Simultaneous nutrient removal and lipid production from pretreated piggery wastewater by Chlorella vulgaris YSW-04

Abstract

The feasibility of using a microalga Chlorella vulgaris YSW-04 was investigated for removal of nutrients from piggery wastewater effluent. The consequent lipid production by the microalga was also identified and quantitatively determined. The wastewater effluent was diluted to different concentrations ranging from 20 to 80 % of the original using either synthetic media or distilled water. The dilution effect on both lipid production and nutrient removal was evaluated, and growth rate of C. vulgaris was also monitored. Dilution of the wastewater effluent improved microalgal growth, lipid productivity, and nutrient removal. The growth rate of C. vulgaris was increased with decreased concentration of piggery wastewater in the culture media regardless of the diluent type. Lipid production was relatively higher when using synthetic media than using distilled water for dilution of wastewater. The composition of fatty acids accumulated in microalgal biomass was dependent upon both dilution ratio and diluent type. The microalga grown on a 20 % concentration of wastewater effluent diluted with distilled water was more promising for generating high-efficient biodiesel compared to the other culture conditions. The highest removal of inorganic nutrients was also achieved at the same dilution condition. Our results revealed the optimal pretreatment condition for the biodegradation of piggery wastewater with microalgae for subsequent production of high-efficient biodiesel.

Phycoremediation of municipal wastewater by microalgae to produce biofuel

“…26 On ACCEPTED MANUSCRIPT ACCEPTED MANUSCRIPT 7 beginning of the experiment, wastewater was filtered using 0.2µm filters (Corning® bottle-top vacuum filters) and filtrates were analysed for physic-chemical parameter. On end of the experiment (10 th ), algal biomass was harvested by centrifugation at 3000 rpm for 15 min at 4 o C as reported, 27 and remaining wastewater (supernatant) was filtered using 0.2µm filters. Then, filtrates were subjected to physico-chemical analysis.…”

Simultaneous nutrient removal and lipid production with Chlorella vulgaris on sterilized and non-sterilized anaerobically pretreated piggery wastewater

“…In fact, Chlorella like species has been reported to release up to 12.5% from the total assimilated carbon as extracellular organic compounds [28]. Many flask studies without additional CO 2 feeding to boost autotrophic growth demonstrated algae-mediated COD removal from piggery wastewater [9,11,25,26]. Some studies with additional CO 2 feeding also demonstrated removal of COD [3,10,12].…”

“…However, the competition with the other microorganisms decreased the lipid productivity slightly in the non-sterilized wastewater compared to the sterilized wastewater. Microalgal lipid production from piggery wastewater has previously been mainly studied using sterilized wastewater [3,[9][10][11]25], although treatment of non-sterilized piggery wastewater in algal ponds has been studied without measuring the lipids [37]. For example, Whang et al [11] studied lipid production of C. pyrenoides with piggery wastewater in 1 L conical flasks.…”

“…removed COD (and thus DOC) from piggery wastewater [3,10,25,26]. However, C. vulgaris has been demonstrated to release DOC in synthetic medium during photoautotrophic growth [27].…”

Gasification of Phycoremediation Algal Biomass

“…Since low phosphorous (P) and nitrogen (N) concentrations are typically the limiting factors of algal blooms in balanced aquatic environments, introducing untreated (nutrient-rich) effluents instigates their growth. Various studies have successfully demonstrated the potential of microalgae as a treatment option for effluent from livestock production (Wilkie and Mulbry 2002;Ji et al 2013) and municipal wastewater treatment plants (Åkerström et al 2014). The N and P uptake by periphytic algal communities grown in an algal turf scrubber system (ATS) was evaluated as a treatment option for a nutrient-rich creek in Northwest Arkansas (Sandefur et al 2011).…”