pH值对生物絮凝剂制备及沼液处理调控效应研究OA

To investigate the regulatory role of pH in bioflocculant preparation and its combined application for biogas slurry treatment,single-factor and two-factor experiments were conducted to analyze the effects of pH during the activated sludge preparation stage,the initial pH of the biogas slurry,and their interaction on treatment performance.In the bioflocculant preparation stage,the flocculant obtained under acidic conditions(pH=2)achieved a kaolin flocculation efficiency of 86.7％,whereas strong alkaline conditions,although releasing more polysaccharide substances,yielded an efficiency of only 22.2％,indicating that the acidic method effectively preserves the structure and function of the active flocculating components.Box-Behnken design(BBD)response surface methodology was employed to establish quadratic response mod-els for chemical oxygen demand(COD)removal efficiency and flocculation efficiency,with a focus on the interactions be-tween pH and other factors to optimize treatment performance.The results showed that during the biogas slurry treatment stage,pH was the most significant factor influencing COD removal,outweighing the effects of calcium chloride(CaCl2)and polyaluminum chloride(PAC)dosages,with an optimal pH range of 8～10.A significant synergistic interaction be-tween pH and CaCl2 dosage was revealed:under alkaline conditions(pH=11),increasing the CaCl2 dosage dramatically enhanced the flocculation efficiency from 23.7％to 95.5％,whereas under acidic conditions(pH=5),CaCl2 addition produced almost no improvement.This study clarifies that pH is a critical factor throughout the entire process from biofloc-culant preparation to biogas slurry treatment,provides clear operational parameters for the low-cost production and applica-tion of bioflocculants derived from activated sludge,and lays a theoretical foundation for understanding the synergistic mechanisms of multiple components in composite flocculation systems.