Evaluation of self-purifying power of cyanobacteria Pseudanabaena galeata: case of dairy factory effluents

Mustapha Ouhsassi,Abdeltif El Ouahrani,Abdellatif El Harsal,El Ouardy Khay,Abdelhakim Bouyahya,Jamal Abrini

doi:10.1007/s13201-020-01270-8

Abstract

This study aims to evaluate the treatment of wastewater from dairy plants using the self-purifying power of filamentous cyanobacterium Pseudanabaena galeata. The performance and the reliability of using cyanobacteria as wastewater treatment technique were also assessed based on total bacterial flora, total nitrogen (NK), chemical oxygen demand (COD), and total organic carbon (TOC). The results obtained show promising treatment of wastewater if 25% and 50% dilutions were applied. Thus, respectively, for 25 and 50% dilutions, the reduction of the total bacterial flora was 67 and 45%, NK removal was close to 92 and 77%, the COD decreased by 77% and 65%, and the TOC decreased by 78 and 77%. The final concentration of cyanobacteria biomass increased from 15.72 to 585 mg/l and 475 mg/l, respectively, for 25 and 50% dilutions. These results suggest that cyanobacteria (Pseudanabaena galeata) may play an effective role in the biological treatment of wastewater.

Highlights

Water resources in Morocco are limited due to the semiarid climate that characterizes most of the country that often undergoes episodic droughts
The overall objective of this study is to evaluate the behaviour and the growth mode of cyanobacteria subjected to different concentrations of wastewater of dairy liquid discharge (COLAINORD Dairy Cooperative), which produces yogurt and various dairy products
The species was identified according to the work of Komárek and Anagnostidis (2005), Acinas et al (2009) and based on its fatty acid composition (Ouhsassi et al 2017), which is generally used as a phylogenetic marker to characterize different species of cyanobacteria (Los and Mironov 2015)

Summary

Introduction

Water resources in Morocco are limited due to the semiarid climate that characterizes most of the country that often undergoes episodic droughts. This issue is not limited to the quantity of water resources, and to their quality, which attracts global intention more than ever nowadays (EL Addouli et al 2009). Increasing population and industrialization are key contributors to water pollution (Rawat et al 2011; Sood et al 2012) These wastewaters are highly hazardous for ecosystem and human health. In Morocco, domestic and industrial wastewaters are often reused without prior treatments, leading to major risk for public health such as epidemics including typhoid and cholera. Wastewater treatment is becoming a priority today to reuse in agriculture, industry, and other sectors

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