PESTICIDE SUSTAINABLE MANAGEMENT PRACTICE (SMP) INCLUDING POROUS BIOCHAR/GEOPOLYMER STRUCTURES FOR CONTAMINATED WATER REMEDIATION

Abstract

As a result of agribusiness in Australia and across the world, water is contaminated with nutrients
and pesticides which threaten riverine environments, wetlands, urban drinking water supplies and also marine
assets such as the Great Barrier Reef (GBR). Much can be done and sustainable management practices (SMP) can
be put into place to reduce water impacts from agriculture. Required investment levels are insignificant compared
to the economic advantages to be gained from adopting appropriate SMP across Australian and global
agribusiness. SMP technologies need to be targeted at specific pesticides (eg. atrazine, simazine, diruron, ametryn,
hexazinone, tebuthiuron, dieldrin, metalochlor, 2,4 D, triclopyr, picloram and bromacil). Surface runoff from
agricultural enterprises is conventionally managed by retention lagoons facilitating water reuse on-farm, but these
can be breached during heavy storms. Long term deep drainage from fields and seepage from lagoons can also lead
to contaminated groundwater. Research, development and testing of appropriate non-leaking/reactive spillways
and subsurface geostructures needs to take place across the various agricultural industries. For surface water it is
suggested that spillways could be designed with replaceable biochar baffles, and for groundwater, trenches of
biochar could form Permeable Reactive Barriers (PRB). The potential for green or brown waste material derived
biochar products, which could be readily manufactured from farm refuse and manure, needs to be thoroughly
investigated in this regard. The challenge for engineers is to come up with geostructural designs which are
efficient, cost effective and which will be taken up and embraced by Australian and world agribusiness.