Water Quality Analysis of Fuping Section of the Shichuan River Based on Different Evaluation Methods

In order to study the water quality of the Shichuan River basin in Fuping,Shaanxi Province,based on improved Nemerow index method,comprehensive pollution index method and principal component analysis method,eight water quality indexes such as pH,dissolved oxygen(DO),total dissolved solids(TDS),COD,total hardness,total phosphorus,total nitrogen and Zn in three monitoring sections of Fuping section of the Shichuan River in Shaanxi Province were detected and analyzed.The results show that the water quality of the surface water in the Shichuan River basin is gradeⅢorⅣwater,that is,the water is slightly polluted and moderately polluted.It is necessary to monitor the water quality after regulation and clarify the main factors causing the water pollution.

Evaluation of Farmland Drainage Water Quality by Fuzzy–Gray Combination Method

The complex relationships between indicators and water conditions cause fuzzy and gray uncertainties in evaluation of water quality. Compared to conventional single-factor evaluation methods, the combination evaluation method can consider these two uncertainties to produce more objective and reasonable evaluation results. In this paper, we propose a combination evaluation method with two main parts:(1) the use of fuzzy comprehensive evaluation and gray correlation analysis as submodels with which to consider the fuzzy and gray uncertainties and(2) the establishment of a combination model based on minimum bias squares. In addition, using this method, we evaluate the water quality of a ditch in a typical rice–wheat system of Yixing city in the Taihu Lake Basin during three rainfall events. The results show that the ditch water quality is not good and we found the chemical oxygen demand to be the key indicator that affects water quality most significantly. The proposed combination evaluation method is more accurate and practical than single-factor evaluation methods in that it considers the uncertainties of fuzziness and grayness.

Statistical Analysis of Bursa Nilufer Creek’s Water Quality Parameters for Period of 2002-2010

Increasing contamination of water resources in the world and our country and decreasing water quality over time, not having met the objectives of utilization of water resources;it has increased the importance of water management. The monitoring of the water resources and evaluation of these monitoring results have given direction to the studies’ outcome in order to control factors that pollute water resources and reduce water quality. Nilüfer Creek is very important for both being a source of drinking and potable water and a discharge area for wastewaters for the city of Bursa. In this study, the results of the analysis belonging to the period between 2002-2010 which are taken from 15 points by General Directorate of Bursa Water and Sewerage Administration (BUWSA) were evaluated in relation to water quality of the Nilüfer Creek. Non-parametric methods were used in the evaluation of the water quality data due to the lack of normally distributed data. The identification of the best represented parameters of the water quality was provided by applying Principal Component Analysis. According to results of the analysis, the best representative 9 parameters from the 19 water quality parameters were defined as parameters of BOD5, COD, TSS, T.Fe, Zn, conductivity, NO2-N, Ni and NO3-N that taking part of the first two components.

Evaluation, prediction, and protection of water quality in Danjiangkou Reservoir, China

The water quality in the Danjiangkou Reservoir has attracted considerable attention from the Chinese public and government since the announcement of the Middle Route of the South to North Water Diversion Project （SNWDP）, which commenced transferring water in 2014. Integrated research on the evaluation, prediction, and protection of water quality in the Danjiangkou Reservoir was carried out in this study in order to improve environmental management. Based on 120 water samples, wherein 17 water quality indices were measured at 20 monitoring sites, a single factor evaluation method was used to evaluate the current status of water quality. The results show that the main indices influencing the water quality in the Danjiangkou Reservoir are total phosphorus （TP）, permanganate index （CODM,）, dissolved oxygen （DO）, and five-day biochemical oxygen demand （BODs）, and the concentrations of TP, BODs, ammonia nitrogen （NH3--N）, CODM,, DO, and anionic surfactant （Surfa） do not reach the specified standard levels in the tributaries. Seasonal Mann--Kendall tests indicated that the CODMn concentration shows a highly significant increasing trend, and the TP concentration shows a significant increasing trend in the Danjiangkou Reservoir. The distribution of the main water quality indices in the Danjiangkou Reservoir was predicted using a two-dimensional water quality numerical model, and showed that the sphere of influence from the tributaries can spread across half of the Han Reservoir if the pollutants are not controlled. Cluster analysis （CA） results suggest that the Shending River is heavily polluted, that the Jianghe, Sihe, and Jianhe rivers are moderately polluted, and that they should be the focus of environmental remediation.

