Enhanced excess sludge hydrolysis and acidification in an activated sludge side-stream reactor process with single-stage sludge alkaline treatment: a pilot scale study

A pilot-scale side-stream reactor process with single-stage sludge alkaline treatment was employed to systematically investigate characteristics of excess sludge hydrolysis and acidification with alkaline treatment and evaluate feasibility of recovering a carbon source (C-source) from excess sludge to enhance nutrient removal at ambient temperature. The resulting C-source and volatile fatty acid specific yields reached 349.19 mg chemical oxygen demand (COD)/g volatile suspended solids (VSS) d⁻¹ and 121.3 mg COD/g VSS d⁻¹, respectively, the process had excellent C-source recovery potential. The propionic-to-acetic acid ratio of the recovered C-source was 3.0 times that in the influent, which beneficially enhanced biological phosphorus removal. Large populations and varieties of hydrolytic acid producing bacteria cooperated with alkaline treatment to accelerate sludge hydrolysis and acidification. Physicochemical characteristics indicated that recovered C-source was derived primarily from extracellular polymeric substances hydrolysis rather than from cells disruption during alkaline treatment. This study showed that excess sludge as carbon source was successfully recycled by alkaline treatment in the process.

     

嵌入式旁路污泥减量污水处理系统研究

为了减少活性污泥工艺中剩余污泥的产量以及解决目前污水处理厂无机物积累的问题,开发了一种集旁路污泥减量、污泥淤砂分离、侧流化学除磷、强化氮磷去除于一体的嵌入式旁路污泥减量污水处理系统,中试反应器规模10m3/d,并稳定运行超过90d.试验结果表明:出水ρ(NH4+-N)、ρ(TN)、ρ(TP)、ρ(COD)分别为(0.5±0.3),(8.6±1.6),(0.14±0.04),(26.8±8.8)mg/L,出水水质能够稳定的达到一级A标,并且远低于其限值.系统运行期间,活性污泥系统的MLVSS/MLSS值逐渐升高,其值从初始的0.33增加到了0.52;该工艺系统有效的防止了无机颗粒在活性污泥系统中的积累.在系统稳定运行过程期间,其表观产率系数Yobs为0.103gVSS/gCOD,该工艺系统展示了良好的污泥减量性能.