Assessment and analysis of aged refuse as ammonium-removal media for the treatment of landfill leachate

Abstract

This is the first attempt to explore the sustainability of aged refuse as ammonium-removal media. Batch experiments combined with the aged-refuse-based reactor were performed to examine how the adsorption and desorption processes are involved in the ammonia removal via aged refuse media in this research. The results showed that the adsorption of ammonium by aged refuse occurred instantly and the adsorbed ammonium was stable and less exchangeable. The adsorption data fit the Freundlich isotherms well and the n value of 0.1-0.5 indicated that the adsorption of ammonium occurred easily. The maximum adsorbed ammonium occupied less than 10% of the cation exchange capacity in aged-refuse-based reactors owing to the high solid/liquid ratios (50:1-120:1). The synergistic transformations of ammonium within the aged-refuse-based reactor indicated that the cation exchange sites only provide temporary storage of ammonium, and the subsequent nitrification process can be considered the predominant restoration pathway of ammonium adsorption capacity of the reactor. It seems reasonable to assume that there is no expiry for the aged-refuse-based reactor in terms of ammonium removal owing to its bioregeneration via nitrification.

Treatment of Low Biodegradability Leachates in a Serial System of Aged Refuse-Filled Bioreactors

“…According to Li et al [11], ARFB systems in series show strong nitrification capacity, where ammonium is first adsorbed before being removed by nitrifying microbial populations. This synergy allows the restoration of the adsorption capacity of the AR [38], which explains the stability of the ARFB system in series in the removal processes for long periods of operation. Ammonia concentrations in the influent ranged between 297 and 1073 mg/L (Figure 8), while, in the case of effluents E1 and E2, it ranged between 9 and 31 mg/L and 8 and 13 mg/L, respectively, corresponding to an average global removal rate of 97%.…”

“…According to Li et al [11], ARFB systems in series show strong nitrification capacity, where ammonium is first adsorbed before being removed by nitrifying microbial populations. This synergy allows the restoration of the adsorption capacity of the AR [38], which explains the stability of the ARFB system in series in the removal processes for long periods of operation. Figure 9 shows the elimination of total nitrogen (TN) in the raw leachates, where an average total removal of 97% was observed, independently of the fluctuations of the influent (377-1104 mg/L).…”

Comparison of two leachate treatment systems by use of bioreactors packed with stabilized material of different age

“…The most common methods for the final disposal or treatment of these wastes are landfills, incineration, and composting. The sanitary landfill is widely used in developing countries, due to its treatment capacity, adaptability and cost of operation (He et al, 2017;Li et al, 2009;Zhang et al, 2018). A sanitary landfill involves engineering methods for waste disposal to control environmental impacts (Aranda-de la Teja et al 2020).…”

“…Zhao et al, (2002), developed a new biological treatment method using a biofilter that uses aged solid waste as a substrate. Aged waste can be defined as the waste of various materials that have been deposited in the FDS, which after eight years of being buried contains organic matter present that is considered mineralized (He et al, 2017;Li et al, 2017). In the present study, aged waste is called Stabilized Material (SM).…”

“…Recent studies with this technology have shown its good performance in the treatment of leachates, where high efficiencies in the elimination of COD, BOD 5 and total nitrogen were found, in ranges of 75-85, 86-95 and 49-97%, respectively (Erabee and Ethaib, 2018;Nájera-Aguilar et al, 2019;Xie et al, 2012). The use of SM as packaging for bioreactors for treating leachates has been reported mainly with waste extracted from landfills (Li et al, 2010;He et al, 2017;Xie et al, 2012;Bautista-Ramírez et al, 2018). However, there is no knowledge related to SM from open dumps.…”