Carbon Dioxide Fixation by Chlorella sp. Uptaking Nutrient from Industrial Wastewater

• Main Authors: Hsiang-Yun Cheng, 鄭翔勻
• Other Authors: Dyi-Hwa Tseng
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/50837841093371858860

碩士 === 國立中央大學 === 環境工程研究所 === 102 === This study is aimed to removal of nutrients from opto-electronics (OE) and semi-conductor (SC) effluent, and fixed CO2 simultaneously by Chlorella sp.. The experimental design included: (1) adaptation test in batch mode and; (2) laboratory scale treatment system in semi-continuous mode. In adaptation test find out Chlorella sp. could uptake nitrogen and phosphate from OC and SC effluent, and synthesize biomass in the meanwhile. Results showed out Chlorella sp. in OE effluent (low N/P) was affected by initial nitrogen and phosphate concentrations, Chlorella sp. uptake ability of ammonium was poor when phosphate concentration was high (>12.25 (mg P) L-1) ; in SC effluent (high N/P) was affected by initial biomass concentrations (Xal0 = 0.1, 0.5, and 1.0 (g DW) L-1), biomass producti- vity (Pal = 0.100-0.634 (g DW) L-1d-1) would be higher when Xal0 was increased. The results showed out the optimum parameter was SRT=21 d、HRT=4 d and 6% CO2 (v/v), and the greatest nitrogen and phosphate of removal rate was 78.9-79.2% and 5.7-7.8%, respectively, by Chlorella sp. in OE effluent (37.06 (mg NH4+-N) L-1 and 27.85 (mg PO43--P) L-1) under semi-continuous operation. When STR=30 d, Xal= 4.6 (g DW) L-1 was caused self-shadowing effect and Chlorella sp. activity become lower and nitrogen and phosphate uptake rate was decreasing to 22.9% and 3.7%, respectively. When HRT=4 d, pH would be under 4, and ammonium-nitrogen removal rate was decreasing from 96.4 to 73.4%, and the biomass productivity was lowest (Pal = 0.114 (g DW) L-1d-1). In contrast, HRT=2 d and pH about 6, and ammonium-nitro- gen removal rate (54.9%) was lowest, but the biomass productivity was highest (Pal = 0.171 (g DW) L-1d-1). CO2 concentration was increasing from 6 to 12 and 18% CO2 (v/v), and biomass productivity was rapidly decreasing from 0.157 to 0.049 (g DW) L-1d-1, and CO2 fixed rate (RCO2) was decreasing from 0.220 to 0.098 (g CO2) L-1d-1. Chlorella sp. could uptake nitrogen and phosphate from OE and SC effluent, and the uptake ability was affected to various effect factors. Under semi-continuous operation, SRT is the most significant factor, and followed by pH.