No abstract

Manganese is removed from drinking water because of aesthetic, health, and corrosion concerns. Like iron, manganese removal in biofilters depends on homogeneous, heterogeneous, and biological processes. This study aims to add further understanding to the importance of homogeneous processes for manganese removal in drinking water biofilters. Data collected from 10 groundwater biofilters across filter depth were analyzed using Pourbaix diagrams and thermodynamic modelling software (PHREEQC). Both methods predicted that iron would precipitate in all samples, but the predictions differed for manganese. The software approach provided a more precise look into the minerals predicted to form by homogeneous oxidation, allowing for deeper interpretation of biofilter oxidation-reduction (redox) conditions. Results suggest that multiple manganese removal mechanisms occur across biofilters, but homogeneous manganese oxidation may be essential to meet new Canadian guidelines. Utilities operating manganese removing biofilters should measure redox conditions to determine if changing biofilter pretreatment could decrease effluent manganese concentrations.

No abstract

Microorganisms were allowed to inhabit flow-through systems containing representative Pb corrosion products, Pb(IV) oxide and Pb(II) carbonate. Local tap water was fed to the system. After 277 days of operation,...

In light of increasing interest in water quality and health concerns related to manganese (Mn) at elevated levels, it's important for water utilities to optimize existing treatment processes to enhance Mn control.