Removal of ammonium as struvite using magnesite as a source of magnesium ions

2010 ◽  
Vol 5 (1) ◽  
Author(s):  
H. M. Huang ◽  
X. M. Xiao ◽  
L. P. Yang ◽  
B. Yan
Keyword(s):  
Reaction Time ◽  
Reaction Rate ◽  
Low Cost ◽  
Magnesium Ions ◽  
Batch Experiments ◽  
Optimum Conditions ◽  
Ammonium Removal ◽  
Time Required ◽  
Solid Liquid ◽  
Operation Cost

In this study, magnesite was used as a low-cost magnesium source to remove ammonium as struvite from the wastewater generated in the rare-earth elements separation process. Since the solubility of magnesite is low, before it was used it was decomposed to magnesia which has a higher reaction rate than magnesite. To optimize its usage, the optimum temperature of decomposition of magnesite and the time required for the process were determined by batch experiments to be 700 °C and 1.5 h, respectively. Besides, batch experiments using the residues of magnesite decomposed under optimum conditions were undertaken to investigate the effects of solid (magnesite)/liquid (wastewater) ratio and reaction time on ammonium removal as struvite. Results indicated that for the solid/liquid ratios tested and for a reaction time of 6 h, phosphorus concentrations fell steeply from the initial 9105 mg/L to a range of 198.8–29.8 mg/L, and ammonium concentrations from the initial 5287 mg/L to 540–520 mg/L. An economic analysis conducted indicated that the operation cost of the struvite process could be reduced by about 34% using decomposed magnesite instead of pure MgCl2.

Pretreatment of Herbicides Production Wastewater by Spherical Micro-Electrolysis Media

2013 ◽  
Vol 295-298 ◽  
pp. 1079-1083 ◽  
Author(s):  
Ling Zhang ◽  
Jing Liang Xie
Keyword(s):  
Reaction Time ◽  
Biological Treatment ◽  
Low Cost ◽  
Good Effect ◽  
Post Processing ◽  
Reaction Conditions ◽  
Effects Of Ph ◽  
Optimum Reaction ◽  
The Cost ◽  
Operation Cost

[Objective] The aim is to study the pretreatment effect of herbicides production wastewater by spherical micro-electrolysis media. [Method] Spherical micro-electrolysis media is preferred for the pretreatment of herbicides production wastewater and effects of PH, amount of media and reaction time on the pretreatment was investigated. The change of pre- and post-processing herbicides production wastewater was determined; the operation cost was also analyzed. [Result]The optimum reaction conditions are as follows: the PH was 3; the amount of media was 1.0kg/L wastewater; and the reaction time was 3.0h. Under the optimum reaction conditions, the removal of COD, Chromaticity and TP reached 26.3%, 86.4% and 95.6% respectively; BOD5/COD varied from 0.10 to 0.35, and the biodegradability was improved greatly; the cost of pretreatment was 1.0yuan/t, and it was lower than that of electrolysis. [Conclusion] The pretreatment of herbicides production wastewater by spherical micro-electrolysis media has good effect, low cost and no soiling hardening, so it provides a good foundation for subsequent biological treatment.

ADSORPTION AND REGENERATION OF SUNGAI PASAK PUMICE AS AN ADSORBENT FOR AMMONIUM REMOVAL IN WATER

2019 ◽  
Vol 10 (1) ◽  
pp. 38-46
Author(s):  
Ningsih Ika Pratiwi ◽  
Annisa Huwaida ◽  
Shinta Indah ◽  
Denny Helard
Keyword(s):  
Waste Water ◽  
Porous Structure ◽  
Adsorption Capacity ◽  
Contact Time ◽  
Low Cost ◽  
Optimum Conditions ◽  
Isotherm Equation ◽  
Ammonium Removal ◽  
Adsorbate Concentration ◽  
Adsorbent Dose

Pumice is known as a low-cost material with a porous structure, has the potential as an adsorbent to remove various kinds of pollutant compounds. The abundance of pumice is found in Sungai Pasak area and it never been utilized. This study was performed to see the ability of Sungai Pasak pumice as an adsorbent for ammonium removal in water along with its ability to be regenerated. The study was carried out triplo in batches to obtain optimum adsorption conditions which were then used in desorption experiments using HCl 0.1 M agent for regeneration process. The optimum conditions obtained: adsorbate pH 6, adsorbent dose 0.3 g/l, contact time 30 minutes, adsorbent diameter 63 µm and adsorbate concentration 4 mg/l. The results showed that pumice has ability to remove ammonium with adsorption capacity at optimum conditions were 47.06% and 6.27 mg/g with Freundlich's isotherm equation (R2=0.997). Acid agents are able to adsorb ammonium from pumice with an average desorption percentage 88.89% after 2 times of reuse, proving that acidic agents are able to regenerate pumice adsorbents so they can be reused. The potential for adsorption and regeneration of the Sungai Pasak pumice can be utilized to treat water with ammonium such as groundwater and waste water.

