Removal of reactive dyes from single and binary mixture by Mg/Al-NO3-layered double hydroxide

The adsorption of two reactive dyes, Orange 16 (RO16) and a Reactive Red 120 (RR120) by Mg/Al-NO₃ layered double hydroxide in single and binary mixture (1:1 ratio) was conducted in a batch mode. Spectrophotometric method using first order derivative and zero crossing was applied to analyse colour removal of RO16 and RR120 dyes from solutions. The effects of contact time in single and binary systems were compared. The results obtained at pH of 5 indicated that the percentage removal of dyes initially increased rapidly as contact time increased, then gradually until saturation was reached in both single and binary mixture. Increasing initial dye concentration lowered efficiency. The presence of RO16 in binary mixture RO16-RR120 did not alter the efficiency removal of RR120 and vice versa to a significant level at 50 mg/L.