河流底泥重金属浓度与粒径分布规律及脱水剂优化研究

发布时间：2018-07-05 18:17

本文选题：底泥 + 泥质　；参考：《青岛理工大学》2015年硕士论文

【摘要】：我国污水处理设施的建设滞后于城市发展和工业企业扩张,使得很多河流和湖泊被污染。目前,我国大多数污染河流的综合治理措施是先控制外源污染,然后采用底泥疏浚的方法治理内源污染。在山东省水环境外源污染逐渐得到控制的前提下,我省将环境治理的工作重点转向对底泥这种内源污染源的治理上。本研究以山东省内四条典型污染河流柱状样底泥(沙质、泥质)为研究对象,通过探究不同泥质重金属污染底泥粒径分布与重金属富集之间的规律,结合不同资源化处置利用途径对重金属含量的限值要求,针对不同河流的疏浚底泥提出相应的资源化利用途径。在此基础上,以三条典型污染河流的表层底泥(沙质、泥质、泥沙混合质)为研究对象,采用污泥比阻作为脱水效果的考察指标,探究几种典型脱水药剂在不同投加量下对各泥质类型底泥脱水性能的影响,通过正交实验确定优选脱水药剂在不同工况下的最优投加量,最终通过两方面研究为疏浚底泥的资源化利用和减量化提供技术支持。本文的主要研究结论如下:(1)典型河流底泥重金属分布规律研究结果表明:泥质底泥以粒径150μm以下的泥沙为主,沙质底泥以粒径150μm以上的泥沙为主;重金属污染物随底泥颗粒粒径的减小,对污染物的吸附能力也随之有不同程度的提高;泥质底泥的重金属主要集中在粒径75μm以下的底泥中,沙质底泥的重金属主要集中在粒径300μm以下的底泥中。(2)湿筛后底泥重金属分布规律及资源化利用途径研究结果表明:对典型河流底泥湿筛后,各粒径的重金属含量均有不同程度的降低,如果只考虑重金属含量对底泥资源化利用途径的影响,娄山河的重金属污染底泥适于制砖,筛分粒径目标为150μm;墨水河泥质底泥适于制砖,沙质底泥粒径在600μm以上的底泥适于农用,粒径在150μm以上的底泥适于园林利用和土地改良,粒径在75μm以上的底泥适于制砖;沂河的重金属污染底泥适于制砖,筛分粒径目标为38μm;小清河的重金属污染底泥可以用于园林利用、土地改良和制砖。(3)不同泥质类型河流底泥脱水药剂单因素优化筛选实验结果表明:针对本实验中所考察的三条河流底泥,无机絮凝剂建议选择PAFC(聚合氯化铝铁)或PAC(聚合氯化铝),其中PAFC的最佳投加量为干泥质量的0.4%~1.2%,PAC的最佳投加量为干泥质量的0.8%~1.6%;有机高分子絮凝剂建议选择CPAM(阳离子聚丙烯酰胺),最佳投加量为干泥质量的0.01%~0.04%;在各絮凝剂最优投加条件下,泥质底泥的脱水性能提高最为明显,其比阻最大可下降86%,泥沙混合质底泥污泥比阻最大可下降82%,沙质底泥污泥比阻则最大可下降65%。(4)不同泥质类型河流底泥脱水药剂正交实验结果表明:优选脱水剂在不同工况下的最优投加量为:PAC的投加量控制在干泥质量的1.2%,PAFC的投加量控制在干泥质量的0.8%,CPAM的投加量控制在干泥质量的0.02%~0.03%。
[Abstract]:The construction of sewage treatment facilities in China lags behind the urban development and the expansion of industrial enterprises, which pollutes many rivers and lakes. At present, the comprehensive control measures of most polluted rivers in China are to control the exogenous pollution first, and then to control the internal pollution by dredging the sediment. On the premise of gradually controlling the external pollution of the water environment in Shandong Province, the emphasis of environmental control in Shandong Province is shifted to the treatment of the internal pollution source of sediment. In this study, four typical polluted rivers in Shandong province were studied. The distribution of sediment particle size and the accumulation of heavy metals were studied. According to the limit requirement of heavy metal content in different ways of disposal and utilization of resources, the paper puts forward the corresponding ways of resource utilization for dredged sediment of different rivers. On this basis, the surface sediment (sand, sediment mixture) of three typical polluted rivers is taken as the research object, and the specific resistance of sludge is used as the index to investigate the dewatering effect. The effects of several typical dewatering chemicals on the dewatering performance of various mud types under different dosages were investigated. The optimum dosage of the selected dewatering chemicals under different working conditions was determined by orthogonal experiment. Finally, it provides technical support for the reuse and reduction of dredged sediment through two aspects. The main conclusions of this paper are as follows: (1) the distribution of heavy metals in sediment of typical river shows that sediment with diameter less than 150 渭 m is the main sediment, and sediment with diameter of more than 150 渭 m is the main sediment. With the decrease of sediment particle size, the adsorption capacity of heavy metal pollutants increases in varying degrees, and the heavy metals of mud sediment are mainly concentrated in sediment with particle size below 75 渭 m. Heavy metals in sandy sediment are mainly concentrated in sediment with diameter below 300 渭 m. (2) the distribution of heavy metals in sediment after wet sieve and the way of utilization of resources are studied. The results show that: after wet sieve of typical river sediment, The heavy metal content of each particle size is reduced in varying degrees. If only the influence of heavy metal content on the utilization of sediment is considered, the heavy metal contaminated sediment in Loushan River is suitable for brick making. The sieving size is 150 渭 m, the sediment of the ink river is suitable for making bricks, the sediment with the diameter of more than 600 渭 m is suitable for agriculture, the sediment with the diameter of more than 150 渭 m is suitable for garden use and land improvement, and the sediment with the diameter of more than 75 渭 m is suitable for making bricks. The heavy metal contaminated sediment of Yihe River is suitable for brick making, and the sieving size target is 38 渭 m, and the heavy metal contaminated sediment of Xiaoqing River can be used in gardens. Land improvement and brick making. (3) the results of single factor optimization screening of dewatering agent in river sediment of different muddy types show that: according to the three rivers sediment studied in this experiment, It is suggested that PAFC (polyaluminum ferric chloride) or PAC (polyaluminum chloride) should be chosen as inorganic flocculant, in which the optimum dosage of PAFC is 0.4% of dry mud mass. The best dosage of PAFC is 0.810% of dry mud mass, and the best dosage of PAFC is 0.810% of dry mud mass. The organic polymer flocculant suggests CPAM (cationic flocculant). Polyacrylamide), the optimum dosage is 0.01g / 0.04 of the dry mud mass; under the optimum conditions of each flocculant, The dewatering performance of mud sediment is the most obvious. The maximum specific resistance of sediment sludge can be reduced 86%, the maximum specific resistance of sediment sludge can be reduced 82%, and the maximum specific resistance of sand sediment sludge can be decreased 65%. (4) orthogonal experiment of dewatering agent for different mud types of rivers shows that the optimum selection of dehydrating agent The optimal dosage under different operating conditions is the control of the weight of dry mud at 1.2% of the weight of dry mud and the control of the dosage of PAFC at 0.8% of the mass of dry mud. The dosage of CPAM is controlled at 0.02% of the mass of dry mud.
【学位授予单位】：青岛理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X703;X52

【相似文献】