基于亚临界技术的铬革屑水解工艺研究OA北大核心CSTPCD

The hydrolysis of chromium shavings with subcritical water was studied by single factor experiments and optimized by orthogonal test.The optimized parameters were temperature of 150 ℃,liquid ratio of 25,reaction time of 75 min,and calcium oxide dosage of 6％.Under these conditions,the hydrolysis ratio of chromium shavings was(83.98±0.16)％,and the chromium content of the hydrolysate was(34.81±2.29)mg/kg,which was lower than that of the organic fertilizer standard of the agriculture department.The main components of the hydrolysate were peptides and short peptide as well as a small amount of amino acids.The results indicated that the hexavalent chromium content of the hydrolysate and the solid residue were 1.317 mg/kg and 30.882 mg/kg,respectively,which means most of the chromium(trivalent and hexavalent)mainly exists in the solid residue.The leaching chromium content and the hexavalent chromium content in the solid residue were 14.285 mg/L and 1.544 mg/L,respectively,which were lower than the standard limits of"identification standard for hazardous wastes-identification for extraction toxicity".These results indicate that subcritical water hydrolysis for chrome shavings is a really harmless treatment and resource utilization.