Algal immobilization as a green technology for domestic wastewater treatment

Abstract

wastewater treatment technology is an important issue because of numerous organic and inorganic impurities in municipal, industrial, and agricultural waters. Different systems of wastewater treatment used the microorganisms for the removal of organic materials, most species of algae represent promising biosystems for treating of wastewater by transformation or direct uptake of pollutants and improving the purification performance of bacterial systems. This work aimed to study the efficiency of immobilization technology using immobilized cells of green algae Chlorella vulgaris in the treatment of domestic wastewater. Some physical and chemical characteristics of domestic wastewater were examined and the percentage of treatment efficiency with free and immobilized cells of alga were compared. The results of the study presented high reduction of EC, salinity, TDS, total alkalinity, hardness, calcium, and chloride with slight induction of pH values to the basal side after treatment with free and immobilized algae. After (3,5,7) days of treatment with free microalgae and immobilized microalgae, the recorded value of wastewater had been eliminated to (2.09, 2, 1.8) μs/cm and (2.36, 1.27, 1.07) μs/cm of EC; (689, 580, 520) mg/L and (620,520,489) mg/L of the total hardness; (320, 244, 220) mg/L and (300, 244, 204 ) mg/L of the calcium; (420, 369, 309) mg/L and (400, 340, 289) mg/L of chloride, respectively, while pH value increased to (8.6, 8.7, 8.6) after treated with free microalgae. The results showed high efficiency of mobilized algae compared with free algal cells in reducing many physical and chemical parameters and the immobilized algal cell technique is useful as tools in the treatment process of wastewater.