PRI-SC® PEROXIDE REGENERATED IRON – SULFIDE CONTROL

PRI-SC® PEROXIDE REGENERATED IRON – SULFIDE CONTROL

Introduction

Sulfide odor control within sanitary sewers has been practiced for over 50 years, yet only recently have substantive advances been made. Where once the choice of chemical treatment was either chlorine or iron salts, safer and more environmentally benign technologies based on hydrogen peroxide, nitrates and/or magnesium hydroxide have gained acceptance. These new alternatives, however, can increase treatment costs substantially and present limitations in themselves. USP Technologies identified and addressed this issue by lessening the adverse impacts of the older, cheaper mainstays, particularly iron salts such as ferrous/ferric chloride or sulfate that provide other benefits to wastewater treatment operations.

USP Technologies developed a proprietary technology called PRI-SC® (Peroxide Regenerated Iron-Sulfide Control). PRI-SC is a combination treatment that integrates iron salts with hydrogen peroxide (H2O2) in a synergistic fashion. At the most basic level, PRI-SC treatment may be viewed as an oxidant (hydrogen peroxide) regenerating the spent iron salt (FeS) in-situ, yielding fresh ferric (Fe3+) iron and colloidal sulfur. The combined treatment provides cost benefits superior to either chemical alone, while allowing greater flexibility as to the placement of storage and dosing facilities. For example, practical control of sulfides to very low levels (e.g. <0.1 mg/L dissolved sulfide) is afforded with minimal reaction time (<5 minutes). Other benefits are accrued to the reaction, including: reduced solids (FeS) loadings, accelerated reaction rates and enhanced flocculation in clarifiers. The process has particular benefit when employed for gravity interceptors, force main discharges and headworks treatment.

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Download PRI-SC-Tech-Bulletin-17-LR (pdf)