| 摘要: | 本研究利用Chlorella sp.攝取光電(OE)和半導體(SC)放流水中的氮磷，並固定外添加的CO2。試驗設計主要分成適應性試驗與固碳去氮除磷試驗兩大部分。
批次操作下，初步瞭解Chlorella sp.確實能生存於光電(OE)和半導體(SC)放流水中，並攝取氮磷合成藻體。研究結果顯示，Chlorella sp.生長於低N/P的光電(OE)放流水中，生物質產率(Pal)受初始氮磷濃度影響甚大，藻體攝取氨氮的能力會因磷濃度(>12.25 (mg P) L-1) 過高而受抑制；Chlorella sp.生長於高N/P的半導體(SC)放流水，生物質產率(Pal)則受初始藻體濃度(Xal0)影響較大，當初始藻體濃度(Xal0)為0.10、0.50和1.0 (g DW) L-1時，生物質產率(Pal)隨其增加而提升，介於0.100-0.634 (g DW) L-1d-1之間。
半連續操作下，各參數的最佳條件為SRT=21 d、HRT=4 d以及6% CO2 (v/v)，Chlorella sp.對低N/P的光電(OE)放流水(水質為37.06 (mg NH4+-N) L-1和27.85 (mg PO43--P) L-1)之最佳氮磷去除率分別為78.9-79.2%和5.7-7.8%。當SRT=30 d時，槽中藻體濃度(Xal=4.6 (g DW) L-1)過高，藻體因自我光遮蔽效應而活性漸失，最終氮磷去除率分別為22.9%和3.7%。當HRT=4 d時，水質pH值趨於酸性(<4)，氨氮去除率自96.4%降至73.4%，且生物質產率最低(Pal=0.114 (g DW) L-1d-1)。反觀HRT=2d時，水質pH=6左右，平均氨氮去除率只有54.9%，但其生物質產率(Pal=0.171 (g DW) L-1d-1)最高。將CO2濃度自6% CO2 (v/v)提高至12及18% CO2 (v/v)，生物質產率(Pal)自0.157驟降至0.049 (g DW) L-1d-1，固碳速率(RCO2)也自0.220降至0.098 (g CO2) L-1d-1。
本研究發現，Chlorella sp.能攝取光電(OE)和半導體(SC)放流水中的氮磷，其攝取能力受環境之各種負荷影響。於半連續操作中，受SRT之影響最為顯著，表示Chlorella sp.對光能的利用率是最重要的因子，pH值的影響則次之。
;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. |