Construction and Application of Combined Evaluation Model of Regional Water Quality Plan

[Objective] The aim was to study the construction and application of combined evaluation model of regional water quality plan. [Meth- od] By dint of layer analysis, subjective and objective model of entropy evaluation, the water quality plan in Jinghe was evaluated. Combined evalu- ation model based on information entropy were constructed, and considering the single model evaluation result, the optimal water quality plan was selected. [ Result] The combination weight result suggested that COD amount was the most essential indicator in water quality plan and embodied the importance of water environment protection, which met basic objective of environment protection and social, economic effects. Combined evalu- ation indicated that in the sixteen plans, plan 16 was of highest comprehensive evaluation value, and can be considered as optimum water quality plan. [ Conclusion] Combined evaluation model can effectively list the advantages of each evaluation model and improve the dependability of water quality plan, and provided a new research idea for the optimal evaluation of water pollution control plan.

An Analysis of Water Environment Factors and an Evaluation of Water Quantity of Liangzi Lake

The experiments of single factor evaluation method, principal component analysis and voronoi area weighting factor method on the sample data of Liangzi Lake in October 2012 combined with the national surface water environment quality standards can get the map of comprehensive water quality distribution by Kriging interpolation. The analysis shows, the grades of comprehensive water quality gained by three methods are all only class III or class IV, and the quality of water is different from east and west that the water quality of east is better. However, the percent of IV class water is higher in the result of single factor evaluation method means class IV is the main grade of water quality. The result of principal component analysis shows the percent of class Ⅲ water is higher than other classes. The result of voronoi area weighting factor method shows the percent of IV class is higher than other classes. CODMn is the main factor that influences the method of singal factor evaluation and reduces the grade of water quality overall. The effect of single factor is reduced by principal component analysis, and the analysis on water quality is more accurate. The voronoi area weighing factor method reduces the effect of single factor and extends the content, can make a comprehensive evaluation on water quality.

Water Quality Assessment of Dachangshan ArtificialHabitat Development Demonstration Area

[Objective] The paper was to evaluate the water quality environment in Dachangshan artificial habitat development demonstration area.[Method] From 2013 to 2015, an environmental survey was conducted for eight voyages in Dachangshan artificial habitat development demonstration area of Changhai County, Dalian City, and 20 hydrochemical indexes including salinity, pH, and COD were monitored. The water quality of thesea area was analyzed by principal component analysis and single factor index method. [Result] Except for that the control area of the August 2014voyage belonged to IIclass sea water standard, the water quality in other stations of all voyages conformed toIclass sea water standard. Totally 20water quality indicators were synthesized into six principal components using principal component analysis, which explained 79.165% of the results;the principal component score was ranged from -1.536 to 3.706; the score in August 2014 was the highest, and the evaluation results were basicallyconsistent with the results of single factor index analysis. [Conclusion] The overall water quality is good in Dachangshan artificial habitat development demonstration area.

Simulation of Water Pollution Diffusion Based on WebGIS

Taking Liyang City of Jiangsu Province as the research object, a water pollution accident diffusion simulation and analysis system, taking WebGIS as the core, was established by taking finite difference method to do the system dynamics water quality model solution. This paper introduces the construction process of the model, the integration of the model with GIS, the interactive application of the system and users and the visual dynamic expression of water pollution accidents. By combining the statistical analysis of the spatial and environmental database in the system, the scientific simulation of the temporal and spatial relationship of the development of water pollution accidents on the client side is realized and providing precise decision support for early warning and control of water pollution diffusion.

