苏州河水环境质量变化特征及其黑臭风险评估

发布时间：2018-01-08 09:02

本文关键词：苏州河水环境质量变化特征及其黑臭风险评估　出处：《华东师范大学》2017年硕士论文　论文类型：学位论文

【摘要】：苏州河是上海的城市标志之一,对上海市水生态系统起着重要作用。1988年苏州河开始进行了十余年的苏州河环境综合整治,苏州河综合面貌得到较大程度的改善。目前苏州河干流已经基本消除了黑臭,主要水质指标维持在V类水(景观用水)标准;然而由于近年苏州河水生生态恢复过程较为缓慢,生态系统较为脆弱,仍会出现短时水污染甚至黑臭现象,严重影响上海市的形象。为分析评价苏州河水环境质量变化特征及其黑臭风险和污染来源,依托上海市环保科研项目"苏州河生态风险评估及生态恢复监测评价指标体系研究"(项目批号:2015-15),在上海市环境监测中心支持下完成。整理了 1996～2015年苏州河水质时空数据,以及2013～2015年苏州河典型断面的在线监测数据,典型泵站2013～2015年的放江量数据和泵站放江前后的水质采样数据,综合运用单因子分析、基于灰色关联度的TOPSIS模型、污染指数法、相对累积概率曲线、Pearson相关性分析、方差分析和住建部提出的黑臭水体评价方法,分析评价苏州河的水质变化时空特征、黑臭发生的时空特征变化和污染来源。从而为改善苏州河水质防治苏州河发生黑臭提供依据。论文的主要研究内容和成果如下:(1)分析1996～2015年苏州河年际水质数据和2013～2015年月际水质数据变化特征,结果表明:①苏州河水质呈逐年改善的趋势,变化趋势分为三个时期:1996～2001年水体明显改善时期,2001～2010年水质整体稳定有所反复,2011～2015年水质改善有所反复,基本保持在V类水;②空间上苏州河综合水质水平基本均能达到V类水质标准,沿程综合水质水平逐渐降低,苏州河市区段的水质水平明显低于上游;③苏州河水质不达标的水质指标溶解氧、氨氮、总磷、高锰酸盐指数指数和生化需氧量的权重值分别占总权重值的23.4%、30.9%、25.8%、7.6%、12.3%,氨氮、溶解氧和总磷是苏州河水质不达标的主要指标。(2)为全面分析苏州河水体综合水质达标率以及苏州河水质变化特征,利用在线监测数据选取了氨氮和溶解氧利用基于灰色关联度的TOPSIS模型综合评价水质水质情况。上游华漕断面在2014年和2015年综合水质达标率分别为30.66%和53.85%,且达标时间主要集中在冬春季节,秋夏季节的达标水质相对较低,下游的三个断面:北新泾、凯旋和武宁路桥断面综合水质水平基本处于劣V类水平,北新泾在2013年达标水平为26.06%,凯旋和武宁路桥在2015年综合水质达标率分别是13.89%、18.61%,其达标水平时间分布特征与上游华漕断面相似。上游华漕断面的水质达标率明显高于下游断面,四个断面的溶解氧和氨氮变化趋势相似,均是春冬季节高于夏秋季节。(3)利用住建部提出的黑臭评价方法分析2014～2015年苏州河水质在线监测数据,评估苏州河典型断面黑臭发生的时空特征。结果表明:①苏州河发生轻度黑臭较为严重,已成为常态,华漕、凯旋和武宁断面的轻度黑臭时间分别占总监测时间的32.1%、74.5%、73.4%,且均呈倒"V"型变化,在汛期轻度黑臭时间约占总黑臭时间的79.8%、70.9%、66.8%;②苏州河城区段断面间发生轻度黑臭具有同步性,下游断面发生轻度黑臭的风险大于上游,原因是放江时排水管道里的大量沉积物和沿岸大量有机营养物质进入河流,导致水体的综合水质水平下降,使水体产生黑臭现象;下游发生轻度黑臭现象是上游水质差的必要条件,上游来水的水质直接影响下游的水质质量;③苏州河下游市区段发生重度黑臭有两种表现形式:第一种是重污染水团流经导致水体迅速进入重度黑臭,重污染水团过后断面的水体迅速恢复;第二种是污染源的持续进入,即泵站长时间持续放江导致苏州河进入黑臭状态时间长,水质恶化严重,长时间黑臭的影响导致重度黑臭结束后会进入轻度黑臭溶解氧的浓度不会迅速恢复到正常水平;④苏州河沿岸泵站放江与发生黑臭具有显著的相关性,在春冬季节单次放江不一定产生黑臭,夏秋季节单次放江或连续两天以上的持续放江单次放江事件以及春冬季节连续两天以上的溢流放江事件会使苏州河进入短期的间歇性轻度黑臭状态;其中重度黑臭主要发生在汛期,连续两天的的降雨溢流事件会增大重度黑臭现象发生的可能性。⑤苏州河水质不达标与黑臭发生呈明显的线性相关,因此提高水质达标率可降低黑臭发生的风险,同时降雨与放江量呈明显的相关性,如何控制降雨径流是今后重点防止苏州河发生间歇性黑臭的重点。(4)对苏州河水质不达标和水体黑臭的原因进行分析:①苏州河上游来水的氨氮和总磷是导致苏州河水质不达标的主要原因,上游氨氮和总磷浓度值分别是V类水质标准的2.1、1.1倍,下游氨氮和总磷浓度值分别是V类水质标准的2.3、1.3倍,上下游水体的高锰酸盐指数、五日生化需氧量和化学需氧量水平均优于V类水质标准,是V类水质标准的1.5、0.25、0.5、0.38倍;②苏州河主要支流的BOD5、COD、CODMn浓度值稍高于干流但支流的浓度值均是在V类水质标准值以内,对干流的水质浓度的贡献量较小,支流的溶解氧浓度高于干流,平均浓度值是干流的2倍左右,对苏州河的水质达标和黑臭影响较小;③苏州河发生溢流放江是苏州河发生间歇性黑臭的关键性因素,放江后BOD5和COD是放江前的2倍左右,溶解氧浓度是V类水质标准值的0.5倍左右。
[Abstract]:The Suzhou river is one of the symbol of Shanghai City, the Suzhou River comprehensive regulation environment plays an important role of.1988 in the Suzhou river has been more than ten years of water ecosystem in Shanghai City, Suzhou River comprehensive development has been greatly improved. At present, the Suzhou river has been basically eliminated black odor, the main water quality index maintained at V water (landscape water standards); however in recent years due to the Suzhou river ecological restoration process is relatively slow, the ecological system is fragile, there will still be short of water pollution and the phenomenon of black odor, seriously affected the image of Shanghai City, Suzhou water environmental quality evaluation. The change characteristics and black odor risk and pollution source analysis, relying on the Shanghai municipal environmental protection scientific research project "Suzhou river ecological risk assessment and ecological restoration of the monitoring and evaluation indicator system" (project number: 2015-15), completed in the Shanghai Municipal Environmental Monitoring Center under the support of finishing 19. From 96 to 2015 in Suzhou river water quality spatio-temporal data, as well as 2013 ~ 2015 Suzhou River typical cross section of the on-line monitoring data, a typical pumping