Root Zone WSB Model: towards a framework for the sustainable application of saline effluent on land

摘要

The sustainability of a system for land disposal of saline effluent is fundamentally dependent on whether salt concentrations in the soil can be maintained at levels that allow adequate plant growth to remove water, salt or other undesirable solutes.Hence a suitably high leaching fraction is required to limit salt accumulation. If other undesirable solutes are present, the excessive amount of water application may give rise to other environmental problems of excessive solute accumulation or discharge. A framework is required to balance these opposing requirements for a sustainable land disposal system. A simple and robust Root Zone WSB (Water and salt balance) model has been developed on an excel spreadsheet that can accurately predict the deep drainage and salt concentrations in the root zone. This model has been successfully applied to land disposal sites for non-saline and saline industrial effluents in Queensland and results show reasonably accurate prediction of deep drainage and salt concentration in the root zone over a 4 year period.