Abstract: Mixing abandoned tyre rubberized powder as filler into cement-soil to form rubberized cement-soil can improve physical mechanical properties of cement-soil. By the methods of natural immersion and chemical titration, the rubberized cement-soil resistance to chlorine-ion permeation was tested and measured. With rubber content increasing, the chlorine-ion content and the apparent diffusion coefficient gradually reduces. The effects of large rubber particle size are better than that of the small. The soluble chlorine-ion content decreases with the erosion depth increasing. In the same depth, as erosion solution concentration increases, the apparent diffusion coefficient increases manyfold. It deduces that rubberized cement-soil resistance to chlorine-ion permeation is superior to common cement-soil.
Abstract: MnO2-loaded D301 weak basic anion exchange resin was used as adsorbent to simultaneously remove Co2+, Ni2+, Cd2+, Zn2+ and Cu2+ from aqueous solution contained high concentration of alkali and alkaline-earth metals ions. The effects of solution pH and coexistent ions on the adsorption were investigated. The results indicated that Co2+, Ni2+, Cd2+, Zn2+ and Cu2+ can be simultaneously removed in the wide pH range of 3 to 8. The coexistence of PO43− decreased the heavy metal ions removal rate, but for other high concentrations coexistence cations and anions such as Na+, K+, Cl−, NO3−, SO42− and HCO3−, there is no significant impact on removal rate of heavy metals. The adsorption isotherm can be well described by Langmuir isotherm. The adsorption processes followed the pseudo first-order kinetics model. High adsorption capacity makes it a good promising candidate material for simultaneous removal of Co2+, Ni2+, Cd2+, Zn2+ and Cu2+ from aqueous solution with the co-existence of high concentration of alkali and alkaline-earth metals ions.
Abstract: Effect of environment factors such as initial pH value, dissolved oxygen (DO) and temperature on phosphorus removal efficiency of phosphate reduction system was discussed in treating pickled mustard tube wastewater. Results indicate that environment factors have significant influence on dephosphorization efficiency. And, the impact of DO on phosphate reduction is mainly by affecting the distribution of micro-environment inner biofilm, manifest as phosphate removal rate decreased with a fall in DO concentration, while overhigh DO can lead to detachment of biofilm, thus causing the increase of effluent COD concentration, and so DO need to be controlled in the range of 6 mg/L. Moreover, a higher temperature is more beneficial to phosphorus removal by PRB. Unfortunately, exorbitant temperature can result in mass rearing of Leuconostoc characterized with poor flocculability in reactor, and that cause turbidity in effluent appeared as a rise in COD of effluent. Hence, the optimal temperature is found to be about 30°C.
Abstract: In this paper, the effect of utilizing first urban rail transit on decreasing energy consumption as well as air pollution in Ahvaz has been investigated. The No. 1metro path in Ahvaz with 23 kilometers length will connect the north eastern part of the city to its south western part by passing through the central area and crossing Karun River. At the beginning, some points will be mentioned regarding railway systems around the world and then the specification of Ahvaz No. 1 metro will be introduced. Finally, the amount of decreasing energy consumption and air pollution after utilizing 4 urban metro lines will be investigated. The results have shown considerable effects on decreasing these items.
Abstract: A kind of recharge well with filter layer exists in recharge engineering of Wanghe groundwater reservoir in Laizhou city of China. During artificial recharge of groundwater, layered sediments will silt in the surface layer of recharge well with filter layer. Through doing vertical permeability test of combined soil specimen of silt and sand, we simulate permeability influence to filter layer of recharge well with filter layer during artificial recharge of groundwater. The test indicates that silt reduces permeability of filter layer and recharge capacity of recharge well with filter layer. Also we discover that there are errors in theoretical calculated value of coefficient of permeability for combined soil specimen by the formula of equivalent coefficient of permeability in layered soil, which need to be corrected.
Abstract: Sorption of Pb, Zn, Cu by natural soils was investigated under conditions of variable pH, ionic strength and temperature. The results obtained from adsorption isotherm indicated that these data can be better fitted with the Freundlich equation than with the Langmuir equation in terms of regression coefficients. The parameters in the adsorption process were influenced greatly by solution pH and ionic strength. The Freundlich parameter KF increased with increasing pH and decreasing ionic strength, but the Freundlich parameter n changed adversely. Thermodynamic parameters of the process were calculated from sorption studies performed at different temperatures, and enthalpy changes (△H°) and entropy changes (△S°) of adsorption were found as -20.70 kJ/mol and 34.76 J/mol.K for Pb(II), -7.762 kJ/mol and 1.139 J/mol.K for Cu(II), -20.60 kJ/mol and 51.93 J/mol.K for Zn(II) respectively, showing that adsorption of Pb2+, Cu2+, and Zn2+ on natural soil were exothermic and spontaneous at 5-45°C.
Abstract: This study focused on star-up of the partial nitriﬁcation in sequencing batch biofilm reactor (SBBR) with domestic wastewater at room temperature. No signiﬁcant nitrate formation was observed during the full period of operation and the nitrite oxidizing bacteria (NOB) was successfully outcompeted. When influent ammonium concentration decreased from 200mg/L to 80mg/L, a stable inﬂuent at a ratio of 1.03 NO2-N/NH4-N was produced after 44 continuous cycles（33d）and that indicated partial nitrification achievement. A recommended start-up strategy based on high FA concentration and aeration control was proposed to achieve partial nitrification with low ammonium strength wastewater at room temperature.
Abstract: The disposal of sewage sludge is an important issue in practical engineering. This study proposes a new method of solidifying sewage sludge with stone material waste and portland cement. The effects of mass ratio were discussed by the investigations of unconfined compressive strength and volume change of the solidified samples for different curing time. Experimental results show that the binders appeared effective for improving the strength of matrices. it was also found that the volume capacity of matrices increased little, which is important to municipal solid waste disposal. Overall, the work suggests that stone material waste can be utilized as a substitution material for cement to reduce the cost of sludge disposal.
Abstract: This paper is about how diversification of evaluation subjects promotes reform of evaluation means of environmental performances of local Party and government leaders, completes evaluation index system, improves transparency and scientificalness of the evaluation and strengthens democratic supervision to the evaluations; besides, it suggests a series of measures, which are about building independent evaluation committee for environmental performances of Party and government leaders, setting diversified evaluation subjects and weight system in a scientific way, completing legislative work attended by diversified subjects, enhancing trainings for diversified evaluation subjects, cultivating performance management culture participated by diversified evaluation subjects, etc.
Abstract: This paper investigates the comprehensive assessment of water quality, which is generally a multi-attribute assessment problem. In this context, the grey relational analysis is adopted to settle the no uniformity problem of water quality attributes. The principal component analysis is applied to calculate the weighting values corresponding to various attributes of water quality so that their relative importance can be properly and objectively described. Results of study reveal that grey relational analysis coupled with principal component analysis can effectively solve the multi-attribute water quality assessment. The method is universal and can be a useful tool to improve the comprehensive assessment of water quality.