Cultivation of Chlorella vulgaris and Arthrospira platensis with recovered phosphorus from wastewater by means of zeolite sorption.

Giorgos Markou,Dries Vandamme,Orily Depraetere,Koenraad Muylaert

doi:10.3390/ijms16024250

Abstract

In this study, zeolite was employed for the separation and recovery of P from synthetic wastewater and its use as phosphorus (P) source for the cultivation of the green microalga Chlorella vulgaris and the cyanobacterium Arthrospira (Spirulina) platensis. At P-loaded zeolite concentration of 0.15–1 g/L, in which P was limited, the two species displayed quite different behavior regarding their growth and biomass composition. C. vulgaris preferred to increase the intracellular P and did not synthesize biomass, while A. platensis synthesized biomass keeping the intracellular P as low as possible. In addition under P limitation, C. vulgaris did display some little alteration of the biomass composition, while A. platensis did it significantly, accumulating carbohydrates around 70% from about 15%–20% (control). Both species could desorb P from zeolite biologically. A. platensis could recover over 65% and C. vulgaris 25% of the P bounded onto zeolite. When P-loaded zeolite concentration increased to 5 g/L, P was adequate to support growth for both species. Especially in the case of C. vulgaris, growth was stimulated from the presence of P-loaded zeolite and produced more biomass compared to the control.

Highlights

Microalgae and cyanobacteria are a potential source of biomass for the production of various chemicals for the food, pharmaceutical, industrial and bio-energy sector [1,2]
These waste streams beside the desired nutrients may contain some other contaminants which can negatively affect the microalgae and cyanobacterial growth but may reduce biomass quality, rendering the direct use of the wastewaters as cultivation medium or as supplement in the medium problematic [5,6]
Desorption of bounded P was performed using various types of solutions, such as HCl, NaOH, KCl, deionized (DI) water and the two cultivation media BG-11 and Zarrouk, which were used for the cultivation of C. vulgaris and A. platensis, respectively

Summary

Introduction

Microalgae and cyanobacteria are a potential source of biomass for the production of various chemicals for the food, pharmaceutical, industrial and bio-energy sector [1,2]. Among the nutrients phosphorus (P) is one of the most significant and essential for the cultivation of microalgae and cyanobacteria [3]. Several wastewaters types are identified as potential nutrient sources for microalgae and cyanobacteria cultivation, including municipal, industrial and agro-industrial wastewaters [4]. These waste streams beside the desired nutrients may contain some other contaminants which can negatively affect the microalgae and cyanobacterial growth but may reduce biomass quality, rendering the direct use of the wastewaters as cultivation medium or as supplement in the medium problematic [5,6]

Methods

Results

Discussion

Conclusion