Water hyacinth (Eichhornia crassipes and Epipremnum aureum) - a potent tool for the removal of cadmium and chromium from industrial discharges

Industrial discharge is one of the major reasons for increasing heavy metal intoxication in the ecosystem and is a cause of global apprehension. The introduction of policies for periodically limited duration shutdown of industries might provide a way forward for reducing the pollutant loads in river bodies. Further, hyper-accumulator plants could serve as cost-effective alternatives to conventional sewage treatment facilities but comparative studies with native water hyacinth as natural water filtration systems with limnological studies and risk assessment remain to be determined. We here investigated the most polluted industrial effluent among ten industries during SARS-CoV-2 pandemic confinement (pre- and post-lockdown, that is, February 2020 and October 2020) in Mathura industrial area, India in terms of chromium and cadmium toxicity. Besides, the biosorbent potential of native Eichhornia crassipes and Epipremnum aureum plants was also estimated by triplicate batch experiments (7 d) from the most polluted industrial effluent. For risk assessment, the Metal Quality Index (MQI), Pearson’s correlation coefficient analysis, and Heavy Metal Pollution Index (HPI) were calculated, while the students’ paired sample t-test was employed to determine the statistical significance of changes in HPI and MQI. The findings revealed that the mean HPI for Cr (166, 545 and 53, 797) and Cd (96.11 and 9.78) were found to be extremely high during the pre-lockdown period which reduced significantly in the post-lockdown period. For student’s t-test analysis, the p-values for the investigated sites were initiated to be considerably below the 0.05 level of significance. While results demonstrate removal efficiency of 67.66% and 61.22%, respectively in E. crassipes, whereas it was 44.26% and 38.90% in E. aureum. Low levels of student’s t-test and p-values suggest a transient statistical impact of pandemic confinement on the water quality of studied sites and may help to alter pollution control policies and actions to make sure the environment is sustainable and safe. In addition, information makes it possible to conclude that money plants and water hyacinths both are effective candidates for removing chromium and cadmium from industrial effluents. This paper also summarizes the prospects for the scientific area of biosorption and bioaccumulation, focusing on its underlying assumptions, potential environmental benefits, and practical applications.