Recent advances and perspectives in the treatment of hydroponic wastewater: a review

摘要

Rapid development of hydroponic farming which is soilless cultivation method of growing plant using mineral nutrient solution dissolved in water produces large amount of wastewater rich in nutrients and organic matters thus imposes great harms to human and environment, if the waste nutrient solution is not correctly treated. The objective of this review is to present information concerning hydroponic systems, including: the different classes and methods of operation; advantages and drawbacks and the recent approaches and development in hydroponic wastewater treatments. Particular emphasis has been placed on removal of root exudates from reused waste nutrient solution in closed system. The reviewed technologies for nutrient removal or recovery include denitrification, microalgae cultivation, constructed wetlands and activated carbon methods. The alternatives byproducts i.e. biogas as agriculture fertilizer for hydroponic cultivation to attain sustainable agriculture was further highlighted. In addition, current challenges and future prospects in this field are carried out. About 118 published studies are reviewed in this paper. It is evident from the literature survey articles that activated carbon is the most frequently studied for the nutrient recovery of hydroponic wastewater.