanced the sediment's skeletal structure and porosity through gel product formation and fiber"bridging"effects,thereby improving the micro-stability.At the same time,the solidification materials changed the state of nutrient salts in the sediment,increasing the content of SOM,STN and SAP by 11.93%～271.37%,7.43%～60.32%,and 11.12%～304.51%,respectively,compared to CK,where Z7,Z8 and Z9 may be unsuitable for aquatic plant growth due to excessively high nutrient concentrations.Comprehensive evaluation identified that Z6(rice straw 1%,cement 5 g/kg,fly ash 10 g/kg and Bacillus compound 0.1 g/L)not only showed high sediment compaction and compressive strength but also effectively controlled nutrient release,balancing engineering strength requirements with ecological safety,providing a feasible solution for low-cost and eco-friendly sediment stabilization technology.This holds significant importance for promoting the resource utilization of agricultural waste and the industrialization of river and lake sediment remediation.