Advanced Materials Research Vols. 610-613

Abstract: On the condition of natural rainfall and through the measure method of field runoff plots, an field experiment with six water and fertilizer managements (i.e. none fertilization and routine irrigation, routine fertilization and routine irrigation, optimization fertilization and routine irrigation, increasing nitrogen fertilization and routine irrigation, increasing phosphorus fertilization and routine irrigation, optimization fertilization and optimization irrigation) in 3 years ( 6 stubbles of rice) was carried out to study the effects of water and fertilizer managements on yield, nutrition uptake of rice and loss of nitrogen and phosphorus by runoff from paddy field. The results show that, under the 6 water and fertilizer managements, the dry matter yield of rice is 11629 ~ 19709 kg hm-2 a-1, the uptake of nitrogen, phosphorus and potassium in rice plant are 90 ~ 174 kg•hm-2 a-1, 36 ~ 62 kg hm-2 a-1, 151 ~ 288 kg hm-2 a-1, respectively, and the loss of nitrogen and phosphorus by runoff from paddy field are 14.0 ~ 42.9 kg hm-2 a-1 and 0.244 ~ 0.559 kg hm-2•a-1, respectively. Moreover, the dry matter yield of rice, the uptake of nitrogen and potassium in rice plant and the loss of nitrogen by runoff from paddy field under the treatment of “increasing nitrogen fertilization and routine irrigation” are relative higher than others. And the rice yield and nutrient uptake of “optimization fertilization + optimization irrigation” treatment is equivalent with “routine fertilization + routine irrigation”, but nitrogen and phosphorus loss of surface runoff reduce obviously, and the irrigation water is saved by 900.5 m3 hm-2 a-1, synchronously. Thus, better economical and environmental benefit would be reached by the treatments of “optimization fertilization and optimization irrigation”.

Abstract: Based on the Selective Catalystic Reduction (SCR) DeNOx project for 2×330MW-unit in a coal power plant, the gas flow field in SCR system has been optimized by numerical simulation. The optimized simulation results were compared with the physical model experiment, and the fly ash sedimentation in the duct was also investigated. Correlation analysis of the results shows that, the flow field predicted by numerical simulation matches very well with that of physical model experiment. Numerical simulation can not only predict but also improve the flow field in SCR system. The combination of simulation and physical model experiment provides a reliable basis for flow field optimization design in SCR system.

Abstract: Using modified flavedo as the adsorbent, the sorption process of Zn²⁺ by modified flavedo in wastewater containing heavymetals was studied. The effects of various factors in Zn²⁺ adsorption, such as adsorbtion time, temperature, pH value, initial Zn²⁺ concentration, and pretreatment, were analyzed. The results showed that the pretreatment of modified raised adsorption capacity, and the adsorption capacity was suitable for wastewater with a wide range of pH values. The rate of removal of Zn²⁺ reached 98% when the Zn²⁺ initial concentration was under 100mg/L. The optimal conditions for Zn²⁺ adsorption by Modified orange peel were a wastewater pH value of 5.5, at 25°C, an adsorption time of 60 minutes , and a dosage of modacrylic flavedo of 2 g/L.

Abstract: In water environment management, a mixing zone is an area within which the concentration of pollutants are allowed to be higher than the water quality standards and beside which the water quality should satisfy the standards. A reasonable range of a mixing zone is important for the water function and environment manage. At present, there is no agreed method for mixing zone calculation. In this paper, a new calculation method of a hydrodynamic-based marine pollution mixing zone was proposed; it comprehensively considered both the source intensity and the specific hydrodynamic conditions. The example results showed that the method could really reflect the mixed state after sewage entering into the sea water and could be used in a mixing zone calculation.

Abstract: According to the situation that the N and P indexes in the MSBR process of municipal wastewater treatment plant can’t meet the I-A wastewater discharge standards of China, the optimized operation parameters were put forward, including improving the sludge within the reflux ratio, opening the return ratio, increasing SBR hypoxia anoxic mixing time, controlling of dissolved oxygen in the aerobic tank,and so on. Through industrial experimentation, the effects of enhanced bio-denitrification were also discussed. The experiment results show that the wastewater treatment plant with 7-tank process of MSBR will meet the I-A wastewater discharge standards of China of the N concentration in effluent through enhanced bio-denitrificaion, but it have bad impact on the TP removal, then through chemical dephosphorization in advanced treatment the effluent water quality will satisfy the I-A wastewater discharge standards of China entirely.

