Chemical Characterisation of Effluents from Battery Recycling Operations in Onitsha, Anambra State

Informal battery recycling is a significant source of lead, sulphuric acid, and other toxic substances in urban environments across Nigeria, posing severe risks to environmental and public health. This study characterises the chemical composition of effluents and drainage water from battery recycling workshops in the Onitsha industrial corridor, Anambra State, South East Nigeria. Liquid samples were collected from workshop floors, drainage channels, and surface runoff points at ten recycling sites. Parameters analysed include pH, total dissolved solids, sulphate, lead, cadmium, arsenic, and antimony, using ion chromatography and inductively coupled plasma mass spectrometry. Soil samples adjacent to workshop sites were also collected and analysed for lead contamination depth profiling. Results show that effluent pH was extremely acidic, ranging from 1.3 to 3.8, reflecting the sulphuric acid content of lead-acid batteries. Lead concentrations in workshop drainage exceeded 12,000 micrograms per litre, more than 800 times the WHO guideline value for lead in water. Soil lead concentrations at 30-centimetre depth remained above 4,000 milligrams per kilogram at most sites. The findings document alarming contamination levels and recommend urgent regulatory intervention, formalisation of battery recycling operations, provision of protective equipment, and remediation of contaminated soils at identified hotspots. Keywords: battery recycling, lead contamination, effluent characterisation, Onitsha, Anambra State