METHOD AND APPARATUS FOR PERFORMING SURFACE FILTRATION FOR WASTEWATER MERCURY REMOVAL

摘要

A method and treatment unit for removing particulate mercury from aqueous streams such as wastewater streams from hydrocarbon processing is disclosed. Mercury solids are removed by means of a surface filter configured in the shape of a bag. The separated solid mercury can be thickened and dewatered by removing the spent filter bag from service and allowing the water to drain and/or evaporate. The dewatered solids can then be disposed of together with the spent bag to an approved solid waste disposal facility. Coagulants, flocculants, and mercury precipitants can be injected upstream of the filter bag if required to increase removal efficiency by precipitating dissolved ionic mercury and increasing the particle size of the mercury solids. Following bag filtration, activated carbon or an alternative technology (e.g., mercury specific ion exchange resin or adsorbent) can be applied to remove any trace concentrations of dissolved elemental and organic forms of mercury if required based on local discharge requirements.