Fabrication of immobilized algal-bacterial beads and its application in synthetic mariculture tail water treatment

Abstract

With the rapid expansion of the maricultural scale, the treatment of mariculture tail water (MTW) has become a focus of marine environmental protection. Meanwhile, as a cost-effective wastewater treatment technology, immobilized algal-bacterial beads (IABB) has received wide attention. The nutrients removal of wastewater by IABB is limited by the stability and strength of the beads during the treatment process. In this study, the fabrication of IABB composing Chlorella vulgaris and activated sludge with different concentration of SA (1.5%, 2.5% and 3.5% w/v) and Ca2+ (2%, 3.5% and 5% w/v) and their application in the treatment of synthetic MTW was primarily investigated. The SA concentration has significant impact on the characteristics of IABB. Specifically, 2.5% of SA resulted in the formation of IABB with the best homogeneity, chemical and mechanical stability. Ca2+ concentration affect the nutrient removal efficiency during MTW treatment. The IABB fabricated under the conditions of 2.5% SA and 2% Ca2+ showed the highest removal efficiency of NH3-N, TP and COD within the 48 h of experiment, i.e. 66.7 ± 3.2, 81.0 ± 2.8 and 90.7 ± 1.9%, respectively. Therefore, the application of IABB offers promising prospects for MTW treatment and marine environmental safety.