Sustainable phycoremediation of mushroom farm wastewater using novel isolated microalga (Chlamydomonas asymmetrica SAG70.72): Experimental and kinetic studies

This study aimed to assess the mushroom farm wastewater (MFW) treatment potential using novel isolated microalga Chlamydomonas asymmetrica strain SAG70.72. Microalga was isolated from the Ganga River located in Haridwar, India, and identified using an 18S rRNA-based sequencing technique. For phycoremediation experiments, different concentrations of MFW (i.e., 0 % as control, 50, and 100 %) were used to cultivate isolated C. asymmetrica under laboratory conditions. The results showed that the maximum significant (p < 0.05) reduction in total dissolved solids (TDS: 87 %), biochemical oxygen demand (BOD: 93 %), chemical oxygen demand (COD: 92 %), total Kjeldahl's nitrogen (TKN: 87 %), and total phosphorus (TP: 97 %) were observed in 50 % MFW treatment. Moreover, proximate, biochemical, and fatty acids methyl esters (FAMEs) composition of C. asymmetrica were also found highest in 50 % MFW treatment. The first-order reaction-based kinetic model also depicted the highest value of rate constant (k) in the same treatment. Moreover, the growth of C. asymmetrica was best simulated using the logistic model as compared to the modified Gompertz models. The findings of this study suggested that the implementation of isolated C. asymmetrica in MFW treatment systems could contribute to the mitigation of environmental impacts associated with mushroom cultivation.