USE OF A RECIRCULATING HYDROPONIC BIOREACTOR FOR CLEANING CONTAMINATED WATER FOR USE IN AQUACULTURE

Clean water is a limiting resource in many parts of the world.  Not only is the availability of clean water detrimental to people's survival , but it is  limiting  to the expansion of aquaculture in many places.  In addition, many water sources that are or could be used for aquaculture, such as treated effluent, contain various contaminants that can have potentially hazardous effects on humans and the environment.  These contaminants include heavy metals, pharmaceuticals and industrial compounds, bacteria and nitrogenous waste, among other pollutants.  Some of these compounds, are referred to as "emerging contaminants" because the effects are not yet known or fully understood.   Even  water that appears clean to the naked eye can contain significant concentrations of contaminants.  

To clean water of these emerging contaminants and other pollutants, a recirculating hydroponic bioreactor was proposed, designed and assessed for its ability to remove contaminants and clean water for use in aquaculture.   It was chosen for its relatively cheap cost to build and operate compared to other water treatment options.  

In order to give a real world assessment, hydroponic bioreactors were used to clean up tertiary effluent from a wastewater treatment plant in Tucson, Arizona.   Results showed that after five days of recirculation in  the bioreactors , there were significant reductions of all measured contaminants in the water as well as complete removal of ammonia .  Based on performance, a larger-scale bioreactor could be built to treat contaminated water to provide a new or improved water source for fish culture.