Removal of boron (B) from waste liquors

2006 ◽  
Vol 53 (11) ◽  
pp. 73-79 ◽  
Author(s):  
J.-Q. Jiang ◽  
Y. Xu ◽  
J. Simon ◽  
K. Quill ◽  
K. Shettle
Keyword(s):  
Model Test ◽  
Current Density ◽  
Boron Concentration ◽  
Economic Advantage ◽  
Molar Ratio ◽  
Low Doses ◽  
Boron Removal ◽  
Industry Waste ◽  
Alum Coagulation ◽  
Industry Effluent

This paper explores the use of electrocoagulation to remove boron from waste effluent in comparison with alum coagulation. In treating model test wastes, greater boron removals were achieved with electrocoagulation at low doses than conventional alum coagulation when reaction was undertaken for the same conditions (pH 8.5, and initial boron concentration was 500 mg/L). Al electrocoagulation can achieve good boron removal performance (68.3%) at a dose of 2.1 (as molar ratio of Al:B, and for current density of 62.1 A/m2), while alum coagulation can only achieve the maximum boron removal of 56% at a dose of 2.4. Also, Al electrocoagulation can remove 15–20% more boron than alum coagulation for the same dose compared in the treatment of both model test wastes and industry effluent. The estimation of running costs shows that to achieve 75% boron removal from industry waste effluent, i.e. removing 150 g of boron from 1 m3 of effluent, electrocoagulation was 6.2 times cheaper than alum coagulation. The economic advantage of electrocoagulation in the treatment of boron-containing waste effluent is thus significant.

Ammonia synthesis by N2 and steam electrolysis in molten hydroxide suspensions of nanoscale Fe2O3

Science ◽  
2014 ◽  
Vol 345 (6197) ◽  
pp. 637-640 ◽  
Author(s):  
Stuart Licht ◽  
Baochen Cui ◽  
Baohui Wang ◽  
Fang-Fang Li ◽  
Jason Lau ◽  
...  
Keyword(s):  
Current Density ◽  
Steam Reforming ◽  
Ammonia Synthesis ◽  
Coulombic Efficiency ◽  
Steam Pressure ◽  
Molar Ratio ◽  
Applied Current ◽  
Bosch Process ◽  
Electron Conversion ◽  
Steam Reforming Of Methane

The Haber-Bosch process to produce ammonia for fertilizer currently relies on carbon-intensive steam reforming of methane as a hydrogen source. We present an electrochemical pathway in which ammonia is produced by electrolysis of air and steam in a molten hydroxide suspension of nano-Fe2O3. At 200°C in an electrolyte with a molar ratio of 0.5 NaOH/0.5 KOH, ammonia is produced at 1.2 volts (V) under 2 milliamperes per centimeter squared (mA cm−2) of applied current at coulombic efficiency of 35% (35% of the applied current results in the six-electron conversion of N2 and water to ammonia, and excess H2 is cogenerated with the ammonia). At 250°C and 25 bar of steam pressure, the electrolysis voltage necessary for 2 mA cm−2 current density decreased to 1.0 V.

Layer-by-Layer Structure Design of G@SiOx@PPY Materials as Promising High-Performance Anodes for Lithium-Ion Batteries

NANO ◽  
2021 ◽  
pp. 2150120
Author(s):  
Jiaying Zhang ◽  
Ting Li ◽  
Chao Li ◽  
Jingjing Zhang ◽  
Chun Ju Lv ◽  
...  
Keyword(s):  
Current Density ◽  
Layer Structure ◽  
Synergetic Effect ◽  
Lithium Ion ◽  
Structure Design ◽  
Molar Ratio ◽  
Electrochemical Performances ◽  
Cyclic Stability ◽  
Discharge Cycle ◽  
Charge Discharge

