Study On Microwave Assisted Detoxification Of Chromate Waste With Biomass

Chromium and its compounds are widely used in many manufacturing fields, including metallurgy, metal processing, electroplating, process hides, paint, printing and dyeing, pharmaceutical, and so on. It also shows that annually at present, the amount of waste residue with chromium is approximately within 200～300 thousand tons in metallurgy and chemical industry, and the volume of waste drainage containing chromium in whole industry is close to 9.32 million m3, which contain 699 tons of hexavalent chromium. All these wastewater containing chromium greatly pose harm to natural environment.The present method to detoxify the waste containing chromium is expensive and it will bring much sludge. This processing method, which utilizes biomass to process the wastewater and waste residue containing chromium, has become a hot point in recent years. Its advantages for the processing of heavy metal pollutant are strong adsorption ability and reducibility, and lower cost.The study aimed to comprehensive treatment and deep innocent treatment for wastewater and waste residue with chromium. The method utilizes the biomass with good biocompatibility and biodegradation, combining microwave treatment to detoxify the wastewater and waste residue with chromium. The proposed method achieved the purpose of reduction, regeneration and innocent treatment, realized comprehensive utilization of resource, and supplied the base of theory and experiment for future sustainable development.The paper focused on the study of simulating wastewater with potassium dichromate and real chromium residue. Initial pH value, rice husk dosage, microwave power, and contact time were taken into consideration and were investigated under experimental conditions. Results indicated that rice husk biomass had a good detoxification effect, detoxification ratio of waste water containing chromium is 57.2%, biosorption capability of rice husk for chromium is 0.48mgCr/ g(biomass), and detoxification ratio of chromium residue is 98% under the optional conditions . Moreover, Research on stability and toxicity for chromium residue after detoxification indicated that the residue after detoxification was stable and the concentration of Cr(Ⅵ) was constant.