A new study shows wastewater generated from the production of olive oil can be converted into ‘green’ resources including water that can irrigate crops.

More than eight billion gallons of wastewater is produced from olive mills in the Mediterranean countries every year, which contaminates water and marine life. Now research published in the journal ACS Sustainable Chemistry & Engineering reveals a more eco friendly outcome is possible.

Dr Mejdi Jeguirim, associate professor at the University of Haute Alsace, and his team has pioneered methods that turn olive mill wastewater (OMW) into a range of valuable and sustainable products. These include mixing it with another waste product found in the Mediterranean, cypress sawdust, swiftly drying the blend and gathering the evaporated water. This water, the team says, is suitable for use in agricultural irrigation. Another process resulted in a biofertilizer that proved capable of triggering plant growth over a five-week period.