基于回灌处理渗滤液浓缩液中重金属的迁移行为研究
发布时间：2019-02-15 04:36
【摘要】：出于经济性和可操作性考虑,目前我国卫生填埋场产生的渗滤液膜滤浓缩液普遍采用填埋体回灌方法进行处理。但目前学者对浓缩液回灌填埋体中重金属的迁移转化研究较少,而重金属的合理去除不仅对保障填埋场周围土壤和地下水的安全至关重要,而且对垃圾渗滤液处理设施的正常运行也有明显影响。因此,本文借助于室内模拟试验,采用浓缩液回灌的方式,分别研究不同埋龄垃圾介质及不同回灌条件下回灌体系中重金属的迁移行为,确定影响重金属迁移的主要因素,通过正交方法探讨回灌浓缩液中重金属去除的最优回灌参数,并对重金属的迁移转化行为进行了初探。研究结果表明：埋龄为1年的填埋介质对浓缩液中典型重金属Cu、Zn、Ni、Cr表现出一定的去除作用。回灌周期内,上述四种重金属的平均去除率依次为：19.58%、39.30%、20.39%和26.12%。5年柱和15年柱中填埋介质趋于稳定,生物反应变弱,随着填埋体内环境的变化,填埋体内重金属Cu、Zn不断溶出,Ni则出现回灌前期浓缩液中Ni被去除,后期从填埋体溶出的现象,浓缩液中Cr则得到了有效去除,其中5年柱对浓缩液中Cr去除率分别为16.35%,15年柱对浓缩液中Cr平均去除率为34.58%。回灌负荷为3.0L/d的重金属出水浓度明显低于4.5L/d和6.0L/d,回灌速率为0.2L/min的重金属出水浓度低于0.3L/min和0.4L/min,说明在回灌系统中,当其他因素确定时,随着回灌负荷和回灌速率的降低,出水中重金属浓度也随着减少,即重金属出水浓度与回灌负荷及回灌速率表现出明显的正相关关系。而不同的回灌频次(1次/d、3次/d、6次/d)和回灌方式(全分布布水、中间布水、四周布水)对出水浓度基本无影响。在最优回灌参数探究试验中,通过正交试验确定了有利于回灌出水中重金属浓度控制的具体回灌参数,即回灌量为2.0L/d、填埋介质粒径为5mm、调pH(8.5)、压实、回灌速度为0.2L/min。不同回灌参数中回灌量和回灌介质pH对浓缩液回灌出水中重金属含量的影响最为显著,且保持较低回灌量(2.0L/d)、高pH(8.5)有利于回灌出水中重金属的去除。回灌前后填埋体内重金属不同形态含量的对比研究表明,Cu、Zn、Ni、Cr的迁移率随着垃圾埋龄的增加而降低,即随着垃圾稳定化进程的增加,重金属迁移率逐渐降低；同时,酸可溶态重金属含量对其迁移率有很大影响,重金属迁移率与酸可溶态重金属含量的排序比较一致。四种典型重金属迁移率从大到小的顺序为：ZnCuNiCr。以15年柱为例,其迁移率依次为1.81%、1.75%、0.9%和0.68%。Cr存在形式最稳定,浓缩液回灌过程中能够迅速被固定。本研究可为渗滤液反渗透浓缩液回灌系统的合理设计提供依据,对渗滤液中重金属的污染防治亦有参考意义。
[Abstract]:In view of economy and maneuverability, leachate membrane concentrate produced from sanitary landfills in China is generally treated by landfill recharge. However, there is little research on the migration and transformation of heavy metals in the recharge landfill, and the reasonable removal of heavy metals is not only important to ensure the safety of the soil and groundwater around the landfill. Moreover, it has obvious influence on the normal operation of landfill leachate treatment facilities. Therefore, with the help of indoor simulation test, the migration behavior of heavy metals in the recharge system of different buried age garbage medium and different recharge conditions was studied by using concentrated liquid recharge method, and the main factors affecting heavy metal migration were determined. The optimal parameters of heavy metal removal in recharge concentrate were studied by orthogonal method, and the migration and transformation of heavy metals were studied. The results showed that the landfill medium with the age of one year could remove the typical heavy metal Cu,Zn,Ni,Cr in the concentrated solution to a certain extent. During the recharge cycle, the average removal rates of the above four heavy metals were 19.58%, 39.30% and 26.12.5 years, respectively, and the landfill medium tended to stabilize, and the biological reaction became weaker, the average removal rate of the above four heavy metals was 19.58%, 39.30% and 26.12.5 years, respectively. With the change of the landfill environment, the heavy metal Cu,Zn in the landfill was dissolved continuously, the Ni was removed from the concentrated solution in the early stage of recharge, the Ni was removed from the landfill at the later stage, and the Cr was effectively removed from the concentrated solution. The removal rates of Cr in concentrated solution were 16.35 for 5 years and 34.58 for Cr in 15 years respectively. The effluent concentration of heavy metals with recharge load of 3.0L/d was significantly lower than that of 4.5L/d and 6.0L / d, and the effluent concentration of heavy metals with recharge rate of 0.2L/min was lower than that of 0.3L/min and 0.4L / min. When other factors were determined, with the decrease of recharge load and recharge rate, the concentration of heavy metals in the effluent water decreased, that is, the concentration of heavy metals in effluent showed a positive correlation with the recharge load and the recharge rate. However, different recharge frequency (1 / d, 3 / d / d, 6 times / d) and recharge methods (full distribution of water, intermediate distribution of water, and distribution of water around) had no effect on the effluent concentration. In the research of optimal recharge parameters, the specific parameters of recharge were determined by orthogonal test, that is, the amount of recharge was 2.0L / d, the particle size of landfill was 5mm, pH (8.5) was adjusted and compacted. The rate of recharge is 0.2 L / min. Among the different recharge parameters, the amount of recharge and the recharge medium pH had the most significant effect on the heavy metal content in the recirculation water of concentrated liquid, and maintained a relatively low recharge rate (2.0L/d), and high pH (8.5) was beneficial to the removal of heavy metals in the recirculation water. The comparative study on the different forms of heavy metals in landfill before and after recharge showed that the mobility of Cu,Zn,Ni,Cr decreased with the increase of landfill age, that is, with the increase of stabilization process, the migration rate of heavy metals decreased gradually. At the same time, the content of acid soluble heavy metals has a great influence on its mobility, and the heavy metal mobility is consistent with the order of acid soluble heavy metals. The order in which the mobility of four typical heavy metals ranges from large to small is: ZnCuNiCr. Taking the 15-year column as an example, the mobility was 1.81% and 1.750.9%, respectively, and the form of 0.68%.Cr was the most stable, and it could be fixed rapidly during the recharge of concentrated liquid. This study can provide the basis for the rational design of the reverse osmosis concentrated leachate recirculation system, and also have reference significance for the prevention and control of heavy metal pollution in the leachate.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X703
