Removal of nitrogen compounds from landfill leachate using reverse osmosis with leachate stabilization in a buffer tank

In this paper, a removal of nitrogen compounds from a landfill leachate during reverse osmosis (RO) was evaluated. The treatment facility consists of a buffer tank and a RO system. The removal rate of NNH4, [GRAPHICS] and [GRAPHICS] in the buffer tank reached 14%, 91% and 41%, respectively. The relatively low concentration of organic carbon limits NNH4 oxidation in the buffer tank. The removal rate for the total organic nitrogen (TON) was 47%. The removal rate in RO was 99% for [GRAPHICS] , 84.1% for [GRAPHICS] and 41% for [GRAPHICS] . The accumulation of [GRAPHICS] may be the result of a low pH, which before the RO process is reduced to a value of 6.0-6.5. Besides it, the cause for a low removal rate of the [GRAPHICS] in the buffer tank and during RO may be free ammonia, which can inhibit the [GRAPHICS] oxidation. The removal rates of total inorganic nitrogen and TON in the RO treatment facility were similar being 99% and 98.5%, respectively.