丝状真菌调理对柠檬酸污泥脱水性能的影响

利用实验室分离的丝状真菌Aspergillus niger SS5对柠檬酸污泥进行了污泥脱水前的生物调理.结果表明，菌液浓度和调理时间是影响污泥脱水性能的主要因素，调理后污泥的脱水性能、沉降性能均有明显改善，调理后的污泥负电荷减少，粒径显著增大，结合水含量比未投加菌液的空白对照降低了近40%.同时，真菌调理显著降低了上清液COD及污泥各EPS层的蛋白质和多糖含量，EPS中蛋白质的降解与污泥结合水含量、D₅₀和Zeta电位显著相关，是影响柠檬酸污泥脱水性能改善的重要因素，且有机物的降解并未导致污泥pH值的显著变化，这和柠檬酸污泥拥有较大的酸碱缓冲容量有关.采用20mL/g DS的Aspergillus niger SS5调理柠檬酸污泥，调理3d可使泥饼含水率降至71.98%，且调理过程无化学药剂加入，更有利于柠檬酸等食品发酵类工业污泥的后续资源化综合利用.

The effects on citric acid sludge dewatering with filamentous fungi conditioning

The citric acid sludge was conditioned biologically with the separated filamentous fungi Aspergillus niger SS5 before dewatering in the paper. Results showed that fungi concentration and conditioning time both had strong effects on the sludge dewaterability, and the performance of sludge dewatering and settlement were improved significantly. Combined with the analysis of Zeta, particle distribution and bound water concentration, it was observed that negative charge of sludge decreased accompanied by obviously increasing particle size. The concentration of bound water had a reduction of approximate 40% to the control sample without fungi conditioning. Meanwhile, the concentrations of COD in supernatant and protein and polysaccharide in each EPS layer were all decreasing during the sludge conditioning with fungi. There were significant correlations between protein degradation in EPS and bound water content, D₅₀ and Zeta potential, which indicated it was the important factor affecting citric acid sludge dewaterability. Due to the large pH buffering capacity of citric acid sludge, the great pH change was not observed during the decomposition of organic matter in sludge. 71.98% water content of the dewatered sludge cake was obtained with 20mL/g DS Aspergillus niger SS5 conditioning for 3d without chemical additives. It should make for further resource utilization of these food fermentation sludge as citric acid sludge.