Biodiesel production potential of mixed microalgal culture grown in domestic wastewater

Abstract

In this study, a mixed microalgal culture grown in secondarily treated domestic wastewater effluent was investigated for biodiesel production using in situ transesterification method with conventional heating. The total lipid content of the mixed culture was found as 26.2% ± 0.6 by weight of dry biomass, and 74% of the lipids were contributed by total glycerides. In situ transesterification with conventional heating process under acidic conditions produced higher biodiesel yield with chloroform as the co-solvent (82.1% ± 3.9) compared to hexane (55.3% ± 3.9) under the same reaction conditions. The gas chromatography analysis showed that FAME composition was mainly composed of palmitic, palmitoleic, stearic, oleic, linoleic and linolenic acid methyl esters., and thus the mixed microalgal culture fed by domestic wastewaters has had comparable biodiesel conversion yields and FAME composition to mono-culture and pure cultures fed by synthetic culture media. Hence, this study showed that secondarily treated domestic wastewater could potentially be a suitable and sustainable medium for microalgae grown to be used as biodiesel feedstock.

Biodiesel production potential of wastewater treatment high rate algal pond biomass

“…Methyl esters of palmitic (C16:0), palmitoleic (C16:1), stearic (C18:0), oleic (C18:1) and linolenic (C18:3) acids were the most abundant FAMEs species in the pond biomass lipids (Table 4). The composition was in agreement with what has been reported for wastewater microalgae/biomass lipids (Chinnasamy et al, 2010;Doma et al, 2016;Soydemir et al, 2016;Zhou et al, 2011). The biomass methyl esters during the pond monitoring were dominated by the saturated FAMEs (23-32.2 wt% of the total FAMEs) while the monounsaturated and the polyunsaturated FAMEs ranged 10.8-19.7 wt% and 4.8-10.7 wt% of the total FAMEs, respectively.…”

“…The values are mean (standard deviations) of two replications during sampling period. quality biodiesel which could meet different standards is 0-1:4-5:0-1 (Ramos et al, 2009;Soydemir et al, 2016). In addition, feedstock lipid profile has a high impact on operational factors and yield of esterification (Knothe, 2005;Marchetti et al, 2007;Ramos et al, 2009).…”

“…Quality biodiesel is comprised of fatty acid methyl esters of C16:0 (methyl palmitic), C18:1 (methyl oleic) and C18:3 (methyl linolenic) that are derived from esterification of the triacylglyceride and hydrocarbon fractions of renewable lipid sources (Ramos et al, 2009;Soydemir et al, 2016;Talebi et al, 2013). It has been shown that the optimum ratio of C16:0, C18:1 and C18:3 for production of Table 3 Biomass concentrations and productivities, ash-free lipid weight fraction and productivities and the biomass ash content over the course of study.…”

Chlorella Biomass Production in Annular Photobioreactor Using Palm Oil Mill Effluent (Pome): Effect of Hydrodynamics and Mass Transfer, Irradiance, Aeration Rate and Pome Concentration

“…A good quality biodiesel may be achieved by a mixed culture of selected microalgae, appropriate blending of oils from different monocultivated microalgae or with conventional diesel and the use of polymeric additives. In general, the lipid quality of C. vulgaris UMACC001 cultivated in POME can meet the biodiesel standards and is comparable to previous reports on C. vulgaris (Mallick et al, 2012) and microalgae cultivated in wastewater (Chinnasamy et al, 2010;Soydemir et al, 2016). C. vulgaris UMACC001 had been suggested as a potential strain serving as a biodiesel feedstock based on its fast growth (µ = 0.42 per day) and high SFA content (68.2 wt%) (Vello et al, 2014).…”

“…Recent studies showed that Chlorella is one of the potential microalgae to be used as feedstock for biodiesel production due to its high biomass and lipid productivities and suitable fatty acid composition (Praveenkumar et al, 2014;Vello et al, 2014). Chlorella has been successfully used in bioremediating wastewaters such as rubber industry effluent (Phang et al, 2001), textile discharge (Lim et al, 2010), carpet mill effluent (Chinnasamy et al, 2010), landfill leachate (Mustafa et al, 2012) and domestic wastewater (Soydemir et al, 2016). Culturing Chlorella in wastewaters can reduce the cost of biomass production (Chinnasamy et al, 2010;Soydemir et al, 2016).…”