Abstract:

To promote the process of resource utilization of sludge incineration, this article used bituminous coal to mix activated sludge, and then the electro-dewatering performance of the mixed sludge was studied. The variations of physical and chemical properties, organic properties, and low calorific value of mixed sludge during the electro-dewatering process were examined. The results showed that the dewatering content of sludge first increased and then decreased with the increase in bituminous coal dosage. When the optimal coal dosage was 50%DS, the moisture content of the mixed sludge decreased from 81%±0.8% to 50.1%±0.6%, and the dewatering time was shortened by 30.8% compared to no-mixed sludge. Mixing bituminous coal could improve the conductivity and Ohmic heating effect of sludge, thereby improving the dewatering efficiency. The moisture content of sludge was highly correlated with the content of hydrophilic amino acids such as threonine, serine, histidine, glutamic acid, and hydrophobic amino acids such as valine (|r|>0.883, p<0.05). Electro-dewatering after mixing bituminous coal could reduce the content of hydrophilic amino acids and oxygen-containing functional groups in the sludge cake, improving the hydrophobicity of the sludge. After the electro-dewatering of mixed sludge, the low calorific value of sludge cake was increased by more than 60% compared to the no-mixed electro-dewatering treatment. This result was helpful for the subsequent resource utilization of mixed combustion of sludge and coal.

Key words: sludge, electro-osmosis, dewaterability, drying, resource utilization, environment

摘要：

为推进污泥焚烧资源化利用进程，本文采用烟煤对活性污泥进行掺混，然后对掺混污泥的电脱水性能进行了研究，考察了掺混污泥在电脱水过程中的理化性质、有机性质和低位热值的变化。结果表明：污泥的脱水量随烟煤掺混量的增加呈先增大后减小的趋势。最佳煤粉掺混量50%污泥干重时，掺混污泥的含水率由81%±0.8%降至50.1%±0.6%，脱水时间较无掺混缩短30.8%；烟煤掺混可提高泥饼的电导率和欧姆热效应，从而提高脱水效率。污泥含水率与亲水性氨基酸苏氨酸、丝氨酸、组氨酸、谷氨酸及疏水性氨基酸缬氨酸的含量呈高度相关（|r|>0.883，p<0.05）。烟煤掺混后电脱水可降低泥饼亲水性氨基酸和含氧官能团含量，提高污泥疏水性能。掺混污泥电脱水后泥饼的低位热值较无掺混电脱水处理提高60%以上，有助于后续污泥和煤混烧资源化利用。

关键词: 污泥, 电渗透, 脱水性能, 干燥, 资源化, 环境