Thermosynechococcus sp CL-1 applied to CO2 fixation estrogen degradation and bioenergy production potential analysis

Abstract

Since industrial revolution CO2 concentration in atmosphere has risen and influenced on extreme weather and global warming Carbon capture and sequestration (CCS) technologies are therefore under researched in recent decades to solve the problems Biological carbon mitigation (BCM) was considered as a sustainable process which uses microalgae or cyanobacteria to absorb CO2 from atmosphere through photosynthesis In recent years the impact of environmental hormones is noticed “Environmental hormones” are also named “endocrine disruptor compounds” and have been found in rivers Those chemicals affect human health through air water soil and food chain EDCs are defined by the US Environmental Protection Agency as exogenous chemicals that affect the structure or function of the endocrine system and cause adverse effects In this study the combination of the advantage of the chemical-alkaline-absorption and BCM is applied as the technology of carbon fixation from one of the main CO2 emission sources power plant CO2 has much more solubility in the alkaline solution and becomes HCO3- or CO32- as the carbon source for cyanobacteria In order to increase the biomass productivity and carbon fixation rate the higher surface-area-ratio flat panel was used as the photobioreactor (PBR) with high initial biomass concentration For meeting this practical requirement thermophilic and basophilic cyanobacteria Thermosynechococcus sp CL-1 (TCL-1) was chosen in this study TCL-1 is expected to degrade 17 β-estradiol (E2) reduce the CO2 level in the atmosphere and be applied in the production of bioenergy 17 β-estradiol (E2) concentration light intensity and DIC concentration have been used as the operating parameters to affect the degradation of E2 and the accumulation of the carbohydrate lipid and protein in this study The results show TCL-1 can achieve the highest biomass productivity 56 4 ± 0 0 mg/L/h CO2 fixation rate 79 8 ± 0 1 mg/L/h biomass increment 23 2 ± 2 0 % if cultivated in the 113 2 mM initial DIC under 2 000 μE/m2/s with 10 mg/L E2 It’s enough for E2 photolysis while the light intensity of LED is 500 μE/m2/s The highest biodegradation rate of E2 by TCL-1 under 56 6 mM DIC and 2 000 μE/m2/s is 73 7 ± 4 0 % The highest total degradation rate of E2 by TCL-1 is 86 9 ± 0 2 % under 1 mg/L E2 113 2 mM DIC and 2 000 μE/m2/s 8 The maximum carbohydrate content is 43 3 ± 0 6 % at 8h if cultivated in the 56 6 mM initial DIC under 2 000 μE/m2/s with 10 mg/L E2 The maximum carbohydrate productivity is 23 9 ± 0 5 mg/L/h at 4h if cultivated in the 113 2 mM initial DIC under 2 000 μE/m2/s with 10 mg/L E2 The maximum lipid content is 23 3 ± 0 9 % at 4h if cultivated in the 113 2 mM initial DIC under 500 μE/m2/s with 10 mg/L E2 The maximum lipid productivity is 19 6 ± 1 5 mg/L/h at 12h if cultivated in the 113 2 mM initial DIC under 2 000 μE/m2/s with 3 mg/L E2 The maximum protein content is 52 9 ± 0 1 % at 12h if cultivated in the 113 2 mM initial DIC under 2 000 μE/m2/s with 3 mg/L E2 The maximum protein productivity is 42 4 ± 0 1 mg/L/h at 8h if cultivated in the 113 2 mM initial DIC under 1 000 μE/m2/s with 10 mg/L As E2 concentration increases from 1 mg/L to 10 mg/L it may induce carbohydrate and lipid productivity for producing bioethanol and biodiesel

Date of Award	2016 Jul 28
Original language	English
Supervisor	Hsin Chu (Supervisor)