The graphene/silicon oxide/polypyrrole (G/SiOx/PPY) material was prepared in this paper. The G/SiOx/PPY material has good electrochemical performances including high capacity and cyclic stability. It has 2068/2130[Formula: see text]mAh g[Formula: see text] of capacity after 100th charge/discharge cycle at 200[Formula: see text]mA[Formula: see text]g[Formula: see text] of current density and 575/569[Formula: see text]mAh[Formula: see text]g[Formula: see text] of capacity after 100th charge/discharge cycle at 2000[Formula: see text]mA g[Formula: see text] of current density when G/SiOx molar ratio is 1:5. Its capacity increases but its cyclic stability decreases with G/SiOx molar ratio decreasing from 1:1 to 1:3 and 1:5. The electrochemical performance improvement of the G/SiOx/PPY material is due to the synergetic effect of graphene and polypyrrole, which improve the conductivity of SiOx and prevent its dropping from the surface of the electrode caused by the stress due to the volume expansion and shrinkage in charge/discharge cycles.

scholarly journals The efficiency of electrocoagulation using aluminum electrodesin treating wastewater from a dairy industry

2015 ◽  
Vol 45 (9) ◽  
pp. 1713-1719 ◽  
Author(s):  
Gerson de Freitas Silva Valente ◽  
Regina Célia Santos Mendonça ◽  
José Antônio Marques Pereira
Keyword(s):  
Current Density ◽  
Suspended Solids ◽  
Operating Cost ◽  
Dairy Industry ◽  
Optimum Operating ◽  
Optimum Operating Condition ◽  
Treated Effluent ◽  
Dairy Plant ◽  
Aluminum Electrodes ◽  
Industry Effluent

<p>This research deals with the investigation of electrocoagulation (EC) treatment of wastewater from a dairy plant using aluminum electrodes. Electrolysis time, pH, current density and distance between electrodes were considered to assess the removal efficiency of chemical oxygen demand (COD), total solids (TS) and their fractions and turbidity. Samples were collected from the effluent of a dairy plant using a sampling methodology proportional to the flow. The treatments were applied according to design factorial of half fraction with two levels of treatments and 3 repetitions at the central point. The optimization of parameters for treating dairy industry effluent by electrocoagulation using aluminum electrodes showed that electric current application for 21 minutes, an initial sample pH near 5.0 and a current density of 61.6A m<sup>-2</sup> resulted in a significant reduction in COD by 57%; removal of turbidity by 99%, removal of total suspended solids by 92% and volatile suspended solids by 97%; and a final treated effluent pH of approximately 10. Optimum operating condition was used for cost calculations show that operating cost is approximately 3.48R$ m<sup>-3</sup>.</p>

scholarly journals Boron removal from aqueous solutions by a polyethylenimine-epichlorohydrin resin

2018 ◽  
Vol 83 (2) ◽  
pp. 251-264 ◽  
Author(s):  
Sofia Sarri ◽  
Panagiotis Misaelides ◽  
Dimitrios Zamboulis ◽  
Jolanta Warchoł
Keyword(s):  
Aqueous Solutions ◽  
Boron Concentration ◽  
Kinetic Studies ◽  
Alkaline Solutions ◽  
Competitive Sorption ◽  
Boron Removal ◽  
Boron Uptake ◽  
Acidic Solutions ◽  
Ph Values ◽  
Batch Technique

The use of a polyethylenimine?epichlorohydrin resin for the boron removal from aqueous solutions (boron concentration: 100?5000 mg L-1) of non-adjusted and pre-adjusted pH (pHnat, pHinit 8.0, 9.0 and 10.0) aqueous solutions was investigated using a batch technique. The boron concentration in the solutions after sorption was determined photometrically. The results indicated that the pH-dependent boron uptake was related to the protonation/deprotonation of the surface functional groups of the resin and to the boron speciation in solutions of different pH values. The maximum boron sorption capacity observed in solutions of pH 9.0 was 55 mg g-1 exceeding the majority of other commercial or alternative sorbents. Five empirical adsorption equations (Freundlich, Langmuir, Redlich?Peterson, Langmuir?Freundlich and Toth) were applied to the modelling of the boron adsorption equilibrium. The modelling results identified the homogenous boron sorption from acidic and heterogeneous from alkaline solutions. At alkaline pH, the system non-ideality can originate either from the different binding mechanism or from the competitive sorption of different boron species. The homogenous type boron sorption from acidic solutions was further confirmed by kinetic studies

scholarly journals Optimization of electro-Fenton oxidation of carbonated soft drink industry wastewater using response surface methodology

