pH Dependent Toxicity of Pyridine Raffinate to a Common Duckweed, Lemna minor L.

This article investigates the hydrogen-ion concentration (pH)-dependent toxicity of pyridine raffinate to duckweed Lemna minor in India. Physico-chemical analysis revealed pyridine raffinate had high chemical oxygen demand, biochemical oxygen demand, total solids, total phenols, formaldehyde, total nitrogen and heavy metals. In general, the effluent sample was characterized as highly complex and any alteration in the pH of the effluent also altered composition. Toxicity assessment of pyridine raffinate with Lemna minor was determined in terms of total chlorophyll, protein and biomass.