1.Write down a mass balance expression for a chemical release in a lake given the following: the lake is completely mixed, in-flow and out-flow are equal, degradation of the chemical is occurring through biodegradation (k1) and chemical transformation (k2).
2.A weir is to be installed to measure flows in the range of 0.5 to 1.0 m3/sec. If the maximum (total) depth of water that can be accommodated at the weir is 1m and the width of the channel is 4m, determine the crest height of a suppressed weir that should be used to measure the flowrate.