Determination of the Chemical Oxygen Demand in Wastewater Using Microwave Energy

• Main Authors: Chen, Shin-Jiun, 陳信君
• Other Authors: Hsu, Tau-Ping
• Format: Others
• Language: zh-TW
• Published: 1997
• Online Access: http://ndltd.ncl.edu.tw/handle/75385075936059482979

碩士 === 淡江大學 === 水資源及環境工程學系 === 85 === (1)Deteimination of the Chemical Oxygen Demand in the Wastewater Using Microwave Energy A method for the determination of chemical oxygen demand(COD) by the dichromate reflux method is used as a measure of the organic matter content of a sample. Although it is the standard method of the EPA, but it takes a long time and a lot of liquid waste. The use of microwave in analytical and environmental chemistry has increased markedly in recent year, in this study, a method to determine the COD using household microwave oven and mercury-free has been developed. From the results of experiment, the microwave condition of real samples is microwave power 419.4W, time 4min, sample 5mL, sulfuric acid reagent 7mL, silver nitrate solution 1mL(0.0705N), potassium dichromate solution 2mL(O.1N). This method for the quantitave recovery of APG Q.C. sample is 97.7%, standard deviation 2.58mg/L, the quantitave recovery of real samples is between 89%∼105%, this method could be developed for real samples with chloride concentration less then 800mg/L and COD less then 200mg/L. For determination different diluted radio samples simultaneously, we need to increase the microwave power to 713.2W. this method could be developed for real samples with chloride concentration less then 800mg/L and COD less then 200mg/L. ln the results, the microwave and mecury-free method to replace the conventional dichromate reflux method is possible. (2)Microwave Extration of the Collection of PCBs in the Ambient Air by Solid Adsorbent Sampling of PCBs is collected by solid adsorbent, extracted by Soxhlet extraction method, but it takes a long time and consumes lots of solvents. So in this study, we collected gas samples by PS-1 samper and discussed PCBs in the solid adsorbent(XAD-2)which used microwave extraction method to extract. In this study, we adopted orthogonal array to find the best microwave condition, the best microwave condition is temperature 100℃, sovent 30mL(Hexane:Acetone)1:1, time 1Omin. Sampling in the vicinity of TamSui campus and different sites, extraction by microwave condition and detected by GC/ECD. From the results of experiment, the PCBs can not be found in gas phase(XAD-2), butPCB-52、PCB-87、PCB-138、PCB-191、PCB-195、PCB-206、PCB-207 can be found in solid phase(filter).