scholarly journals Electrochemical removal of nitrate from a Donnan dialysis waste stream

2019 ◽  
Vol 80 (4) ◽  
pp. 727-736 ◽  
Author(s):  
Judah Makover ◽  
David Hasson ◽  
Yunyan Huang ◽  
Raphael Semiat ◽  
Hilla Shemer
Keyword(s):  
High Salinity ◽  
Nitrate Removal ◽  
Waste Stream ◽  
Contaminated Groundwater ◽  
Nacl Solution ◽  
Promising Technique ◽  
Donnan Dialysis ◽  
Batch System ◽  
Anionic Composition ◽  
Electrochemical Removal

Abstract The objective of this work was to investigate electrochemical removal of nitrate from a high salinity waste stream generated by Donnan dialysis. Donnan dialysis for nitrate removal is a promising technique. It produces a distinctive composition of a high salinity waste stream of NaCl or Na2SO4 that requires a viable disposal method. The waste stream has the full anionic composition of contaminated groundwater, but the only cation is sodium. Experiments were conducted in a batch system setup. A copper cathode was chosen over brass, aluminum and graphite cathodes. A dimensionally stable anode (DSA), Ti/PbO2, was selected over a Ti/Pt anode. Electrochemical denitrification of high salinity Donnan dialysis nitrate wastes was successfully achieved, with different behavior exhibited in high salinity NaCl solution than in high salinity Na2SO4 solution. NaCl inhibited nitrate removal at high salinities while Na2SO4 did not. The maximum removals after 4 h operation in the high salinity wastes were 69 and 87% for the NaCl and Na2SO4 solutions respectively.

Integration of electrodialysis and Donnan dialysis for the selective separation of ammonium from high-salinity wastewater

2021 ◽  
Vol 405 ◽  
pp. 127001
Author(s):  
Rui Ding ◽  
Ziyi Ding ◽  
Xiongjian Chen ◽  
Jianling Fu ◽  
Zijing Zhou ◽  
...  
Keyword(s):  
High Salinity ◽  
Selective Separation ◽  
Donnan Dialysis ◽  
Salinity Wastewater

scholarly journals Modification of Xanthan Gum for a High-Temperature and High-Salinity Reservoir

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4212
Author(s):  
Mohamed Said ◽  
Bashirul Haq ◽  
Dhafer Al Shehri ◽  
Mohammad Mizanur Rahman ◽  
Nasiru Salahu Muhammed ◽  
...  
Keyword(s):  
High Temperature ◽  
Oil Recovery ◽  
Xanthan Gum ◽  
Elevated Temperatures ◽  
High Salinity ◽  
Residual Oil ◽  
Core Flooding ◽  
Nacl Solution ◽  
The Core ◽  
Tertiary Oil Recovery

Tertiary oil recovery, commonly known as enhanced oil recovery (EOR), is performed when secondary recovery is no longer economically viable. Polymer flooding is one of the EOR methods that improves the viscosity of injected water and boosts oil recovery. Xanthan gum is a relatively cheap biopolymer and is suitable for oil recovery at limited temperatures and salinities. This work aims to modify xanthan gum to improve its viscosity for high-temperature and high-salinity reservoirs. The xanthan gum was reacted with acrylic acid in the presence of a catalyst in order to form xanthan acrylate. The chemical structure of the xanthan acrylate was verified by FT-IR and NMR analysis. The discovery hybrid rheometer (DHR) confirmed that the viscosity of the modified xanthan gum was improved at elevated temperatures, which was reflected in the core flood experiment. Two core flooding experiments were conducted using six-inch sandstone core plugs and Arabian light crude oil. The first formulation—the xanthan gum with 3% NaCl solution—recovered 14% of the residual oil from the core. In contrast, the modified xanthan gum with 3% NaCl solution recovered about 19% of the residual oil, which was 5% higher than the original xanthan gum. The xanthan gum acrylate is therefore more effective at boosting tertiary oil recovery in the sandstone core.

