[Study on thermogravimetric characteristics of simulated medical waste by using TG-DTA-FTIR analysis].

Thermogravimetric behavior of simulated medical waste was studied in the atmosphere of nitrogen and air at different heating rates by thermogravimetric analysis and differential thermal analysis (TG-DTA), and the influence on the thermogravimetric behavior of simulated medical waste by the atmosphere and heating rate was also discussed. The results indicate that the initial separating temperature of the volatile organic matter ( T(s)) moves toward higher temperature and the peak value of the weight loss velocity (DTGmax) has a remarkable increase with the increasing heating rate when simulated medical waste is heated at these two atmospheres. There are two weight loss peaks when the experimental material is pyrolyzed at the atmosphere of nitrogen and the corresponding weight loss rate is about 31% and 59% . There are three weight loss peaks at the atmosphere of air and the corresponding anterior two weight loss rate is about 44% - 59% and 31% - 46%. At the same time, qualitative analysis of evolved gases under different conditions was analyzed by the coupled simultaneous fourier transform infrared spectroscopy (FTIR). In addition, quantitative analysis of CO, CO2, H2O and CH4 was conducted. Experimental results show that the main thermogravimetric stages of simulated medical waste in the atmosphere of nitrogen and air have the similar products, and the typical absorbed peaks of CO2, CO, alkanes, aldehydes, carbonyl acids, alcohols and alkenes were detected. And result shows that the heating rate and atmosphere have an effect on the yield of CO, CO2, H2O and CH4. In the main stages of the process, the curves of water content changing along with the heating time show downward peaks, which count for the participation of water during the reaction.

[Experimental study on the treatment of low level radioactive waste water by inorganic nanofiltration membrane].

Soluble sodium poly(acrylic) acid (NaPAA) with molecular weight of 2000-5000 was selected as an assistant reagent of inorganic nanofiltration membrane which was used to treat low level radioactive waste water mainly containing radionuclides 90Sr, 137Cs and 60Co. The effect of non-active simulated wastewater pH and NaPAA concentration on the retention efficiency of non-active nuclides strontium, cesium and cobalt ions and membrane permeation flux were explored, and the effect mechanism was also preliminarily discussed. The optimum process parameters were decided: pH 7-8, NaPAA volume concentration no lower than 0.1%. Real radioactive waste water was treated under optimum experiment condition. The results show that the decontamination efficiency of total beta and gamma emitters of low-level radioactive wastewater were both up to about 95% by inorganic nanofiltration assisted by NaPAA, and the permeation flux was also satisfying.

Composting MSW and sewage sludge with effective complex microorganisms.

The effects of complex microorganisms in composting process of the municipal solid waste (MSW) and sludge were examined through inspecting biomass, temperature, oxygen consumption, organic mater, and C/N (the ratio of carbon and nitrogen). The experimental results shows: complex microorganisms are effective to compose organic matter and speedup composting change into humus.