Quantitative Analysis法在木兰溪水质模型选择中的应用

木兰溪是闽中最大的溪流,为福建省八条主要水系之一.对木兰溪水质模型进行选择可以根据Quantitative Analysis法,由Pe(Peclet Number)的范围来判断污染物在河流三维上的混合情况.通过将木兰溪划分为四个计算(控制)单元,对控制单元4的Pe值进行计算,快速准确地确定了适合木兰溪的简单实用的水质数学模型.

改进的FA-FCE模型在矿井水质评价中的应用

酸性矿井水会对水环境造成严重污染,对遭受污染的矿井水质进行评价是矿山环境保护与治理的重要前提。因此,以贵州省内的酸性矿井水分布区为研究区,采用因子分析(FA)、模糊综合评价法(FCE)和加权平均法,并引入级别特征值构建了FA-FCE水质评价模型,对矿井水质和水环境质量进行综合评价。结果显示,所评价的水样中V类水的占比达到70.37%,水质整体偏向于V类水,各地区的平均级别特征指数均大于2,矿井水水体环境遭受污染的程度较高。相较于传统的评价模型,文中提出的水质评价模型在选取评价指标及权重分配等方面有显著的优势,并综合考虑了所有评价指标在整体评价中的影响,使得评价结果更加科学合理。

熵权模糊改进法在宁夏黄河水质评价中的应用

为了解宁夏境内黄河流域的水质状况,选取银古公路桥、平罗黄河大桥、中卫香山湖、吴忠金沙湾、固原沟圈5个监测断面在2021年4月、6月、8月、12月4个时期的溶解氧、高锰酸盐指数、氨氮、总磷、总氮5项评价指标,共获得80组水样。针对熵权模糊评价法在权重趋于1时其微小变化会引起熵权成倍变化的病态问题和由于最大隶属度原则不能普遍适用而导致评价失效的问题,提出了一种熵权模糊改进的评价方法,通过改进熵权法确定权重和加权等级,建立改进的模糊综合评价模型,对水质样品进行水质分析和综合评价。结果表明,在权重分配方面,相比于隶属度法和传统的熵值法,改进熵权法分配的权重更为合理;在水质评价方面,加权等级法评定出的结果更符合研究区域的真实水质状况;宁夏境内黄河流域Ⅰ类和Ⅱ类水质占比超过90%,水质状况良好,5个断面4个时期的水质综合评价结果显示,12月份的水质最优,Ⅰ类水质占比85%;对水质的时空分析显示氨氮为全局性污染因子,溶解氧为区域性污染因子。改进的模糊综合评价模型对宁夏黄河水质的评价结果更为客观合理。

地下水水质分析的检测方法及质量控制

地下水是重要的自然资源之一,是我国城市居民主要的用水来源。但是地下水非常容易受到周边环境的干扰,导致发生污染,而一旦地下水遭到污染,如果继续饮用,将会给人们的身体健康造成严重的伤害,同时,对于周边自然生态环境来说,也会产生严重的影响,导致生态环境遭到破坏。本文通过对地下水常见的污染物进行分析,对地下水水质分析检测方法进行了探讨,并就如何提升地下水水质分析质量进行了探究,以供参考。

排水系统提质增效的外水定量分析及剥离措施研究

污水处理厂进水COD低是制约活性污泥工艺降解污染物效果提升的瓶颈。针对污水处理厂进水COD低的问题,建立了一种联用基于污水管网简化的水质水量模型逆向分析和正向摸查的外水入侵评估方法。通过污水管网简化的水质水量模型的逆向分析,确定了各级管网外水入渗量,并准确找出外水入侵的重点区域为主城区东北和西南侧。通过正向摸查发现,地下水入渗、雨水错接混入和河水倒灌为外水入侵主要原因,且外水侵入重灾区与定量分析结果一致。针对外水入侵的重点区域和外水入侵主要途径,实施了外水剥离措施,释放了管道内外水、增加污水收集量、提高旱天污水处理厂的进水COD浓度和保证旱天无溢流,最终达到污水处理厂进水COD浓度显著提升的目标。