Synthesis and Evaluation of a Novel Retarded Acid Additive

2012 ◽  
Vol 554-556 ◽  
pp. 95-104
Author(s):  
Hong Ping Quan ◽  
Hong Sheng Lu ◽  
Tai Liang Zhang ◽  
Shan Shan Dai
Keyword(s):  
Reaction Time ◽  
Reaction Temperature ◽  
Reaction Rate ◽  
Monomer Concentration ◽  
Mass Ratio ◽  
Optimum Conditions ◽  
Acid Rock ◽  
Secondary Precipitate ◽  
Polymerization Inhibitor ◽  
Core Displacement

A novel acidizing additive is developed to improve acidizing effectiveness, especially to solve the problems during acidizing process, like rapid acid-rock reaction rate etc. The monomer was synthetized by Mannich reaction. Experimental results indicate that the optimum conditions are: mass ratio 18.5:8:14 of formaldehyde to amine A and phosphorus B, reaction temperature 90°C, reaction time 14h, polymerization inhibitor hydroquinone dosage 0.25%, under which the degree of conversion amounts to 91%. Infrared spectrum shows the feasibility of synthesis scheme. Then the monomer copolymerized with AMPS under the conditions: mass ratio 24.2:4 of monomer to AMPS, reaction temperature 80°C, reaction time 1h, monomer concentration 40%, and initiator dosage 2.0%. The corrosion and secondary precipitate performance of the retarded acid system was investigated. The results indicate that this operating fluid has superior retarding effectiveness and excellent secondary precipitate behavior. By core displacement experiment, the excellent retarding property of the retarded acid was further confirmed.

scholarly journals Oxidative Degradation of Hazardous Benzene Derivatives by Ferrate(VI): Effect of Initial pH, Molar Ratio and Temperature

Toxics ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 327
Author(s):  
Dian Majid ◽  
Il-Kyu Kim ◽  
Fajar Budi Laksono ◽  
Aditya Rio Prabowo
Keyword(s):  
Reaction Time ◽  
Aquatic Environment ◽  
Batch Reactor ◽  
Oxidative Degradation ◽  
Molar Ratio ◽  
Benzene Derivatives ◽  
Batch Experiments ◽  
Optimum Conditions ◽  
Initial Ph ◽  
Degradation Ability

Two of the most hazardous benzene derivatives (HBD) that have polluted the aquatic environment are bromobenzene and chlorobenzene. Ferrate can degrade various pollutants quickly and efficiently without producing harmful byproducts. This study aims to determine the ability of ferrate to degrade harmful contaminants such as bromobenzene and chlorobenzene. A series of batch experiments were carried out, including for the molar ratio, initial pH solution, and temperature. The study was conducted at an initial pH of 3.6 to 9.6, a molar ratio of 2 to 8 and a temperature of 15 to 55 °C. The study will also examine the differences in functional groups in these pollutants. As a result of the experiments, the optimum conditions to oxidize HBD in a batch reactor was found to have an initial pH of 7.0, a molar ratio of 8, and a temperature of 45 °C, with a 10 min reaction time. Ferrate has a degradation ability against chlorobenzene greater than bromobenzene. The functional cluster in pollutants also significantly affects the degradation ability of ferrate. The results of the degradation experiment showed that ferrate(VI) could effectively oxidize hazardous benzene derivatives in a solution.

scholarly journals Treatability of Biodiesel Wastewaters By Using KMnO4 And KMnO4/O3 Processes And Kinetic Analysis

2021 ◽  
Author(s):  
Pınar N. TANATTI
Keyword(s):  
Reaction Time ◽  
Potassium Permanganate ◽  
Rate Constants ◽  
Reaction Rate ◽  
Suitable Model ◽  
Order Kinetic ◽  
Optimum Conditions ◽  
Reaction Rate Constants ◽  
Order Kinetic Model ◽  
Removal Efficiencies

