Ammonium removal from digested sludge liquors using ion exchange.
Liquors arising from the dewatering of digested sludge typically contain ammonium levels in the range 200-700mgl(-1) NH(4)(+)-N. These liquors are frequently recycled to the head of the wastewater treatment works (WwTW) untreated and can constitute >25% of the total nitrogen load entering the works at inlet. This paper investigates the use of a clay-based material, MesoLite, as an ion exchange medium for ammonium removal from recycle streams. Pilot-scale studies performed at Didcot WwTW, part of the Thames Water wastewater treatment network, indicate that MesoLite is highly selective for the ammonium ion. Results show that >95% of ammonium was removed from belt press liquors with an initial ammonium nitrogen concentration >600mgl(-1), with an overall ion exchange capacity >51g NH(4)(+)-Nkg(-1) medium and this resulted in an operating capacity in the range 27-36gNH(4)(+)-Nkg(-1).
Thornton
A
A
School of Water Sciences, Cranfield University, Cranfield, Bedfordshire MK43 0AL, UK.
Pearce
P
P
Parsons
S A
SA
D000538:Aluminum Silicates / Q000737:chemistry*; D019149:Bioreactors; D000077215:Clay; D007474:Ion Exchange; D010865:Pilot Projects; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D012722:Sewage / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods*; D018508:Water Purification / Q000379:methods*
D000538:Aluminum Silicates; C517817:MesoLite; D000644:Quaternary Ammonium Compounds; D012722:Sewage; D000077215:Clay