Treatment of synthetic municipal wastewater by H2O2/UV process

• Main Authors: Jian-Zhi Fang, 方建智
• Other Authors: Hsing-Yuan Yen
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/09613905537558064034

碩士 === 高苑科技大學 === 化工與生化工程研究所 === 98 === This study evaluates the H2O2/UV process for the removal of dissolved organic carbon (DOC) from synthetic municipal wastewater. Experiment variables studied include pH, oxidation time, hydrogen peroxide dosage and UV intensity. The DOC reaction kinetic and specific energy consumption were also discussed. Moreover, the efficiency of H2O2/UV combined with membrane separation to removal DOC were evaluated. Results show that the residual DOC increased with an increase of initial pH. Howevwe, there was only little difference residual DOC between pH 3-8. The residual DOC are 30% at pH 3 and 35% at pH 8. In the neutral pH, UV=128W, H2O2 dosage are 250, 300, 350, 400 and 500 mg/L, oxidation time is 180 min, the residual DOC are 67%, 58%, 45%, 37% and 29%, respectively. The DOC removal followed pseudo first-order kinetics and the reaction rate constants increased with increasing H2O2 dosage. The reaction rate constands are 0.25 × 10-2, 0.33 × 10-2, 0.45 × 10-2, 0.57 × 10-2, and 0.74 × 10-2 min-1, respectively. The specific energy consumption are 10880, 8320, 32533, 2400, and 1822 KWhKg-1 DOC, respectively. It indicates that specific energy consumption obviously decreased with increasing H2O2 dosage. On the other hand, H2O2 dosage is 500 mg/L and UV intensity were controlled 16, 32, 64 and 128W at an oxidation time of 180 min. The residual DOC are 85%, 66%, 45% and 29%, respectively. The DOC removal followed pseudo first-order kinetics and reaction rate constants increased with increasing UV intensity. Pretreatment of the synthetic municipal wastewater by H2O2/UV oxidation can decrease silt density index (SDI) values from 6.1 to 0.1 and increase permeate flux from 15.3 L/m2h to 23.7 L/m2h when followed by RO separation. The total DOC removal of H2O2/UV combined with NF and RO separation are 92% and 98%. In addition, either H2O2 or UV light can be a disinfection to prohibit microorganism growth. The removal of nitrogen compounds by H2O2/UV alone was worse. In conclusion, the combined H2O2/UV pre-oxidation and membrane post-process is a promising treatment for synthetic municipal wastewater.