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.

scholarly journals The efficiency of a membrane bioreactor in drinking water denitrification

2015 ◽  
Vol 21 (2) ◽  
pp. 269-275
Author(s):  
Aleksandra Petrovic ◽  
Marjana Simonic
Keyword(s):  
Drinking Water ◽  
Flow Rate ◽  
Membrane Bioreactor ◽  
Nitrate Removal ◽  
Maximum Flow ◽  
Pilot Scale ◽  
Operational Parameters ◽  
Flow Rates ◽  
Removal Capacity ◽  
Removal Efficiencies

The membrane bioreactor (MBR) system was investigated regarding its nitrate removal capacity from drinking water. The performance of a pilot-scale MBR was tested, depending on the operational parameters, using sucrose as a carbon source. Drinking water from the source was introduced into the reactor in order to study the influence of flow-rate on the nitrate removal and denitrification efficiency of drinking water. The content of the nitrate was around 70 mg/L and the C/N ratio was 3:1. Nitrate removal efficiencies above 90% were obtained by flow-rates lower than 4.8 L/h. The specific denitrification rates varied between 0.02 and 0.16 g/L NO3/ (g/L MLSS?d). The efficiencies and nitrate removal were noticeably affected by the flow-rate and hydraulic retention times. At the maximum flow-rate of 10.2 L/h still 68% of the nitrate had been removed, whilst the highest specific denitrification rate was achieved at 0.2738 g/L NO3/ (g/L) MLSS?d). The maximum reactor removal capacity was calculated at 8.75 g NO3/m3?h.

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.

scholarly journals Techno-economical evaluation of nitrate removal using continuous flow electro-coagulation process: optimization by Taguchi model

2017 ◽  
Vol 17 (6) ◽  
pp. 1703-1711 ◽  
Author(s):  
E. Karamati Niaragh ◽  
M. R. Alavi Moghaddam ◽  
M. M. Emamjomeh
Keyword(s):  
Removal Efficiency ◽  
Flow Rate ◽  
Current Density ◽  
Nitrate Concentration ◽  
Nitrate Removal ◽  
Operating Costs ◽  
Inlet Flow ◽  
Inlet Flow Rate ◽  
Initial Ph ◽  
Electro Coagulation

Abstract This study aims to investigate the effect of the main parameters on the performance of a continuous flow electro-coagulation (EC) process for nitrate removal efficiency and its operating costs. For this purpose, the Taguchi experimental design with orthogonal array L27 (313) was applied to analyze the effects of selected parameters, namely initial nitrate concentration, inlet flow rate, current density and initial pH. According to the analysis of variance results, the inlet flow rate and the current density were recognized to be the most effective factors playing a pivotal role in nitrate removal efficiency by using an EC process. The optimum conditions of initial nitrate concentration, inlet flow rate, current density and initial pH were found to be 100 mg/L, 50 mL/min, 80 A/m2 and 8, respectively. As a result, the observed nitrate removal efficiency under these conditions was 61.70%. In addition, operating costs were evaluated as 1.278 US$/g NO3-removed. Finally, a high correlation was observed between the experimental and predicted results indicating an appropriate accuracy of the Taguchi model for nitrate removal efficiency and its operating costs in an EC system.

Removal of nitrate using activated carbon-based electrodes for capacitive deionization

2018 ◽  
Vol 18 (6) ◽  
pp. 2028-2034 ◽  
Author(s):  
Shaojie Jiang ◽  
Hongwu Wang ◽  
Guanquan Xiong ◽  
Xinlei Wang ◽  
Siying Tan
Keyword(s):  
Activated Carbon ◽  
Phosphoric Acid ◽  
Flow Rate ◽  
Nitrate Removal ◽  
Cell Voltage ◽  
Solution Concentration ◽  
Capacitive Deionization ◽  
Optimal Conditions ◽  
Ion Removal ◽  
Initial Solution Concentration

