剩余污泥采用碱热联合预处理时,研究不同处理温度、时间、碱投加量对污泥性质的影响。结果表明:随着处理温度的升高和处理时间的延长。污泥上清液中可溶性COD(SCOD)浓度不断增加,污泥中固体物质溶解,污泥量减少;而碱的使用,增加了SCOD的溶出。经170℃、30min处理后。SCOD溶出率为43.64%,挥发性悬浮固体(VSS)/总悬浮物(TSS)降低至31.98%,污泥的离心含水率减少为77.43%;加入0.10g碱(NaOH,投加以每克挥发性固体(VS)计)后,SCOD溶出率、VSS/TSS和污泥离心含水率分别为69.10%、24.05%和69.73%。水热处理后,上清液色度增加,厌氧消化性能提高,然而温度过高、碱投加量过大时,生成的中间产物在一定程度上抑制厌氧消化。
The alkaline thermal hydrolysis was applied for pretreatment of excessive sludge. Effect of treatment temperature, treatment time and alkali dosage on the characteristics of the excessive sludge was investigated. The results showed that the concentration of SCOD in the sludge supernatant increased with the increasing of hydrothermal temperature and treatment time, the solid substance in sludge was dissolved and the sludge amount reduced during the treatment process. The presence of alkali improved the dissolution of SCOD. After treating at 170 ℃ for 30 min, the SCOD dissolution ratio was 43.64%, VSS/TSS decreased to 31.98% and the moisture content of sludge decreased to 77.43%; When adding certain alkali (0.10 g NaOH per gram VS) in excessive sludge, the SCOD dissolution ratio, VSS/TSS and moisture content changed to 69.10 %, 24.05 % and 69.73 % respectively. After hydrothermal pretreatment, the chroma of supernatant greatly increased, and anaerobic digestion performance improved. However, when alkaline thermal hydrolysis conducted under high temperature or with excessive alkali, the generated intermediate products would inhibit anaerobic digestion.