BOILER WATER PROBLEM & THEIR TREATMENT

PROBLEM	TREATMENT
O2	Mechanically: By de-aerating equipment Chemically: By adding Sodium sulphite or Hydrazine 2Na2SO3 + O2 ® 2Na2SO4  N2H4 + O2 ® 2H2O + N2
Acid corrosion	By lime [Ca(OH)2] and soda ash [Na2CO3] treatment: MgCl2 + Ca(OH)2 ® Mg(OH)2 + CaCl2 CaCl2 + Na2CO3 ® CaCO3 + 2 NaCl      (CaCO3 & NaCl are dissolved salt)
Alkalinity	Caustic soda [NaOH] & Na2CO3
Caustic cracking	Na2SO4 & NaNO3
Scale	Sodium phosphate [Na3PO4]
Phosphate treatment	Tri-sodium phosphate [ Na3(PO4)2], sodium hexa-meta phosphate, sodium meta phosphate, Di-sodium phosphate CaSO4 + Na3(PO4)2 ® Ca3(PO4)2 + Na2SO4
Sludge	Sodium aluminate, poly electrolyte, starch, tannins.
Foaming	Antifoam chemical