2020 ◽  
Vol 39 (2) ◽  
pp. 129
Author(s):  
Reza Davarnejad ◽  
Jamal Azizi ◽  
Amir Joodaki ◽  
Sepideh Mansoori
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Current Density ◽  
Volume Fraction ◽  
Soft Drink ◽  
Oxygen Demand ◽  
Volume Ratio ◽  
Organic Pollution ◽  
Molar Ratio ◽  
The Impact

The immense volume of highly polluted organic wastewater continuously generated in the beverage industry urges the design of new types of wastewater treatment plants. This study aimed to evaluate the applicability of the electro-Fenton (EF) technique to reduce organic pollution of real effluent from a carbonated soft drink factory. The impact of various process variables like pH, time, current density, H2O2/Fe2+ molar ratio, and the volume ratio of H2O2/soft drink wastewater (SDW) was analyzed using response surface methodology (RSM). The observed responses were in good agreement with predicted values obtained through optimization. The optimum conditions showed a chemical oxygen demand (COD) removal efficiency of 73.07 %, pH of 4.14, time of 41.55 min, current density of 46.12 mA/cm2, H2O2/Fe2+ molar ratio of 0.9802, and H2O2/SDW volume fraction of 2.74 ml/l. The EF process was able to effectively diminish the organic pollution, reduce the residence time and, therefore, the operating costs.

Detection of boron removal capacities of different microorganisms in wastewater and effective removal process

2015 ◽  
Vol 72 (10) ◽  
pp. 1832-1839 ◽  
Author(s):  
Bengü Laçin ◽  
Burcu Ertit Taştan ◽  
Gönül Dönmez
Keyword(s):  
Municipal Wastewater ◽  
Boron Concentration ◽  
Bacillus Pumilus ◽  
Micrococcus Luteus ◽  
The Other ◽  
Aspergillus Versicolor ◽  
Rhodotorula Mucilaginosa ◽  
Boron Removal ◽  
Inactive Form ◽  
Effective Removal

In this study boron removal capacities of different microorganisms were tested. Candida tropicalis, Rhodotorula mucilaginosa, Micrococcus luteus, Bacillus thuringiensis, Bacillus cereus, Bacillus megaterium, Bacillus pumilus, Pseudomonas aeruginosa and Aspergillus versicolor were examined for their boron bioaccumulation capacities in simulated municipal wastewater. A. versicolor and B. cereus were found as the most boron-tolerant microorganisms in the experiments. Also boron bioaccumulation yield of A. versicolor was 49.25% at 15 mg/L boron concentration. On the other hand biosorption experiments revealed that A. versicolor was more capable of boron removal in inactive form at the highest boron concentrations. In this paper maximum boron bioaccumulation yield was detected as 39.08% at 24.17 mg/L and the maximum boron biosorption yield was detected as 41.36% at 24.01 mg/L boron concentrations.

Edible Plant Oil Wastewater Treatment Using Electro-Fenton Technique: Experiment and Correlation

2018 ◽  
Vol 16 (8) ◽  
Author(s):  
Reza Davarnejad ◽  
Seyed Amir Mohajerani
Keyword(s):  
Reaction Time ◽  
Current Density ◽  
Oxygen Demand ◽  
Volume Ratio ◽  
Cod Removal ◽  
Interactive Effects ◽  
Molar Ratio ◽  
Plant Oil ◽  
Edible Plant ◽  
High Chemical Oxygen Demand

