剩余污泥机械破碎碳源快速释放与回收技术

Carbon Source Release and Recovery Rapidly from Excess Sludge by Mechanical Disintegration

基于我国城市污水处理厂进水碳氮比低影响生物系统脱氮除磷效果的现状,针对传统污泥厌氧发酵产酸工艺周期长、效率低的问题,开展了剩余污泥机械破碎碳源快速释放与回收技术研究,考察了机械破碎强度与作用时间对污泥絮体结构与碳源释放的影响。结果表明,随着机械破碎强度的增加,溶解性COD的产量逐渐升高;而随着机械破碎作用时间的延长,溶解性COD的产量呈现先升高再缓慢降低的趋势,作用时间为8 min时,溶解性COD的产量达到最大,约910mg/L。激光粒度仪与环境扫描电镜分析结果显示,随着破碎强度与作用时间的增加,污泥絮体粒径逐渐变小,结构松散直至破碎,达到污泥破碎碳源释放的效果。当以产生的溶解性COD为碳源时活性污泥反硝化速率为2. 553 mgNO_3^--N/(gMLSS·h),略高于以葡萄糖为碳源时的脱氮速率。而经过机械作用后剩余污泥絮体破碎,脱氮性能基本丧失,其反硝化速率仅为0. 680 mgNO_3^--N/(gMLSS·h)。机械破碎作用可实现剩余污泥碳源的快速释放,为解决污水处理厂碳源不足与剩余污泥处置困难的问题提供了新的思路与途径。

The problem of low carbon and nitrogen ratio in influent of wastewater treatment plants is common in China, which interferes with biological nitrogen and phosphorus removal. Based on the problem of long period and low efficiency of traditional sludge anaerobic fermentation, the study of carbon source release and recovery rapidly from excess sludge by mechanical disintegration was carried out. The effect of mechanical disintegration strength and time on the sludge flocs structure and carbon source re- lease was analyzed. The results showed that soluble COD （SCOD） yield gradually increased with the in- crease of mechanical disintegration strength. However, with the extension of mechanical disintegration time, the SCOD yield increased first and then decreased slowly. When the mechanical disintegration time was 8 rain, the yield of SCOD reached the peak, it was about 910 mg/L. The results of laser particle size analyzer and environmental scanning electron microscope showed that with the increase of mechanical disintegration strength and time, the sludge floc size gradually decreased, and the structure became loose until it was broken. Using SCOD produced from sludge activated sludge was 2. 553 mgNO3^- - N/（ gMLSS · h）, as the carbon source, the denitrification rate of which was slightly higher than the denitrification rate using glucose as the carbon source. After the mechanical disintegration, the sludge flocs were broken, and the denitrification performance was basically lost. The denitrification rate was only 0.680 mg- NO3^- - N/（ gMLSS · h）. The mechanical disintegration can realize the rapid release of carbon source in excess sludge, which provides a new idea and approach for solving the problem of insufficient carbon source and excess sludge disposal in the wastewater treatment plant.