Wastewater treatment challenges faced by the petrochemical and refinery industry, and opportunities for water reuse

Industrial wastewater differs from municipal wastewater. The limits for treated effluent discharge and targets for re-use are typically the same, and derived from the best available technology for municipal wastewater treatment. The main treatment unitary processes are also the same; although proper adaptation to specific, different, industrial wastewater streams is needed. This paper provides some examples of the challenges presented by specific wastewater sources (high total dissolved solids, high temperature, spent caustic, etc.), lack of previous similar experience - e.g., using membrane bioreactors for refinery wastewaters, and/or absorption chillers, and plate and frame heat exchangers) or to legislation protecting sensitive environments (limits on total nitrogen or soluble metals). The methods by which these were faced and overcome to achieve treatment and/or re-use standards are described. General water cycle optimization issues around industrial facilities with appropriate use of existing wastewater treatment units are also discussed, as well as selecting between treated municipal and industrial effluents as sources for water re-use.