Applied Mechanics and Materials Vols. 295-298

Abstract: Solidification is one effective method to treat the oil contained sea drill cuttings. To understand the pollutant leaching behaviors of the solidified oily sludge from Bohai drill cuttings, a series of experiments of solidification, curing, soak and analysis were carried out. The pollutant indexes of oil content and COD in the soak solution were tested. The influence of the composition of solidified agents, curing time and soak method of static soak or dynamic soak are discussed. The new concepts of C-O diagram and C/O value were proposed to present the characteristics and behaviors of pollutant leaching from the solidified oily sludge.

Abstract: As an effective method in automobile tail gas treatment, dielectric barrier discharge（DBD）is introduced. There are many parameters In DBD reactor that influence nitrogen oxide treatment reaction including discharge voltage, discharge frequency, discharge distance, gas influence and electrode structure. Discuss the influence of discharge voltage, discharge distance and medium thickness to electric field distribution in cylindrical DBD reactor through 2D numerical simulation

Abstract: Thermal compression is effective for solid-liquid separation of various materials. In this paper, thermal compression was applied on the dewatering of sewage sludge with coal as a filter aid. Experiments with 0.25-1 mm coal particles (0.2 kg coal/kg dry sludge solid) obtained cakes of solid content over 49%. Higher dosage of coal generated cakes with lower moisture content. The combustion behavior of the sludge cake was studied using TG/DTG analysis. The results showed that a total weight loss of 65.1% occurred from 25 °C to 800 °C, including two major weight loss stages corresponding to loss of moisture and volatile materials respectively.

Abstract: The application of the concepts in oil and gas distillation to membrane desalination process to lower the energy cost for seawater desalination was studied in this paper. Drawing on the close analogy between multistage RO and conventional distillation separation processes, a hybrid membrane processes employing reflux and recycle concepts was developed. Reflux in membrane processes involves taking a portion of the effluent stream on the high pressure side and sending it to the low pressure side of the membrane, while recycle involves taking a portion of the permeate stream on the low pressure side and sending it to the high pressure side of the membrane. A predictive model was developed to study the effect of reflux and recycle on the specific energy consumption (SEC) and permeate quality when compared to conventional systems. In this study, the water permeability coefficients of membranes and brine recycle ratios were investigated. The results show that the SEC for a hybrid membrane processes comprising of RO and NF membrane was lower than conventional methods with the same recovery and feed concentration, suggesting that it is feasible to apply reflux and recycle concepts of distillation on desalination. Through the careful selection of RO membranes and NF membranes, benefits of reflux and recycle can be enjoyed for seawater desalination.

Abstract: The carbonitriding treatment of deep reduced slag obtained in the smelting process of the non blast furnace with the vanadic titanomagnetite from PanZhiHua were carried out in a high temperature carbolic pipe furnace with nitrogen gas in order to obtain Ti(C,N). The results are found: there are a few of Ti (C, N) presented in the carbonitriding reaction production with theoretical amount of carbon at 1400°C; the content of Ti (C, N) increases with temperature; the carbonitriding reaction tends to finish at 1500°C; the average size of Ti(C,N) particles are 7.8452μm and the maximum is 21μm above 1600°C; the content of N in the Ti (C, N) decrease with temperature below 1400°C and that of N increase and the change of C content is opposite above 1400°C; To increase appropriately carbon amount can promoto the carbonitride reaction which is benefit for the formation and grow of the Ti (C, N); when the amount of carbon beyond the theoretical value, the maximum and average size of grains obtained is smaller. It shows that the bigger Ti(C,N) grains can be obtained and the high temperature is very important for the carbonitride treatment of the deep reduced slag to obtain Ti (C, N).

Abstract: The technology used the coagulation-sedimentation + electro-oxidation joint reactor has been studied to treat landfill leachate. First adding FeCl30.4g/L into all leachate for coagulation and sedimentation, its CODcr elimination rate can achieve 35%, but does have no effect on ammonia nitrogen. Then using electro-oxidation reactor to deal with effluent water, the reaction order of electro-oxidation reactor is first-level, as the reaction conditions are 20mA/cm2 of electric current density, 140min of reaction time, the leachate CODcr elimination rate can reach to above 90%, the ammonia nitrogen elimination rate meets to 98% around. Using coagulation-sedimentation + electro coagulation joint reactor to treat landfill leachate can get stable effluent water quality with good treatment effect, has very high elimination efficiency of CODcr and ammonia nitrogen. It is a suitable treatment technology for landfill leachate.

Abstract: Traditional wastewater treatment methods can no longer remove effectively nitrogen and phosphorus that are the direct murderers of water eutrophication hazard. Enhanced coagulation method was adopted to improve the treatment effect by dosing suitable coagulants and coagulant aids. The raw water was from the reclaimed water in a University. TP and ammonia nitrogen removal of the water had been researched through an enhanced coagulation process with dosing ferric chloride, aluminum sulfate, polymeric ferric chloride, and poly-aluminum chloride (PAC) in this study. The coagulants effects were estimated by determining the removal rate of ammonia nitrogen, TP, COD and turbidity. When dosing the raw water with 80 mg/L PAC, the removal rates of ammonia nitrogen, TP, COD and turbidity are respectively 6.12%, 67.79%, 26.21%, 85.41%. The experimental results can be used as a reference of water treatment in the reclaimed water station.

Abstract: Two tests were designed to investigate activated carbon adsorbing gasoline vapor. In the inlet vapor-air mixture of the adsorption towers, the vapor volume fractions were 0.05 and 0.40, and the mixture flow were 40 m3/h and 65 m3/h respectively. The test results showed that their recovery rate were above 95％. A new integrated technology of absorption-adsorption for gasoline vapor recovery was developed. The recovery rate was up to 99.6％, and the outlet vapor volume fraction can be controlled below 0.0032. The integrated system will appear distinct comprehensive benefit.

Abstract: The paper give the method of microwave catalytic oxidation process to treat UDMH waste water. The effects of microwave power, irradiation time, H2O2 dosage and activated carbon dosage on the degradation rate of UDMH were examined. Under the conditions of microwave power 490W, irradiation time 9min, H2O2 dosage 1mL and activated carbon dosage 1g per 100ml UDMH sewage, the degradation rate of UDMH is over 97%. The method is effective by experiments, which will be the new way to treat the UDMH waste water.

Abstract: Due to its influence on iron corrosion and involvement in dechlorination reaction, the concentration of H+ (i.e. reaction pH) is crucial to the reactivity and efficiency of nanosized Pd0/Fe0. In this study, PCP dechlorination by smectite-templated Pd0/Fe0 was studied and the effect of pH on PCP dechlorination was investigated in detail. The reaction rate constant is critically dependant on the reaction pH over the range 6.0~10.0. When the pH is 6.0~8.0, the dechlorination rate constant () increases rapidly with decreasing the reaction pH value; the rate change is up to 3.346 folds with decreasing of per pH unit; while it decreases down to 0.3338 when pH is in the range 8.0~10.0. The reductive efficiency of zero-valent iron (ZVI) was further investigated by spiking excess PCP in the reaction system. The maximal reaction efficiency of ZVI for PCP dechlorination attains to 78% when pH is 9.0. The difference between the dechlorination rate and reductive efficiency with respect to reaction pH suggest that ZVI could not be effectively utilized to reduce PCP under acidic condition.