Treatment of 2,4,6-Trinitrotoluene Wastewater by Freeze Crystallization

摘要

Treatment of TNT redwater by freeze crystallization has been studied in a scraped surface crystallizer. Crystal growth of ice from wastewater was accessed. Using initial supercooling levels between 0.1 and 3.5°C and concentration range of 1,000 to 10,000mg/L COD, the growth anisotropy of ice crystals was in the range from 0.8 to 5×10~(-7)m/s. The efficiency of separation was determined by the percentage reduction in original COD of the melt and effective distribution coefficient between the crystals and the residual melt. For initial COD of a 3000mg/L, the red water was treated under 90mg/L COD, which represented 97% COD reduction. With different ice seed mass, size and ratios, the yield and purity of the product crystals were also studied. Eventually freeze crystallization can be used for treatment of TNT wastewater.