Plants help clean up meatworks’ wastewater

Tea tree and bamboo are some of the crops that have been trialled to determine their effectiveness in value-adding the meat processing industry’s wastewater in a research project being led by Southern Cross Plant Science.

The crops are being harvested this week at the Northern Co-Operative Meat Company Ltd (NCMC) trial site in Casino, with the water samples being sent to the Southern Cross University laboratories for testing.

Associate Professor Bronwyn Barkla and Associate Professor Terry Rose, both from Southern Cross Plant Science, and the NCMC management are investigating phytoremediation of the abattoir’s wastewater.

Phytoremediation, the use of plants to clean up polluted soils and water, is not only energy and cost efficient but can emerge as a more sustainable measure towards wastewater management.

The 12-month ‘Identification of suitable crops for sustainable bio-remediation of wastewater from a bovine service abattoir’ project was funded by the Meat and Livestock Australia Limited and the Northern Co-Operative Meat Company for $47,362.

"The reuse of wastewater and effluents for irrigation can result in excessive nutrient build-up in the soil, in particular significant amounts of nitrogen, phosphorus and organic carbon, but also sodium, which over time may cause land degradation and water pollution," said agronomist Professor Rose.

"Our project will make tactical agronomic decisions for selection of optimal crops based on growth, yield, nutrient use efficiency, and sodium accumulation, as well as options for industrial end use."

The trial crops are the perennial species tea tree, bamboo and Arundo donax (a giant reed native to Asia), and annual summer/winter combinations of rhodes grass/ryegrass or forage sorghum/ryegrass.

The meat processing industry, including NCMC, is under increasing pressure to meet new wastewater management regulations.

"Processing activities required for meat production generate large quantities of wastewater and solid waste with predominantly high salt and organic content," said Systems Manager at NCMC, Trevor Moore.

Associate Professor Barkla said the project had benefits for the whole industry.

"This project will provide knowledge and solutions to help the industry sustainably manage their wastewater while providing appreciable environmental and economical returns including ecological integrity, carbon sequestration, as well as the potential for valuable resources in the form of end use products like oils, biofuel feedstock, timber and fodder."

Mr Moore agreed.

"Conventional remediation of the effluent is not only costly but is a waste of good organic matter that is much more economical when applied to cropping," he said.

"Whilst we have been irrigating crops for a number of years, this project will identify plants that will not only improve nutrient uptake but also generate greater bio-mass providing opportunities for bio-energy recovery, already under investigation by NCMC."

Photo: Inspecting the crops at the trial site in Casino (left to right), Trevor Moore from Northern Co-Operative Meat Company (NCMC), Associate Professor Bronwyn Barkla from Southern Cross Plant Science (SCPS), Alicia Hidden from SCPS, NCMC CEO Simon Stahl and Associate Professor Terry Rose from SCPS.