Removal of ammonium from municipal landfill leachate using natural zeolites

Abstract

Ammonium ion-exchange performance of the natural zeolite was investigated in both batch and column studies. The effects of zeolite dosage, contact time, stirring speed and pH on ammonium removal were investigated in batch experiments. The result showed that ammonium removal efficiency increased with an increase in zeolite dosage from 25 to 150 g/L, and an increase in stirring speed from 200 to 250 r/min. But further increase in zeolite dosage and stirring speed would result in an unpronounced increase of ammonium removal. The optimal pH for the removal of ammonium was found as 7.1. In the column studies, the effect of flow rate was investigated, and the total ammonium removal percentage during 180 min operation time decreased with the flow rate though the ion-exchange capacity varied to a very small extent with the flow rate ranging from 4 to 9 mL/min. The spent zeolite was regenerated by sodium chloride solution and the ammonia removal capacity of zeolite changed little or even increased after three regeneration cycles.

Clinoptilolite augmented electrocoagulation process for the reduction of high‐strength ammonia and color from stabilized landfill leachate

“…This is within the normal ranged used by other workers, such as 187.5–562.5 A/m 2 , Pirsaheb et al (2015); and 200–1,000 A/m 2 , and Mohajeri et al (2018). The sample solution was then added with a fixed amount clinoptilolite dosage in range between 10 g and 140 g, which is in agreement with a previous study by Ye et al (2015). Next, the mixture was agitated for 1 min to ensure uniform electrolyte mixing.…”

“…This can be attributed to the increased in the movement of ions within the electrolyte when the desirable stirring speed was performed on the zeolite adsorbent, thus reducing the resistance to the external barrier for convenient mass transfer (Hamid et al, 2020b). Furthermore, the high removal rates were due to the flocs development in a short period when the movement of the ions was enhanced (Ye et al, 2015). The reverse effect, however, occurs when the stirring speed is increased to more than required from 200 rpm to 400 rpm.…”

Optimization and Analysis of Zeolite Augmented Electrocoagulation Process in the Reduction of High-Strength Ammonia in Saline Landfill Leachate

“…A progressive response would change the pH of an electrolyte that, in turn, affects organic matter reduction [48]. As can be observed in Figure 4, the maximum reduction of NH3-N was found at a lower pH range, between 8.0 and 8.5, and zeolite dosage range of 105-110 g. This can be explained by the transformation of NH3-N into uncharged ammonia at higher pH (pH > 9) [49]. As a result, it would reduce the removal of NH3-N. As reviewed by [47], they mentioned that, at a lower pH, neutralization of charges is encouraged as higher metal amounts are dissolved owing to the greater current density, which leads to floc formation and increases in the effectiveness of removal.…”

Application of alkali-activated materials for water and wastewater treatment: a review

“…is the commonly occurring nitrogen species in, for instance, untreated municipal wastewater. Its removal has been studied extensively via ion-exchange on natural and synthetic zeolites as an alternative to the traditionally used microbial nitrification-denitrification (Couto et al 2016;Hedström 2001;He et al 2016;Leyva-Ramos et al 2010;Niu et al 2012;Zhang et al 2011;Ye et al 2015;Sarioglu 2005;Ji et al 2007). In fact, anaerobic digestion followed by natural zeolite-based ion exchange had potential for the recovery of nitrogen, lower operational costs, and better nitrogen-removal performance in comparison to the conventional nitrification-denitrification or the Anammox processes (Lin et al 2016).…”