【作者】 王其进；

【导师】 陶玉贵；

【作者基本信息】 安徽工程大学 ， 微生物学， 2011， 硕士

【摘要】 环境中农药的残留及污染是全世界普遍关注的问题,我国是农药生产和使用大国,农药污染问题显得尤为严重。因此,寻找经济、高效的毒死蜱降解方法已成为是环保方面的重要课题。采用传统的或单一的生物、化学方法处理各有缺陷,本文旨在探索生物法、光催化法联合降解对水中毒死蜱降解的可行性及规律,以期找到一种降解毒死蜱污水的新方法。本文利用胶束电动毛细管色谱(MEKC)建立了测定水中毒死蜱含量的方法,研究了检测波长、运行缓冲液的种类浓度以及pH、有机添加剂、脱氧胆酸钠(NaDCh)的浓度和分离电压等实验条件对毒死蜱测定的影响。实验结果表明：以25 mmol·L-1硼砂(pH9.0,含20%(V/V)乙腈和50 mmol·L-1NaDCh)作为缓冲溶液,毒死蜱能在15 min内实现很好的基线分离,线性范围为15.625-500 mg·L-1,线性相关系数为0.9998,检出限(以信噪比(S/N)为3计)为0.135 mg·L-1,加标回收率为98.91%-100.9%。精密度和稳定性试验中,峰面积和迁移时间的相对标准偏差均小于3%,表明重复性良好。该方法简便、快速、灵敏,可用于水中毒死蜱含量的测定。本文采用富集培养的方法,从农药厂废水处理池污泥中分离到一株对毒死蜱有较强降解能力的菌株TW-1,TW-1能以毒死蜱为唯一碳源生长。研究了初始pH、外加碳源浓度、毒死蜱初始浓度、培养温度、接种量对降解菌降解能力的影响。采用Box-Behnken优化哈夫尼菌降解毒死蜱的条件,并建立了降解模型,优化结果表明：哈夫尼菌降解毒死蜱的最优条件为：蔗糖浓度0.31%,毒死蜱初浓度51.33 mg·L-1,培养温度30.7℃,在该条件下理论预测毒死蜱降解率可达74.7%。通过假设和验证,得出哈夫尼菌降解毒死蜱为一级动力学模型,哈夫尼菌能水解毒死蜱P-O键,属一级酶促反应。利用Ti02粉末作为催化剂,研究不同催化时间、温度、pH值、光源和光强等单因素对水中毒死蜱光催化效果的影响。结果表明：当pH>7时,降解率较高；光照距离5 cm,毒死蜱降解率达70.6%,去除效果随光强减弱显著下降；毒死蜱的降解率随Ti02催化时间的增加而增大,但从30 min开始,降解率提升幅度逐渐减小；当反应温度在20-30℃范围时,毒死蜱降解率没有明显变化,当温度高于45℃时,降解率明显增加,当温度达到65℃时,降解率达到77.9%。在生物法和光催化法降解毒死蜱的研究基础上,研究了生物法／光催化法联合降解毒死蜱的可行性,并对试验装置和反应模式进行了初步探索。发现用生物法／光催化法联合降解毒死蜱可以有效缩短反应时间,同时提高毒死蜱的降解浓度。初步研究结果表明：在使用生物法处理81h后,由光催化降解毒死蜱6h,通过两个系统联合作用一共耗时87h,与单独使用生物法降解毒死蜱相比,时间节省了12.1%,与单独使用光催化法降解毒死蜱相比,降解能力提高了5倍。更多还原

【Abstract】 The residule and pollutant are attended by the whole world,the pesticides are yielded and used much in China. So, it is an important issue of environment protection to approach for an economic,high efficient treatment of chlorpyrifos wastewater degradation.The efficiency is low with single biological or chemical treatment.In the hope of providing foundations to establish a kind of new degradation technology,the subject intended to explore the feasibility and regulations of the synergetic treatment for chlorpyrifos wastewater degradation which combined biodegradation and photocatalysis.A method for chlorpyrifos determ ination in water based on micellar electrokinetic capillary chromatography has been developed.The assay conditions including inspection wavelength,pH and the concentration of running buffer,organic additive,the concentration of sodium deoxycholate (NaDCh),and the separation voltage were optimized.Under the optimized conditions (25 mmol·L-1 borate buffer (pH9,containing 20%(V/V) acetonitrile,50 mmo·L-1 NaDCh),the chlorpyrifos can be separated within 15 min,with the linearworking range of 15.625～500 mg·L-1(r2=0.999 8) and a lim it of detection (S/N=3) of 0.135 mg·L-1.It had good recoveries (98.91%～100.9%) and the relative standard deviations lower than 3%.The method is simple,rapid,sensitive,highly reproducible and can be successfully applied in the determination of chlorpyrifos in water.A bacterial strain designated as TW-1 capable of degrading chlorpyrifos was isolated from sludges by enrichment culture,Strain TW-1 can grow with chlorpyrifos as its sole carbon source.The effects of initial pH,culture temperature,initial chlorpyrifos concentration,carbon source concentration,inoculation amount and chlorpyrifos-degradation of strains were studied. Response surface methodology (RSM) was used to determine the optimal conditions for degradation of chlorpyrifos,and to establish a model of the degradation kinetics.Response surface methodology based on the Box-behnken design of experiment was used to determine the optimum conditions.On the basis of the response surface and contour plots,the optimum conditions for chlorpyrifos degradation were;0.31%(w/v) glucose,initial chlorpyrifos concentration 51.33mg/L,and culture temperature 30.67℃.The predicted extent of chlorpyrifos degradation under these optimum conditions was 74.7%.According to the hypothetical kinetic model for chlorpyrifos degradation,the kinetics for chlorpyrifos degradation could be described by a first-order rate equation.The feasibility and performances of photocatalysis technology were explored to degrade chlorpyrifos.Based on TiO2 photocatalytic process, experiments were carried out to evaluate influence of time,pH, temperature,light intensity and light source on removal of chlorpyrifos residue in water.It arrived at a higher level when pH was over 7.The removal rate decreased with decreased light intensity and was 70.6% when the treating distance was 5cm. It was discovered that removal rates increased with treating times, but no significant alteration between 30min and 60min after treatment. Under all tested temperatures, the removal rate of more than 60.0% was achieved,not significantly different between 20～30℃and increased significantly when the temperature was over 45℃,the removal rate achieved 77.9% when the temperature was 65℃.Based on the study of photocatalysis and biology treatment,the photocatalysis and bioreactor was integrated for chlorpyrifos degradation. The feasibility and integrated mode was primary explored.Results showed that the reaction time was efficiently shortened, and the degradation concentration was raised,simultaneously,in the combined chlorpyrifos/biological system.The least reaction time for this system was determined to be 81h at biological treatment reaction time of 87h with bi-energy fields reaction time of 6h.Time was saving of 12.1% compared to using biological treatment exclusively,chlorpyrifos degradability was enhancing of 5 times compared to using photocatalysis exclusively.更多还原