Feasibility Study on Removals of Pollutants in Eutrophic Lake Water byPhoto-Bioelectrochemical Systems

• Main Authors: Chu, Chih-Heng, 朱志恆
• Other Authors: Lee, Chi-Yuan
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/ke29vu

碩士 === 國立臺灣海洋大學 === 河海工程學系 === 102 === This study is intended to examine the feasibility of removing pollutants in eutrophic lake water by photo-bioelectrochemical system (PBES). This PBES has photosynthetic oxygenation in cathode chamber by planting algae or algae combined with hyacinth. Experimental works included the investigation of water quality and photosynthetic oxygenation coefficients of a eutrophic lake (Kinsa reservoir) in kinmen and the continuous operation of two PBESs (Reactor 1 and Reactor 2) fed with the Kinsa reservoir water in laboratory. Reactor 1 was developed by installing a column packed with activated carbon (anode chamber) inside an algal reactor (cathode chamber), whereas Reactor 2 was constructed by directly placing activated carbon on the bottom (anode chamber) of algal reactor (cathode chamber). There were two phases and in each phase four water velocities were controlled inside the cathode chamber, 0, 0.2, 0.4, and 0.6 m/sec. In phase I, Test 1 to Test 4, both reactors were planted with algae only and in Phaes II, Test 5 to Test 8, planted with algae and hyacinth. Results indicated that the Kinsa reservoir had DOC 10 ~15 mg/L, total nitrogen 0.069 ~ 0.287 mg/L, and total phosphor 0.048 ~ 0.125 mg/L. The photosynthetic oxygenation coefficients were reaeration constant Ka -1.15 ~ 13.18 d-1, algal oxygen production rate Pav 2.38 ~ 32.68 mg/L-d and microbial resperiation rate R -4.84 ~ 31.02 mg/L-d. Compared to light intensity, the water velocity in cathode chamber had insignificant effect on photosynthetic oxygenation. Based on the obtained coefficients of photosynthetic oxygenation Reactor 2 that planted with algae could properly simulate the actual conditions of Kinsa Reservoir. The Reactor 1 with planting algae achieved DOC removals 31~ 53 % total nitrogen removal 42 ~ 99%. When Reactor 1 had mixed growth of algae and hyacinth, the DOC removals increased to 53 ~ 71 % and nitrogen to 47 ~ 86%. The Reactor 2 with algae alone achieved DOC removals 26 ~ 46 % and nitrogen removal 81 ~ 99%. When Reactor 2 further planted both algae and hyacinth, the DOC removals also increased to 39 ~ 68 % and nitrogen 33 ~ 86 %. The phosphorus could not be removed in the PBES. This study suggested that the PBES had potential to the treatment of eutrophic lake water to remove dissolved organics and nitrogen. Nevertheless, the coulombic efficiencies for the both reactors were 0.05 ~ 4.1 %, indicating that most dissolved organic carbon was biodegraded through the pathway of other than electricity generation. Even So, the high removal efficiencies of DOC in the PBES might be attributed to the potentials created in both chambers, which needs to clarify in the subsequent researches.