Advanced Materials Research Vols. 518-523

Abstract: The characteristic and mechanism of o-chlorophenol degradation in a micro-electrolysis contact oxidation system has been investigated．The degradation rate of o-chlorophenol is higher in acid solution than that of in neutral or alkaline solution．Addition of activated carbon can make the degradation of o-chlorophenol easier by the surface contact catalysis．The dissolved oxygen in solution can take part in the electrode reaction and intensify the degradation of o-chlorophenol. Most intermediate products are 1,2-Benzenediol, glycerol, oxalic acid and acetic acid. By the analysis of intermediates for degraded o-chlorophenol, the possible degradation pathway of o-chlorophenol has been proposed.

Abstract: The treatment of Reactive Brilliant Blue KN-R in wastewater was conducted by using the zero-valent iron/activated carbon (Fe⁰/AC) combined with ultrasound (US). Although ultrasound alone had a little effect on the KN-R degradation and Fe⁰/AC had some disadvantages when it acted on the KN-R, the efficiency of the degradation was dramatically enhanced which used the combination of Fe⁰/AC /U.S. that also could eliminate the shortcomings. The decolorization percentage was nearly up to 100% and the COD removal rate has approached to 87.38%.

Abstract: Trichloromethane (TCM) is a harmful halogenated organic compound usually used in the industry and a typical disinfection by-product in the water treatment with the use of chorine as disinfectant. The degradation of TCM by peroxymonosulfate combined with UV irradiation at λ= 254 nm (UV/PMS) was investigated. Results showed that TCM was efficiently degraded by UV/PMS and about 80% of TCM was decomposed when the concentration of PMS was 0.5mM. Radical-scavenging experimental results indicated that both HO^• and SO₄^•- might contribute to the degradation of TCM. However, HO^• might first be captured by PMS to form SO₅^•- and then partly decomposed into SO₄^•-, which might react with TCM. The increased concentration of PMS led to the increased removal efficiency of TCM. Whilst, the efficiency was little affected by initial concentration of TCM, indicating that there might be competition reaction with TCM degradation for radicals.

Abstract: This paper describes the automobile production, sales and ownership in china during the past two years, then analyses the composition of vehicle exhaust emissions which are harmful gases to human body. Due to the urgency of the control of pollution from motor vehicles in china, emissions detection and treatment technology need to be further developed. Specially, this article puts forward some suggestions and solutions strengthening the maintenance of in-use vehicles and accelerating the pace of pollution control.

Abstract: Thiobacillus ferrooxidans is one of the main strains in the field of flue gas biological desulfurization. In the paper the removal of sulfur dioxide was studied in the biotrickling filter by the synergistic effect of the biofilm of Thiobacillus ferrooxidans and iron ion system. The Mass transfer and reaction process in the biotrickling filter were analysed and the relationship between sulfur dioxide concentration and time during the desulfurization was discussed. Then the dynamic equations of sulfur dioxide removal in biotrickling filter were established.

Abstract: In this investigation, An Expanded Granular Sludge Bed (EGSB) was used to treat tapioca starch wastewater containing low concentration cyanide and the influence of cyanide concentration on the startup of EGSB reactor was conducted. On the condition of 13.4h of HRT, the chemical oxygen demand (COD) and cyanide concentration varied, The EGSB performance was assessed in terms of COD, pH, alkalinity, volatile fatty acids (VFA) and methane variation during the process. The results showed that cyanide was harmful to the anaerobic bacteria of the granular sludge in EGSB reactor for the treatment of tapioca starch waster, as the cyanide concentration was at 15mg/L, COD removal efficiency for cyanide free wastewater nearly 90%, however the efficient dropped to 80% with increasing cyanide concentration up to15mg/L; the methane production was nearly 200mg/L with cyanide concentration and dropped to a value of 2mg/L for 15 mg/L cyanide; and methanogenic activity decreased; while the influent VFA was increased, at an cyanide concentration of 0 and 5mg/L, the concentration of VFA was maintained below 100.00mg/L, but it was higher than 600mg/L in most of the cases with influent cyanide concentration of 15mg/L; SEM observation of the granules showed the predominance of Methanosaeta. sp. and the obvious damage of the bacteria located on the surface or in the inner part of some granules, leading to a deterioration of granular sludge settling velocity, and even some granules washed out.

Abstract: A series of electrokinetic experiments were conducted on fluorine-contaminated soil with different anolyte (NaOH) concentrations in a self-made electrolyzer to investigate the effects of anolyte concentration on removal of fluorine. Experimental results showed that anolyte concentration (0.1mol L^-1) was more suitable of the six anolyte concentration tested, in contrast to the removal efficiency of fluorine and the cost of the high concentration of anolyte. On this anolyte concentration that 57.75% fluorine could be removed from contaminated soil within 10 days under the applied voltage (1.0 V cm^-1). The results also indicated that electromigration was a dominant transport mechanism responsible for the removal of fluorine from contaminated soil than electroosmosis.

Abstract: The electrochemical degradation of the wastewater of acid blue 41 was studied with Ti/Sb-SnO₂ as an anode in which the Sb-SnO₂ coating was prepared with a polymeric precursor method. The conversion of acid blue 41 was carried out under galvanostatic control. The effects of current density, initial concentration of acid blue 41 and the concentration of supporting electrolyte on color removal, COD removal and instantaneous current efficiency (ICE) were investigated. The experimental results show that the color removal and COD removal enhance with increasing current density, but ICE decreases. Acid blue 41 can firstly be oxidized by the destroying the conjugated chromophore group and it is difficult that the intermediates produced during the degradation process of cid blue 41 is further degraded.

Abstract: In this paper the desulfurization and denitration of simulation flue gas using calcium hypochlorite as absorbent was studied experimentally. Absorption experiments of the desulfurization and denitration in calcium hypochlorite solutions were carried out in a Porous Globular Gas Liquid Reactor (PGGLR) which was a new and innovative core design. Three experiments were conducted at NTP conditions. The mechanism of removal for SO2 and NOX was investigated. Under these experiment conditions, the removal efficiency of 100%, 67% for SO2 and NOX were achieved. The results can offer valuable references for industrial application.

Abstract: To reflect the problem of Black-odor of the urban river for the qualitative and quantitative,Used in Extenics matter-element analysis to establish Taiyuan urban river Black-odor extension model, refering to "Surface Water Environmental Quality Standard" (GB3838-2002) and other standards, drawing on the experience of a large number of parameters to determine the urban river five Black-odor Rank.Determined by the actual characteristics of the river Black-odor river monitoring indicators, though analytic hierarchy process (AHP) determine the level of the weight of each index coefficient, reflected the lower degree of influence on the upper index.Taiyuan urban rivers in the dry season, water level monitoring period and the wet period that the mian dry season and water level monitoring period with mild and moderate Black-odor,the wet period was mainly in black and stinky critical state. Taiyuan city has been black-odor rating and level of the river black-odor are basically consistent, indicating extenics matter element analysis in the urban river black-odor application is feasible.