A&B Test Questions - Florida Rural Water Association

16: Selective Carbonate hardness removal requires the use of:A: soda ashB: carbon dioxideC: limeD: lime and soda ash17. The softening process samples indicate the following data:T Alkalinity: 90 mg/l. P Alkalinity 40 mg/l.Treatment parameters call for a treatment range of +2 to +5 hydroxide alkalinity. From theanalysis what action should you take?A: decrease Lime feedB: increase carbon dioxide feedC: decrease carbon dioxide feedD: increase lime feed18: You are operating a lime softening plant where magnesium removal is necessary. The processincludes lime addition, recarbonation and filtration. How could you maintain the quality oftreatment and also save on operating costs?A: eliminate recarbonation and use split treatment to lower the pH and save on limeB: add calcium carbonate to saturate the softened waterC: feed lea lime and more soda ashD: recarbonate after filtration19: You are operating a lime softening plant which produces a finished water with a total hardnessof 80 mg/l as Ca CO3, and a Langelier Index of +0.6.What is the problem?A: the finished Water is aggressiveB: too much CO2 was addedC: the finished water hardness is too lowD: the finished water will be scale forming20: What caused the problem in the question above?A: the pH was too lowB the excessive CO 2 increased the L. I.C: too much blendingD: excessive calcium carbonate15