松花江哈尔滨段沉积物污染评估及重金属富集规律研究
发布时间：2018-10-19 12:14
【摘要】：本课题以松花江哈尔滨市区段底泥沉积物为主要研究对象,对重金属进行了空间分布分析、基于总量的污染特性分析和潜在生态危害性分析、基于可反应性/的潜在生态危害分析、单因素及其正交条件下重金属及氮、磷的富集规律研究。松花江哈尔滨市区段重金属空间分布中,Cd含量超过黑龙江省表层沉积物背景值4.43至6.94倍,Zn含量略超背景值,Cr、Pb和Cu含量低于背景值。就各重金属总量而言:ZnCrCuPbCd,就与背景值的比值关系而言:CdZnCuPbCr。在选取的4个采样点中,哈尔滨音乐公园附近采样点处污染较严重。重金属多元统计分析结果表明,Cd与Pb具有较高的同源性,且主要来源于工业源和市政污水排放,而Cu、Zn与Cr主要来源于天然母岩,并可能受到一定人类活动的影响。重金属地积累指数法显示A点Cd污染为3级,其余为2级,Cd是此区段主要污染元素,余下元素污染等级为0;潜在风险评价结果4点均为4级偏强度污染,且Cd对RI贡献均超过95%。重金属赋存状态分析中,Cd与Pb可交换态含量较高,具有较大的潜在风险;在可交换态中,Cr、Cu元素以有机硫化物结合态为主,Pb、Zn元素以铁锰氧化物结合态为主;Cd在A点可弱酸提取态明显升高,具有明显的工业源注入。基于可反应性的生态风险评估指数RAC:镉铅铬锌铜,各采样点RAC:ABCD。单因素下重金属富集试验表明,温度的提高有助于重金属向沉积物的快速富集,后期温度的降低会促使吸附向正方向进行提高重金属富集量;铬、镉和锌富集量均随着p H的降低而降低,p H值对三者影响的显著性:镉锌铬;紊流下重金属富集速率高于层流和静置,试验运行后期吸附量铬和锌元素为层流静置紊流,镉元素为紊流层流静置,差异源于流速变化对浓度梯度传质驱动力的影响和水体流动对表层沉积物结构及有效吸附层厚度的影响的综合作用。浓度控制结果显示沉积物对于锌和镉具有较大的吸附容量,对铬吸附容量较小。在多因素正交下重金属富集试验中,流速与p H正交下各元素富集规律与单因素下的趋势基本相同。流速与温度正交下各元素富集规律与单因素下的富集规律相似,但相比于单因素正交条件对吸附量差异的显著性有所削弱。单因素下氮磷富集试验结果表明,低温下TN、TP富集量较大;流速控制中的TN、TP吸附量层流静置紊流;酸碱度对TN富集的影响在于对物理化学吸附和离子交换过程的作用上,对TP富集通过改变磷与金属元素的结合状态和磷酸根离子或磷酸氢根离子的离子交换过程来影响,过酸或过碱均不利于TN、TP的富集。
[Abstract]:Based on the analysis of the pollution characteristics of the total amount and the potential ecological hazard analysis, based on the potential ecological hazard analysis of the reactive/ potential, Study on the enrichment of heavy metals and nitrogen and phosphorus under single factor and its orthogonal condition. The contents of Cd in the heavy metal spatial distribution of Harbin Harbin section exceed 4.43 to 6.94 times the background value of the surface sediments in Heilongjiang Province, and the Zn content is slightly higher than the background value, and the content of Cr, Pb and Cu is lower than the background value. For the total amount of heavy metals: ZnCrCuPbCd, in relation to the ratio of background values: CdZnCuPbCr. At the selected four sampling points, the pollution at sampling points near Harbin music park is serious. The results of multivariate statistical analysis of heavy metals show that Cd and Pb have higher homology and are mainly derived from industrial sources and municipal sewage discharge, while Cu, Zn and Cr are mainly derived from natural parent rocks and may be affected by certain human activities. The heavy metal accumulation index method showed that Cd pollution at point A was Grade 3, the rest is grade 2, Cd is the main pollution element in this section, and the remaining element pollution level is 0. The potential risk assessment result is 4-stage partial intensity pollution, and Cd has more than 95% contribution to RI. In the analysis of the occurrence of heavy metals, the exchangeable state of Cd and Pb is higher, and it has a great potential risk; in exchangeable state, Cr and Cu are dominated by organic sulfide, Pb and Zn are dominated by iron-manganese oxide, Cd is obviously raised in weak acid extraction state at point A, with an obvious industrial source injection. Based on the reactive ecological risk assessment index RAC: Pb-Cr-Zn-Cu, each sampling point RAC: ABCD. The results of heavy metal enrichment under single factor indicate that the increase of temperature will help to enrich the heavy metal to the deposit rapidly, the decrease of later temperature will promote the adsorption to the positive direction to increase the concentration of heavy metal, and the concentration of Cr, Pb and Zn decreases with the decrease of p H. The influence of p-H value on three factors: zinc-zinc-chromium; the concentration rate of heavy metal in turbulent flow is higher than laminar flow and static state; the adsorption quantity of chromium and zinc in the later stage of experiment is laminar flow static turbulent flow, the turbulent flow element is turbulent laminar flow standing, The difference is due to the influence of flow velocity variation on the mass transfer driving force of the concentration gradient and the effect of water flow on the surface sediment structure and the effective adsorption layer thickness. The results of the concentration control show that the deposit has a large adsorption capacity for zinc and silver, and the adsorption capacity of chromium is small. In the experiment of heavy metal enrichment under multi-factors, the enrichment regularity of each element under the orthogonality of flow velocity and p H is basically the same as that under single factor. The enrichment regularity of each element under the condition of flow velocity and temperature is similar to that under single factor, but the significance of the difference of adsorption quantity is weakened compared with single factor orthogonal condition. The results of nitrogen and phosphorus enrichment under single factor show that the concentration of TN and TP is relatively large at low temperature; TN and TP in flow rate control are laminar and turbulent; the effect of pH on TN enrichment is on the function of physical and chemical adsorption and ion exchange process. The enrichment of TN and TP is not conducive to TP enrichment by changing the binding state of phosphorus to metal element and ion exchange process of phosphate ion or hydrogen phosphate ion.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X824;X522