[Abstract]:In view of economy and maneuverability, leachate membrane concentrate produced from sanitary landfills in China is generally treated by landfill recharge. However, there is little research on the migration and transformation of heavy metals in the recharge landfill, and the reasonable removal of heavy metals is not only important to ensure the safety of the soil and groundwater around the landfill. Moreover, it has obvious influence on the normal operation of landfill leachate treatment facilities. Therefore, with the help of indoor simulation test, the migration behavior of heavy metals in the recharge system of different buried age garbage medium and different recharge conditions was studied by using concentrated liquid recharge method, and the main factors affecting heavy metal migration were determined. The optimal parameters of heavy metal removal in recharge concentrate were studied by orthogonal method, and the migration and transformation of heavy metals were studied. The results showed that the landfill medium with the age of one year could remove the typical heavy metal Cu,Zn,Ni,Cr in the concentrated solution to a certain extent. During the recharge cycle, the average removal rates of the above four heavy metals were 19.58%, 39.30% and 26.12.5 years, respectively, and the landfill medium tended to stabilize, and the biological reaction became weaker, the average removal rate of the above four heavy metals was 19.58%, 39.30% and 26.12.5 years, respectively. With the change of the landfill environment, the heavy metal Cu,Zn in the landfill was dissolved continuously, the Ni was removed from the concentrated solution in the early stage of recharge, the Ni was removed from the landfill at the later stage, and the Cr was effectively removed from the concentrated solution. The removal rates of Cr in concentrated solution were 16.35 for 5 years and 34.58 for Cr in 15 years respectively. The effluent concentration of heavy metals with recharge load of 3.0L/d was significantly lower than that of 4.5L/d and 6.0L / d, and the effluent concentration of heavy metals with recharge rate of 0.2L/min was lower than that of 0.3L/min and 0.4L / min. When other factors were determined, with the decrease of recharge load and recharge rate, the concentration of heavy metals in the effluent water decreased, that is, the concentration of heavy metals in effluent showed a positive correlation with the recharge load and the recharge rate. However, different recharge frequency (1 / d, 3 / d / d, 6 times / d) and recharge methods (full distribution of water, intermediate distribution of water, and distribution of water around) had no effect on the effluent concentration. In the research of optimal recharge parameters, the specific parameters of recharge were determined by orthogonal test, that is, the amount of recharge was 2.0L / d, the particle size of landfill was 5mm, pH (8.5) was adjusted and compacted. The rate of recharge is 0.2 L / min. Among the different recharge parameters, the amount of recharge and the recharge medium pH had the most significant effect on the heavy metal content in the recirculation water of concentrated liquid, and maintained a relatively low recharge rate (2.0L/d), and high pH (8.5) was beneficial to the removal of heavy metals in the recirculation water. The comparative study on the different forms of heavy metals in landfill before and after recharge showed that the mobility of Cu,Zn,Ni,Cr decreased with the increase of landfill age, that is, with the increase of stabilization process, the migration rate of heavy metals decreased gradually. At the same time, the content of acid soluble heavy metals has a great influence on its mobility, and the heavy metal mobility is consistent with the order of acid soluble heavy metals. The order in which the mobility of four typical heavy metals ranges from large to small is: ZnCuNiCr. Taking the 15-year column as an example, the mobility was 1.81% and 1.750.9%, respectively, and the form of 0.68%.Cr was the most stable, and it could be fixed rapidly during the recharge of concentrated liquid. This study can provide the basis for the rational design of the reverse osmosis concentrated leachate recirculation system, and also have reference significance for the prevention and control of heavy metal pollution in the leachate.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X703
【参考文献】
相关期刊论文 前10条
1 刘保成;吕国庆;高祯;郑学娟;安丽;;垃圾渗滤液浓缩液的回灌试验研究[J];中国给水排水;2011年19期
2 黄铭珠;刘小芳;侯h，
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