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691.
《印度化学会志》2021,98(11):100223
West Bengal is a rich cultural state for a number of religious festivals. One of the most important festival is Kali Puja and Diwali. Idol is supposed to be the image of God which is used for worship. After worshiping immersion of idols took place in the various Ghats of the river. Several accessories of worship such as flowers, food offerings, plastic sheets, polythene bags etc. are also poured in water. Materials of idols consist of clay, plaster of Paris, varnish, oil paint etc. These paints are highly pigmented and consist of white lead, lithopone, chrome yellow, cadmium sulphide, barium chromate, vermillion, red lead etc. heavy metal salts. This study is an attempt to assess the change in water quality before and after the immersion of idols giving emphasis on heavy metal. The above investigation were carried out by collecting the water samples from six immersion ghats of the river Hooghly before & after immersion of Kali idols of the year 2019 followed by the analysis of the different parameters of water. Investigation reveals a significant changes in heavy metal concentration between pre and post immersion of the idols. A pollution due to the idols immersion into the water bodies cause adverse effect to the aquatic life or entire ecosystem.Use of natural dyes for idols obtained from flowers, leaves roots of plants, wood, seeds may reduce this pollution to a significant level. Moreover, awareness among the people of the society may have a significant responsibility in controlling this pollution satisfactorily.  相似文献   
692.
利用三维荧光光谱法(3D-EEM)研究了保定府河溶解性有机质(DOM)的荧光特性,根据三维荧光光谱图中荧光峰的位置、数量及强度变化,荧光峰之间的相关性,初步判断荧光物质的类别、分布和来源。府河水体溶解性有机质主要有类蛋白质和类溶解性微生物代谢产物两类,类蛋白荧光峰Ex/Em=225~230/340nm(A);类溶解性微生物代谢产物荧光峰Ex/Em=275/340~350nm(B)。不同采样时间和采样点,府河水体基本上都存在类蛋白荧光峰和类溶解性微生物代谢产物荧光峰。分析各荧光峰强度与水质指标相关性发现,两荧光峰之间呈显著性相关,表明研究区域中类蛋白质和类溶解性微生物代谢产物具有同源性;DOM两类荧光峰与COD,TN,TP,NH3-N呈显著正相关,表明通过两类荧光峰强度可推测府河污染程度,为府河污染防治和沿河流域生态环境治理提供参考。  相似文献   
693.
With the intensification of people’s production and life behaviors, the systemic risks of water, energy and food in the Yangtze River Basin have become increasingly prominent, which has become a bottleneck for sustainable development of social, economic and ecological in the basin. Therefore, studying the symbiotic coordination between water, energy and food is of great significance to promoting regional sustainable development. First, from the perspective of water–energy–food symbiosis, with the water–energy–food ecosystem conceptual model as the nexus, the two-step measurement model of the symbiotic index and the symbiotic level index is used to study the water–energy–food symbiosis of the Yangtze River. Then, we use the BP-DEMATEL-GTCW model to identify the key influencing factors that affect the symbiotic security of the water–energy–food ecosystem. In this research, it is found that the average value of the symbiotic degree of the water–energy–food ecosystem of the 11 provinces or municipalities in the Yangtze River Basin only reached the risk grade. It can also be seen from the identification results of key influencing factors that energy microsystem-related indicators have a greater impact on the symbiotic development of the entire WEF ecosystem. Therefore, special attention needs to be paid to increasing energy sources and reducing expenditure. Relevant departments need to effectively develop primary energy production and expand energy-saving investment through multiple channels to expand energy self-sufficiency and ultimately promote the coordinated and effective development of water, energy and food in the Yangtze River Basin.  相似文献   
694.
