The effectiveness of four algal technologies in removing nutrients and antibiotics from biogas slurry induced by different concentrations of diethylaminoethyl hexanoate

This study investigates the effects of different concentrations of exogenously added Diethylaminoethyl Hexanoate (DA-6) on the biomass, photosynthesis, and pollutant removal efficiency of four microalgal treatment systems (Chlorella vulgaris monoculture, Chlorella vulgaris+S395-2+ Pleurotus ostreatus, Chlorella vulgaris+ S395-2+ Ganoderma lucidum, Chlorella vulgaris +S395-2+ Clonostachys rosea) in biogas slurry containing antibiotics. The results indicate that Chlorella vulgaris exhibited optimal growth at a DA-6 concentration of 10⁻⁷ M, with the Chlorella vulgaris + S395-2 + Clonostachys rosea system showing superior performance in all measured parameters compared to other systems. Under optimal DA-6 conditions (10⁻⁷ M), the average removal rates of COD, TN, and TP in the biogas slurry by the Chlorella vulgaris + S395-2 + Clonostachys rosea system were 89.42 ± 7.13 %, 87.71 ± 6.74 %, and 89.85 ± 7.14 %, respectively. The average removal rates of tetracycline hydrochloride (TC), ciprofloxacin hydrochloride (CPFX), and sulfamethoxypyridazine (SMM) were 99.53 ± 0.19 %, 88.26 ± 6.17 %, and 86.31 ± 6.78 %, respectively, with the system demonstrating a more effective reduction of TC antibiotics compared to CPFX and SMM antibiotics.