Abstract:In this paper, rice husk mortar made from rice husk and cement was prepared and the effect of two pretreatment processes, including water soaking and saturated lime water soaking, on the properties of rice husk mortar were studied. The results indicate that the mechanical properties of rice husk mortar made from pretreated rice husk were significantly higher than that made from untreated rice husk. The saturated lime water soaking pretreatment method is better than the water soaking method. The hydration heat peak and heat release in 3 days of rice husk mortar made from saturated lime water soaking is the highest. This paper also analyzes the change of surface functional groups of rice husk by infrared spectrum. The results show that after pretreatment the hemicellulose absorption peak reduces and the aliphatic absorption peak disappears on rice husk surface.

Abstract:The effect of thermal pretreatment with temperature between 70 and 120℃ and last for 20min on sludge organic matter solubilization, heavy metal release and anaerobic digestion was investigated. Flocs as well as cells were broken down and organic matter was released to liquid phase. Solubilisation of properties such as COD, carbohydrate, protein, DNA and ammonia all increased with temperature below 110 ◦C and experienced a significant jump at 100◦C .However, solubilisation of major organic compounds decreased at 120◦C. Cells of microorganism were broken down at 100◦C. The concentrations of heavy metals in the soluble phase increase with temperature. But no remarkable increase was observed for heavy metal release. VS removal and biogas production were investigated to evaluate the effect of thermal pretreatment on efficiency of anaerobic digestion. Both the two characteristics reached peak at 110◦C. Correlation matrices of biogas production per VS eliminated and VS removal rate with SCOD, soluble protein and soluble carbohydrates were explored to determine the influence of these selected variables on anaerobic digestion. Then the influence of soluble protein and soluble carbohydrates on biogas production per VS is illustrated by the stepwise linear regression equations.

Abstract:A method based on the coupling of microwave digestion and inductively coupled plasma optical emission spectroscopy determination was developed for heavy metals in printed circuit board (PCB). Detailed optimizations of sample preparation, digestion temperature setup and digestion regents usage were enabled to obtain the maximum extraction efficiency of metals from PCB samples. The recommended multi reagent microwave digestion technology, in which the volumes of HNO3 H2O2 HF were 7 ml, 2 ml and 4 ml respectively, could decompose PCB matrix efficiently and dissolve heavy metals into solvent very well. By using the optimized method, the analysis results of practical PCB samples were accurate and reproducible. And the results show that the contents of heavy metals in different PCB samples are quite discrepant and the amounts of Cu and Pb are even up to 27.1~441 g·kg-1 and 0.2~29 g·kg-1.

Abstract:The paper presents a novel method which enhances the capability of the reversible binary image data hiding scheme using runlength(RL)histogram modification algorithm.Before adopting the reversible binary image data hiding scheme using histogram RL modification algorithm,some pretreatments like AND operation and XOR operation are processed first.Experimental results prove its superiority to other methods.

Abstract:The selective inhibition mechanisms of various pretreatment methods like heat-,acid-,alkali-,chemical inhibitor-,aerate-,as well as the load shock pretreatment are reviewed and their corresponding bio-hydrogen performance are compared and discussed.The disagreement in optimal pretreatment methods should be attributable to the difference in the tested seed sludge,kinds and concentration of substrate,temperature,pH and reactor type.In addition,pure substrates of glucose or sucrose are currently used as substrate for hydrogen production in many studies.Practical organic wastes are recommended to be used as substrate for comparison of the effectiveness of different pretreatment methods.

Abstract:Related indexes of biostabilization,the pretreatment of municipal solid waste (MSW) prior to landfill are determined,and changes of pollution potential for landfill are discussed.After 44 days of biostabilization (active degradation stage and curing stage),the weight of MSW reduces by about 70% (in wet weight).The fractions of the readily degradable organic matters diminish significantly,but the lignocelluloses become the major components,reaching 62% (in dry weight).The biological reactivity value AT4 reduces by 80%.The methane emissions are estimated to decrease by 80%.Both chemical oxygen demand(COD) and total organic carbon(TOC) in the eluates plummet by 90%.TN and NH4—N in the eluates decrease to 60% and 20% respectively.The above results show that the process of biostabilization can reduce the pollution potential for landfill.

Abstract:The study determined related indexes during the process of biostabilization, the pretreatment of municipal solid waste (MSW) prior to landfill, and discussed changes of pollution potential for landfill. After 44 days of biostabilization (active degradation stage and curing stage), the weight of MSW reduces by about 70% (in wet weight). The fractions of readily degradable organic matters diminish significantly and lignocelluloses become the major components, reaching 62% (in dry weight). The biological reactivity value AT4 reduces by 80%. The methane emissions are estimated to decrease by 80%. Both COD and TOC in the eluates plummet by 90%. TN and NH4-N in the eluates decrease to 60% and 20% respectively. The above results show that the process of biostabilization can reduce the pollution potential for landfill.