(VOVworld) - Four environmental firms from the Japanese prefecture of Hiroshima introduced their technologies to their Vietnamese counterparts in the Mekong Delta province of Soc Trang on Thursday, in an exchange aimed at strengthening their tie-ups. The technologies are used to treat hazardous waste and water treatment, process farm by-products and develop aquaculture. The exchange is also meant to spread the practices of sustainable farming in the locality. The delegation grouped representatives from the Japan External Trade Organization in Ho Chi Minh City, the Director of the Hiroshima Department of Commerce Industry and Labour and consultants from the Japanese association of environmental enterprises.