station from 2013 to 2015 on the river and the amount of data before and after the river water pumping station on the sampling data, comprehensive analysis using single factor TOPSIS, grey correlation model based on pollution index method, relative cumulative probability curve Pearson, correlation analysis, variance analysis and evaluation of the smelly water Ministry of housing method, analysis of water quality change of evaluation of the Suzhou River, changes in spatial characteristics and pollution sources of black odor occur. So as to improve the water quality of Suzhou River Suzhou river black odor control provide the basis. The main research contents and results are as follows: (1) from 1996 to 2015 were analyzed in Suzhou river water quality data and annual 2013 ~ 2015 years when the data of water quality variation characteristics, results show that: the water quality of Suzhou river was gradually improving trend, change The trend is divided into three periods: from 1996 to 2001 2001 to improve water period, the overall stability of the water quality in 2010 has been repeated, 2011 ~ 2015 water quality improvement has been repeated, remained in the V class II water; space comprehensive water quality can meet the basic level of Suzhou river water quality standard V, decreased gradually along the path of comprehensive water quality level. The water level of Suzhou river section is significantly lower than that of the upstream water quality index; dissolved oxygen, the Suzhou river water quality is not up to the ammonia nitrogen, total phosphorus, potassium permanganate index weight index and BOD value respectively of the total weights of 23.4%, 30.9%, 25.8%, 7.6%, 12.3%, ammonia nitrogen, dissolved oxygen and total phosphorus is the main index of the Suzhou river no matter the standard. (2) for a comprehensive analysis of Suzhou River comprehensive water quality compliance rate and the change of water quality in Suzhou River, ammonia nitrogen and dissolved oxygen were selected based on grey correlation degree by using the on-line monitoring data of TOPSI S comprehensive evaluation model for water quality. The upstream section Huacao in 2014 and 2015 comprehensive water quality compliance rate were 30.66% and 53.85%, and the standard time mainly concentrated in the winter and spring, summer autumn season, the water quality standards are relatively low, the three section downstream: Beixinjing, triumph and Wuning Luqiao section of comprehensive water quality in basic level inferior to V level, Beixinjing standard level in 2013 26.06%, triumph and Wuning Luqiao in 2015 comprehensive water quality compliance rate were 13.89%, 18.61%, the standard level of the distribution of time and the upstream section. Similar Huacao upstream water quality compliance rate of Hua Cao section was significantly higher than that in the downstream, four ammonia nitrogen and dissolved oxygen change the section is similar to that of spring and winter than in summer and autumn. (3) of 2014 ~ 2015 Suzhou river water quality on-line monitoring data using black odor evaluation method of the Ministry of housing, assessment of the Suzhou River Temporal and spatial characteristics of the typical section of black odor occurs. The results show that the Suzhou river had mild black odor is more serious, has become the norm, Huacao, triumph and Wuning section of the mild black odor time respectively of the total monitoring time of 32.1%, 74.5%, 73.4%, and showed an inverted "V" type changes in light and dark in the flood season the total time of smelly black odor time of 79.8%, 70.9%, 66.8%; the city of Suzhou river