scholarly journals Poly(Oxyethylene)-Amidoamine Based Gemini Cationic Surfactants for Oilfield Applications: Effect of Hydrophilicity of Spacer Group

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1046 ◽  
Author(s):  
S. M. Shakil Hussain ◽  
Ahmad Mahboob ◽  
Muhammad Shahzad Kamal
Keyword(s):  
Surface Tension ◽  
High Temperature ◽  
Critical Micelle Concentration ◽  
Cationic Surfactants ◽  
Structural Integrity ◽  
High Salinity ◽  
Heat Stability ◽  
High Heat ◽  
Gravimetric Analysis ◽  
Nacl Solution

Thermal stability, salt tolerance, and solubility in normal and high salinity brine are the major requirements for any surfactant designed for oilfield applications because the surfactant stays in a non-ambient environment inside the reservoir for a long period of time. Herein, a series of new gemini cationic surfactants (GSs) with varying spacer hydrophilicity were synthesized and elucidated using MALDI-ToF-MS, NMR (1H, 13C), as well as FTIR spectroscopy. GSs found to be soluble in normal as well as high salinity brine and aqueous stability tests revealed that GSs possess the ability to retain their structural integrity at high salinity and high temperature conditions because no suspension formation or precipitation was detected in the oven aged sample of GSs at 90 °C for 30 days. Thermal gravimetric analysis displayed a higher decomposition temperature than the real reservoir temperature and the GS with a secondary amine spacer exhibited high heat stability. The significant reduction in surface tension and critical micelle concentration was observed using 1 M NaCl solution in place of deionized water. The difference in surface tension and critical micelle concentration was insignificant when the 1 M NaCl solution was replaced with seawater. The synthesized surfactants can be utilized for oilfield applications in a challenging high temperature high salinity environment.

scholarly journals Nitrate removal from natural water by coupling adsorption and Donnan dialysis

2016 ◽  
Vol 17 (3) ◽  
pp. 771-779 ◽  
Author(s):  
Thouraya Turki ◽  
Mohamed Ben Amor
Keyword(s):  
Flow Rate ◽  
Natural Water ◽  
Nitrate Removal ◽  
New Combination ◽  
Retention Efficiency ◽  
Donnan Dialysis ◽  
Removal Capacity ◽  
Widespread Availability

A hybrid adsorption/Donnan dialysis (DD) process for nitrate removal using PUROLITE A520E resin as an adsorbent was investigated in this work. PUROLITE resin was introduced into the DD process due to its good selectivity adsorption for nitrate and widespread availability. This study was conducted in order to benefit from each process, and it was an original and new combination. The retention efficiency of nitrate was discussed by considering the factors of adsorbent mass, nature of the receiver electrolyte and flow rate. The coupling was a solution to improve the resin mass and the amount of nitrate removed. The coupling was successfully performed, with a nitrate removal capacity of about 7 mg/g.

Enhanced removal of nitrate from water using nZVI@MWCNTs composite: synthesis, kinetics and mechanism of reduction

2015 ◽  
Vol 72 (11) ◽  
pp. 1988-1999 ◽  
Author(s):  
Ali Akbar Babaei ◽  
Ali Azari ◽  
Roshanak Rezaei Kalantary ◽  
Babak Kakavandi
Keyword(s):  
Nitrate Reduction ◽  
Nitrate Removal ◽  
Nitrogen Gas ◽  
Initial Concentration ◽  
Multi Wall Carbon Nanotubes ◽  
Batch System ◽  
Low Concentrations ◽  
End Products ◽  
Nano Zero Valent Iron ◽  
Influential Parameters

