The polyaluminium chloride(PAC)waste residue produced by a company in Hubei province is viscous and colloidal

and of weak acidity and large moisture.If it was piled or landfilled directly

environment would be polluted.The experimental investigation was carried out for treatment and utilization of the waste.Two ways were proposed for modification and utilization of the waste.One is to be used as building materials in stead of part cement to produce fired common brick;the other is to be used as additive of decolorant for refinement of petrochemical.The results show that the acidic mud with pungent swell can be changed to near neutral or neutral，and become odorless

non-toxic and environment-friendly by adding 2% of calcium lime.When the adding amount for modifying waste is within 10%—20%，the fired bricks with it could reach the requirements of the national standard and calcination temperature did reduce about 50—100℃.The modified waste could be used as additive of decolorant. When the ratio of waste/base material was in the range of （1∶9）—（2∶8）

not only the cost of deodorant could be decreased but also the influence on its two main indexes decolorizing ability and surface area was little and its performance could meet the product requirement.