section between the mild black odor is synchronous, larger than the upstream downstream mild black odor risk, because a large amount of nutrients and organic drainage sediments along the pipeline in large amount into the river on the river, leading to a comprehensive the water level of the water drops, the water black odor phenomenon; downstream mild black odor phenomenon is a necessary condition for the upstream of poor water quality, water quality in the upper reaches of the water quality directly affects the quality of downstream; the Suzhou River section of the occurrence of severe black smelly Two forms: the first one is the heavy pollution water flows cause the water quickly into the severe black odor, heavy pollution water section of the water after the rapid recovery; second is the source of pollution continue to enter, which lasted into the river pump station in Suzhou River into the black and stink state a long time, water quality deterioration, effect of long time black smelly black odor after severe lead concentration will enter a mild black odor of dissolved oxygen will not quickly return to normal level; the Suzhou river pumping station and put river black odor has significant correlation in spring and winter, not a single discharge black smelly, summer season, single or continuous discharge two more days of continuous discharge of single discharge events and spring and winter relief more than two consecutive days of discharge events will make the Suzhou River into short-term intermittent and mild black odor; the severe black odor mainly occurred in the flood season, continuous Two days of rainfall events will increase the possibility of severe flooding. The phenomenon of black odor of Suzhou river water quality standards showed a significant linear correlation with black odor, thereby improving water quality compliance rate can reduce the risk of occurrence of black odor, while rainfall and river discharge amount was significantly correlated, how to control the rainfall runoff is the focus of the future to prevent the Suzhou river due to the intermittent black odor focus. (4) analysis of non-compliance on the water quality of Suzhou River and the black and odorous water causes: ammonia nitrogen and total phosphorus of Suzhou river runoff is the main reason leading to the Suzhou river water quality standards, the upstream ammonia nitrogen and total phosphorus concentration were 2.1,1.1 times V water quality standard downstream, ammonia nitrogen and total phosphorus concentrations were 2.3,1.3 times V water quality standard, permanganate index on the water downstream of the V five day BOD and cod were better than those of the standard of water quality, water quality is V 1.5,0.25,0.5,0.38 times the standard; the Suzhou River main tributaries of the BOD5, COD, CODMn concentrations were slightly higher than the river but tributaries concentration was in V water quality standard value, the contribution of the main stream of water concentration is smaller, the dissolved oxygen concentration is higher than the average concentration of River tributaries, the value is about 2 times the main stream. The smaller water quality of the Suzhou River and the Suzhou river black odor effect; the overflow discharge is the key factor in the occurrence of intermittent black odor of the Suzhou River, into the river after BOD5 and COD is about to put the river 2 times before, the dissolved oxygen concentration is about 0.5 times of V water quality standard value.

【学位授予单位】：华东师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X824

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