optimized-procedure-for-determining-adsorption-phosphonates-onto

Optimized Procedure for Determining the Adsorption of Phosphonates onto Granular Ferric Hydroxide using a Miniaturized Phosphorus Determination Method

This paper introduces a procedure to investigate the adsorption of phosphonates onto iron-containing filter materials, particularly granular ferric ...

University of Stuttgart

Phosphonates are an important group of phosphorus-containing compounds due to their increasing industrial use and possible eutrophication potential. This study involves investigations into the methods UV/Fe, Fenton and UV/Fenton for their removal from a pure water matrix and industrial wastewaters. It could be shown that the degradability of phosphonates by UV/Fe (6 kWh/m) in pure water crucially depended on the pH and was higher the less phosphonate groups a phosphonate contains. The UV/Fe method is recommended in particular for the treatment of concentrates with nitrogen-free phosphonates, only little turbidity and a low content of organic compounds. Using Fenton reagent, the degradation of polyphosphonates was relatively weak in a pure water matrix (<20% transformation to o-PO). By means of the Photo-Fenton method (6 kWh/m), those phosphonates with the smallest numbers of phosphonate groups were easier degraded as well at pH 3.5 in a pure water matrix (o-PO formation rates of up to 80%). Despite an incomplete transformation of organically bound phosphorus to o-PO with Fenton reagent in an organically highly polluted wastewater (max. 15%), an almost total removal of the total P occurred. The most efficient total P elimination rates were achieved in accordance with the following Fenton implementation: reaction → sludge separation (acidic) → neutralization of the supernatant → sludge separation (neutral). Accordingly, a neutralization directly after the reaction phase led to a lower total P removal extent.

Removal of phosphonates from industrial wastewater with UV/Fe, Fenton and UV/Fenton treatment.

Effluent of a municipal wastewater treatment plant (WWTP) was treated on-site with the UV/chlorine (UV/HOCl) advanced oxidation process (AOP) using a pilot plant equipped with a medium pressure UV lamp with an adjustable performance of up to 1 kW. Results obtained from parallel experiments with the same pilot plant, where the state of the art UV/H₂O₂ AOP was applied, were compared regarding the removal of emerging contaminants (EC) and the formation of adsorbable organohalogens (AOX). Furthermore, the total estrogenic activity was measured in samples treated with the UV/chlorine AOP. At an energy consumption of 0.4 kWh/m³ (0.4 kW, 1 m³/h) and in a range of oxidant concentrations from 1 to 6 mg/L, the UV/chlorine AOP had a significantly higher EC removal yield than the UV/H₂O₂ AOP. With free available chlorine concentrations (FAC) in the UV chamber influent of at least 5 mg/L (11 mg/L of dosed Cl₂), the total estrogenic activity could be reduced by at least 97%. To achieve a certain concentration of FAC in the UV chamber influent, double to triple the amount of dosed Cl₂ was needed, resulting in AOX concentrations of up to 520 &micro;g/L.

Removal of Emerging Contaminants and Estrogenic Activity from Wastewater Treatment Plant Effluent with UV/Chlorine and UV/H₂O₂ Advanced Oxidation Treatment at Pilot Scale.

Ralf Minke

Institute for Sanitary Engineering,
Water Quality and Solid Waste Management,
Institute for Sanitary Engineering, Water Quality and Solid Waste Management

University of Stuttgart

Optimized Procedure for Determining the Adsorption of Phosphonates onto Granular Ferric Hydroxide using a Miniaturized Phosphorus Determination Method

Ralf Minke

Institute for Sanitary Engineering,Water Quality and Solid Waste Management,Institute for Sanitary Engineering, Water Quality and Solid Waste Management

University of Stuttgart

Optimized Procedure for Determining the Adsorption of Phosphonates onto Granular Ferric Hydroxide using a Miniaturized Phosphorus Determination Method

Institute for Sanitary Engineering,
Water Quality and Solid Waste Management,
Institute for Sanitary Engineering, Water Quality and Solid Waste Management