Abstract: Wastewater is an inevitable by-product in human production and life. And with development of human society and enhancing of urbanization level and citizens living standards, wastewater quantity will sharply increase. Greenhouse gas (GHG) from wastewater treatment will drastically do, too. In especial CO₂, its emission quantity is most, its greenhouse effect is highest among GHG from wastewater treatment. But current wastewater treatment engineering does not relate to GHG in the design and operation process. In the case of global climate change, obviously the problem of CO₂ emission from wastewater treatment has to be solved. And because of this the paper sum up China and other country's research results, current status, and future direction.

Abstract: In this paper,TiO₂ was prepared by the sol-gel Method,which has high activity and oxidation abilities .The polyurethane is famous for its transmittance and film forming properties,we use polyurethane and titanium dioxide to produce TiO₂/polyurethane films. In this paper, phenolic wastewater was considered as the research object,Discussed photocatalytic properties and photocatalytic reaction kinetics model of TiO₂/polyurethane film at 253.7nm UV irradiation.The results show that degradation rate of phenolic wastewater approached to 14.6mg.L-1.h-1.m2-1 when Ti0₂ dosage of 60 mg/L,reaction time of 240 min,Phenolic wastewater initial concentration of 10mg/L and pH5.0.The dosage of TiO₂,wastewater initial concentration and pH have significant influence on apparent first-order rate constants of photocatalytic degradation,Reaction kinetics of photocatalytic degradation to phenolic wastewater accordances with the quasi-one grade equation of Langmuir-Hinshelwood.

Abstract: This paper introduces the preparation and activation methods of sludge activated carbons, including physical activation,chemical activation,chemicophysical activation,catalytic activation,etc. Among these methods,catalytic activation has better application prospect as it owns many advantages.The applications of rare-earth element Ce in TiO2 photocatalysis modification and flue gas desulfurization are described. At the end of the paper , the current research situation and application prospect of sludge activated carbon doped with Ce are discussed.

Abstract: The series of stable A-F/PDM composite coagulants prepared by combining polydiallyldimethylammonium chloride (PDM) with the composite (A-F) of aluminum sulfate (AS) and ferric chloride (FeCl₃) were used to research the treatment effects to Taihu Lake prechlorinated algae-containing water in winter. The composite coagulants were tested by jar tests for the effects of mass percents (5%~20%) and intrinsic viscosity values (0.55~3.99dL/g) of PDM on algae- and turbidity-removal efficiencies. The results show that when the residual turbidity of supernatant after sedimentation reaches the control standard of 2 NTU, the dosages of A-F and A-F/PDM (0.55/5%~3.99/20%) are 4.52 mg/L and 4.27~2.52 mg/L respectively, and the algae-removal rates are 90.1% and 92.0%~96.3% respectively. When the dosages are 4.52 mg/L, the algae-removal rates are 90.1% and 92.5%~99.0% respectively, and the residual turbidities are 2.00 NTU and 1.76~0.60 NTU respectively. Therefore, using A-F/PDM composite coagulants can enhance evidently the treatment effect of A-F to Taihu Lake prechlorinated algae-containing water in winter.

Abstract: Biological removal of nitrogen and phosphorus species from an artificial wastewater was investigated in a sequencing batch reactor ( SBR) by changing operating mode which simulation oxidation ditch aeration realization of point and achieved alternate anoxic/aerobic, The results show that: the total control for 6 h reaction time, including aeration 3 h, stop aeration 3 h, four conditions under the condition of 30 min, 10 min, 5 min, 3 min anoxic/ aerobic alternate of COD, ammonia nitrogen removal not too big effect, TN, TP influence is bigger. COD removal efficiency is above 89% for four modes and effluent COD is lower than 35mg/L.Ammonia nitrogen average removal efficiency is above 90% for four modes and effluent ammonia is less than 5mg/L.Total nitrogen removal rates was 68.71%, 67.70%, 60.36%, 37.27% respectively for four modes. In instantaneous influent, anoxic and aerobic alternating time should not be less than 5min for TN removal. Mode Ⅰto Ⅳ removal efficiency of TP was 23.05%, -2.17%, 1.19%, 43.61% respectively.