Advanced Materials Research Vols. 356-360

Abstract: Wet Biochemical Flue Gas Desulphurization technique (WB-FGD) is combined both catalyst of transition metal with microbial metabolize to achieve flue gas desulphurization. In the self-designed device of power plant flue gas desulphurization, study the desulphurization kinetics according to the absorption solution pH, Fe³⁺ concentration, inlet concentration of SO₂, temperature and other factors. The results show that: Concentration of Fe³⁺ is the most critical factors in the desulphurization process, the desulphurization efficiency is decreased with the increasing of Fe³⁺ concentration, which in the range of 0~0.01mol·L^-1, and the desulphurization efficiency do not change significantly with the further increasing of the concentration of Fe³⁺.the desulphurization efficiency is decreased with the increasing concentration of H⁺ when pH of the solution in the range of 1.5~3.5. The efficiency of desulphurization decrease with the increasing concentration of SO₂, which in the range of 1145-3432mg·L^-1. The oxidation rate increase with the increasing temperature at 20~40°C.The kinetic equation and controllable parameters of changes of Fe³⁺ concentration are obtained according to the experimental data in WB-FGD.

Abstract: Contact oxidation is used to deal with the paper effluent from an enterprise of Tieling in this paper. The practical operation indicates that this technology overcomes the shortcomings of the traditional activated sludge process and has the characteristics of high anti-impact ability, high load, ran stably, the water quality of effluent is high and so on. At the same time, its one-time investment and occupation area are small, and its operation management is convenient. The wastewater quality of Contact oxidation can achieve that: CODcr≤80mg/L; SS≤20mg/L; BOD5≤30mg/L. Every index of the effluent can accord with the pulp and paper industry standards.

Abstract: The effects of the added EDTA and organic acids (oxalic acid, tartaric acid and acetic acid) on Cd desorption of Zhangshi Irrigation Area (ZIR)contaminated soil of Shenyang city was investigated by batch balance experiments, in which the concentrations of acids, pH and temperature were examined. The results showed that EDTA, oxalic acid, tartaric acid and acetic acid modified the desorption behaviors of Cd. And the desorption level was EDTA>tartaric acid >oxalic acid >acetic acid. Also, the desorption amount of Cd increased with the concentration ranges from 5 to 40mmol/L; the desorbed amount obviously reduced with elevating pH when the pH was below 6; the adsorption was facilitated and the desorption was weakened when the pH was above 6. In addition, the Cd desorption amount raised with the temperature increasing.

Abstract: A leaching solution of white mud was prepared from this waste material of soda production, and used for treatment of waste cutting oil emulsion. In alkaline conditions, the leaching solution of white mud generates hydroxide precipitates, which have relatively high specific surface area and excess surface energy, and readily adsorb the pollutants in waste cutting oil emulsion. The chemical composition of the white mud was determined and the hydroxide precipitates were characterized. The maximum removal efficiency (of turbidity, oil contents and TOC) was obtained at an adsorbent dosage of 4.0 g/L, pH 12.0 and 25°C. Leaching solutions of white mud could be used as an effective and low-cost material for treatment of waste cutting oil emulsion by the precipitation method.

Abstract: Using the secondary settling tank effluent, this paper is going to research the potentials of three coagulations (polyaluminium chloride, ferric sulfate, and self-polymeric aluminum ferric) in deep chemical phosphorus removal by the beaker experiment. The experiment focuses on the dosages, the hydraulic conditions of coagulation and effect of pH on the removal. The results show that three coagulants have good efficiencies in phosphorus removal. After coagulant treatments, phosphorus can be decreased below 0.5mg/L and achieve Grade A standards of urban sewage treatment plants (GB18918-2002). The removal efficiencies of polymer silicate are superior to those of poly aluminum chloride and polymeric ferric sulfate.

