Separation Science and Technology, Vol.36, No.15, 3311-3335, 2001
Pervaporation-based hybrid processes in treating phenolic wastewater: Technical aspects and cost engineering
In this study, the feasibility of combining pervaporation with adsorption in a hybrid process to recover phenol from wastewater is analyzed with the technical aspects and the cost of the processes taken into account. The pervaporation unit in the hybrid process is combined with a decanter on the permeate side and an adsorption unit on the retentate side. Two modes of regeneration, steam and heat, are considered for the adsorption unit. Through comparisons of the stand-alone units with the hybrid processes, we found that hybrid processes were feasible economic alternatives. In addition to meeting the environmental standard, the hybrid processes also recovered over 98% of the phenol at a concentration of 76% (wt). Even though the cost data showed that the use of heat regeneration for the adsorption unit is the cheaper option, the integration of steam regeneration improves the phenol recovery rate to over 99%. A sensitivity analysis of the economic boundaries of the hybrid processes revealed that the membrane life cycle and not the membrane cost is the key cost parameter in the hybrid processes. The advantages of the hybrid process are further increased when the processes are scaled up. Overall, this study demonstrates that pervaporation-based hybrid processes that combine pervaporation, adsorption, and a decanter could be used effectively to recover phenol from industrial waste streams.