Evaluation of mass transfer effect and response surface optimization for abatement of phenol and cyanide using immobilized carbon alginate beads in a fixed bio-column reactor

Coke oven sectors dispense phenol and cyanide into the circumferential ecosystem, which becomes a serious concern to the subsistence of the flora and fauna. The current study investigates phenol-cyanide treatment using carbon alginate beads immobilized with mixed bacterial consortium. Response surface using central composite design was contrived for the batch and packed bed bio-column optimization study. The optimal removal conditions obtained in batch study were 89.77% and 82.33% for phenol and cyanide, respectively, with 10-g/L adsorbent dosage, time 2 hr, and particle diameter 0.3 cm, whereas 87.22% and 90.97% with 22-cm column height, column diameter 3 cm, 10-ml/min flow rate, and 1-hr operation time. The actual exposure time of the pollutants in the bio-column reactor was calculated to be 22.15 min. Analysis of variance and model statistics predicted a high coefficient of determination for column operation with R-2 = .9950 (phenol), R-2 = .9976 (cyanide), and p values < .0001 stating significant model. The quantitative estimation of the combined external mass transfer and biodegradation effect was performed to evaluate correlation as (phenol) and (cyanide) with k(m) = 0.052 and k(m) = 0.055 cm/hr, respectively. The surface morphological study was executed by field emission scanning electron microscopy and Brunauer-Emmett-Teller surface area analysis depicting bacterial film development on the porous carbon matrix for effective treatment of binary system.