Advanced Materials Research Vols. 726-731

Abstract: Regarded as an effective treatment to many kinds of industry wastewater, CWS technology is introduced to treat coking-wastewater, to simplify treating procedure. A low rank coal from Ximeng (in China) was prepared to slurry with clean water and three kind of wastewater at different treating depth. The results indicated that: (1) the coking-wastewater performed a slightly better effect than the clean water for preparing CWS; (2) the apparent viscosity decreases rapidly by heating the slurry, but increases when the temperature reaches to a unique value. The value is 40°C for cleaning-workshop feed CWS, 30°C for membrane filter feed CWS, and 50°C for membrane filter underflow.

Abstract: This article first applied correlation analysis to identify the key factors in factors influencing people's medical service demands, such as the population, economy and people's living level and so on. Then, it built the forecast model of the medical waste generation amount based on the GM (1, n). finally, it took Dalian city as an example for empirical study. The results show the forecast method has higher accuracy, and it is a useful method for the prediction of the medical waste generation amount.

Abstract: Magnesium silicate (MS) was successfully prepared and the physico-chemical properties were determined by N₂ adsorption/desorption isotherm and Scanning Electron Microscopy (SEM). Surface area and the average pore size were 120 cm³·g^-1 and 10 nm. Adsorption experiments of removal of nickel and cobalt ions were investigated as the function of initial concentration, adsorbent dose, adsorption time and solution pH value. The maximum removal was reached with pH equal to 5 for the removal of nickel and cobalt ions. Adsorption process was rapid and adsorption equilibriums were attained in a short time.

Abstract: Compression box is a major part of MSW transfer station's compression unit. Box structure's design should meet load requirement and achieve weight optimization. Based on the analysis of the box structure, a load distribution model of compressed MSW in the compression box was made. Using SolidWorks and ANSYS to analyze the model, the analysis result can provide scientific basis for the optimization design of the MSW transfer station's compression boxes.

Abstract: This paper study was commenced to treat fatal contamination at the Er-Jen River, supplied water for agricultural irrigation, aquaculture and industrial in Kaohsiung and Tainan Area, when the Sixth River Management of Water Resources Agency (WRA) developed the project to build flood embankment. The fatal contamination was throw into the discard by illegal manufacturer which discarded the wastage of printed circuit boards, toxic heavy metal contained sludge, and waste aluminum slag. The treatment project was conducted by Industrial Technology Research Institute (ITRI) on preliminary tests, cleanup planning, and process supervision to ensure contamination removal, flood protection, and landscape improvement. The accumulative volume cleaned and screened on this site reached 45,159 cubic meters, whereas 378.25 tons of waste printed circuit boards, 12,833 tons of toxic heavy metal contained sludge, and 31,000 tons of general industrial wastages. The waste printed circuit boards through stripping/acid washing and screening, there are 334.653 tons valuable (including 0.143 tons of copper and 334.51 tons of wire casting materials) from the recycle extract and 43.597 tons of wastes that were not valuable for reutilize. Toxicity characteristic leaching procedure (TCLP) tests were conducted on the site after cleanup to verify the treatment work successful, because the rate of contamination removal was greater than 90%.

Abstract: The use of coal fly ash for CO₂ sequestration has been proposed as a promising option for its utilization. However, research is quite necessary for advancing this technology. Indirect carbonation of high-calcium coal fly ash for CO₂ sequestration was investigated in this study. In these processes, calcium was first extracted from a high-calcium coal fly ash sample with NH₄Cl solution. The obtained leachate was subsequently carbonated by bubbling CO₂. It was shown that NH₄Cl could extract about 35% of the total calcium into the solution under the conditions investigated. The dissolution of calcium is nearly accomplished in half an hour. Further increasing the extraction solution temperature (10-90°C) and the concentration of NH₄Cl (0.5-3mol/L) only has subtle positive effects on the calcium extraction efficiency. The carbonation efficiency of the extraction leachate, namely the percentage of the calcium in the solution transformed into calcium carbonates is about 47%. The sharp drop in pH after bubbling CO₂ due to weak acid buffering capacity of the solution hinders the further precipitation of Ca²⁺. Calcium carbonate samples with a purity of up to 97% are obtained, meeting the purity requirements for industrial use.

Abstract: The possible exploitation of two-phase anaerobic digestion for swine manure was investigated in this study. One-phase and two-phase anaerobic digestion process were investigated in continuous stirred-tank reactor with hydraulic retention times 15 days (hydrolysis and acidification for 3 days and methanogenic12 days in two-phase). When the organic loading rates were equal to or less than 4 g VS/L day, the biogas yield and volumetric production of two processes were no significant difference. However, in the case of organic loading rates being equal to or higher than 5.0 g VS/L day, two-phase biogas yield and volumetric biogas production averaged 0.294 L CH₄/g VS added and 2.218 L/L day, compared with one-phase averaged 0.255L CH₄/g VS added and 2.168 L/L day, respectively. Significant advantages in saving cost of biogas project were indicated by the comparison of biogas production and COD degradation in the one-phase and two-phase processes.

Abstract: Boron slurry is the waste of borax manufacture. Here, the property and compositions in Boron slurry were analyzed by FTIR, TGA and XRD, which is derived from a borax factory in Dashiqiao of Liaoning Province, China. Some valuable inorganic elemental compositions in Boron slurry, such as Mg, Si, Ca, Fe and Mn were recovered by the processes of calcination, precipitation and filtration. Results have shown that the recovery of MgCO₃ can be reached at 90% when the calcinations temperature is 750°C.

Abstract: Pyrolysis of sewage sludge for the fixed bed were investigated at different final temperatures (300-900 °C) to acquire distribution and characteristics of pyrolysis products. The mass balance was established on base of continuous on-line measurement of gases and integration of gas compounds to give a more accurate reflection on the yields distribution. It was observed that at low temperatures the liquid was the main product with maximum yield of 57 wt%(daf) at 500°C and the gas composition was mainly CO₂. Under the condition of a higher pyrolysis temperature (above 600°C), secondary reaction occurred among phase of solid, liquid and gas and generated more CO and H₂. From the perspective of energy utilization and accumulation of heavy metals, a lower temperature no more than 600°C is suitable for sewage sludge pyrolysis.

Abstract: The difficulty occurred in nuclear power plants that the accumulated radioactive solid waste is beyond the design capacity and unable to be sent to disposal is focused on in this paper. The deep reasons for the difficulty occurred are concluded to be the unclear responsibility for disposal of radioactive waste and the divided national function of nuclear power development and radioactive waste management, by analyzing the disposal demand of radioactive solid waste caused by continuous development of nuclear power and the current situation and existing problems for the disposal of low-intermediate level radioactive solid waste in China. The policy suggestions of issuing the disposal siting plan of radioactive solid waste, forming independent firms of radioactive waste storage and disposal and improving radioactive waste management fund system are proposed based on above analysis and investigation.