Advanced Materials Research Vols. 807-809

Abstract: With the wide application of SCR technology, the deactivation of SCR catalyst has caught attention in the coal-fired power plants. The activities of fresh and used SCR catalysts were compared and the deactivation reasons were analyzed by using scanning electron microscope (SEM), BET, X-ray diffraction (XRD), and X-ray fluorescence (XRF). The results showed that the specific surface area of the used catalyst decreased significantly, caused by the pore blockage of fly ash or sulfates on the surface of the used catalyst. The activity of the used catalyst decreased seriously, and the relative activity of the field sample had declined to 0.60. Moreover, according to the results of X-ray fluorescence, alkali poisoning was one of the main reasons for the decline in the activity of the catalyst.

Abstract: Effect of the presence of acetic acid on the pretreatment of dye wastewater by flocculation was studied. The effects of pH, PAC and PAM dosage on the flocculation of dye wastewater containing acetic acid were studied, with the dye wastewater without acetic acid as the blank. The results showed that the optimal pH of the dye wastewater with acetic acid by flocculation was 8, and that of the dye wastewater without acetic acid was 6, but the COD_Cr removal efficiencies were no significant difference. The best dosage of PAC and PAM of dye wastewater containing acetic acid was 4g/L and 0.15mg/L respectively. The presence of acetic acid was no influence on the flocculation treatment of dye wastewater. Then the effect of different concentrations of dye wastewater containing acetic acid on the flocculation treatment was followed. The results showed that the treatment effect increased with the increase of wastewater concentration.

Abstract: the effect of pH shock on the magnetic micro-aerobic activated sludge system used to deal with low load glucose wastewater was studied. After pH shocking under the condition of pH=6.0 and 9.0 for 15 days, COD_Cr removal efficiency of the reactor with magnetic powder was higher than that of the reactor without magnetic powder, and remained above 80% in the 5 days recovery experiment at pH=7.5, while about 50% of the reactor without magnetic powder. SVI in the reactor with magnetic powder was lower than that of the reactor without magnetic powder after pH shocking, and after the 5 days' recovery experiments, SVI of the sludge with magnetic powder could recovered to the original value, but the indicators of the sludge without magnetic powder could not recovered to the original value.

Abstract: A bioleaching experiment was carried out in two sequencing batch reactors (SBR) of 80 L. Acidithiobacillus thiooxidans (A. t) and Acidithiobacillus ferrooxidans (A. f) were enrichment cultured by adding sulfur powder and ferrous sulfate as substrate respectively. Sequential batch leaching ran for three periods in succession. The average removal rate of As, Cd, Cr, Cu, Ni, Pb, Zn was 90.46%, 90.28%, 90.70% and 79.70%, 81.19%, 84.52% respectively. The average loss rate of total nutrient (total account of organic matter, TN, TP and TK) is 35.36%, 33.36% and 35.54% for three runs in sequence. Comparing with A. f, the acidification time of A. t is shortened by 3.0, 6.6 and 4.9 d, with the increase of 13.5 %, 11.2% and 7.3% for the removal rate of heavy metals.

Abstract: The pollution of livestock sewage is one of important pollution sources that can cause non-point pollution in Chinese country. On the basis of analyzing the characters of the livestock sewage, the treatment principles of livestock sewage are discussed. At last, the comprehensive treatment processes of livestock sewage are put forward and analyzed.

Abstract: In order to study the effect and influencing factors of bromate removal by ultraviolet treatment in drinking water, by carrying out laboratory test in simulated water and raw water samples, the action of UVC and UVA on bromate were investigated. The results indicated that bromate transformes into bromine ion under UVC treatment, but there was a small amount of UVA in the UVC lamp emission spectrum. Separate experiments on UVA treatment of bromate indicated that UVA could be considered as an interference factor for UVC treatment of bromate, and it should be restricted in the UVC lamp emission. The conversion of bromate to bromide was inhibited by suspended matter, which led to a rise of water turbidity and had influence on the reduction of bromate by UVC. When the water pH was 5.5~9 the same UV dose, the reduction of the bromate concentration by UVC treatment did not change significantly.

Abstract: With calcium carbonate and barium carbonate as desulfurizers, combustion desulphurization experiments of coal water slurry and pulverized coal were respectively done in the ZCL. The results show that desulfurization efficiency in coal water slurry is prior to the same pulverized coal. The desulfurization characteristic of desulphurizing coal water slurry was analyzed by comparing the desulfurization efficiency of coal water slurry and pulverized coal. The reaction atmosphere in the boiler is different from the pulverized coal because of water evaporation ,and the CO content was lower ,so the decomposing rate for desulphurization products was reduced,after water evaporated ,it formed microstructures which was considered as favorable to the desulfurization rate .

Abstract: The experimental study on startup process of half-nitrosofication for high ammonia nitrogen simulated wastewater has been accomplished with a reactor of completely autotrophic nitrogen removal over nitrite (CANON). The startup process and its influences of the concentration of influent , DO and pH were analyzed with the experimental results. The results show that the conversion rate of to is close to 55%, the accumulation rate of is over 95% and the rate of to steadily keeps as 1.02~1.24 under the condition of influent of 400 mg/L, pH of 7.6~8.2, DO of 0.95~1.3mg/L, HRT of 1.5d and water temperature of 17~27°C, which meet the environmental requirements for anaerobic ammonia oxidation bacteria growth, and half-nitrosofication was achieved in the CANON reactor, which create good conditions for further enrichment of anammox bacteria for the operation of the CANON reactor.

Abstract: Groundwater pollution under the intense of human activities in the Quanzhou coastal area strongly threatens the supply safety of groundwater sources. Based on hydrogeological conditions and the pollution load in this field, the multi-index evaluation method of pollution sources and improved DRASTIC model were employed to assess groundwater pollution risk. The rating and weights of each important factor were determined by expert evaluation method and three-level groundwater pollution risk index were obtained using ARCGIS software. The results show that groundwater pollution risk at the industrial-intensive areas are dominant. So it is necessary for government to control the emmision of pollutant from inducstry in the Quanzhou area.

Abstract: In this paper, aqueous methanol (methanol concentration 1000 mg·l^-1) degradation was studied by using UV/Fenton, and effect of methanol degradation was evaluated with COD removal rate. When pH was determined, H₂O₂ dosage, Fe²⁺ dosage and reaction time were investigated by single factor test, respectively. In the orthogonal experiment, UV/Fenton was used to deal with wastewater of 1000 mg·l^-1methanol, the order of the influent factors on COD removal was: H₂O₂ dosage > reaction time > Fe²⁺ content. Under the optimal condition (6%H₂O₂50 ml·l^-1, Fe²⁺ 0.9 g·l^-1, reaction time 60 min), 95.77% COD removal rate was obtained. In addition, a comparison of UV, Fenton regent and UV/Fenton system indicated that UV and Fe²⁺ had synergistic effect on catalytic decomposition of H₂O₂, and reaction time to obtain the highest COD removal was shorted 10 min when UV/Fenton was used.