Abstract The removal performance of nitrate using capacitive deionization (CDI) of activated carbon (AC)-based electrodes were studied. The AC electrode was prepared and the effect of cell voltage, flow rate and initial solution concentration on ion removal were investigated. Furthermore, the AC was modified with phosphoric acid (ACP) and the surface structure of AC and ACP were analyzed. The results showed that the specific surface area of AC increased by 10.71% after the modification. The mesopore ratio and micropore ratio increased by 14.69% and 24.06%, respectively. The optimal conditions of AC electrode was a voltage of 1.4 V and flow rate of 20 mL/min while the ACP electrode was a voltage of 1.4 V and flow rate of 10 mL/min. The electrosorption capacity of ACP electrode was improved and the unit of electrosorption load was high to 19.28 mg/L. For the AC or ACP electrode, the nitrate removal efficiency decreases with the increase in the initial feed solutions, but the unit electrosorption load gradually increased with the improvement of initial feed solutions' concentration and the ACP electrode was superior to the AC electrode. Therefore, the ACP electrode would be suitable for the application of CDI on the nitrate removal.

scholarly journals Macadamia Nutshell Biochar for Nitrate Removal: Effect of Biochar Preparation and Process Parameters

2019 ◽  
Vol 5 (3) ◽  
pp. 47 ◽  
Author(s):  
Salam Bakly ◽  
Raed A. Al-Juboori ◽  
Les Bowtell
Keyword(s):  
Treatment Time ◽  
Agricultural Waste ◽  
Nitrate Removal ◽  
Waste Product ◽  
Agricultural Practices ◽  
Agricultural Runoff ◽  
Operating Parameters ◽  
Column Experiments ◽  
23 Factorial Design ◽  
Removal Capacity

Agricultural runoff is a major cause of degradation to freshwater sources. Nitrate is of particular interest, due to the abundant use of nitrogen-based fertilizers in agricultural practices globally. This study investigated the nitrate removal of biochar produced from an agricultural waste product, macadamia nutshell (MBC). Kinetic experiments and structural analyses showed that MBC pyrolsed at 900 °C exhibited inferior NO3− removal compared to that pyrolsed at 1000 °C, which was subsequently used in the column experiments. Concentrations of 5, 10 and 15 mg/L, with flowrates of 2, 5 and 10 mL/min, were examined over a 360 min treatment time. Detailed statistical analyses were applied using 23 factorial design. Nitrate removal was significantly affected by flowrate, concentration and their interactions. The highest nitrate removal capacity of 0.11 mg/g MBC was achieved at a NO3− concentration of 15 mg/L and flowrate of 2 mL/min. The more crystalline structure and rough texture of MBC prepared at 1000 °C resulted in higher NO3− removal compared to MBC prepared at 900 °C. The operating parameters with the highest NO3− removal were used to study the removal capacity of the column. Breakthrough and exhaustion times of the column were 25 and 330 min respectively. Approximately 92% of the column bed was saturated after exhaustion.

scholarly journals Structured fibrous carbon-based catalysts for continuous nitrate removal from natural water

2012 ◽  
Vol 123-124 ◽  
pp. 221-228 ◽  
Author(s):  
T. Yuranova ◽  
C. Franch ◽  
A.E. Palomares ◽  
E. Garcia-Bordejé ◽  
L. Kiwi-Minsker
Keyword(s):  
Natural Water ◽  
Nitrate Removal ◽  
Fibrous Carbon ◽  
Carbon Based

Phosphorus removal under anoxic conditions in a continuous-flow A2N two-sludge process

2004 ◽  
Vol 50 (6) ◽  
pp. 37-44 ◽  
Author(s):  
Y.Y. Wang ◽  
Y.Z. Peng ◽  
T.W. Li ◽  
M. Ozaki ◽  
A. Takigawa ◽  
...  
Keyword(s):  
Flow Rate ◽  
Nitrogen Removal ◽  
Phosphorus Removal ◽  
Continuous Flow ◽  
Domestic Sewage ◽  
Organic Substrate ◽  
Optimum Conditions ◽  
Factors Affecting ◽  
Anoxic Conditions ◽  
Removal Capacity

