Problem 2. One of the drawbacks for treating domestic wastewater in an activated sludge treatment is its lowered temperature during winter seasons. The efficiency of biological treatment decreases with a decrease in water temperature due to slow microbial growth. One approach to overcome this drawback is to heat water. Assume that a wastewater with a flow rate of 6000m3/d will be heated to increase its temperature from 15C to 25C in an aim to improve the biological treatment efficiency in an activated sludge treatment during winter season. Based on information given in the problem; a) Calculate the daily heat necessary as kcal/d to increase the temperature of wastewater from 10C to 25C. (6p) b) Estimate the cost of heating as TL per cubic meter (m3) wastewater treated if coal is used as an energy source. Do you think the cost you calculated for heating wastewater is feasible? Heat of coal =7800kcal/kg (7p) c) Assume 2m3 of wastewater is evaporated daily during heating process, calculate the annual heat loss through evaporation as kcal/y. (7p)