Applied Mechanics and Materials Vols. 675-677

Abstract: Aerobic denitrifying bacteria, a fast and efficient strain, is extensively adopted in the wastewater sphere, and immobilized aerobic denitrifying bacteria denitrification Technology, to some extent, solves many problems existing in the direct application of aerobic denitrifying bacteria. Concentrated sulfuric acid, nitric acid, potassium permanganate, ferric chloride etc. are used to pretreat carbon fiber respectively, and then the modified the carbon fiber is applied to fix the activated aerobic denitrifying bacteria to investigate the effects of the modification of the carbon fiber and the effects of wastewater treatment with immobilized aerobic denitrifying bacteria. The results showed that the fixed efficiency of the strain with carbon fiber pretreated by nitric acid reached 50% and when the strain fixed by the modified carbon fiber in adsorption method treated wastewater, the ammonia nitrogen removal rate reached 78% and the COD removal rate was always stabilized above 40% in three days.

Abstract: A set of bench scale ASBR reactors with 0.5 L effective volume were carried out to culture anaerobic ammonia oxidizing bacteria, while the anaerobic granular sludge was inoculated into these reactors as well as the operating temperature is 30±1°C, HRT is 72h and pH is approximate 7.8 in this experiment. After 60 days running, these reactors appeared anaerobic ammonia oxidation phenomenon. When the influent NH₄⁺-N and NO₂^--N concentrations were approximately 50 mg/L and 70 mg/L, the NH₄⁺-N, NO₂^--N and TN removal were 80%, 90% and 70%, respectively, the ratio of the NH₄⁺-N and NO₂^--N removal and NO₃^--N production is approximately 1:1.5:0.25, close to the theoretical valve of 1:1.32:0.26 and that mainly accord with the chemical equilibrium of anaerobic ammonia oxidation mode. Furthermore, when the phenomenon of anaerobic ammonia oxidation appeared, effluent pH value was slightly higher than influent and the sludge become red.

Abstract: The amount of hair dye wastewater largest stage formed by oxidative hair dye in terms of quantity and quality, there is a serious pollution problem in the aquatic environment. Through analysis of the main component of hair dye to verify the use of activated carbon adsorption - Coagulation - potassium permanganate oxidation technology of wastewater treatment which is effective measures.According to different types of hair dye,about 80% of the market demand oxidative hair dye brown was selected to study. The results showed that the COD of 2427mg / L, the chromaticity of the hair 1000 times wastewater using 1300mg / L activated carbon adsorption treatment alone, the removal rates were 37.79%, 18.29%; in this condition and 140mg / L of mixed PAC condensate combined treatment, removal rates were 90.09%, 90.56%; potassium permanganate solution 70mg / L continues oxidation treatment, the removal rate reached 90.34 %, 97.37 %.

Abstract: Air quality has been deteriorated seriously in Shanghai as a result of urbanization and modernization. Air pollution concentrations were decreased during the period of 2008-2011. PM₁₀, SO₂ and NO₂ concentrations were higher in winter than in summer. Meteorological conditions affect air pollution levels in the urban atmosphere significantly due to their important role in transport and dilution of the pollutants. Multiple linear regression models were used to predict next day’s PM₁₀, SO₂ and NO₂ concentrations, respectively. The calculated R² values were 0.753, 0.800 and 0.861 for PM₁₀, SO₂ and NO₂ regression model, respectively. This result shows the multiple regression model analysis, providing simple and faster application facilities, is useful for modeling the impacts of meteorological factors on air pollutant levels.

Abstract: Mg-Fe hydrotalcite-like compounds (Mg-Fe-HTLCs) were synthesized via hydrothermal method, and characterized by XRD and FT-IR. The roasted products were used to remove sulfate ions by the adsorptive ability from aqueous solution. The effects of adsorbent dosage, initial pH and temperature on the sulfate ions removal were fully investigated, and the adsorption kinetics and adsorption isotherms were also studied. Results showed that the synthesized materials with CO₃^2- as the interlayer anions had fine crystallinity. The materials of Mg-Fe hydrotalcite-like compounds had a very good adsorption capacity for aqueous solution with the initial sulfate ions concentration was 500mg/L, pH range from 4 to 8 and temperature of 35°C. Moreover, the adsorption equilibrium was about 90 min under the optical condition. The experimental data showed a good compliance with the pseudo-second-order kinetic model, and the adsorption isotherm data met Langmuir models well. It was found that the maximal adsorption capacity reached 151.51mg/g.

Abstract: In this study we compared the efficiency of four kinds of amendments (silkworm excrement, coconut husk, red mud, sepiolite) and their mixtures to immobilize the heavy metals present in a contaminated acidic soil (Pb:420 mg ·kg⁻¹ ; Zn :334 mg· kg⁻¹) and to influence several enzymatic activities. The results showed that, silkworm excrement, coconut husk and their mixtures, which had high pH and/or high content of organic matter, reduced exchangeable Pb in the soil by 18% to 46%, and reduced available Zn by 24% to 35%, which was more efficacious than single sepiolite. The complex of silkworm excrement and red mud had a great influence on soil pH, while coconut husk increased the content of organic matter in soil significantly.

Abstract: A series of BiOCl_(1-x)Br_x catalysts were prepared by the precipitation method using cetyltrimethylammonium bromide ( CTAB ) and cetyltrimethylammonium chloride ( CTAC ) as template and source of halogen. UV-Visible, XRD and FTIR were employed to investigate the composition and catalytic properties of the catalyst. The results show that the BiOCl_0.8Br_0.2 composite exhibits the highest photocatalytic activity at room temperature. The degradation rate of dye wastewater containing 3mg/mL catalysts is 82%.

Abstract: As the grim situation of the contamination caused by the sludge is gradually expanded in China, the target to make sludge harmless, stable, reduced, and available is increasingly aimed. Traditional methods and techniques of sludge treatment, disposal, and resource utilization are mature and widely used in many waterworks. With the fast progress of science and technology, some new technologies in treating sludge are appearing to manage the incoming challenge of sludge treatment and disposal. Therefore, the traditional methods and novel development of sludge treatment and disposal are reviewed in this paper in order to find optimal solutions to solve the problems of the sludge pollution.

Abstract: The internal structure and the working principle of gravity oil-water separator used for self-circulation well-flushing equipment were given. Based on CFD, the flow field was calculated and analyzed with partition plate settings. The influences on separation efficiency were analyzed, according to velocity vector diagrams and oil drop trajectory diagrams. The results show that the location of the primary partition plate is installed more reasonable, the efficiency of separation is more advantage. Also, the structure and size of the primary partition plate and the size of the auxiliary partition plate can influence the efficiency of oil-water separation regularly.

Abstract: To reduce environmental pollution caused by waste drilling fluid , Liaohe Oilfield takes methods of sewage pit seepage control and waste drilling solidification disposal.Firstly,different impermeable material comparation has been taken , as a result , high-density polyethylene geomembrane (HDPE) was choosn as the impermeable material for sewage pit .which has features of good seepage control, good chemical stability, low price ,non-toxic and environment friendly.According to features of five different landforms in Liaohe Oilfield, corresponding seepage control programs are developed. impermeable material, implementation and measurement of sewage pit are unified and standardized.which prevent contamination of underground water caused by waste drilling fluid effectively. Finally, curing treatment of the waste drilling fluid is carried out ,forming a system engineering to meet the needs of environment protection and costs control.