Abstract The edible plant oil production factories consume high amounts of water and contaminate the water resources. This type of wastewater consists of high chemical oxygen demand (COD) which should properly be treated by an efficient technique. Furthermore, it is containing some chemicals obtained from several sources such as H3PO4 (from hydration section), NaOH (from neutralization section) and citric acid (from nickel removal section). The conventional techniques cannot efficiently treat it which is full of COD. Therefore, the electro-Fenton process as a rapid, compact and efficient one has been encouraged to be applied. For this purpose, 47 experiments were designed and carried out using iron electrodes to evaluate the effects of five significant independent variables such as reaction time (min), pH, current density (mA/cm2), volume ratio of H2O2/wastewater (ml/l) and H2O2/Fe2+ molar ratio on the COD removal. Response surface methodology (RSM) was employed to assess individual and interactive effects of the parameters. The optimum conditions were experimentally obtained at reaction time of 87.33 min, pH of 3.03, current density of 57 mA/cm2, H2O2/wastewater volume ratio of 2.13 ml/l and H2O2/Fe2+ molar ratio of 3.61 for COD removal of 62.94 %.

Boron Removal from Water Using Takovite: Adsorption vs. Anion Exchange

2013 ◽  
Vol 781-784 ◽  
pp. 2150-2156 ◽  
Author(s):  
Yao Wu Cao ◽  
Qing Hai Guo
Keyword(s):  
Anion Exchange ◽  
Boron Concentration ◽  
Boron Removal ◽  
Boron Uptake ◽  
X Ray Diffraction ◽  
Structural Restoration ◽  
Experimental Conditions ◽  
Sorption Data ◽  
Freundlich Model ◽  
Higher Temperature

Takovite, a kind of hydrotalcite-like compounds (HTlcs), was used for boron removal from water. It was prepared by coprecipitation method and characterized by X-ray diffraction technique (XRD). The equilibrium time of boron sorption by takovite as well as its boron uptake capacities was determined by the reaction kinetic experiments and isotherm sorption experiments. The effects of experimental conditions on boron removal efficiency were also evaluated. Generally, the boron uptake by takovites increases with increasing initial boron concentration in solution. The isotherm sorption data match well with the Freundlich model, indicating that the anion exchange contributes a lot to solution deboronation. Moreover, at higher temperature, greater boron removal by takovite was observed. As compared to calcined takovite, uncalcined takovite has better performance in terms of boron uptake, since the structural restoration of calcined takovite didnt happen during its contact with boron-containing solution, which is quite different from the behavior of other HTlcs as reported.

scholarly journals Electrocatalytic Degradation of Azo Dye by Vanadium-Doped TiO2 Nanocatalyst

Catalysts ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 482 ◽  
Author(s):  
Jih-Hsing Chang ◽  
Yong-Li Wang ◽  
Cheng-Di Dong ◽  
Shan-Yi Shen
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Current Density ◽  
Azo Dye ◽  
Pure Tio2 ◽  
Molar Ratio ◽  
Tio2 Electrode ◽  
Electrocatalytic Degradation ◽  
Vanadium Doping

In this work, nano V/TiO2 catalysts at different molar ratios were prepared and fabricated as the electrocatalytic electrodes for electrocatalytic degradation. The effect of the vanadium doping on the surface morphology, microstructural, and specific surface area of V/TiO2 catalysts was probed by field emission scanning electron microscope (FESEM) x-ray diffractometer (XRD), and Brunauer–Emmett–Teller (BET), respectively. Afterward, the solution of Acid Red 27 (AR 27, one kind of azo dye) was treated by an electrocatalytic system in which the nano V/TiO2 electrode was employed as the anode and graphite as the cathode. Results demonstrate that AR 27 can be effectively degraded by the nano V/TiO2 electrodes; the highest removal efficiency of color and total organic carbon (TOC) reached 99% and 76%, respectively, under 0.10 VT (molar ratio of vanadium to titanium) condition. The nano V/TiO2 electrode with high specific surface area facilitated the electrocatalytic degradation. The current density of 25 mA cm−2 was found to be the optimum operation for this electrocatalytic system whereas the oxygen was increased with the current density. The electricity consumption of pure TiO2 and nano V/TiO2 electrode in this electrocatalytic system was around 0.11 kWh L−1 and 0.02 kWh L−1, respectively. This implies that the nano V/TiO2 electrode possesses both high degradation and energy saving features. Moreover, the nono V/TiO2 electrode shows its possible repeated utilization.

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