Optimization and action mechanism of composite conditioner for lake sludge dewatering and solidification
Aiming at the difficult problem of dewatering and solidification of lake sludge,the composite conditioner formed by the combination of organic flocculant,inorganic flocculant and skeleton builder was used to modify the lake sludge.The ratio of each component was optimized by response surface method,and the mechanism of composite conditioner was discussed.The re-sults showed that the optimal combination of composite conditioner was 4.11 g/L polyaluminium chloride(PAC),0.18 g/L anion-ic polyacrylamide(APAM)and 18.06 g/L low alkaline sludge consolidation agent(LAC).After using the composite conditioner,the sludge specific resistance of lake sludge was reduced by 87.6%,the pressure filtration dehydration time was reduced by 70.6%,the tail water pH reached the discharge standard,and the dehydration efficiency was 5.9%higher than that of quicklime.The mechanism of the composite conditioner was as follows:the PAC component reduced the absolute value of the Zeta potential of the sludge by 9.5 mV,thereby reducing the electrostatic repulsion between the sludge particles;the subsequent addition of APAM played the role of adsorption-bridging,and aggregated the fine particles of the sludge into larger flocs,which was conducive to the discharge of water between the sludge particles;the final doping of LAC played the role of skeleton builder,creating a drainage channel in the process of sludge dewatering and compaction,increasing the porosity of sludge cake by 6.4%,and further impro-ving the dewatering effect.The research results can provide reference for the efficient and environmentally friendly disposal of lake sludge.
lake sludgesludge dewateringflocculantskeleton builderresponse surface method
国家科技期刊平台
NSTL
万方数据
维普