The Anaerobic-Anoxic/Nitrification (A2N) system is a continuous-flow, two-sludge process in which Poly-P bacteria are capable of taking up phosphate under anoxic conditions using nitrate as an electron acceptor. The process is very efficient because it maximizes the utilization of organic substrate for phosphorus and nitrogen removal. An experimental lab-scale A2N system fed with domestic sewage was tested over a period of 260 days. The purpose of the experiment was to examine phosphorus removal capacity of a modified A2N two-sludge system. Factors affecting phosphorus and nitrogen removal by the A2N system were investigated. These factors were the influent COD/TN ratio, Sludge Retention Time (SRT), Bypass Sludge Flow rate (BSF) and Return Sludge Flow rate (RSF). Results indicated that optimum conditions for phosphorus and nitrogen removal were the influent COD/TN ratio around 6.49, the SRT of 14 days, and the BSF and RSF were fixed at about 26-33% of influent flow rate.

scholarly journals Assessment of Nitrate Removal Capacity of Two Selected Eukaryotic Green Microalgae

Cells ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 2490
Author(s):  
Vaishali Rani ◽  
Gergely Maróti
Keyword(s):  
Nitrate Concentration ◽  
Nitrate Removal ◽  
Synthetic Wastewater ◽  
Green Microalgae ◽  
Chlorella Sp ◽  
Removal Capacity ◽  
High Nitrate Concentration ◽  
Chlamydomonas Sp ◽  
Carbohydrate Contents ◽  
Phosphate Medium

Eutrophication is a leading problem in water bodies all around the world in which nitrate is one of the major contributors. The present study was conducted to study the effects of various concentrations of nitrate on two eukaryotic green microalgae, Chlamydomonas sp. MACC-216 and Chlorella sp. MACC-360. For this purpose, both microalgae were grown in a modified tris-acetate-phosphate medium (TAP-M) with three different concentrations of sodium nitrate, i.e., 5 mM (TAP-M5), 10 mM (TAP-M10) and 15 mM (TAP-M15), for 6 days and it was observed that both microalgae were able to remove nitrate completely from the TAP-M5 medium. Total amount of pigments decreased with the increasing concentration of nitrate, whereas protein and carbohydrate contents remained unaffected. High nitrate concentration (15 mM) led to an increase in lipids in Chlamydomonas sp. MACC-216, but not in Chlorella sp. MACC-360. Furthermore, Chlamydomonas sp. MACC-216 and Chlorella sp. MACC-360 were cultivated for 6 days in synthetic wastewater (SWW) with varying concentrations of nitrate where both microalgae grew well and showed an adequate nitrate removal capacity.

scholarly journals INORGANIC MICROPOLLUTANTS REMOVAL BY MEANS OF MEMBRANE PROCESSES - STATE OF THE ART

2013 ◽  
Vol 20 (4) ◽  
pp. 633-658 ◽  
Author(s):  
Michał Bodzek
Keyword(s):  
Drinking Water ◽  
Natural Water ◽  
Water Sources ◽  
Membrane Bioreactors ◽  
Inorganic Contaminants ◽  
Membrane Processes ◽  
Donnan Dialysis ◽  
Inorganic Substances ◽  
Treatment Technologies ◽  
Permissible Levels

Abstract A number of inorganic anions and metals, especially heavy metals, at certain conditions, have been found in potentially harmful concentrations in numerous water sources. The maximum permissible levels of these compounds, in drinking water and wastewaters discharged to environment, set by the WHO and a number of countries are very low (from μg/dm3 to a few mg/dm3). Several common treatment technologies, which are nowadays used for removal of inorganic contaminants from natural water supplies, represent serious exploitation problems. Membrane processes such as reverse osmosis and nanofiltration, ultrafiltration and microfiltration in integrated systems, Donnan dialysis and electrodialysis as well as membrane bioreactors, if properly selected, offer the advantage of producing high quality drinking water without inorganic substances as well as purified wastewater which can be drained off to natural water sources

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