温度对微好氧消化处理高含固厌氧消化污泥的影响

TEMPERATURE'S EFFECT ON TREATMENT OF HIGH-SOLID ANAEROBICALLY DIGESTED SLUDGE USING MICRO-AEROBIC DIGESTION

采用微好氧消化对高含固厌氧消化污泥进行后处理,考察了在常温、中温及高温条件下反应器的运行性能以及污泥植物毒性的改善。结果表明:在污泥停留时间为8 d,供气量为2.4 L/min的微氧条件下,高含固厌氧消化污泥VS进一步降解,比耗氧速率降低,挥发性脂肪酸及氨氮等小分子物质浓度显著降低,污泥趋于更加稳定的状态。随着处理温度的提高,污泥VS、比耗氧速率和总氨氮呈逐渐下降趋势。种子发芽实验表明:经微好氧消化处理后,污泥对向日葵、矢车菊、牵牛花等种子发芽的抑制作用均逐渐下降,说明微好氧消化有利于改善高含固厌氧消化污泥的植物毒性。而且随着处理温度的增加,处理后污泥的植物毒性呈增加趋势,这可能与挥发性脂肪酸含量的增加有重要关系。总体看来,与常温和高温条件相比,中温微好氧消化是改善高含固厌氧消化污泥土地利用性能更为可行的工艺。

Micro-aerobic digestion was used to treat high-solid anaerobically digested sludge（ ADS） further. Treatment performance and sludge ＇s phyto-toxicity improvement during the process were investigated at ambient,mesophilic and thermophilic condition. Results showed that high-solid anaerobically digested sludge achieved further stabilization,with further VS removal,SOUR reduction and lower content of VFA and ammonia nitrogen,under micro-aerobic condition of the aeration rate of 2. 4 L / min and SRT of 8 days. As the temperature rised,VS,SOUR and total ammonia nitrogen in the sludge tended to decline gradually. The germination tests showed that weakened inhibition of sludge to the germination of sunflower,cornflower and purple morning glory was found after micro-aerobic digestion treatment,implying that micro-aerobic digestion was effective to improve the phyto-toxicity of ADS. Further,the phyto-toxicity of micro-aerobically digested sludge increased with the increase of temperature,which may realate to higher VFA concentration. In general,the mesophilic micro-aerobic digestion was a more feasible process to improve the land-utilization quality of high-solid anaerobically digested sludge.