Herein, multi-wall carbon nanotubes (MWCNTs) were used as the carrier of nano-zero valent iron (nZVI) particles to fabricate a composite known as nZVI@MWCNTs. The composite was then characterized and applied in the nitrate removal process in a batch system under anoxic conditions. The influential parameters such as pH, various concentrations of nitrate and composite were investigated within 240 min of the reaction. The mechanism, kinetics and end-products of nitrate reduction were also evaluated. Results revealed that the removal nitrate percentage for nZVI@MWCNTs composite was higher than that of nZVI and MWCNTs alone. Experimental data from nitrate reduction were fitted to the Langmuir–Hinshelwood kinetic model. The values of observed rate constant (kobs) decreased with increasing the initial concentration of nitrate. Our experiments proved that the nitrate removal efficiency was favorable once both high amounts of nZVI@MWCNTs and low concentrations of nitrate were applied. The predominant end-products of the nitrate reduction were ammonium (84%) and nitrogen gas (15%). Our findings also revealed that ZVI@MWCNTs is potentially a good composite for removal/reduction of nitrate from aqueous solutions.

scholarly journals Molybdenum Availability Is Key to Nitrate Removal in Contaminated Groundwater Environments

2015 ◽  
Vol 81 (15) ◽  
pp. 4976-4983 ◽  
Author(s):  
Michael P. Thorgersen ◽  
W. Andrew Lancaster ◽  
Brian J. Vaccaro ◽  
Farris L. Poole ◽  
Andrea M. Rocha ◽  
...  
Keyword(s):  
Nitrate Reduction ◽  
Nitrate Removal ◽  
Pseudomonas Stutzeri ◽  
Contaminated Groundwater ◽  
Content Type ◽  
Oak Ridge ◽  
Groundwater Samples ◽  
Almost All ◽  
Toxic Concentrations ◽  
Global Nitrogen Cycle

ABSTRACTThe concentrations of molybdenum (Mo) and 25 other metals were measured in groundwater samples from 80 wells on the Oak Ridge Reservation (ORR) (Oak Ridge, TN), many of which are contaminated with nitrate, as well as uranium and various other metals. The concentrations of nitrate and uranium were in the ranges of 0.1 μM to 230 mM and <0.2 nM to 580 μM, respectively. Almost all metals examined had significantly greater median concentrations in a subset of wells that were highly contaminated with uranium (≥126 nM). They included cadmium, manganese, and cobalt, which were 1,300- to 2,700-fold higher. A notable exception, however, was Mo, which had a lower median concentration in the uranium-contaminated wells. This is significant, because Mo is essential in the dissimilatory nitrate reduction branch of the global nitrogen cycle. It is required at the catalytic site of nitrate reductase, the enzyme that reduces nitrate to nitrite. Moreover, more than 85% of the groundwater samples contained less than 10 nM Mo, whereas concentrations of 10 to 100 nM Mo were required for efficient growth by nitrate reduction for twoPseudomonasstrains isolated from ORR wells and by a model denitrifier,Pseudomonas stutzeriRCH2. Higher concentrations of Mo tended to inhibit the growth of these strains due to the accumulation of toxic concentrations of nitrite, and this effect was exacerbated at high nitrate concentrations. The relevance of these results to a Mo-based nitrate removal strategy and the potential community-driving role that Mo plays in contaminated environments are discussed.

Evaluation of reversible fixed-film static-bed bio-denitrification reactors

1998 ◽  
Vol 38 (1) ◽  
pp. 311-318 ◽  
Author(s):  
B. L. Woodbury ◽  
M. F. Dahab ◽  
P. Miháltz ◽  
Zs. Csikor
Keyword(s):  
Suspended Solids ◽  
Nitrate Removal ◽  
Capital Cost ◽  
Single Stage ◽  
Contaminated Groundwater ◽  
Two Stage ◽  
Removal Rates ◽  
Treated Effluent ◽  
Fixed Film ◽  
Flow Cycle

This paper reports the results of a study to investigate the performance of fixed-film two-stage reversible bio-denitrification reactors operated at very short detention times for the removal of nitrates from contaminated groundwater. The results demonstrate that these systems imparted lower concentrations of organics and suspended solids into the treated effluent than traditional single-stage systems while maintaining higher levels of nitrate removal rates at HRT values as low as 30 minutes. The lower detention times translate into substantial reductions in capital cost on scaled-up systems. The results also demonstrate the ability of two-stage reversible flow systems to withstand the stresses associated with low HRT and flow cycle reversals.

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