【作者】 徐华成；

【导师】 徐晓军；

【作者基本信息】 青岛理工大学 ， 环境工程， 2008， 硕士

【摘要】 城市污水处理厂排放的剩余污泥因有机物含量高,颗粒较细,含水率高,难以脱水沉降。洗煤废水含大量的煤泥颗粒,悬浮物和浊度高,表面带负电荷,颗粒稳定,难以自然沉降。目前,对剩余污泥和洗煤废水的处理多采用絮凝沉淀法,但该法需要的絮凝剂投加量大,絮凝剂成本高。本试验将微波技术和絮凝技术组合起来形成微波絮凝组合技术处理剩余污泥和洗煤废水,减少了絮凝剂投加量,降低了絮凝剂处理成本,试验取得了理想效果。试验考察了单一Al₂（SO₄）₃和PAC两种絮凝剂对剩余污泥和洗煤废水的处理效果,并确定了单一絮凝剂作用时的最佳投加量。研究了微波辐射时间、微波功率、pH值等因素对处理效果的影响,确定了各因素的最佳组合。试验对污泥脱水性能、滤液浊度、滤饼含水率、洗煤废水浊度、Zeta电位等进行了研究,进一步探讨了絮凝机理和絮体沉淀机理,分析了微波絮凝组合技术处理剩余污泥和洗煤废水的机理。试验结果表明:（1）当用Al₂（SO₄）₃絮凝剂处理剩余污泥和洗煤废水时,单一絮凝剂作用时最佳投加量分别为1.25g/L和1.188g/L。若用微波絮凝组合技术作用时,絮凝剂投加量可分别降至0.50g/L和0.375g/L。（2）当用PAC絮凝剂处理剩余污泥和洗煤废水时,单一絮凝剂作用时最佳投加量均为0.50g/时。若用微波絮凝组合技术作用时,絮凝剂投加量可分别降至0.10g/L和0.20g/L。（3）洗煤废水颗粒Zeta电位为-9.23mV,Zeta电位随絮凝剂投加量的增加而增大,当达到等电点时,PAC投加量为0.50 g/L,Al₂（SO₄）₃投加量为0.65g/L。（4）絮体沉速ν与颗粒密度ρ_s、液体密度ρ_L、絮体直径d、液体粘度μ等有关,增大颗粒密度和絮体直径,减小液体粘度等均能提高絮体沉降速度。（5）用微波絮凝组合技术处理剩余污泥和洗煤废水时,微波的热效应和非热效应特性均各自得到了充分的发挥。（6）微波辐射使得颗粒运动速度增大,絮凝剂网捕的颗粒物数量增多,絮体粒径增大,有利于絮体沉降。（7）微波具有高效热效应,普通加热与絮凝组合技术对洗煤废水的除浊效果远不如微波加热与絮凝组合技术对洗煤废水的除浊效果。适宜的微波辐射可以引起污泥颗粒的加速运动,促使污泥结构脱稳,改善污泥的沉降及脱水性能,但过大的微波辐射使得微生物细胞结构过度破坏,导致污泥胞内物质的大量溢出,黏度增大,沉降及脱水性能恶化。（8）用微波辐射处理剩余污泥时,可明显提高污泥上清液的可生化性,便于后续处理。微波絮凝组合技术是一种全新的废水处理工艺,国内外尚未见有文献报道,该工艺充分发挥了微波的特性,可以减少絮凝剂投加量,降低絮凝剂处理成本,具有较高的理论价值和现实意义,建议进一步中试试验研究时,考虑该组合技术在实际运行过程中的可操作性和经济性。试验所用污泥为生活污水处理厂的剩余污泥,因此该工艺对于非生活污水剩余污泥处理的适用性还需进一步研究。更多还原

【Abstract】 The excess sludge of municipal sewage treatment plant has the characteristics of high content organic compounds,thin grain, high rate of aquifer, difficult to sedimentation and dehydration. The coal-washing wastewater has lots of grains, high concentration of suspended substance and turbidity, the surface has minus charge, the grains was steady and difficult to subside.At present, the excess sludge and coal-washing wastewater are almost disposeed by flocculation and sedimentation,but that need large dosage of flocculant and high cost of flocculant.In this experiment, we combined microwave technology with flocculation technology to deal with excess sludge and coal-washing wastewater,reduced the dosage and cost of flocculant,. The experiment obtained the ideal intentions.The experiment investigated the effects of solo-Al₂（SO₄）₃ and PAC on excess sludge and coal-washing wastewater, and confirmed the best dosage of flocculant, It also researched the affects of microwave irradiation time、microwave power、pH value, confirmed the best combination of all factors. The experiment also investigated dehydration performance of sludge、turbidity of filtrate、moisture content、turbidity of coal-washing wastewater and Zeta potential, discussed the mechanism of flocculation and sedimentation, and in the last,discussed the mechanism of microwave and flocculation on excess sludge and coal-washing wastewater.the result of experiment indicated:（1） When used Al₂（SO₄）₃ to treat excess sludge and coal-washing wastewater, the best dosage of solo-agent was 1.25g/L and 1.188g/L, and when used combinatorial technique of microwave and flocculation, we can reduce the dosage of flocculant to 0.50g/L and 0.375g/L.（2） When used PAC to treat excess sludge and coal-washing wastewater,the best dosage of solo-agent was 0.50g/L, and when used combinatorial technique of microwave and flocculation, we can reduce the dosage of flocculant to 0.10g/L and 0.20g/L.（3）The Zeta potential of coal-washing was -9.23mV,the Zeta potential was augmented when the dosage of flocculant was increased. When reached isoelectric point,the dosage of PAC was 0.50 g/L, the dosage of Al₂（SO₄）₃ was 0.65 g/L.（4） The sedimentation speed of floc was related withρ_s、ρ_L、the diameter offloc、viscosity of liquid,when increased the density of grain, increased the diameter of floc, minished the viscosity of liquid, the sedimentation rate of floc can be enhanced.（5）When treated excess sludge and coal-washing wastewater with combinatorial technique of microwave and flocculation, the thermal effects and non-thermal effects of microwave played the adequate roles respectively.（6）Microwave irradiation can increase the speed of grain, the amount of grains neted by flocculant and the diameter of flocs, all of these were propitious to sedimentation of flocs.（7）Microwave has efficient thermal effects,the removeal efficiency of coal-washing wastwater with combinatorial technique of common calefaction and flocculation was worse than combinatorial technique of microwave calefaction and flocculation. Fit microwave irradiation can increase the speed of grain, reduce the stability of sludge, ameliorate the performance of sedimentation and dehydration,but excessive microwave irradialization can cause the destroy of cytoarchitecture of microbe, bring on the overflow of substance in the cell, increase the viscosity, deteriorate the performance of sedimentation and dehydration.（8）When treated excess sludge with combinatorial technique of microwave and flocculation,the biodegradability of supernatant of sludge was enhanced, so was easy for follow-up treatment.The combinatorial technique of microwave and flocculation is fire-new waste water treatment technics, and there is no report in the literature at home and abroad,the technics exert the characteristic of microwave sufficiently, reduce the dosage and cost of flocculant, so it possess high theoretical value and practical significance, when commence pilot study in the future, the operability and economicly of the technics should be considered.the sludge in the experiment was the excess sludge of urban sewage treatment plant, so the applicability of the technics on excess sludge of non-domestic sewage should be researched further more.更多还原