中小型石材企业污水处理系统研究及其沉淀池设计

发布时间：2018-01-02 06:25

本文关键词：中小型石材企业污水处理系统研究及其沉淀池设计　出处：《山东大学》2017年硕士论文　论文类型：学位论文

【摘要】：石材加工的过程中,为了减小刀头损耗,改善加工质量,需要用到大量的水对锯机进行冷却,由此产生大量石材加工污水。污水中含有高浓度的石粉以及冷却剂等化学添加剂。我国规定,石材加工企业必须配备污水净化处理与循环利用设备,以实现石材污水的重复使用,节约水资源,保护环境。本课题结合中小型石材加工企业污水处理的现状,对石材污水的物理化学特性进行了研究,针对石材污水处理中最重要的沉淀环节,通过试验与数值仿真结合的方法进行了深入分析。本课题的研究可促进石材污水处理技术的发展,具有很大的意义。对石材加工污水的污染物成分进行了分析,调研并测量了多家石材加工企业污水的SS(悬浮颗粒物浓度)、浊度及石粉粒径分布,对石材污水的几个重要的物理化学性质有了基本认识。通过石材污水的烧杯絮凝试验和量筒沉降试验,总结发现不同SS的最佳絮凝剂投放量规律。对于不同浓度的污水,其对应不同的PAC与PAM最佳投放量。PAC随SS的变化关系为y=3.482e-14x.471+194.6,PAM随SS的变化关系为y=6.964e-14x.471+3.929。在最佳絮凝剂投放量下,最终的处理结果与石材污水的初始浓度无关。在最佳絮凝剂用量下,不同SS的石材污水的沉降速度介于3.8mm/min～7.8mm/min之间,沉降4小时后污泥体积约为污水总体积的16%～17%。建立了石粉沉降过程的数学模型,利用CFD软件对沉淀池的内部流场进行了研究,对其结构尺寸进行了优化设计。采用RNGk-ε多相流模型,对沉淀池的石粉运动规律、湍流结构和石粉颗粒的浓度分布进行了仿真模拟,从微观角度揭示了沉降池的结构和尺寸对沉降效果的影响规律。并针对某中等规模的石材加工企业的参数进行了沉淀池的设计与优化,使优化后的沉淀池比经验法沉降效率提高了 3.4%,深度降低了 6.7%。
[Abstract]:In the process of stone processing, in order to reduce the head loss and improve the processing quality, a large amount of water is needed to cool the sawing machine. As a result, a large number of stone processing sewage. Sewage contains high concentration of stone powder and coolant and other chemical additives. In China, stone processing enterprises must be equipped with sewage purification and recycling equipment. In order to realize the reuse of stone wastewater, save water resources and protect the environment. This paper studies the physical and chemical characteristics of stone wastewater in combination with the present situation of sewage treatment in small and medium-sized stone processing enterprises. In view of the most important sedimentation link in stone sewage treatment, the method of combining experiment and numerical simulation is used to deeply analyze. The research of this subject can promote the development of stone sewage treatment technology. It is of great significance. The pollutant composition of stone processing sewage is analyzed, and the SS (suspended particle concentration, turbidity and particle size distribution of stone powder) in the sewage of many stone processing enterprises are investigated and measured. Some important physical and chemical properties of stone wastewater are basically understood. The flocculation test of stone wastewater with beaker and the settling test of measuring tube are carried out. It is found that the best flocculant quantity of different SS is the same as that of wastewater of different concentration. The relationship between the optimal dosage of PAC and PAM with SS was 3.482e-14x.471.194.6. The change of PAM with SS is 6.964e-14x.471.3.929. under the optimum dosage of flocculant. The final treatment results have nothing to do with the initial concentration of stone wastewater. Under the optimum dosage of flocculant, the settling velocity of stone wastewater with different SS is between 3.8 mm / min and 7.8 mm / min. After settling for 4 hours, the sludge volume was about 16 / 17 of the total volume of sewage. The mathematical model of the sedimentation process of stone powder was established, and the internal flow field of the sedimentation tank was studied by CFD software. The RNGk- 蔚 multiphase flow model was used to simulate the movement of stone powder, the turbulent structure and the concentration distribution of stone particles in the sedimentation tank. From the microscopic point of view, the influence of the structure and size of the settling tank on the settlement effect is revealed, and the design and optimization of the sedimentation tank are carried out according to the parameters of a medium scale stone processing enterprise. The results show that the sedimentation efficiency of the optimized sedimentation tank is increased by 3.4 and the depth of the sedimentation tank is decreased by 6.7 than that by the empirical method.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X799.1

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