不同预处理对超磁分离污泥水解产酸效果的影响研究

The Study on Influencing of Hydrolysis and Acidification of Ultra-magnetic Separation Sludge

超磁分离污泥是以磁絮凝反应和磁种回收为核心技术,通过超磁分离机浓缩排出的污泥。污泥具有有机质浓度高、结构紧密等特点。该研究以超磁污泥为研究对象,通过批式试验考察了NaOH,H_(2)O_(2)和Fe预处理后污泥水解酸化的效果以及溶解性有机物特征。结果表明,NaOH预处理加速了污泥的水解酸化,提高了可溶性物质的含量。NaOH处理组的SCOD、溶解性蛋白质、溶解性碳水化合物浓度最高,分别达到8974.5 mg·L^(-1),808.3 mg·L^(-1)和186.0 mg·L^(-1)。同时,VFAs的含量在第6天可以达到最高值,为3505.7 mg·L^(-1)。其中,乙酸含量最高为2124.5 mg·L^(-1),占比67.7%;相较而言,Fe,H_(2)O_(2)处理组丙酸占比逐渐增加,未处理污泥发酵类型从混合型转化为丙酸型。超磁污泥在水解酸化过程中获得内碳源的同时还伴随着N和P的释放,NaOH处理组NH^(+)_(4)-N及PO^(3-)_(4)释放最明显。

The ultra-magnetic separation sludge was the sludge thickened and discharged by ultra-magnetic separator with magnetic flocculation reaction and magnetic seed recovery as the core technology.The sludge was characterized by high concentration of organic matter and compact structure.In this study,the effect of hydrolytic and acidification of ultra-magnetic sludge after NaOH,H_(2)O_(2) and Fe pretreatment and the characteristics of dissolved organic matter were investigated by batch tests.The results showed that NaOH pretreatment accelerated the hydrolytic and acidification of sludge and increased the content of dissolving organic matter compared with H_(2)O_(2) and Fe pretreatment.The concentrations of SCOD,dissolved protein and dissolved carbohydrates were highest,reaching 8974.5 mg·L^(-1),808.3 mg·L^(-1),and 186.0 mg·L^(-1),respectively.Meanwhile,the concentration of VFAs could reach the highest value on the 6th day,at 3505.7 mg·L^(-1).Among them,the highest concentration of acetic acid was 2124.5 mg·L^(-1),accounting for 67.7%.However,the percentage of propionic acid in Fe and H_(2)O_(2) treatment groups gradually increased,and the fermentation type of untreated sludge was transformed from mixed-type to propionic-type,which was not favorable for hydrolytic acidification.The release of N and P was accompanied by the acquisition of internal carbon source during the hydrolytic acidification of ultra-magnetic sludge,and the release of NH^(+)_(4)-N and PO^(3-)_(4) was most obvious in the NaOH treatment group.