Advanced Materials Research Vols. 610-613

Abstract: Air contains oxygen, nitrogen, etc. The gas separated technology and mixed method could increase or decrease the certain components of air. Changing the concentration of the component has a great influence on soot formation of diesel engine. The influences of excess air coefficient and the oxygen, nitrogen proportion of inlet air, the initial temperature and the initial pressure on PAHs (the soot precursor) formation of diesel engine were discussed in this paper. The results showed that the coupling model of diesel PAHs could predict the reaction temperature, the concentration of the reaction intermediates (CO, CO2 and O2), and the ignition delay during the combustion progress accurately. The concentration of the soot and its precursor PAHs could be decreased effectively by changing the proportion of the oxygen and nitrogen in the inlet air. After increasing the excess air coefficient, the numbers of the reaction intermediate free radicals (H and OH) were increased and the concentration of aromatic hydrocarbons was decreased. The beginning angle of chemical reaction was advanced by increasing the initial temperature and pressure. And it is beneficial to decrease the concentration of PAHs.

Abstract: Applying surface flow constructed wetlands/subsurface flow constructed wetlands/UV disinfection compound constructed wetland treating sewage treatment plant tail water，introducing the technological process，engineering design parameters and equipment configuration，and summarizing the design characteristics. The operation results showed that the average removal rate of COD，NH3-N，TN and TP was 24.3%，36.8%，20.7% and 24.2% respectively，and The effluent can fully meet Standard A of the first class in GB18918-2002，“Standard for Discharge of Pollutants from Sewage Treatment Works in Towns and Cities”.

Abstract: The treatment efficiency of Da Huofang Reservoir water in low temperature and low turbidity period by Coagulation/Ultrafiltration process was investigated in pilot study, and the water quality treated by the process was compared with that by the traditional treatment process. When coagulant dosage is 30 mg/L, the average removal rates of turbidity, CODMn and UV254 were 89.2%, 47.3% and 52.8% respectively in the coagulation/ultrafiltration process, and the treatment efficiency was obviously superior to the traditional process. In the study of operation parameters optimization for Coagulation/Ultrafiltration process, the optimum membrane flux was determined that was 50 L/m2h. The cleaning membrane water was treated by coagulation sedimentation process, and the quality of effluent was good which was mixed with raw water for reuse, and the experiment indicated that this method did not affect the stable operation of Coagulation/Ultrafiltration process, eventually the water recycling rate was improved from 89% to 96.5%.

Abstract: In order to evaluate the impacts of N and P mobility from phophogypsum on surface water quality, the dissolved N and P concentrations in the drainage and river waters nearby phophogypsum piles were investigated at the phosphoric acid plant regions in central Guizhou Province, and batch leaching tests for the phophogypsum was performed. The results shown that the concentrations of NH4+ and PO43− in leachate solutions from phophogypsum were 0.325~0.587 mg L−1 and 148.6~266.0 mg L−1, respectively, and higher concentrations of NH4+ (2.86~8.02 mg L−1) and PO43− (201.9~1195.6 mg L−1) in the drainage waters from phophogypsum pile. In phosphoric acid plant areas, the concentrations of NH4+ and PO43− in the stream waters nearby phophogypsum piles were 0.96~2.36 mg L−1 and 1.26~4.89 mg L−1, respectively, as indicated by high concentrations of NH4+ and PO43−, suggesting a eutrophication problem for surface water nearby phophogypsum piles in those areas.

Abstract: Sediments are principal carriers of the trace elements in the hydrosphere. Properties of the sediment (such as grain size, specific surface area and pore volume) decide the concentration level of the pollutant contain in water. The properties of sediment differed in each lake according to the normal geological phenomenon and source of discharge wastewater. The purpose of this study is to investigate the properties and contamination level of the sediment collected from lakes in Universiti Putra Malaysia (UPM). Sediment samples are taken from three different lakes; Lake IT, Lake ENG and Lake PK. These locations are selected due to the type of wastewater has been discharged into the lakes which are from colleges and academic buildings. The sediments were tested in terms of physical, chemical properties and contaminant concentration (Pb, P and Cu). Using the contaminant concentration results; the sediment concentration level of the pollutant of each lakes were referred to the Consensus- Based Sediment Quality Guidelines (CBSQG-2003). The dominant grain sizes of the sediments were found in the range of silt/clay; with the size fraction in the range 12.74% to 12.83%. The specific surface areas of sediments were in the range of 16.3 to 22.5 m2/g with a pore size distribution in the range of 20 to 29 mm3/g. The chemical properties show that the pH values are in normal range; pH 7, TOC values in the range of 10.84 to 12.39% and salinity values in the range of 0.05 to 0.06 dS/m. The contaminant concentrations show that the main heavy metal presents in Lake IT, Lake ENG and Lake PK as Lead (Pb) with 0.033 mg/l, 0.036 mg/L and 0.038 mg/L, respectively. According to the CBSQG-2003, due to the concentration of Lead presents in lakes sediment in UPM area, the sediments were categorised as non-polluted.

