The removal of nitrogen using an autotrophic hybrid hollow-fiber membrane biofilm reactor

Hydrogenotrophic denitrification of potable water: A review

“…However, due to the different hydrogenotrophic cultures used and to the variability of operating conditions, many researchers [8,20,92] indicate that the optimum pH is about 7.5-7.6, whereas denitrification is inhibited or nitrite accumulation is observed above this value.…”

“…In order to avoid pH rise and to increase denitrification efficiency phosphate buffers were used by many researchers [14,15,92,94]. The pH in experiments reported by Lee and Rittmann [5,37] was held nearly constant between 7.0 and 7.2 by a strong phosphate buffer.…”

Chemolithotrophic denitrification in biofilm reactors

“…Hollow-fiber-membrane biofilm reactors (HFMBfRs) were operated for hydrogenotrophic denitrification with membranes of different polymeric materials (Table 5). In particular, polysulfone allows easy membrane manufacturing and its use resulted in the highest denitrification rates [80,81]. Visvanathan et al [82] performed a simultaneous organic and nitrate removal in two double stage HFMBfRs.…”

Characteristics of hydrogenotrophic denitrification in a combined system of gas-permeable membrane and a biofilm reactor

“…Many investigators focus their attention on the latter because a gaspermeable membrane can act as both the hydrogen diffuser and the biofilm carrier. Hollow-fiber membranes are typically employed as gas-permeable membranes [1,5,8,10], although silicon tubes have been tested as well [11,12]. Hydrogen flows through the lumen and diffuses into the bulk liquid through membrane walls.…”