Study On The Treatment And Reuse Of PVC Efflux Wastewater Produced By Calcium Carbide

The PVC efflux wastewater produced by calcium carbide is the carbide slurry wastewater which contains about10%～15%solids, the wastewater is strongly alkaline and contains a lot of sulfur ions, it is able to cause seriously polluted if not treatment before discharge. At present, in the engineering, the carbide slurry wastewater usually through a sedimentation tanks for solid and liquid separation, the supernatant water can be returned to acetylene generator, the precipitated calcium carbide slag by pressure filtration can be used as building materials and thermal power plant flue gas desulfurization. But, if the supernatant water of the carbide slag slurry waste water being used for acetylene without handling sulfur ions, the sulfur ions in the reuse process will be deposited in the calcium carbide slag, carbide slag in the utilization process will exist hidden environment pollution. Therefore, it is necessary to remove the sulfur ions, achieve to the supernatant water reuse and carbide slag utilization completely.Through theoretical analysis and practical engineering, proposed an experimental study of using air catalytic oxidant method to handle sulfur ions in the carbide slurry wastewater. By small experimental test, acquired the best running conditions:Use MnS04as catalyst, the best dosage is:catalyst (m):sulphur(m)=1:7; Select the carbide slag slurry initial value pH (pH=12～14); According to wastewater’s sulfur ion concentration, aeration rate can be selected an appropriate aeration intensity between0.4L/min to0.6L/min; Reaction temperature was controlled at35℃to45℃is the most reasonable; Reaction time is controlled at5hours.The experimental results show that, the sulfur ions which contained in the carbide slurry wastewater in the optimum conditions be able to remove95%, Therefore, effectively overcomed the hidden environmental pollution problems which exist in the supernatant and carbide slag resource utilization process. By the economic analysis, carbide slurry wastewater treatment and utilization can significantly reduced PVC production costs, produce the fairly good economic effect and environmental benefits.