Abstract The purpose of this study is to investigate the treatability of electrocoagulated biodiesel wastewater (ECBD) by potassium permanganate (KMnO4) and potassium permanganate/ozone (KMnO4/O3) processes. The ECBD removal efficiencies of both combined method and KMnO4 methods were compared and the KMnO4/O3 process gave better results than the KMnO4 process. For the ECBD removal efficiencies, the experimental parameters including pH, potassium permanganate dose, ozone dose and reaction time parameters were optimized by changing the one parameter at a time. As a result of 6 h of KMnO4 oxidation, 91.74% of COD and 95.93% of MeOH removal was achieved under the optimum conditions (pH 2, 5 g/L KMnO4 dose). However, under optimum conditions (pH 13, 2 g/L KMnO4 dose, 3000 mg/L O3 dose, 6 h reaction time), the COD and MeOH removal efficiencies have been obtained for KMnO4/O3 as 97.79% and 98.30%, respectively. The second order kinetic model has been found to be the most suitable model for both processes and the regression coefficients (R2) has been found as 0.999 and 0.999 for KMnO4 and KMnO4/O3, respectively. The reaction rate constants (k) have been also calculated as 6x10-5 L/mg.min and 1.63x10-4 L/mg.min for COD and MeOH in KMnO4 oxidation, respectively. Furthermore, the reaction rate constants (k) have been also calculated as 6x10-5 L/mg.min and 1.6x10-4 L/mg.min for COD and MeOH in KMnO4/O3 oxidation, respectively.

Visible Light Assisted Hantzsch Reaction: Synthesis of Polycyclic Dihydropyridines

2019 ◽  
Vol 16 (8) ◽  
pp. 676-682
Author(s):  
Ankusab Noorahmadsab Nadaf ◽  
Kalegowda Shivashankar
Keyword(s):  
Reaction Time ◽  
Light Intensity ◽  
Ammonium Acetate ◽  
Low Cost ◽  
Aromatic Aldehydes ◽  
Light Irradiation ◽  
High Yield ◽  
Short Reaction Time ◽  
Green Protocol ◽  
Dihydropyridine Derivatives

The polycyclic dihydropyridine nucleus represents the heterocyclic system of invaluable core motifs with wide applications in chemical, biological and physical properties. Although this kind of compounds have been extensively synthesized by other groups, the synthesis of these compounds under CFL light intensity were not explored. The synthesis of polycyclic dihydropyridine derivatives were achieved through the reaction of 4-hydroxycoumarin, aromatic aldehydes and ammonium acetate under CFL light irradiation conditions. A series of polycyclic dihydropyridine derivatives were prepared under CFL light irradiation conditions with high yield, short reaction time, ambient condition and without the use of catalyst. The results displayed an efficient method for the synthesis of polycyclic dihydropyridine derivatives. Clean profile, short reaction time, low cost and use of CFL light intensity instead of catalyst making it a genuinely green protocol.

scholarly journals Preparation and Characterization of High-Efficiency Magnetic Heavy Metal Capture Flocculants

Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1732
Author(s):  
Yuanyuan Yu ◽  
Yongjun Sun ◽  
Jun Zhou ◽  
Aowen Chen ◽  
Kinjal J. Shah
Keyword(s):  
Heavy Metal ◽  
Reaction Time ◽  
High Efficiency ◽  
Removal Rate ◽  
Low Cost ◽  
Monomer Concentration ◽  
Synthesis Process ◽  
Response Surface Optimization ◽  
Metal Capture ◽  
Total Monomer Concentration

In this study, a high-efficiency magnetic heavy metal flocculant MF@AA was prepared based on carboxymethyl chitosan and magnetic Fe3O4. It was characterized by SEM, FTIR, XPS, XRD and VSM, and the Cu(II) removal rate was used as the evaluation basis for the preparation process. The effects of AMPS content, total monomer concentration, photoinitiator concentration and reaction time on the performance of MF@AA flocculation to remove Cu(II) were studied. The characterization results show that MF@AA has been successfully prepared and exhibits good magnetic induction characteristics. The synthesis results show that under the conditions of 10% AMPS content, 35% total monomer concentration, 0.04% photoinitiator concentration, and 1.5 h reaction time, the best yield of MF@AA is 77.69%. The best removal rate is 87.65%. In addition, the response surface optimization of the synthesis process of MF@AA was performed. The optimal synthesis ratio was finally determined as iron content 6.5%, CMFS: 29.5%, AM: 53.9%, AMPS: 10.1%. High-efficiency magnetic heavy metal flocculant MF@AA shows excellent flocculation performance in removing Cu(II). This research provides guidance and ideas for the development of efficient and low-cost flocculation technology to remove Cu(II) in wastewater.

scholarly journals Optimizing the Reaction Conditions for the Formation of Fumarate via Trans-Hydrogenation

2021 ◽  
Author(s):  
Laura Wienands ◽  
Franziska Theiß ◽  
James Eills ◽  
Lorenz Rösler ◽  
Stephan Knecht ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Thermal Equilibrium ◽  
Reaction Rate ◽  
Low Cost ◽  
Hydrogen Gas ◽  
Metabolic Imaging ◽  
Reaction Conditions ◽  
Precursor Molecule ◽  
Solution Preparation