为连续、系统地研究不同年份丰水期黄河甘宁蒙段表层沉积物中重金属的含量、污染状况和潜在生态风险,在前期工作的基础上,采用三级四步提取法(BCR)和高分辨电感耦合等离子体质谱(HR-ICP-MS)对2012年丰水期黄河甘宁蒙段包头浮桥(S2)、石嘴山陶乐镇(S6)和乌金峡(S9)等10个采样点水体表层沉积物中Cd,Pb,Cr,Ni,Cu,V,Co,Zn和Mn九种重金属元素进行含量测定和形态分析,并对重金属元素的污染作出评价。结果表明:各重金属元素在每个采样点分布趋势相同,平均含量顺序依次为:Mn>V>Zn>Cr>Cu>Ni>Pb>Co>Cd;表层沉积物中重金属主要以残渣态形式存在,表明重金属的生物有效性低,对环境影响较小;地积累指数法 (Igeo) 的评价结果显示Cd元素的Igeo值最高,对环境污染程度较高,其余元素对环境影响较小,其中Mn元素影响最小;富集因子法(EF)评价结果表明,Cd和Cu元素在某些采样点表现为显著富集,尤其是Cd在S5点处EF值高达4.69,表明该点处Cd受人类活动影响较为明显,其余元素均为非富集元素,这与Igeo评价结果吻合;潜在生态风险指数法(RI)表明,黄河甘宁蒙段S1,S2和S5点的RI值在150~300之间,为中等危害范畴,其余各采样点RI值均小于150,为轻微危害。研究结果为相关部门提供可信的实验数据和理论依据,也为建立该河段泥沙-污染物输移数学模型和系统研究持久性有毒污染物迁移转化规律及环境评价提供技术支撑。  相似文献   
695.
研究了汉江下游武汉段河漫滩7个沉积物的吸附特征及温度和扰动强度对磷吸附等温线的影响,用改进的Langmuir模型和Freundlish模型对实验吸附数据进行拟合,可得到最大吸附容量(Qmax)、原有吸附可交换态磷(NAP)、临界磷平衡浓度(EPC0)和固-液分配系数(Kp)的值.结果表明,改进的Langmuir模型更适用于描述汉江河漫滩沉积物的吸附特征,其物理意义更明确;Kp与Qmax呈较好的线性关系;沉积物吸附和解吸磷能力与温度变化一致;沉积物在等温吸附磷过程中,固体浓度效应在强扰动强度(200r/min)时最强。弱扰动强度(150r/min)时次之,中扰动强度(100r/min)时最弱.  相似文献   
696.
本文以塔里木河下游英苏断面350m处C5井为研究对象,分析了影响下游英苏断面的潜水埋深影响因素,通过三层BP神经网络模型模拟了潜水埋深变化.以Matlab7.0为工作平台,将2000.7-2008.12期间的英苏C5井的步长为3个月数据资料作为一个样本,选取每个样本的输水量、输水持续天数、上季度该井的潜水埋深平均值作为模型输入量,输出量为相应的C5井的本季度的潜水埋深平均值,建立3—11-1的BP神经网络模型,模拟了C5井潜水埋深.结果表明,网络模拟相对误差小于5%,模型具有较高的精度.通过BP模型模拟潜水埋深,为塔河下游生态恢复和水资源决策提供一定的依据.  相似文献   
697.
A recent study on the Taylor series method of second order and the trapezoidal rule for dynamic equations on time scales has been continued by introducing a derivation of the Taylor series method of arbitrary order p $$ p $$ on time scales. The error and convergence analysis of the method is also obtained. The 2-step Adams–Bashforth method for dynamic equations on time scales is concluded and applied to examples of initial value problems for nonlinear dynamic equations. Numerical results are presented and discussed.  相似文献   
698.
In this paper, we study the long-time behavior of solutions of a reaction–diffusion model in a one-dimensional river network, where the river network has two branches, and the water flow speeds in each branch are the same constant β. We show the existence of two critical values c0 and 2 with 0<c0<2, and prove that when c0β<2, the population density in every branch of the river goes to 1 as time goes to infinity; when 2<β<c0, then, as time goes to infinity, the population density in every river branch converges to a positive steady state strictly below 1; when |β|2, the species will be washed down the stream, and so locally the population density converges to 0. Our result indicates that only if the water-flow speed is suitably small (i.e., |β|<2), the species will survive in the long run.  相似文献   
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