Desorption of nitrogen from drinking water treatment residue: Implications for environmental recycling. (20th July 2019)

• Record Type: Journal Article
• Authors: Wang, Changhui; Liu, Xin; Wang, Mengjiao; Shen, Xiaoxiao; Bai, Leilei; Yuan, Ande; Xu, Huacheng; Jiang, Helong
• Is Part Of: Journal of cleaner production. Volume 226(2019)
• Page Start: 96
• Page End: 105
• Publication Date: 2019-07-20
• Subjects: Drinking water treatment residuals -- Adsorption -- Waste recycling -- Nitrogen -- Phosphorus; Factory and trade waste -- Management -- Periodicals; Manufactures -- Environmental aspects -- Periodicals; Déchets industriels -- Gestion -- Périodiques; Usines -- Aspect de l'environnement -- Périodiques; 628.5
• DOI: 10.1016/j.jclepro.2019.04.002
• Languages: English
• ISSNs: 0959-6526

Abstract

Abstract: This study proposed a scheme for drinking water treatment residue (DWTR) pretreatment to eliminate concerns about potential unfavorable effects caused by excessive release of nutrients (typically N) during recycling in restoration of a water environment with relatively low pollution (e.g., eutrophic surface water). Inspired by soil washing, the pretreatment scheme was based on washing processes; correspondingly, the N desorption characteristics, possibility of recycling solutions for subsequent desorption, and variations in DWTR adsorption capabilities were investigated. The results showed that N, mainly as ammonia N (NH4 + -N), was quickly desorbed from DWTR; the concentrations of desorbed NH4 + -N were an order of magnitude higher than those of nitrate N (NO3 − -N). After six rounds of desorption, most ion-exchangeable NH4 + -N was desorbed, and NH4 + -N released from the DWTR (after the desorption test) declined markedly from 11.1 to <0.70 mg L −1 in initial column tests for surface water treatment. The same desorption characteristics of NH4 + -N were observed for six DWTR collected from Australia, Ireland, and China, respectively; after N desorption, the adsorption capability of the six DWTR changed negligibly. Furthermore, electrochemical treatment was found to be effective in removing desorbed NH4 + -N in solutions from DWTR; the treated solutions can be recycled for subsequent desorption without weakening NH4 + -N desorption efficiencies, although NH4 + -N removal efficiencies by electrochemical treatment tended to decline as the recycling of solutions increased to five rounds. Overall, the pretreatment scheme is scientifically feasible and can be applied and optimized based on remediation requirements in practical scenarios. Highlights: The ion-exchangeable N, mainly as NH4 + -N, was quickly desorbed from DWTR. Similar N desorption were observed for DWTR collected from different countries. After N desorption, the adsorption capability of DWTR changed little. The washing pretreatment is feasible for DWTR reuse in surface water restoration.