Industrial Saline Wastewater Treatment Technologies Using Microalgae Biomass

Abstract

Most of the industrial sectors like agro-food, petroleum, seafood processing and leather industries discharge a high amount of saline water with high salinity and high organic content. Saline wastewater comprises plentiful pollutants such as nutrients, heavy metals, micropollutants and inorganic/organic pollutants. The saline effluents are strongly inhibited by salts (mainly NaCl). Saline wastewater is a combination of various pollutants and inorganic salts like NaCl, Na2SO4, MgSO4, KNO3 and NaHCO3, which are generated from several sources including the agricultural soil run-off zones, coastal zones, industrial areas and various concentrated effluent of the membrane. The salinity of the wastewater varies largely in the range of >2% w/v NaCl. Such wastewaters are to be treated before discharge. Compared to other technologies for saline wastewater treatment, the microalgae process is considered to be ‘green’ or environmentally friendly as it generates no secondary pollutants and creates profit. In recent times, microalgae have gained a prominent application in various fields of the biotech industry like biofuels, wastewater treatments, pharmaceutical industry, cosmetic industry and the list goes on. In this regard, microalgae have fascinated their interest in saline wastewater treatment since they can adapt to a variety of salinities by changing themselves in terms of biomass yield, pigment formation, variety of species identification, etc. In this chapter, we discussed various species of microalgae that have been utilized in saline wastewater treatment techniques available. The microalgae possess a strong metabolic pathway system, various metabolic pathways used in treating the saline wastewater elucidating these, their nature, adaptation, saline wastewater treatment remediation alongside a comparison with other performing technologies and future standpoints while reducing pollution, cutting costs were discussed in this chapter.