Opportunities and Challenges of Microalgal Cultivation on Wastewater, with Special Focus on Palm Oil Mill Effluent and the Production of High Value Compounds

Abstract

South East Asia dominates the production of palm oil worldwide. During the traditional wet processing, palm oil mill effluent (POME) wastewater is generated which poses serious environmental problems. Wastewater treatment using microalgae was initiated recently because of the advantages to lower nutrient content efficiently while the biomass can be utilized as bulk biomass or value added product. In the present review the utilization of wastewater for microalgal cultivation is discussed with particular attention to the feasibility of utilizing POME as microalgal growth medium. Whereas much recent research was focused on the production of bulk biomass, the potential for the production of value-added compounds has not often been addressed. Various strategies of obtaining high-value products are discussed. These include cultivation systems, algal species selection as well as and their growth strategies (autotrophic, heterotrophic, mixotrophic). In addition, potential problems associated with microalgal cultivation on POME will be evaluated. Finally, the concept of using stepwise strategies to obtain high value added product will be proposed.

Enhancement of C-phycocyanin productivity by Arthrospira platensis when growing on palm oil mill effluent in a two-stage semi-continuous cultivation mode

“…One of the promising wastewaters to be used as a growth medium for algae is palm oil mill effluent (POME) which is generated from oil palm factories. POME contains high amounts of phosphorus, nitrogen, and micronutrients (Mohd Udaiyappan et al 2017;Nur and Buma 2018). As reported earlier, POME addition promotes the growth of the fucoxanthin and sulfated exopolysaccharide producing marine diatom Phaeodactylum tricornutum (Nur et al 2019a, b).…”

Sulfated exopolysaccharide production and nutrient removal by the marine diatom Phaeodactylum tricornutum growing on palm oil mill effluent

“…As reported previously, POME contains high levels of micro nutrients such as iron, zinc, potassium, and magnesium, which could boost algal growth (Habib et al 2003). Furthermore, POME may also contain acetic acid which could be utilized by P. tricornutum by applying mixotrophic growth (Villanova et al 2017;Nur and Buma 2018).…”

“…Nevertheless, the conventional ponding system has various limitations such as low nutrient removal efficiency, long retention times, and enhanced greenhouse gas emissions (Tabassum et al 2015). The strategy to decrease adverse characteristics of POME by using microalgae while simultaneously producing value added products could be promising due to the fact that POME contains high micro-and macronutrient levels (Nur and Buma 2018). However, the nutrient removal efficiency by microalgae will also depend on cultivation conditions as well as on nutrient composition in terms of speciation and initial N/P ratio (Beuckels et al 2015).…”

“…We chose the marine diatom P. tricornutum as test alga since P. tricornutum was shown previously to grow on POME (Nur and Buma 2018). Furthermore, sEPS composition of P. tricornutum, which mainly consist of glucose, mannose, and galactose, was also affected by environmental conditions such as salinity and nutrient addition (Abdullahi et al 2006).…”

Environmental and nutrient conditions influence fucoxanthin productivity of the marine diatom Phaeodactylum tricornutum grown on palm oil mill effluent

“…Key environmental factors such as light intensity, temperature, salinity, and nutrient composition, regulate algal growth in large-scale facilities (Borowitzka 2016;Nur and Buma 2018). Simultaneously, apart from affecting growth, irradiance level might also affect the fucoxanthin content of P. tricornutum since it is a light harvesting pigment (Gómez-Loredo et al 2016).…”