Abstract: Abstract. In this study, the simultaneous adsorption characteristics of ammonium and phosphate from aqueous solution by calcium chloride-modified zeolite were investigated. Results showed that the adsorption kinetic data of ammonium and phosphate onto the calcium chloride-modified zeolite could be well described by a pseudo-second-order model. The adsorption equilibrium data of ammonium onto the calcium chloride-modified zeolite fitted to the Langmuir isotherm model better than the Freundlich and Dubinin-Radushkevich isotherm models. The phosphate removal efficiency of calcium chloride-modified zeolite increased with the initial concentration of ammonium in aqueous solution. The ammonium removal efficiency of calcium chloride-modified zeolite increased with increasing solution pH from 7.0 to 9.0, but decreased with increasing solution pH from 9.0 to 10.0. The phosphate removal efficiency of calcium chloride-modified zeolite increased dramatically with increasing solution pH from 7.0 to 9.0, but decreased with increasing solution pH from 9.0 to 10.0. The mechanism for the adsorption of ammonium onto the calcium chloride-modified zeolite was ions exchange, and the mechanism for the removal of phosphate by the calcium chloride-modified zeolite was chemical precipitation.

Abstract: Water quality–landscape interaction were explored using multiple line regression in watershed, total stream corridor (200-m riparian buffer extending the entire stream length upstream of the site) and the local stream corridor (200-m riparian buffer extending 1000 m upstream of the site).The results showed that the catchment landscape characteristics appeared to have slightly greater influence on water quality than the total stream corridor and local stream corridor. The edge density of construction land and percent cultivated land had the greatest influence on water quality in watershed scale. The edge density of forest land and percent forest had the greatest influence on water quality in total stream corridor scale, but percent forest and PD had the greatest influence on water quality in the local stream corridor scale.

Abstract: Heavy metal capture experiments were carried out in a tube furnace to investigate the effect of different sorbents and Si-Al ratios on the capture of Zn, Cu, Pb, Cd and Cr during simulated MSW incineration. The incineration bottom ash was digested by aqua regia and HCl/HNO₃/HF, then determined by ICP-AES. Experimental results indicate that HCl/HNO₃/HF is more suitable for the digestion of incineration bottom ash than aqua regia; the volatilization capacities of the five metals during simulated MSW incineration at 1000°C follow the sequence of Pb > Cd > Cu > Cr > Zn; zeolite and limestone have a certain efficiency to capture Zn and Cr while kaolinite has no efficiency to capture all the five metals; the addition of kaolinite and zeolite can prevent the glass and brick powder from melting which can cause the package of heavy metals, but the addition of zeolite can promote Zn and Cr to form silicate, aluminate and aluminosilicate; the mixture of SiO₂ and Al₂O₃ is in favor of the adsorption of Cd and Cr, but against the adsorption of Pb and Cu compared with single SiO₂ or Al₂O₃.

Abstract: Daqing oilfield; oil-contaminated soil; alkaline soil; multi-plant system; phytoremediation Abstract: Daqing oil-contaminated alkaline soil and high concentrations oil-pollutant samples were mixed at the ratio of 4:1, 2:1, 1:1 and 1:2 (vsoil/voil), respectively. Then the oil content of the mixed samples were detected and analyzed after phytoremediation experiment with multi-plant systems. The research results showed that Salsola collina Pall-Chinese wildrye-Thistle Herb-Medicago-Artemisia ordosica multi-plant system had a good degradation effect on oily-pollutants. During the 105-day experiment, the degradation rate of oil-pollutants could be up to 80.5% in the mixed soil (4:1, vsoil/voil). During the whole experiment, removal rate of total petroleum hydrocarbons (TPHs) could raise up 65.5% in the Coronilla varia-Lolium perenne-Amaranthus hypochondriacus multi-plant system mixed soil (2:1, vsoil/voil). Experimental results proved that the degradation effect on TPHs could be improved by the multi-plant systems and they could be reasonably matched to cure and restore the ecological environment of oil-contaminated soils.

Abstract: Hydrogen sulfide (H₂S) is a malodorous gas which can cause nuisance and health effects to people who live and work in the contaminated air environment. Therefore, the main objective of this work was to study the removal of hydrogen sulfide (H₂S) using a biofilter packed with mixture of compost, organic fertilizer, wood chips and municipal wastewater sludge at a ratio of 60:10:20:10 by weight. The experiment was carried out at hydrogen sulfide concentration of 5-200 ppmv and empty bed residence time (EBRT) of 60 seconds. The results indicated that completer H₂S removal can be achieved at H₂S inlet concentration of 200 ppm_v. Elimination capacity of the biofilter reached as high as 24.38 gm⁻³ h⁻¹.