本文编号：2281080
[Abstract]:Based on the analysis of the pollution characteristics of the total amount and the potential ecological hazard analysis, based on the potential ecological hazard analysis of the reactive/ potential, Study on the enrichment of heavy metals and nitrogen and phosphorus under single factor and its orthogonal condition. The contents of Cd in the heavy metal spatial distribution of Harbin Harbin section exceed 4.43 to 6.94 times the background value of the surface sediments in Heilongjiang Province, and the Zn content is slightly higher than the background value, and the content of Cr, Pb and Cu is lower than the background value. For the total amount of heavy metals: ZnCrCuPbCd, in relation to the ratio of background values: CdZnCuPbCr. At the selected four sampling points, the pollution at sampling points near Harbin music park is serious. The results of multivariate statistical analysis of heavy metals show that Cd and Pb have higher homology and are mainly derived from industrial sources and municipal sewage discharge, while Cu, Zn and Cr are mainly derived from natural parent rocks and may be affected by certain human activities. The heavy metal accumulation index method showed that Cd pollution at point A was Grade 3, the rest is grade 2, Cd is the main pollution element in this section, and the remaining element pollution level is 0. The potential risk assessment result is 4-stage partial intensity pollution, and Cd has more than 95% contribution to RI. In the analysis of the occurrence of heavy metals, the exchangeable state of Cd and Pb is higher, and it has a great potential risk; in exchangeable state, Cr and Cu are dominated by organic sulfide, Pb and Zn are dominated by iron-manganese oxide, Cd is obviously raised in weak acid extraction state at point A, with an obvious industrial source injection. Based on the reactive ecological risk assessment index RAC: Pb-Cr-Zn-Cu, each sampling point RAC: ABCD. The results of heavy metal enrichment under single factor indicate that the increase of temperature will help to enrich the heavy metal to the deposit rapidly, the decrease of later temperature will promote the adsorption to the positive direction to increase the concentration of heavy metal, and the concentration of Cr, Pb and Zn decreases with the decrease of p H. The influence of p-H value on three factors: zinc-zinc-chromium; the concentration rate of heavy metal in turbulent flow is higher than laminar flow and static state; the adsorption quantity of chromium and zinc in the later stage of experiment is laminar flow static turbulent flow, the turbulent flow element is turbulent laminar flow standing, The difference is due to the influence of flow velocity variation on the mass transfer driving force of the concentration gradient and the effect of water flow on the surface sediment structure and the effective adsorption layer thickness. The results of the concentration control show that the deposit has a large adsorption capacity for zinc and silver, and the adsorption capacity of chromium is small. In the experiment of heavy metal enrichment under multi-factors, the enrichment regularity of each element under the orthogonality of flow velocity and p H is basically the same as that under single factor. The enrichment regularity of each element under the condition of flow velocity and temperature is similar to that under single factor, but the significance of the difference of adsorption quantity is weakened compared with single factor orthogonal condition. The results of nitrogen and phosphorus enrichment under single factor show that the concentration of TN and TP is relatively large at low temperature; TN and TP in flow rate control are laminar and turbulent; the effect of pH on TN enrichment is on the function of physical and chemical adsorption and ion exchange process. The enrichment of TN and TP is not conducive to TP enrichment by changing the binding state of phosphorus to metal element and ion exchange process of phosphate ion or hydrogen phosphate ion.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X824;X522
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