AbstractParahydrogen-induced polarization is a hyperpolarization method for enhancing nuclear magnetic resonance signals by chemical reactions/interactions involving the para spin isomer of hydrogen gas. This method has allowed for biomolecules to be hyperpolarized to such a level that they can be used for real time in vivo metabolic imaging. One particularly promising example is fumarate, which can be rapidly and efficiently hyperpolarized at low cost by hydrogenating an acetylene dicarboxylate precursor molecule using parahydrogen. The reaction is relatively slow compared to the timescale on which the hyperpolarization relaxes back to thermal equilibrium, and an undesirable 2nd hydrogenation step can convert the fumarate into succinate. To date, the hydrogenation chemistry has not been thoroughly investigated, so previous work has been inconsistent in the chosen reaction conditions in the search for ever-higher reaction rate and yield. In this work we investigate the solution preparation protocols and the reaction conditions on the rate and yield of fumarate formation. We report conditions to reproducibly yield over 100 mM fumarate on a short timescale, and discuss aspects of the protocol that hinder the formation of fumarate or lead to irreproducible results. We also provide experimental procedures and recommendations for performing reproducible kinetics experiments in which hydrogen gas is repeatedly bubbled into an aqueous solution, overcoming challenges related to the viscosity and surface tension of the water.

scholarly journals Chemical Removal of Cu and Zn from Swine Feces before Soil Application

Agriculture ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 377
Author(s):  
Moo-Joon Shim ◽  
Seung-Mok Lee
Keyword(s):  
Reaction Time ◽  
H2so4 Solution ◽  
Optimum Conditions ◽  
Liquid Ratio ◽  
Optimal Method ◽  
Zn Concentration ◽  
Swine Feces ◽  
Removal Efficiencies ◽  
Cu And Zn ◽  
Oxalic Acids

Cu and Zn are known to be abundant in swine feces; hence, concentrations of these metals need to be lowered before swine feces are applied to land in order to prevent potential environmental problems. The main objective of this study was to develop an appropriate chemical process to remove Cu and Zn from swine feces using acid extractions. The removal efficiencies of Cu and Zn decreased in the order of H2SO4 > HNO3 > organic acids (citric and oxalic acids). Owing to the highest removal efficiencies of Cu and Zn by using H2SO4, it was selected for further elimination of Cu and Zn from swine feces. By using H2SO4, the optimal concentration, solid-to-liquid ratio, and reaction time were 2%, 1:50, and 8 h, respectively. At the optimum conditions, Cu concentration was decreased from 198 mg/kg to 40.1 mg/kg and Zn concentration from 474 mg/kg to 80.0 mg/kg, with removal rates of 79.7% and 83.1%, respectively. The low Cu removal efficiency, resulting from the strong complexation between Cu and organic matter of swine feces, was improved by the increase in the reaction time and H2SO4 solution concentrations. However, about half of the total nitrogen (TN) was also removed by using H2SO4, indicating that the swine feces treated with H2SO4 may have poor value as fertilizer. Additional studies are required to find an optimal method to maintain TN concentrations while simultaneously removing Cu and Zn.

scholarly journals Clustering-Based Component Fraction Estimation in Solid–Liquid Two-Phase Flow in Dredging Engineering

Sensors ◽  
2020 ◽  
Vol 20 (19) ◽  
pp. 5697
Author(s):  
Chang Sun ◽  
Shihong Yue ◽  
Qi Li ◽  
Huaxiang Wang
Keyword(s):  
Clustering Algorithm ◽  
Two Phase Flow ◽  
Low Cost ◽  
Fast Response ◽  
New Method ◽  
Phase Flow ◽  
Reference Distribution ◽  
Two Phase ◽  
Long Time ◽  
Solid Liquid

Component fraction (CF) is one of the most important parameters in multiple-phase flow. Due to the complexity of the solid–liquid two-phase flow, the CF estimation remains unsolved both in scientific research and industrial application for a long time. Electrical resistance tomography (ERT) is an advanced type of conductivity detection technique due to its low-cost, fast-response, non-invasive, and non-radiation characteristics. However, when the existing ERT method is used to measure the CF value in solid–liquid two-phase flow in dredging engineering, there are at least three problems: (1) the dependence of reference distribution whose CF value is zero; (2) the size of the detected objects may be too small to be found by ERT; and (3) there is no efficient way to estimate the effect of artifacts in ERT. In this paper, we proposed a method based on the clustering technique, where a fast-fuzzy clustering algorithm is used to partition the ERT image to three clusters that respond to liquid, solid phases, and their mixtures and artifacts, respectively. The clustering algorithm does not need any reference distribution in the CF estimation. In the case of small solid objects or artifacts, the CF value remains effectively computed by prior information. To validate the new method, a group of typical CF estimations in dredging engineering were implemented. Results show that the new method can effectively overcome the limitations of the existing method, and can provide a practical and more accurate way for CF estimation.

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