Determine of ferric chloride dosage for phosphorous removal. How much ferric chloride is required to precipitate phosphorous from untreated wastewater with the characteristics given below. Also determine the required ferric chloride storage capacity if a 15d supply is to be stored at the treatment facility and the added quantity of sludge generated from the ferric chloride addition.

Wastewater flowrate = 3800 m3/d

Wastewater TSS = 220 (mg/L)

TSS removal without iron addition = 55 %

TSS removal with iron addition = 75 %

Influent total P = 7 g/m3

Influent PO43- as P = 5 mg/L

Effluent PO43- as P = 0.1 mg/L

Wastewater alkalinity as CaCO3 = 240 (mg/L)

Ferric chloride solution = 37 %

Ferric chloride, unit weight = 1.35 kg/L

Raw sludge properties: specific gravity of 1.03, and moisture content of 94%.

Chemical sludge properties: specific gravity of 1.05, and moisture content of 92.5%