Treatment of Primary and Secondary Domestic Wastewater Effluents by using Microalga Oscillatoria Sp

Abstract

The scarcity of water all around the world been increasing and has resulted in the development of new water reuse technologies. But, the success of water reuse projects have not been so effective and also with so many disadvantages. Hence Laboratory-scale experiments were performed to develop a procedure for biological treatment of secondary and tertiary wastewater treatment using microalgae. Ten microalgae strains were isolated from Munnakal beach, Kerala and were identified through microscopic examination. Then, the ability of microalgae to remove nutrients and organic carbon from primary and secondary effluents were investigated. Among the isolated strains, M1 strain alone showed maximum reductions in soluble concentrations total nitrogen, phosphorus, and COD (27%, 91.7%, 88.6% and 25.5. 30.8%), in both for primary and secondary wastewater respectively. The high nutrient removal capacity of the M1(Oscillatoria sp.,) microalgae suggests that these microalgae have the potential to be used for tertiary treatment and treatment of side streams at treatment plants under simple and inexpensive operational conditions. Therefore, a microalgae-based treatment system can reduce or eliminate the need for chemical disinfection methods. The results of this study indicate that microalgae-based treatment systems can be incorporated in treatment plants in a very simple and inexpensive way without the need for providing CO2, nutrients, heating, pH adjustment, etc.