污泥脱水性能的中试试验研究

发布时间：2017-12-31 01:06

本文关键词：污泥脱水性能的中试试验研究　出处：《合肥工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着城市污水处理设施的增加,产泥量也越来越大,各污水处理厂的污泥含水率一般在98%左右,其数量巨大,即使用带式压滤机将含水率降低至80%,仍然占据较大面积,再加之成分复杂,对污泥的安全处置迫在眉睫,为了大幅度降低污泥含水率,做到污泥减量化,以某水厂的污泥高干脱水工程装置,研究几种化学改性剂在不同配比下对储泥池污泥的改性,然后结合隔膜式压滤系统进行高干脱水以进一步降低污泥含水率。研究表明：在低压进料压力0.3MPa,高压进料压力0.8MPa,最高压榨压力1.3MPa,压榨时间为40-50min的情况下,亚铁盐与铁盐、熟石灰、PAC, PAM等化学药剂单一或者组合处理可以改善剩余活性污泥(含水率约98%)的脱水性能,改性后的污泥经隔膜压滤后极大的降低了体积,对工程应用具有一定指导意义。化学改性是一种有效的污泥预处理技术,实验结果表明,化学改性处理后脱水泥饼含水率可降至50%左右,完全满足污泥后续填埋、土地利用对含水率低于60%的要求。使用单一化学药剂处理污泥,改性效果一般上比药剂复配的效果较差。污泥脱水中石灰的作用不可忽视,单掺石灰后污泥含水率最低可以降至61%;PAM可以较大幅度的增大污泥絮体,PAM投加量从0.2%增加到0.6%,压滤出的泥饼含水率维持在64%左右,污泥比阻值随着PAM量的增加,先减小后慢慢增大。低投加量的PAC虽对污泥含水率降低的贡献率不大,但增加PAC用量延长总的进料时间,提升板框单位处理能力。利用Design Expert软件对实验结果模拟,得出理论最佳用量为：6.5%PAC+0.25%PAM+10%CaO,通过比较F值,可以判断各药剂对目标效果的影响。对于不同性质的污泥,化学药剂复配的组合要根据对污泥改性效果做出选择,工程应用上也要根据污泥的不同性质甄选改性工艺,使用合理的改性药剂。板框压滤的污泥晾晒1-2天后,污泥含水率可降至50%以下,且为防止臭味,晾晒1-2天后应及时拉走或处置。该污泥适于土地改良,混合填埋以及水泥建筑材料利用。滤液可直接排入污水厂进水泵房,对进水水质几乎没有影响。
[Abstract]:With the increase of municipal sewage treatment facilities, sludge production is also increasing. The sludge moisture content of sewage treatment plants is generally about 98%, its quantity is huge, even if the water content is reduced to 80% by belt filter press. Still occupy a large area, plus complex components, the safe disposal of sludge is urgent. In order to reduce the sludge moisture content significantly, to achieve sludge reduction, a water plant sludge high dry dewatering plant. The modification of sludge in sludge storage tank by several chemical modifiers at different ratios was studied. Then high dry dewatering was carried out with diaphragm pressure filtration system to further reduce sludge moisture content. The results showed that at low pressure feed pressure of 0.3 MPA, high pressure feed pressure was 0.8 MPA. The maximum pressing pressure was 1.3 MPA, the pressing time was 40-50 min, ferrous salt and iron salt, lime PAC. Single or combined treatment of chemical agents such as PAM can improve the dehydration performance of excess activated sludge (moisture content is about 98%), and the volume of modified sludge is greatly reduced after membrane pressure filtration. Chemical modification is an effective pretreatment technology for sludge. The experimental results show that the moisture content of decement cake can be reduced to about 50% after chemical modification. Fully meet the sludge landfill, land use of water content less than 60% requirements, the use of a single chemical treatment of sludge. The function of lime in sludge dewatering can not be ignored, and the minimum moisture content of sludge can be reduced to 61after adding lime. PAM can greatly increase the amount of sludge floc from 0.2% to 0.6, the sludge cake moisture content is maintained at about 64%, and the sludge specific resistance value increases with the increase of PAM content. The low dosage of PAC contributed little to the decrease of sludge moisture content, but increased the amount of PAC to prolong the total feed time. Using Design Expert software to simulate the experimental results, the best theoretical dosage is: PAC 0.25 PAM 10O. By comparing F value, we can judge the effect of each agent on the target effect. For sludge with different properties, the combination of chemical agents should be selected according to the effect of sludge modification. In engineering application, the modification process should be selected according to the different properties of sludge, and reasonable modification agents should be used. After drying sludge for 1-2 days, the moisture content of sludge can be reduced to less than 50%, and in order to prevent stink. The sludge is suitable for land improvement, mixed landfill and the use of cement construction materials. The filtrate can be directly discharged into the sewage treatment plant into the pump room, and has little effect on the water quality.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X703

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