Treatment of metal cyanide bearing wastewater by simultaneous adsorption and biodegradation (SAB)

This paper presents process review and comparative study of biodegradation and adsorption alone with simultaneous adsorption and biodegradation (SAB) process using Pseudomonas fluorescens. Ferrocyanide solution was used for all studies with initial CN− concentrations of 50, 100, 200 and 300 mg/L, and initial pH of 6. Pseudomonas fluorescens used ferrocyanide as sole source of nitrogen and biodegradation efficiency was observed as 96.4, 94.1, 86.2 and 69.3%, respectively after 60 h of agitation. Whereas in adsorption process with granular activated carbon (GAC) as adsorbent, CN− removal efficiency was found to be 85.6, 80.1, 70.2 and 50.2%, respectively. But in SAB process the removal efficiency could be more than 70% for all concentrations only at 36 h of agitation and achieved removal efficiency of 99.9% for 50 and 100 mg CN−/L. It was found that SAB process is more effective than biodegradation and adsorption alone.