Engineered wetland reactors with different media types to treat drinking water contaminated by boron (B)

Abstract

Boron (B) removal is a difficult process, and techniques based on conventional methodology mostly remove little or no B from drinking water. Therefore, an attractive, low cost, and environmental friendly treatment method should be tested in order to recover B from drinking water, especially when instillation, operation, and maintenance costs limit treatment applications. Engineered wetland (EW) treatment technologies are effective, economical, and eco-friendly treatment options for wastewater treatment in semi-arid and arid areas in the world. This study presents four new up-flow engineered wetland (UEW) reactors tested with different media types for B removal from drinking water in 120 days treatment period. The results show that significant amount of B is removed from drinking water with UEW, suggesting that using an up-flow mode in EW treatment technology for B removal seems to be an option more effective than those of the other EW system modes. Using Typha latifolia, the present experiment chooses four different filling materials, namely peat, zeolite, volcanic cinder, and sand as media to design wetland reactors. We found that media type affects the removal capacities of wetland reactors and thus B removal efficiency of four reactors are ordered as peat reactor (91%)>volcanic cinder reactor (84%)>sand reactor (83%)>zeolite reactor (57%). Furthermore, results from the present experiment emphasize that the media type also affects the physicochemical parameter, plant uptake, and soil enzyme activities. Consequently, it can be suggested that a well-designed wetland treatment reactor with an up-flow mode and peat media is an effective tool for drinking water treatment in order to obtain higher B removal efficiency