TY - JOUR AU - Azmi, Azlin Suhaida AU - CHE AZIZ, NURAIN ATIKAH AU - Mohamad Puad, Noor Illi AU - Halim, Amanatuzzakiah Abdul AU - Yusof, Faridah AU - Yusup, Suzana PY - 2018/12/01 Y2 - 2024/03/29 TI - Chlorella vulgaris logistic growth kinetics model in high concentrations of aqueous ammonia JF - IIUM Engineering Journal JA - IIUMEJ VL - 19 IS - 2 SE - Chemical and Biotechnology Engineering DO - 10.31436/iiumej.v19i2.893 UR - https://journals.iium.edu.my/ejournal/index.php/iiumej/article/view/893 SP - 1 - 9 AB - <p><strong><em>ABSTRACT</em></strong><strong><em>:</em></strong> The ability of microalgae to utilize CO<sub>2</sub> during photosynthesis and grow rapidly shows their potential in CO<sub>2</sub> bio-fixation to capture and store the gas. However, CO<sub>2</sub> capture by this biological approach is very slow compared to chemical reaction-based processes such as absorption using amine or aqueous ammonia. Integration between chemical (aqueous ammonia) and biological (microalgae) aspects might enhance the capturing process and at the same time the microalgae can assimilate CO<sub>2</sub> for beneficial bioproduct formation. Thus, it is important to assess the growth of the microalgae in various concentrations of ammonia with CO<sub>2</sub> supply. Hence, the main objective of this study is to investigate <em>Chlorella vulgaris</em> growth and its kinetics in aqueous ammonia. To achieve that, <em>C. vulgaris</em> was cultivated in various concentrations of aqueous ammonia between 0 to 1920 mg/L at room temperature (i.e. 27 °C) and supplied with 15% (v/v) of CO<sub>2</sub> under illumination of 3500 lux of white fluorescent light. Result shows that the maximum growth capacity (<em>X<sub>max</sub></em>) of <em>C. vulgaris </em>is deteriorating from 1.820 Au to 0.245 Au as the concentration of aqueous ammonia increased. However, no significant change in maximum specific growth rate (<em>µ<sub>max</sub></em>) was observed. The growth data was then fitted into the logistic growth model. The model coefficient of determination (<em>R<sup>2</sup></em>) is decreasing, which suggests modification of the model is required.</p><p><strong><em>ABSTRAK: </em></strong>Keupayaan alga-mikro untuk menggunakan CO<sub>2</sub> semasa proses fotosintesis dan pembiakannya yang pesat menunjukkan potensi dalam penggunaan dan penyimpanan gas ketetapan-biologi. Walau bagaimanapun, penggunaan CO<sub>2</sub>&nbsp; melalui cara ini adalah sangat perlahan berbanding proses tindak balas kimia melalui penyerapan amina ataupun cecair&nbsp; ammonia. Percampuran antara tindak balas kimia (cecair ammonia) dan tindak balas biologi, memungkinkan penambahan proses percampuran dan pada masa sama alga-mikro akan menyerap CO<sub>2</sub> bagi kepentingan pembentukan hasil biologi. Dengan itu, adalah sangat penting untuk mengawasi pertumbuhan alga-mikro dalam pelbagai ketumpatan ammonia bersama kandungan CO<sub>2</sub>. Oleh itu, objektif utama penyelidikan ini adalah untuk menyiasat pertumbuhan <em>Chlorella vulgaris</em> dan proses kinetik dalam cecair ammonia. Bagi memperoleh hasil tersebut<em>,&nbsp; C. vulgaris</em> telah dikulturkan pada ketumpatan cecair berbeza antara 0 ke 1920 mg/L pada suhu bilik (iaitu 27 °C) dan dibekalkan dengan 15% (v/v) CO<sub>2</sub> di bawah cahaya putih flurosen&nbsp; 3500 lux. Keputusan menunjukkan kapasiti pertumbuhan terbanyak (<em>X<sub>max</sub>)</em> <em>C. vulgaris</em> telah berkurang daripada 1.820 Au kepada 0.245 Au apabila ketumpatan cecair ammonia dikurangkan. Walau bagaimanapun, tiada perubahan ketara pada kadar pertumbuhan (<em>µ<sub>max</sub></em>) dapat dilihat. Data kadar pertumbuhan kemudiannya dikemas kini pada model pertumbuhan logistik. Model pekali penentu (<em>R<sup>2</sup></em>) telah direndahkan di mana cadangan untuk mengubah model adalah diperlukan.</p> ER -