张家口柴宣盆地浅层地下水水化学特征及水质评价

地下水作为张家口地区的主要供水水源,近年来受人类活动影响水质有恶化的趋势,影响了当地的用水安全,确定地下水化学特征与水质状况对水资源合理利用具有重要意义。基于2020年水质数据,选取Ca^(2+)、Mg^(2+)、K^(+)、Na^(+)、HCO^(-)_(3)、TH、pH、TDS、SO_(4)^(2-)、Cl^(-)、Al^(3+)、NO^(-)_(3)、F^(-)、Cr^(6+)等水质因子,通过数理统计法、Piper三线图、Gibbs图和岩石风化端元图对张家口柴宣盆地地区浅层地下水水化学特征进行分析,并采用模糊综合评价和改进内梅罗指数法对水质进行评价。结果表明:研究区地下水是Ca^(2+)和HCO^(-)_(3)为主的弱碱性淡水,微硬水、硬水和极硬水分别占39.51%、34.57%和25.93%;沿地下水流向,地下水化学类型由HCO_(3)-Ca·Mg、HCO_(3)-Na、SO_(4)·Cl-Na型转变为HCO_(3)-Ca·Mg、HCO_(3)-Na、SO_(4)·Cl-Ca·Mg型,水化学组分的空间分布特征主要受到硅酸盐、碳酸盐的风化溶解和人类活动影响;地下水水质整体满足III类标准,但部分地区水质较差;沿着地下水流向,水质逐渐变差,主要受原生地质环境和工业、农业污染的影响。

2010~2021年重庆市主要河流水质时空变化特征分析

重庆市地处三峡库区,是长江上游的重要生态屏障区,揭示其地表水水质变化特征对评估长江生态环境变化具有重要意义,然而目前其大范围、长时间尺度的地表水质特征分析还较为欠缺。基于2011~2021年重庆市主要流域中的18条河流,共44个河流监测断面的11 a水质数据,采用单因子分析法和水质类别比例法对水质变化进行分析。结果表明:①重庆市河流水质情况整体较好,Ⅰ~Ⅲ类水质断面占比从2012年开始逐渐上升并趋于稳定,水质状况评价均为优。②总体河流水质在汛期与非汛期变化趋势大致相同,但非汛期Ⅳ~劣Ⅴ类水质断面占比低于汛期,整体非汛期水质更好。③川江流域段下游水质明显好于上游,整体上自三峡水库2010年达到175.00 m蓄水位以来,川江流域的水质一直维持较好状态,水质类别多维持在Ⅱ类,实现了国定目标。④不同流域之间水质存在一定差异,水质最好的为嘉陵江流域,其次是涪江、川江和乌江流域。⑤川江、嘉陵江和涪江流域在汛期的水质状况比非汛期差,而乌江流域在两个时段水质状况变化一致。通过对重庆市地表河流进行长时间序列的水质评价,可为河流水资源保护及治理提供参考,以期提升市域水环境质量,促进城市的可持续发展。

连续流动分析法测定水中挥发酚和总氰化物的实验探究

挥发酚和总氰化物是水质监测和水环境保护的关键指标,其准确测定对评估水体质量和环境影响至关重要。随着检测技术的发展,采用在线前处理的流动注射分析法和连续流动分析法已成为其主流的检测手段。而我国尚未制定水中氰化物(除生活饮用水外)的连续流动—分光光度法国家或行业标准,为水质样品中氰化物的准确监测带来不便。本研究通过控制变量法,系统研究了试剂pH及浓度等因素对检测结果的影响,筛选出了合适的检测条件。该方法的测试结果呈现完全线性相关,挥发酚和总氰化物检出限低至0.279μg/L和0.118μg/L,样品加标回收率达到95.0%~105%。本研究不仅为水质挥发酚和氰化物的国家和行业标准制定提供了经验和依据,还为水质监测领域引入了一种更环保的方法。

