The Research Of Integrative Treatment On Waste Water From Gas-making Process

A great deal of gas-making waste-water is produced in compounding ammonia , which contains a certain concentration of SS, S2-, CN- and NH3 , accompanying with high temperature . Currently , precipitation+bio-tower is widely applied in the treatment of gas-making waste-water . In fact , the present approach contains several shortfalls such as the SS is separationless , S2" and CN" can't do away with . Therefore , it results to quadratic transformation , bad ordour.Except for precipitation , no other ways are reported on the treatment of gas making waste-water ' SS . As for S2-, CN-, chloridize . neutralize, blowing . catalyst oxidation are all reported in some documents . But the above four methods can't be adopted in industrializing production . In order to find new ways to treat gas-making waste-water . Coagulation precipitation process is introduced to remove SS in the water ,and chemical oxidation is used to get rid of S2-, CN-.To find which factor is the main impact on coagulation of gas-making waste-water . Temperature, pH, the way of mixing, capacity of Al2 (SO4) 3 18H2O are selected to do cross experiment of coagulation. The cross experiment of coagulation indicates : if T=35 C, pH=8, rapid mixing for 30s and slow mixing for 30min, the capacity of Al2 (SO4) 3 I8H2O adding is l0mg/L. After 30min precipitation , the feculent degree cuts down to 25NTU, which according with the requirement of the craftwork gas-making.The cross experiment of oxidation demonstrates: if pH=8 , T=35 C , reaction time 30min , the liquor of NaClO (9%) requires 6.5 mg/L . And the remain concentrations is [S2-] lmg/L and [CN-] 5mg/L respective.The outcome from techno-economy analyzing shows: Coagulation precipitation process with chemical oxidation is used to integrative treatment on waste water . which has better disposal effect .And if s index of techno-economy achieves advanced level in the same trade.