Ambient iron-mediated aeration (IMA) for water reuse

Water Res. 2013 Feb 1;47(2):850-8. doi: 10.1016/j.watres.2012.11.005. Epub 2012 Nov 21.

Abstract

Global water shortages caused by rapidly expanding population, escalating water consumption, and dwindling water reserves have rendered water reuse a strategically significant approach to meet current and future water demand. This study is the first to our knowledge to evaluate the technical feasibility of iron-mediated aeration (IMA), an innovative, potentially economical, holistic, oxidizing co-precipitation process operating at room temperature, atmospheric pressure, and neutral pH, for water reuse. In the IMA process, dissolved oxygen (O₂) was continuously activated by zero-valent iron (Fe⁰) to produce reactive oxygen species (ROS) at ambient pH, temperature, and pressure. Concurrently, iron sludge was generated as a result of iron corrosion. Bench-scale tests were conducted to study the performance of IMA for treatment of secondary effluent, natural surface water, and simulated contaminated water. The following removal efficiencies were achieved: 82.2% glyoxylic acid, ~100% formaldehyde as an oxidation product of glyoxylic acid, 94% of Ca²⁺ and associated alkalinity, 44% of chemical oxygen demand (COD), 26% of electrical conductivity (EC), 98% of di-n-butyl phthalate (DBP), 80% of 17β-estradiol (E2), 45% of total nitrogen (TN), 96% of total phosphorus (TP), 99.8% of total Cr, >90% of total Ni, 99% of color, 3.2 log removal of total coliform, and 2.4 log removal of E. Coli. Removal was attributed principally to chemical oxidation, precipitation, co-precipitation, coagulation, adsorption, and air stripping concurrently occurring during the IMA treatment. Results suggest that IMA is a promising treatment technology for water reuse.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adsorption
  • Chemical Precipitation
  • Corrosion
  • Electric Conductivity
  • Enterobacteriaceae / growth & development
  • Enterobacteriaceae / isolation & purification
  • Feasibility Studies
  • Hydrogen-Ion Concentration
  • Iron / chemistry*
  • Microbial Viability
  • Oxidation-Reduction
  • Oxygen / analysis*
  • Oxygen / chemistry
  • Reactive Oxygen Species / analysis
  • Reactive Oxygen Species / chemistry
  • Solid Waste / analysis
  • Solubility
  • Steel / chemistry
  • Waste Water / chemistry*
  • Waste Water / microbiology
  • Water Pollutants, Chemical / analysis
  • Water Pollutants, Chemical / chemistry*
  • Water Purification / instrumentation
  • Water Purification / methods*
  • Water Quality*
  • Water Resources / analysis

Substances

  • Reactive Oxygen Species
  • Solid Waste
  • Waste Water
  • Water Pollutants, Chemical
  • Steel
  • Iron
  • Oxygen