Use of Free and Entrapped Spirogyra sp. Algae to Remove Endocrine-Disrupting Chemicals from Polluted Waters Through Biological Intervention

Abstract Algae are used intensively in bioremediation studies due to their cell structure organization, doubling their weight in one day, ease of application in biotechnological processes, low cost, content of many useful substances, ability to remove some harmful substances from the environment, and resistance to environmental factors. In this work, Spirogyra sp . was isolated from freshwater sources in Ankara, and the cultivated algal biomass was entrapped in magnetic alginate beads (MA@ALG). The MA@ALG beads were used for the biosorption and degradation of three different endocrine-disrupting chemicals (EDCs), namely Bisphenol A (BPA), Diclofenac (DCF), and Congo red (CR), using free algal biomass as a control system. The biosorption capacities of the free algal biomass for BPA, CR and DCF were 89.4, 163.1, and 68.2 mg/g, respectively. Whereas the biosorption capacities of MA@ALG for BPA, DCF, and CR were 73.6, 104.4, and 49.5 mg/g, respectively. The presence of laccase-like activity of the Spirogyra sp . in the cell-free medium was assayed after contact with the EDCs. The degradation efficiencies of BPA, CR, and DCF were 79.7, 88.2, and 81.7% by the free algal biomass, and 68.9, 73.3, and 73.4% for MA@ALG, respectively, in a batch reactor for 7 days. Biosorption of BPA, DCF, and CR on the free algal biomass and MA@ALG is described by the Langmuir isotherm model and the pseudo-second order kinetic model. The toxicities of the tested compounds and degradation products were assessed with Daphnia magna , Chlamydomonas reinhardtii , and Triticum aestivum L . The degradation products of BPA, DCF, and CR had no remarkable toxic effect on the test organisms used compared to the parent compounds.