为了了解熟化发酵污泥的性能及挖掘其剩余有机碳源和能源,向熟化发酵污泥中投加Na Cl与Na OH对熟化发酵污泥再发酵。通过投加0、5、15、20 g/L Na Cl,分别考察不同盐度对熟化发酵污泥再发酵性、内碳源再提取情况及脱水性的影响。结果表明:在发酵初期,5、15及20 g/L Na Cl试验组与0 g/L Na Cl试验组相比均可以促进熟化发酵污泥EPS释放且生成挥发性脂肪酸,其中熟化发酵污泥再发酵与原熟化发酵污泥相比水解率可提高36%,酸化率可提高34%,氨化率可提高40%。发酵后期5 g/L试验组与0、15及20 g/L Na Cl试验组相比加速EPS和可挥发性脂肪酸分解,同时发现,NH+4-N含量随着盐度提高而增加,PO3-4-P含量随着盐度浓度的增大而降低。熟化发酵污泥再发酵后5g/L Na Cl条件下可改善发酵污泥脱水性,15及20 g/L条件下恶化了发酵污泥脱水性。
The effect of salinity on sludge alkaline fermentation at low temperature(20°C) was investigated, and a kinetic analysis was performed. Different doses of sodium chloride(Na Cl, 0–25 g/L) were added into the fermentation system. The batch-mode results showed that the soluble chemical oxygen demand(SCOD) increased with salinity. The hydrolysate(soluble protein, polysaccharide) and the acidification products(short chain fatty acids(SCFAs), NH+4–N, and PO_4^(3-)–P) increased with salinity initially, but slightly declined respectively at higher level salinity(20 g/L or 20–25 g/L). However, the hydrolytic acidification performance increased in the presence of salt compared to that without salt.Furthermore, the results of Haldane inhibition kinetics analysis showed that the salt enhanced the hydrolysis rate of particulate organic matter from sludge particulate and the specific utilization of hydrolysate, and decreased the specific utilization of SCFAs. Pearson correlation coefficient analysis indicated that the importance of polysaccharide on the accumulation of SCFAs was reduced with salt addition, but the importance of protein and NH+4–N on SCFA accumulation was increased.
