Using undisturbed columns to predict long term behaviour of effluent irrigated soils under field conditions

Abstract

Soils only have a finite capacity for the removal of wastewater pollutants and with time this capacity could in fact decline. Not all soil types have the capacity to provide adequate treatment and dispersal of sewage effluent. For continued long term application to be successful, it is essential that infiltration and drainage characteristics of soils do not decline. Also it is critical how long term application of nutrients and cations affects the soils and whether any leaching occurs. The research project described in this paper compares the outcomes of detailed field studies with results from an undisturbed soil column study where typical soils in the South East region of Queensland State, Australia have been subjected to sewage effluent application over a period of 12 months. Multivariate analysis helped to classify the influential soil characteristics and to identify relative changes in each soil after the application of effluent. Identification and correlation of influential soil characteristics in field and accelerated column studies confirmed that undisturbed soil column studies can be useful in predicting long term behaviour of effluent irrigated soils.