Title: EDTA in environments subjected to disposal of dairy effluent from processing plants

Authors: Congmin Zoe Xie; Terry Healy; Peter Robinson; Kevin Stewart; John Russell

Addresses: Department of Earth and Ocean Sciences, The University of Waikato, Private Bag 3105, Hamilton 3240, New Zealand ' Department of Earth and Ocean Sciences, The University of Waikato, Private Bag 3105, Hamilton 3240, New Zealand ' Hill Laboratories, 1 Clyde St. Private 3205, Hamilton 3240, New Zealand ' The Waikato Institute of Technology (Wintec), Private Bag 3036, Hamilton 3240, New Zealand ' Fonterra Co-operative Group, P.O. Box 14063, Longburn, Manawatu, New Zealand

Abstract: The presence of Ethylenediaminetetraacetic acid (EDTA) in environments related to the disposal of dairy effluent has been investigated. An HPLC-UV analytical method was used to determine concentrations of EDTA in soil, surface and ground waters. Method detection limits were 1.5 mg/kg (dry weight) for soil, 1 μg/L for surface water and 2 μg/L for groundwater. A quasi one-dimensional vertical mixing model and a numerical simulation of the hydrodynamic processes (the 3DD hydrodynamic model) were applied to simulate the dispersion of EDTA discharged from a large-scale dairy factory into a relatively small river. Based on the modelling results, large volumes of dairy wastewater discharged into the local river had no significant effects on the concentration of EDTA. Analytical results of EDTA in soil and groundwater indicated that there was no concern about the irrigation of dairy sludge onto pasture land. EDTA was, however, detectable in the soil and groundwater, and heavy metals appear to be transported into the groundwater with EDTA chelates in the pasture area irrigated by the dairy wastewater over periods of time.

Keywords: EDTA; ethylenediaminetetraacetic acid; dairy effluent disposal; HPLC-UV; numerical simulation; hydrodynamic modelling; wastewater treatment; heavy metals; dairy wastewater.

DOI: 10.1504/IJEWM.2013.056194

International Journal of Environment and Waste Management, 2013 Vol.12 No.3, pp.243 - 263

Published online: 20 Sep 2014 *

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