水交换进镜方式对结肠镜检查质量影响的Meta分析

目的比较水交换与常规注气进镜方式对结肠镜检查质量的影响。方法计算机检索PubMed、Web of Science、the Cochrane Library、中国生物医学文献数据库、中国知网和万方数据,搜集关于水交换与单纯注气的常规进镜方式对结肠镜检查质量影响的研究,检索时限为建库至2022年10月8日。由2名研究员独立完成对文献的筛选、数据提取和质量评价。采用RevMan 5.4.1软件对纳入文献进行Meta分析。结果共纳入23项研究,10654例患者,Meta分析结果显示,水交换虽延长了进镜时间(MD=1.81,95%CI:1.28~2.35,P=0.000),但其腺瘤检出率(ADR)(O^R=1.40,95%CI:1.26~1.55,P=0.000)、盲肠插管率(O^R=1.62,95%CI:1.24~2.10,P=0.000)和肠道准备质量评分(MD=0.61,95%CI:0.42~0.79,P=0.000)高于常规进镜方式,疼痛评分(MD=-1.07,95%CI:-1.39~-0.76,P=0.000)、腹部按压(O^R=0.42,95%CI:0.29~0.60,P=0.000)和体位变化(O^R=0.59,95%CI:0.42~0.82,P=0.002)低于常规进镜方式,差异均有统计学意义(P<0.05)。结论水交换进镜方式虽延长了进镜时间,但提高了ADR、盲肠插管率和肠道准备质量评分,减轻了疼痛,降低了腹部按压和体位改变的概率,其是进行高质量结肠镜检查的较佳选择。

基于改进主成分分析法的水环境中重金属污染流域水质生态评价方法研究

为了准确掌握水环境中的重金属污染情况,提高水质生态防治效果,提出了基于改进主成分分析法的水环境中重金属污染流域水质生态评价方法研究。选取研究污染流域水质区域,收集4个区域地表水,测定金属元素含量,通过四类分析与评价法,实现对水环境中重金属污染状况及潜在危害的生态评价,得出评价的B区域和C区域水质综合重金属污染较高,铁元素在四个区域均在第一主成分,是污染程度最高的,整体生态评价为及格。评价结果表明所提方法可以对水环境中重金属污染状况进行精确的评价,辅助保护人民身体健康与生态环境。

模糊-主成分分析法在石化企业地下水水质评价中的应用

如果一个石油化工厂的生产过程缺乏防渗措施,就会导致排放物的泄漏,从而引发直接或间接的排放污染,进而影响到周围的环境,并最终导致地下水的严重破坏。因此,对地下水水质的评价尤为重要,关乎到人身安全及生态环境的保护。该文以某石油化工企业地下水水质评价为例,通过建立模糊-主成分分析法模型,首先通过主成分分析法对石化企业厂区周围的5个监测点位、17个污染因子进行分析,选取出主要影响水质评价的污染因子;其次再通过模糊综合评价法建立模糊关系矩阵,计算出主要污染因子的指标权重,最终确定不同监测点位的水质对各级水质的隶属程度。最终得出结论,石化企业厂区的5个监测点位的水质等级均为Ⅴ类标准,该石化厂区地下水污染严重。

深圳龙岗沙湾河水污染特征及水质评价

2021年,研究团队选取深圳市龙岗区沙湾河进行水质监测,采用单因子评价法、单因子水质标识指数法、综合污染指数法、综合水质标识指数法和主成分分析法进行水质评价。结果表明:单因子评价法与单因子水质标识指数法一致得出氨氮、总磷是沙湾河水质的主要影响因子;综合污染指数法评价结果显示,沙湾河水质污染程度基本达到“较清洁”状态;综合水质标识指数法评价结果显示,沙湾河水质基本满足地表水Ⅲ类要求;主成分分析法评价结果显示,河流受有机物、营养盐影响较为显著,雨季水质仍有较大提升空间。本研究表明各种水质评价方法结果虽有差异,但能从不同角度反映河流水质状况,使用多种评价方法能充分挖掘水质数据的意义、更好反映河流水质特征。