Dataset Information

Ammonia Recovery from Wastewater as a Fuel: Effects of Supporting Electrolyte on Ammonium Permeation through a Cation-Exchange Membrane.

ABSTRACT: Electrodeionization (EDI) is used to recover ammonia from wastewater as a fuel, but how its performance for ammonia recovery is affected by the supporting electrolyte is not very clear. This study involved experimental tests and theoretical calculations on NH₃ recovery, NH₄ ⁺ permeation, and NH₄ ⁺ and Na⁺ interacting with the functional groups in a cation exchange membrane (CEM) using Na₂SO₄ as the supporting electrolyte. The results demonstrated that a low concentration (≤0.250 mol L^-1 of Na₂SO₄) was conducive to NH₄ ⁺ permeation, while the a concentration (0.750 mol L^-1 of Na₂SO₄) hindered NH₄ ⁺ permeation. A maximum recovery efficiency of ammonia of 80.00%, a current efficiency of 70.10%, and an energy balance ratio of 0.66 were obtained at 0.250 mol L^-1 of Na₂SO₄. Numerical results indicated that an increase in Na₂SO₄ concentration caused severe concentration polarization that resisted NH₄ ⁺ migration in the CEM. The DFT results demonstrated that competitive adsorption of Na⁺ to the CEM hindered NH₄ ⁺ migration. The weaker interacting force between NH₄ ⁺ and the sulfonate functional group (-SOH₃) in comparison to that between Na⁺ and -SOH₃ might be related to the geometric and orientation effects, which generated an additional energy barrier for NH₄ ⁺ transport. Therefore, this study suggests that the supporting electrolyte concentration should be matched with that of the desalted ions.

SUBMITTER: Xu L

PROVIDER: S-EPMC9219067 | biostudies-literature | 2022 Jun

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Ammonia Recovery from Wastewater as a Fuel: Effects of Supporting Electrolyte on Ammonium Permeation through a Cation-Exchange Membrane.

Xu Linji L Liu Dingyang D Liu Wenzong W Yang Jixiang J Huang Jiansheng J Wang Xinzhu X He Qiang Q

ACS omega 20220607 24

Electrodeionization (EDI) is used to recover ammonia from wastewater as a fuel, but how its performance for ammonia recovery is affected by the supporting electrolyte is not very clear. This study involved experimental tests and theoretical calculations on NH3 recovery, NH4 + permeation, and NH4 + and Na+ interacting with the functional groups in a cation exchange membrane (CEM) using Na2SO4 as the supporting ...[more]

PMID: 35755378

Similar Datasets

Project description:Competition for the migration of interfering cations limits the scale-up and implementation of the Donnan dialysis process for the recovery of ammonia nitrogen (NH4+-N) from wastewater in practice. Highly efficient selective permeation of NH4+ through a cation exchange membrane (CEM) is expected to be modulated via tuning the surface charge and structure of CEM. In this work, a novel CEM was designed to form a graphene oxide (GO)-polyethyleneimine (PEI) cross-linked layer by introducing self-assembling layers of GO and PEI on the surface of a commercial CEM, which rationally regulates the surface charge and structure of the membrane. The resulting positively charged membrane surface exhibits stronger repulsion for divalent cations compared to monovalent cations according to Coulomb's law, while, simultaneously, GO forms π-metal cation conjugates between metal cations (e.g., Mg2+ and Ca2+), thus limiting metal cation transport across the membrane. During the DD process, higher NH4+ concentrations resulted in a longer time to reach Donnan equilibrium and higher NH4+ flux, while increased Mg2+ concentrations resulted in lower NH4+ flux (from 0.414 to 0.213 mol·m-2·h-1). Using the synergistic effect of electrostatic interaction and non-covalent cross-linking, the designed membrane, referred to as GO-PEI (20) and prepared by a 20 min impregnation in the GO-PEI mixture, exhibited an NH4+ transport rate of 0.429 mol·m-2·h-1 and a Mg2+ transport rate of 0.003 mol·m-2·h-1 in single-salt solution tests and an NH4+/Mg2+ selectivity of 15.46, outperforming those of the unmodified and PEI membranes (1.30 and 5.74, respectively). In mixed salt solution tests, the GO-PEI (20) membrane showed a selectivity of 15.46 (~1.36, the unmodified membrane) for NH4+/Mg2+ and a good structural stability after 72 h of continuous operation. Therefore, this facile surface charge modulation approach provides a promising avenue for achieving efficient NH4+-selective separation by modified CEMs.

Project description:Nitrogen in wastewater has negative environmental, human health, and economic impacts but can be recovered to reduce the costs and environmental impacts of wastewater treatment and chemical production. To recover ammonia/ammonium (total ammonia nitrogen, TAN) from urine, we operated electrochemical stripping (ECS) for over a month, achieving 83.4 ± 1.5% TAN removal and 73.0 ± 2.9% TAN recovery. With two reactors, we recovered sixteen 500-mL batches (8 L total) of ammonium sulfate (20.9 g/L TAN) approaching commercial fertilizer concentrations (28.4 g/L TAN) and often having >95% purity. While evaluating the operation and maintenance needs, we identified pH, full-cell voltage, product volume, and water flux into the product as informative process monitoring parameters that can be inexpensively and rapidly measured. Characterization of fouled cation exchange and omniphobic membranes informs cleaning and reactor modifications to reduce fouling with organics and calcium/magnesium salts. To evaluate the impact of urine collection and storage on ECS, we conducted experiments with urine at different levels of dilution with flush water, extents of divalent cation precipitation, and degrees of hydrolysis. ECS effectively treated urine under all conditions, but minimizing flush water and ensuring storage until complete hydrolysis would enable energy-efficient TAN recovery. Our experimental results and cost analysis motivate a multifaceted approach to improving ECS's technical and economic viability by extending component lifetimes, decreasing component costs, and reducing energy consumption through material, reactor, and process engineering. In summary, we demonstrated urine treatment as a foothold for electrochemical nutrient recovery from wastewater while supporting the applicability of ECS to seven other wastewaters with widely varying characteristics. Our findings will facilitate the scale-up and deployment of electrochemical nutrient recovery technologies, enabling a circular nitrogen economy that fosters sanitation provision, efficient chemical production, and water resource protection.

Dataset Information

Ammonia Recovery from Wastewater as a Fuel: Effects of Supporting Electrolyte on Ammonium Permeation through a Cation-Exchange Membrane.

Publications

Ammonia Recovery from Wastewater as a Fuel: Effects of Supporting Electrolyte on Ammonium Permeation through a Cation-Exchange Membrane.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets