Mitigation of microbial biodeterioration and acid corrosion of pipework steel using Citrus reticulata peels extract mediated copper nanoparticles composite

Abstract Citrus reticulata (tangerine) peels extract was used to mediate the synthesis of copper nanoparticles (ETP-CuNPs). The product was characterized and applied as inhibitor for steel corrosion induced by 1 M HCl and Desulfovibrio sp. Round-shaped, monodisperse, non-aggregated crystals of zero-valent Cu with sizes between 54 and 72 nm were obtained. ETP-CuNPs triggered a 3-log reduction in Desulfovibio sp population at 1.96 mg/L MIC with biocorrosion inhibition efficiency of 79.8% and 68.4% at 303 K and 333 K respectively. At these temperatures, 1.0 g/L ETP-CuNPs also inhibited acid corrosion with efficiency of 95.3% and 84.6% respectively. Owing to smaller sizes, the nanoparticles more easily permeate through bacteria cell wall to alter their metabolic activities and growth than the extract. In the acid solution, ETP-CuNPs adsorb spontaneously on the steel surface via both physical and chemical mechanism using C C, O–H, C–O and N–H groups from phyto-compounds capped to Cu. Modification of the extract into nanoparticles enhanced the efficiency and better surface protection as determined by electrochemical, weight loss and surface characterization techniques. An alternative cost effective new material for simultaneous inhibition of acid and biocorrosion in the oilfield has therefore been demonstrated in this study.