Ozonation/Catalytic ozonation of raw water to diminish the acute biotoxicity

• Main Authors: YU-HSUAN,LI, 李佑軒
• Other Authors: 黃文鑑
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/36588932088734009015

碩士 === 弘光科技大學 === 環境工程研究所 === 102 === This study investigates the various characteristics and sources of water samples after catalytic ozone and ozone only processes to observe the variation of acute biotoxicity. Test water samples involve three categories, including industrial wastewater, groundwater and reservoir water. The toxicity test method was used microtoxin test. The ozone dosages were control in 0.5 mg/L and 1.0 mg/L, which reference to the literature reports in industrial and domestic wastewater treatment plants. Experimental results indicated that the effective concentrations (EC50) of various types of raw waters, industrial wastewater have lower EC50 values than other two test waters. The results reveal that the industrial wastewater represents high toxicity response. The results of regression analysis indicated that water quality parameters and EC50 in industrial waste water exists high correlation (R2> 0.64). Comparison of ozone treatment water with raw water, it can be found that the values of ozone has decreased after a short time, which means that there is an increasing trend toxicity, but the longer ozone exposure, the toxicity will be on downward trend. This result was due to some of the raw water is transferred after solid organic compounds dissolved ozone oxidation and toxicity with organic matter, such as this ozone-derived organic matter may generate only a low amount of ozone or the ozone reaction of shorter time. The EC50 was found to decrease its tendency to improve the amount of ozone in the ozone or prolonged contact time. Adding titanium dioxide (TiO2) of catalytic ozone oxidation process to treat industrial wastewater to reduce the toxicity for the comparison were lower ozone only, that the catalytic efficacy is not significant. Presumably complex wastewater ingredients, some chemicals may interfere with the ability of TiO2 catalytic generation of free radicals. For arsenic (As) groundwater ozone treatment, control of 0.5 mg/L can significantly reduce the acute toxicity of water, mainly due to the reduced state of the ozone to As (III) oxidation of As (V), while the partial oxidation of organic matter to reduce its toxic effects. For raw water reservoir and toxicity tests after ozone treatment, the toxic reactions were not found, showing algae and other contaminants present in the reservoir has not been transferred to toxic substances from generate ozone. For toxicity testing of raw water reservoir and after treatment by ozone, toxic reactions were not found, showing algae and other contaminants present in the reservoir has not been transferred to generate ozone and toxic substances. It also did not produce ozone toxicity after the experiment, which means that the ozone reservoir water toxicity program has no effect. Consolidated results for the raw water using ozone disinfection or oxidation unit, controlling the amount of ozone and the contact time should be considered microbial indicators, and also the toxicity of the water.