Biological Treatment of Agricultural Waste Water Using a Lemna minor L. and Ceratophyllum demersum L. Plant in Dujail City

Abstract

Abstract The study’s objective was to treat and repurpose some physical and chemical water contaminants for use in agriculture. It also included the analysis and assessment of certain pollutants compatible with heavy metals. The implementation of the phytoremediation method to treat agricultural waste water was the subject of the study. The purpose of this research is to find out whether Ceratophyllum demersum and Lemna minor.L can be used to remediate water that has been used for farming. For irrigation or other purposes, the research took place in the months of September, October, and November 2023 AD. We looked at and tested a few pollutants, including pH. The study found a noticeable divergence in the measured values of many heavy metals, including pH, total dissolved solids (TDS), nitrates (NO3), biological oxygen demand (BOD5), and lead (Pb) and cadmium (Cd). Research into the feasibility of using C. demersum and L. minor plants to purify agricultural effluent is the primary objective of this project. For irrigation or other purposes, the research took place in the months of September, October, and November 2023 AD. We looked at and tested a few pollutants, including pH. It was shown from the results that the pH values tended to be basic despite the treatment, as they ranged between 7.7-7.8. In terms of treatment techniques, the plant treatment produced the greatest reductions in biological oxygen requirement (BOD5) values. Following treatment, its concentration dropped from 10.4 mg/L to 1.28 and 2.72 mg/L, with removal rates for the solids of both plants being 87.69% and 73.85%, respectively. When compared to the agricultural waste water, total dissolved substances (TDS) clearly indicated a considerable difference. as their concentrations decreased from 1522 mg/L to 844 and 1064 mg/L, with removal rates reaching 44.55% and 30.09%, respectively, for both plants after treatment. Plant nutrients represented by nitrates (NO3) were also recorded. A significant decrease using plant treatment, where the nitrate values after treatment reached 0.65 and 0.37 mg/L, with removal rates of 82.89% and 90.26%, respectively, for both plants. Regarding heavy metals, plant treatment had a high role in removing lead (Pb) and cadmium (Cd) with high rates of removal efficiency, as lead recorded a value of 0.98 mg/L in the agricultural waste water before treatment, and it became 0 and 0.04 mg/L with removal efficiency. 100% and 95.92%, respectively, for both plants. As for cadmium metal, the plant treatment recorded complete removal of it, reaching 0 and 0 mg/L, with a removal efficiency of 100% and 100%, respectively, for both plants, after its percentage in the agricultural waste water was 0.073 mg/L before treatment.