For each of the two water samples below, (a) and (b), calculate (pts per water sample):

meq/L required chemical addition of soda ash (Na2CO3) to achieve softening

kg/L of total solids produced in the softening process, considering that 7 mg/L of suspended solids is also removed through coagulation in the lime-soda softening process

actual chemical additions if lime is 88% pure and soda ash is 98% pure

the annual cost to treat 0.5 m3 /s (~11.5 MGD) of water if lime is $61.70 per megagram (Mg) and soda ash is $172.50 per megagram (Mg)

meq/L of CO2 added to water to convert half of the 0.6 meq/L of carbonate in the finished water to bicarbonate and to react with the 1.45 meq/L of OH- ions in the finished water to avoid pipe corrosion