Feasibility of using brewery wastewater for biodiesel production and nutrient removal by Scenedesmus dimorphus

ABSTRACT

This work investigates the potential use of a brewery wastewater as a medium for the cultivation of the oleaginous species Scenedesmus dimorphus with the double aim of removing nutrients and to produce biomass as feedstock for biodiesel. For this purpose, effects of nitrogen (61.8–247 mg L⁻¹), phosphorous (1.4–5.5 mg L⁻¹), and iron (1.5–6 mg L⁻¹) concentrations on growth, nutrients uptake, lipid accumulation, and fatty acids profile of this microalga were investigated.

Results showed that brewery wastewater can be used as a culture medium even if nitrogen and phosphorous concentrations should have been modified to improve both biomass (6.82 g L⁻¹) and lipid accumulation (44.26%). The analysis revealed a C16–C18 composition of 93.47% fatty acids methyl esters with a relative high portion of unsaturated ones (67.24%). High removal efficiency (>99%) for total nitrogen and total phosphorous and a reduction of up to 65% in chemical oxygen demand were achieved, respectively.

The final microalgae biomass, considering its high lipid content as well as its compliance with the standards for the quality of biodiesel, and considering also the high removal efficiencies obtained for macronutrients and organic carbon, makes the brewery wastewater a viable option as a priceless medium for the cultivation of microalgae.

KEYWORDS:

• Scenedesmus dimorphus
• brewery wastewater
• fatty acids methyl esters
• nutrients uptake
• COD removal

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was carried out with the following financial supports: ‘Qingdao Municipality Program Research Bursary’ [Y43304110E], ‘National Natural Science Foundation of China’ [41276144], and ‘Science and Technology Development Planning of Shandong Province’ [2013GHY11520].