南王水库引水工程水体污染物运移规律及突发事故应急响应分析

发布时间：2019-06-21 06:25

【摘要】：为了研究输水渠道中水体污染物的运移规律,并对沿线突发水污染事故进行有效预警与应急处置,本文以南王水库引水工程高唐段为研究对象,采用公式法计算了研究对象在不同工况下的水环境容量,利用数值模拟的方法对不同工况下水体污染物的运移衰减过程、突发水污染事故的预警及应急进行了研究与分析,具体研究内容与结论如下:对一维水环境容量计算模型中排污口的不同概化方法进行了分析,并在此基础上推导出了多点概化水环境容量计算模型。根据南王水库引水工程高唐段沿线污染源的实际分布状况,采用不同水环境容量计算模型分别计算了丰水、平水、枯水三种工况(以下简称不同水期)下输水干渠的水环境容量。计算结果表明利用三点概化水环境容量计算模型得到的水环境容量要小于顶点概化水环境容量计算模型而大于中点概化水环境容量计算模型,此外,还可以看出输水干渠在不同水期条件下的水环境容量差异较大,有必要根据输水工况合理确定其水环境容量。将非恒定流水动力学方程与一维对流扩散水质方程进行耦合,利用耦合数学模型模拟了正常排污条件下典型水体污染物在不同水期条件下的运移降解过程,从模拟结果可以看出,在不同水期条件下,同一断面的污染物浓度值相差较大,污染物浓度线从渠首至渠尾呈锯齿状间歇性上升,其中,沿程有三处上涨幅度较大,符合实际排污情况,干渠水体满足地表水IV类水质标准。分析确定干渠沿线突发性水污染事故的易发地,构建不同突发性水污染事故,利用耦合水质模型模拟了不同水期条件下特征污染带的运移衰减过程,模拟结果表明,事故发生后,污染带的浓度变化大致呈对称抛物线状,由上游尖瘦型逐渐过渡到下游的矮胖型,浓度峰值也会逐渐削减。对于同一控制断面而言,在不同水期条件下,污染物对断面的影响时间、水体污染物浓度超过目标水质标准的时间段(以下简称不可取水时间)差别很大,而从事故发生至水体污染物浓度升至目标水质标准的这段时间(以下简称预警时间)受水期的影响不是很显著。对于同一水期而言,不同断面的预警时间、不可取水时间有所不同,距离事故点较近的下游断面的预警时间比距离事故点较远的下游断面要短,前者在丰水期时的不可取水时间要比后者长,但随着丰水期向枯水期过渡,后者的不可取水时间会超过前者。对构建的两起突发水污染事故进行应急处置分析,采用多种应急措施联用的方法对事故一进行应急处理,采用引水冲污措施对事故二进行应急处理,并利用构建的水质模型对后者的应急效果进行了模拟,在确定合理的引水点、引水时间之后,引水入渠能够使干渠内的污染带浓度得到有效的削减,并且随着引水流量的加大,渠尾的污染带浓度基本可以满足在地表水V类水质标准值以下。
[Abstract]:In order to study the transport law of water pollutants in the water transmission channel, and to effectively warn and deal with the sudden water pollution accidents along the route, this paper takes the Gaotang section of Nanwang Reservoir diversion Project as the research object, calculates the water environment capacity of the research object under different working conditions by means of formula method, and uses the numerical simulation method to calculate the transport and attenuation process of water pollutants under different working conditions. The early warning and emergency of sudden water pollution accident are studied and analyzed. The concrete research contents and conclusions are as follows: the different generalization methods of sewage outlet in one-dimensional water environmental capacity calculation model are analyzed, and on this basis, a multi-point generalized water environmental capacity calculation model is derived. According to the actual distribution of pollution sources along Gaotang section of Nanwang Reservoir diversion Project, the water environmental capacity of main canal under three working conditions of abundant water, flat water and dry water (hereinafter referred to as different water periods) is calculated by using different water environmental capacity calculation models. The calculation results show that the water environment capacity obtained by using the three-point generalized water environment capacity calculation model is smaller than that of the Vertex generalized water environment capacity calculation model, but larger than that of the midpoint generalized water environment capacity calculation model. In addition, it can be seen that the water environment capacity of the main canal under different water conditions is quite different, so it is necessary to reasonably determine its water environment capacity according to the water transportation conditions. The transient flow dynamics equation is coupled with the one-dimensional convective diffusion water quality equation, and the coupling mathematical model is used to simulate the transport and degradation process of typical water pollutants under different water periods. It can be seen from the simulation results that the pollutant concentration values of the same section vary greatly under different water periods, and the pollutant concentration lines rise in a serrated and intermittent manner from the beginning of the canal to the end of the canal. Along the way, there are three areas of rising range, which accords with the actual discharge situation, and the main canal water body meets the IV water quality standard of surface water. The prone places of sudden water pollution accidents along the main canal are analyzed and determined, and different sudden water pollution accidents are constructed. The transport and attenuation process of the characteristic pollution zone under different water periods is simulated by using the coupled water quality model. The simulation results show that the concentration change of the pollution zone is approximately symmetrical parabola after the accident, and the concentration peak value will be gradually reduced from the upstream sharp thin type to the low fat type downstream. For the same control section, the influence time of pollutants on the section is very different under different water periods, and the time when the concentration of water pollutants exceeds the target water quality standard (hereinafter referred to as the non-fetching time) is very different, but the time from the occurrence of the accident to the increase of the concentration of water pollutants to the target water quality standard (hereinafter referred to as the early warning time) is not significantly affected by the water period. For the same water period, the warning time of different sections is different, and the warning time of the downstream section closer to the accident point is shorter than that of the downstream section far from the accident point. The non-fetching time of the former is longer than that of the latter during the high water period, but with the transition from the high water period to the low water period, the non-fetching time of the latter will exceed the former. The emergency treatment of two sudden water pollution accidents is carried out, and the emergency treatment of accident one is carried out by using various emergency measures, and the emergency treatment of accident 2 is carried out by using water diversion measures, and the emergency effect of the latter is simulated by using the constructed water quality model. After determining the reasonable water diversion point and diversion time, the concentration of pollution zone in the main canal can be effectively reduced. With the increase of diversion flow, the concentration of pollution zone at the end of the canal can basically meet the standard value of Class V water quality of surface water.
【学位授予单位】：济南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TV67;X52

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