| Chromium and its compounds are the absolutely necessary material for metal working, widely applied to all kinds of industry manufactures, including metallurgy, electroplating, process hides, painting, pharmacy, printing and dyeing etc. These manufactories distribute all over the country, venting a great deal of wastewater and waste residue with chromium every day. According to incomplete statistics from State Environmental Protection Administration of china, about 200-300 thousand tons waste residue and 9.32 million m~3 wastewater with chromium will be discharged in china, which contain 7 million tons hexavalent chrome. All these wastewater and waste residue with chromium greatly harm natural environment and human bodies, which have been paid high attention to by related department such as industrial management, urban construction and environmental protection of our country.This processing method, which utilizes biomass method to process the wastewater and waste residue containing chromium, has become a hot point in recent years. The biomass can be any kind of organic compounded by photosynthesis, and is the direct or indirect result deriving from the growth of plant, which contains Fuel Wood, agricultural waste, forest waste, animal waste (excreta), and so on. Its advantages for the processing of heavy metal pollutant are as follows: 1) Powerful adsorption ability and reducibility; 2) Lower cost. Therefore, the utilization value of biomass material will deserve to be paid more extensive attention to by Environment Protection Team.The study in this paper aims 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, realizing comprehensive utilization of resource, and supplied the base of theory and experiment for future sustainable development.The paper will focus on the study of potassium dichromate simulating waste water and real chromium residue. The exploratory studies are as follows:① Study of chromium-bearing waste water detoxified by microwave and biomassI The adsorption dynamics and mechanism for contaminants in waste water with high concentration chromium are studied by selecting the biomass with high absorption property. Amount of biomass, concentration of chromium-contained waste, pH, and time of adsorption for the influence of absorption behavior are discussed.II The study of basic physical and chemical changes for biomass under the conditionof microwave irradiation is done; and it is also discussed that the rules of physical and chemical properties of biomass are influenced by microwave power, time of function, and so on.III Study of detoxification behavior of biomass absorbing chromium under the condition of microwave irradiation.IV Stability and toxicity analysis for remainder residue after detoxification.(2) Study of chromium-contained waste residue processed by microwave and biomass.I The detoxification dynamics and mechanism for waste residue with chromium are studied under the condition of microwave by selecting the biomass with high deoxidization property. The study also discussed that detoxification behavior is influenced by the factor of amount of biomass, amount of residue with chromium, microwave power and time of microwave function;II Research on stability and toxicity for chromium residue after detoxificationTwo innovations were applied in the paper. Firstly, providing a new way to disposed the waste by the waste, given biological treatment to microorganism of agriculture and forestry. Secondly, treating wastewater and waste residue with chromium by microwave, a cleaning energy which heats quickly and accelerate chemical reaction, have no temperature grads, heat stress and lagged effect, put forward a new process to dispose other heavy metal pollutant. |
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