Papers by Author: Shu Yao Wen

Abstract: Five types of TiO₂-bentonite catalyst, #1, #2, #3, #4, and #5, were prepared separately using hydrochloric acid, nitric acid and perchloric acid by the sol-gel method. The original concentration of sodium dodecyl benzene sulfonate (SDBS) in the aqueous solutions was 20 mg/L. The amounts of SDBS degraded by #1, #2, #3, #4 and #5 under a 6 W ultraviolet lamp were compared, the influences of #1 and #2 on the chemical oxygen demand (COD) of the aqueous solutions studied. And the influences of the initial pH on the degradation of SDBS and on the COD of aqueous solutions were investigated. The results showed as the following. (1) When the catalyst input was 0.5‰ and the solutions were irradiated with a 6 W ultraviolet lamp, 81.0%, 90.5% 47.5%, 39.5% and 26.5% of the SDBS in the aqueous solutions was degraded within 2 hours by catalysts #1, #2, #3, #4 and #5, respectively. The COD was reduced by 8.81% and 50.84%by catalysts #1 and #2, respectively. (2) Under an ultraviolet lamp, 94.5% and 99.3% of the SDBS in the aqueous solutions was degraded and 33.59% and 96.93% of the COD was reduced within 6 hours by catalysts #1 and #2, respectively. TiO₂-bentonite catalyst #2 was the best based on the effects on the degradation of SDBS and on the reduction of the COD of aqueous solutions. Using nitric acid was better than using hydrochloric acid or perchloric acid for the preparation of TiO₂-bentonite. (3) Under the same conditions (20 mg/L SDBS, 20°C, ultraviolet light irradiation time of 2 h, electromagnetic mixing, 0.5‰ input of TiO₂-bentonite #2 ), 90.3% and 90.5% of SDBS was degraded by TiO₂-bentonite #2 at pHs 6 and 8, respectively. The optimal pH range for SDBS degradation was 6~8. The COD was reduced by 59.5% and 63.5% pHs 4 and 6, respectively. The optimal pH range for the COD reduction was 4 ~ 6. The pH had a clear effect on SDBS degradation and the COD of the aqueous solutions.

Abstract: Previous studies predominantly degraded organic matter in simulated water samples containing one or two organic components, while a few literatures reported organic matter degradation in natural and actual sewage water samples. This is likely due to the ingredient of surface water or actual sewage coexisted with many kinds of organic pollutants being complex. The relationship among coexisting organic materials is complex during photocatalytic degradation. Moreover, the coexistence of many kinds of inorganic pollutants in natural or actual sewage water samples is also common. Thus, the influence of coexisting inorganic pollutants on degradation is also worthy of study. This work explored these influences of TiO₂-bentonite composite catalysts. 8.6%~11.5% sodium dodecyl benzene sulfonate (SDBS) in surface water or clothes laundering drain water was degraded by 3‰ TiO₂-bentonite within 6h under 6W ultraviolet light. Under the same conditions, 86.5% of the SDBS in aqueous solution was degraded. The difference was obvious, but the causes were complicated. For example, the influence of , , and on the degradation was discussed. The results show that the influence of on the above degradation was obvious, while and was not obvious. In addition, and were captured by resulting a decrease of degradation speed. Competition of , and SDBS for surface active sites decreased the efficiency of the degradation. Based on these results, pretreatment such as filtering, deposition and impurity removal before actual sewage is degraded could improve the degradation efficiency. Further study, such as on the reasons for efficiency reduction, on new pretreatment methods and on the application of multi-treatment measures, is needed to conduct.

Abstract: The photodegradation of organic pollutants by TiO₂ has previously been shown to be efficient, but the TiO₂ particles are typically so fine that they are easily washed away. This problem was solved by forming a complex between TiO₂ and bentonite. Four different photodegradation conditions (i.e., no catalyst, addition of 3 bentonite, addition of 1 TiO₂, and addition of 3 TiO₂-bentonite) were investigated for their degradation efficiencies of 20 mg/l sodium dodecyl benzene sulfonate (SDBS) under ultraviolet light for 6 h. The titanium content of 1 titanium oxide was equal to that of the 3 Ti-bentonite. The results showed that, under the four above conditions, 36.7%, 25.9%, 96.7%, and 99.3%, respectively, of SDBS were degraded in the aqueous solutions. The latter two conditions degraded SDBS more efficiently than the former two conditions. The TiO₂-bentonite complex possessed more advantages than TiO₂ or bentonite alone, making the bentonite an appropriate carrier for TiO₂.

Abstract: Choose to use different size a coleus blumei，with natural palm tree hair fiber for suspend to carry a body and regulate to go together with heavy to constitute to certainly plant system, observe a coleus blumei the growth condition in water body and improvement fluid matter effect in eutrophic waters. The results showed that coleus blumei completely can give birth very well in water suspend growth；that every coleus blumei could bring about many fibrous roots which reached 0.10cm to 0.15cm in the first day and that the longest fibrous roots reached about 16.5cm to 24.0cm during 15 days. The biomass measurement discovers that the plant more big its biomass increase more big，the plant is more small it the clean increment biomass be more big.The water body clarity raises to from the 41cm to 97cm and compare to change into almost transparent clear water for the muddy lake water；and the concentrations of CODCr,TP and TN were decreases to 80.0%，88.6% and 93.8% respectively.The DO concentrations also kept in certain satisfied level for using the coleus blumei method.

Abstract: Aimed at the feature of annual precipitation,this paper puts forward a predicting Markov chain method based on entropy weight. Data of precipitation in Hangzhou,from 1956 to 2009,was used as an example. The precipitation can be predicted year by year using the Markov chain models based on entropy weight. Hangzhou past 5 years the results of precipitation yearly basis,respectively：the absolute error of 73mm,27mm,-22mm,-17mm and 20mm;the relative error was 5.66%, 2.03%,-1.59%,-1.08% and 1.30%.The error value of smaller than ±5％ and ±10％ was 36.67% and 60.00% respectively in the 30 years of precipitation prediction. M-K test was applied for nearly 30 years of predicting results for time series analysis, the results show that the prediction data with the increase in prediction accuracy tends to gradually increase.

Abstract: Application of brown hair fiber, ramie fiber, jute fiber and flax fiber to degrade PAHs in water was studied. The experimental results show that the plant fibers which enrich the microbial has better effect of degradation on PAHs in water,and the degradation effects are highly related with plant fiber’s layout density,HRT and aeration rate. The higher the layout density of jute fiver,HRT and aeration rate,the better the effects of decontamination,which means the water quality of effluent meets the GB5749-2006 standard that the total content of PAHs is less than 2000 ng•L-1. Select No11~No14 Tank plant fiber density,6h HRT and 12h aeration,the effect of degradation of PAHs is the best. This result shows that microbial enriched by plant fiber has a good effect of degrading PAHs in water. Plant fibers provide a space as large as possible for indigenous bacteria attached to the growth in water,and also provide a good micro-environment for their biochemical reaction. The indigenous microorganisms attached to the surface of plant fibers rapidly grow to achieve strengthen the natural degradation of the PAHs in water. Except the biodegradable role of plant fiber enrich the microorganisms to degrade PAHs,in addition,there also exists absorption and evaporation effects. Macrocyclic PAHs ring has a more strong hydrophobicity than the small ring,so that in the process of biodegradation,the small ring is more easily to be absorbed by the plant fiber and biofilm surface,and more easily to be degraded. Therefore,plant fiber enriched microbial to degrade PAHs is the main process,then followed by adsorption and evaporation process.