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It is common to use mathematical models to estimate how point source discharges influence concentrations within receiving waters. Although the residuals have been modeled in streams, lakes and estuaries, this introduction considers only streams. Discharges and stream-flows are considered to be constant and steady-state conditions ate assumed. It is also assumed throughout that only a single point source is involved.
Models foe predicting how the discharge of conservative substance affects stream quality are invariably based on the law of conservation of mass, also referred to as the “mass balance equation.” chlorides and total dissolved solids are the indicators modeled most frequently. As shown in figure 6-1,a mass balance analysis for conservative substances uses two equations, one for the conservation of flow and one for the conservation of residuals.
The units shown(cfs and mg/L)are illustrative; other flowrate and concentration units can also be used. because the substance is conservative and streaflow is constant, the increase in concentration caused by the discharge is independent of the distance downstream. This analysis assumes the effluent is completely mixed once it enters the stream and the concentration of residuals is uniform throughout any stream cross section. Equation 6-1is used to determine how chloride reduction by the Margarita Salt Company influences the concentration of chlorides in the Cedro River.
参考答案:It is common to use mathematical models to estimate how point source discharges influence concentrations within receiving waters. Although the residuals have been modeled in streams, lakes and estuaries, this introduction considers only streams. Discharges and stream-flows are considered to be constant and steady-state conditions ate assumed. It is also assumed throughout that only a single point source is involved.(通常使用数学模型估计点源怎样在收到水内卸影响集中。 虽然残余已经被在溪，湖和河口里塑造，但是这个介绍只考虑溪。 卸并且流量考虑恒定和稳态条件吃以为。 可以也认为在整个那只有单个的点源被包含。)
Models foe predicting how the discharge of conservative substance affects stream quality are invariably based on the law of conservation of mass, also referred to as the “mass balance equation.” chlorides and total dissolved solids are the indicators modeled most frequently. As shown in figure 6-1,a mass balance analysis for conservative substances uses two equations, one for the conservation of flow and one for the conservation of residuals. (预言保守的物质的解除怎样影响溪的模型仇敌质量不变基于质量守恒定律， 此外称为"质量平衡方程式"。 氯化物和总数溶解立体图形是最经常塑造的指标。 如图6-1中所示， 保守的物质的一个质量平衡分析使用两个方程式，一为流动的保护和一为残余的保护。 )
The units shown(cfs and mg/L)are illustrative; other flowrate and concentration units can also be used. because the substance is conservative and streaflow is constant, the increase in concentration caused by the discharge is independent of the distance downstream. This analysis assumes the effluent is completely mixed once it enters the stream and the concentration of residuals is uniform throughout any stream cross section. Equation 6-1is used to determine how chloride reduction by the Margarita Salt Company influences the concentration of chlorides in the Cedro River.(显示的单位(cfs 和毫克/ L)是说明性的； 其他flowrate 和集中单位也能被使用。 因为物质是保守的，streaflow是恒定的，解除引起的集中的增加顺流不依赖距离。这个分析以为一旦它进入这条溪，残余的集中在整个任何溪横断面相同，废水被完全混合。 第6-1 方程式用来确定玛格丽塔盐公司的氯化物削减怎样在Cedro 河里影响氯化物的浓度。)