Abstract: A new method, NOx reduction by in-situ catalytic effects of additives loaded in coke, was proposed. A series of coke samples with different loading amounts of CaCl₂, Ce(SO₄)₂ and La₂(SO₄)₃ were prepared by using the impregnation method, the rules of NOx and CO emissions in the combustion were investigated. The results show that CaCl₂, Ce(SO₄)₂ and La₂(SO₄)₃ play in-situ catalytic effects on the NOx reduction reactions. When the loading of CaCl₂ is 4.0%, the amount of NOx emission is reduced by 13.9%. When the loading of Ce(SO₄)₂is 4.0%, the amount of NOx emission decreases by 17.2%. When the loading of La₂(SO₄)₃ is 4.0%, the amount of NOx emission decreases by 8.7%. Ce(SO₄)₂ possesses the combustion-supporting effect. As 4.0% Ce(SO₄)₂ in coke, the CO emission is reduced by 26%, which improves the combustion efficiency of coke.

Abstract: In view of the defects of existing much “dead area” and decreased effective volume causing by distributing water device of UASB reactor, a new-style of external circular(EC) reactor was developed in this research. In this paper, through laboratory scale and pilot scale study on the external circular anaerobic reactor to treat coal chemical wastewater, we conducted profoundly theoretic and testing analysis on external cyclone-flow distribution water device, the results reveal that the new-style anaerobic reactor can largely advance the mixture of granular sludge with wastewater, enhance the availability of reactor’s cubage, heighten mass-transfer efficiency between substrate and microbes, and avoid effectively the losing of granular sludge, further reduce the cost of disposing coal chemical wastewater, which had very important theoretical indication function and practical application value in the development of coal chemical wastewater treatment by anaerobic technology.

Abstract: Experiments were conducted in small bubbling absorber apparatus to study the effect of organic additives such as adipic acid, inorganic additives such as sodium sulfate, and self developed compound additives on wet flue gas desulphurization which using CaCO₃ as sorbents. Experimental results show that adding these additives not only speed up limestone dissolving, but also intensify calcium sulfite oxidation, which provides theoretical support for application of additives in the WFGD.

Abstract: Input-output model on cement plants were established. Carbon dioxide emissions of key steps and carbon footprint of products were calculated and predicted using the input-output model. The results showed that CO2 emission in the plant (the production of the plant is 1320000t a year) reached 910000 t a year and CO2 emission per ton product is 0.689 ton. Over 80% of the total CO2 was emitted during the process of firing，so the firing process is the key step for reducing CO2 emission in the cement plant. Carbon footprint of three kinds of cement products including ordinary portland cement, portland pozzolan cement and portland blast furnace slag cement are 0.76, 0.59, 0.72 respectively.

Abstract: Reducing heavy metals mobility and improve the soil physical-chemical property in order to reduce plant uptake would be an urgent demand for safe rice production in China. A field experiment was conducted for the research of biochar (BC) amendment on the dynamics of soil enzyme activities in a contaminated paddy soil after 2 years. BC was applied in 2009 before rice transplantation at rates of 0, 10, 20, 40 t ha-1, and three undisturbed soil cores of 0 to 15 cm depth were sampled from each plot for physicochemical analysis and enzymatic monitoring. Compared to the control, the soil pH and SOC were significantly increased by 2–5 % and 16–51 % after BC amendment. The activities of cellulase, urine enzyme, neutral phosphatase and sucrase were also found to increase by 117.4–178.3 %, 31.1–37.6 %, 29.7–193.8 % and 36.5–328.6 %, respectively. Furthermore, there were positive correlation of soil enzyme activities with soil pH and SOC content. Data in this research indicated that BC amendment may be potential in improvement of soil properties to some extent to achieve the agricultural use. Introduction