Corrosion Inhibition Performance of Selected Green Plants and Their Blends on Stainless Steel in Cassava Pulp Filtrate

A comparative study of the corrosion inhibition performance of Neem (NM) and bitter leaf (BL) extracts when used individually and in combined form (NMBL 1:1, NMBL 1:3 and NMBL 3:1) to mitigate the corrosion of stainless steel in cassava pulp filtrate was undertaken. The corrosion rates obtained in the presence of Neem (NM) extract were lower compared to corrosion rates obtained in environments containing blends of the extracts (NMBL 1:1, NMBL 1:3, NMBL 3:1). This implies that the inhibition efficiency of Neem (NM) extract was better than blends of Neem (NM) and bitter leaf (BL) in ratios of 1:1, 1:3 and 3:1. Also, the corrosion rates obtained in environments containing Bitter leaf (BL) extract are lower compared to corrosion rates obtained in environments containing blends of extracts (NMBL 1:1, 1:3 and 3:1). This is an indication that the corrosion inhibition performance of Bitter leaf (BL) extract is better than the blends of Neem (NM) and Bitter leaf (BL) in ratios of 1:1, 1:3 and 3:1. The adsorption of the extracts (Neem (NM), Bitter leaf (BL) and blend of Neem and Bitter leaf extracts in ratio of 1:3) obeyed Langmuir adsorption isotherm. The adsorption of the extracts (blends of Neem and Bitter leaf extracts in ratios of 1:1 and 3:1) did not obey Langmuir adsorption isotherm. The extracts inhibited the corrosion of the metal samples by physical adsorption.