热碱处理破解污泥效果研究

Investigation on Sludge Hydrolysis by Alkaline-Thermal Treatment

利用碱热方法对污泥进行预处理,研究了污泥的破解效果及主要影响因素。研究表明:随着热水解处理温度的升高及时间延长,污泥上清液中的溶解性化学需氧量(SCOD)、氮(N)、磷(P)等浓度不断增加,而碱的使用提高了SCOD,N,P等的溶出率,且NaOH破解效果明显优于Ca(OH)2。污泥经90°C处理5 h后,单独热水解、加NaOH和加Ca(OH)2预处理后的SCOD溶出率分别达到了23.1%,54.4%和32.5%;N的释放主要以有机氮为主,P的释放则是以正磷酸盐为主。碱热联合处理时污泥减量化效果突出,对污泥脱水性能影响显著,90°C时污泥中每克挥发性固体(VS)投加0.2 g Ca(OH)2处理5 h,污泥离心含水率可达75.7%。

Effects of alkali-heat pretreatment on sludge hydrolysis arid its influencing factors were studied. The results showed that the SCOD, N and P in the supernatant increased with increasing temperature and time. The dissolution rate of SCOD, N and P in the supernatant improved by adding the base, and NaOH has higher efficiency than C a（OH）2. At the temperature of 90℃ and after 5 hours, the dissolution ratio of SCOD after thermal hydrolysis, NaOH and Ca （OH）2 pretreatment was 23.1%, 54.4% and 32.5%, respectively. The released nitrogen was mainly organic nitrogen, and orthophosphate was the main component of the released phosphorus. Sludge reduction effect was prominent and the dewaterability greatly changed when combined alkaline and thermal hydrolysis, the water content of the sludge reduced to 75.7% on the conditions of temperature 90℃, Ca（OH）2/VS 0.20 and treatment time 5 hours.