scholarly journals Removal of Arsenic Oxyanions from Water by Ferric Chloride—Optimization of Process Conditions and Implications for Improving Coagulation Performance

2021 ◽  
Vol 18 (18) ◽  
pp. 9812
Author(s):  
Muhammad Ali Inam ◽  
Rizwan Khan ◽  
Kang-Hoon Lee ◽  
Young-Min Wie
Keyword(s):  
Drinking Water ◽  
Ferric Chloride ◽  
Iron Hydroxide ◽  
Operating Conditions ◽  
Effect Of Temperature ◽  
Optimum Operating ◽  
Process Conditions ◽  
As Species ◽  
Adsorption Affinity ◽  
Optimum Ph

The chronic ingestion of arsenic (As) contaminated water has raised significant health concerns worldwide. Iron-based coagulants have been widely used to remove As oxyanions from drinking water sources. In addition, the system’s ability to lower As within the maximum acceptable contamination level (MCL) is critical for protecting human health from its detrimental effects. Accordingly, the current study comprehensively investigates the performance of As removal under various influencing factors including pH, contact time, temperature, As (III, V) concentration, ferric chloride (FC) dose, and interfering ions. The optimum pH for As (V) removal with FC was found to be pH 6–7, and it gradually decreased as the pH increased. In contrast, As (III) removal increased with an increase in pH with an optimum pH range of 7–10. The adsorption of As on precipitated iron hydroxide (FHO) was better fitted with pseudo-second order and modified Langmuir–Freundlich models. The antagonistic effect of temperature on As removal with FC was observed, with optimum temperature of 15–25 °C. After critically evaluating the optimum operating conditions, the uptake indices of both As species were developed to select appropriate an FC dose for achieving the MCL level. The results show that the relationship between residual concentration, FC dose, and adsorption affinity of the system was well represented by uptake indices. The higher FC dose was required for suspensions containing greater concentration of As species to achieve MCL level. The As (V) species with a greater adsorption affinity towards FHO require a relatively smaller FC dose than As (III) ions. Moreover, the significant influence of interfering species on As removal was observed in simulated natural water. The author hopes that this study may help researchers and the drinking water industry to develop uptake indices of other targeted pollutants in achieving MCL level during water treatment operations in order to ensure public health safety.

scholarly journals The Effect of the Operating Conditions on the Apparent Viscosity of Crude Palm Oil During Oil Clarification

1970 ◽  
Vol 5 (1) ◽  
Author(s):  
Sulaiman Al-Zuhair, Mirghani I. Ahmed and Yousif A. Abakr
Keyword(s):  
Shear Rate ◽  
Boundary Conditions ◽  
Palm Oil ◽  
Apparent Viscosity ◽  
Operating Conditions ◽  
Effect Of Temperature ◽  
Optimum Operating ◽  
Crude Palm Oil ◽  
Different Boundary Conditions ◽  
Rotary Viscometer

This paper discusses the apparent viscosity of crude palm oil, using rotary viscometer, under different boundary conditions. It was experimentally shown that the apparent viscosity of palm oil drops with increasing of the shear rate and the temperature.  However, the effect of temperature on the viscosity tends to fade at temperatures beyond 80 oC.  A correlation between the apparent viscosity of crude palm oil and the operating conditions was developed. This correlation can be used in design of crude palm oil settlers and in determining the optimum operating conditions.Key Words:  Crude palm oil, apparent viscosity, shear rate, modelling, separation 

Taguchi Approach and ANOVA in Optimization of the Dissolution of Colemanite in CO2 and SO2- Water Systems

2020 ◽  
Vol 10 (2) ◽  
pp. 88-97
Author(s):  
Zafer Ekinci ◽  
Esref Kurdal ◽  
Meltem Kizilca Coruh
Keyword(s):  
Particle Size ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Gas Flow ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Process Conditions ◽  
Liquid Ratio ◽  
Positive Effects ◽  
Controllable Factors

Background: Turkey is approximately 72% of the world’s boron sources. Colemanite, tincal, ulexite and pandermite are among the most significant in Turkey. Boron compounds and minerals are widely used in many industrial fields. Objective: The main purpose of this study was to investigate the control of impurities in the boric acid production process using colemanite by carrying out the reaction with a mixture of CO2 and SO2 - water, and determining the appropriate process conditions to develop a new process as an alternative to the use of sulfuric acid. Due to worrying environmental problems, intensive studies are being carried out globally to reduce the amount of CO2 and SO2 gases released to the atmosphere. Methods: The Taguchi method is an experimental design method that minimizes the product and process variability by selecting the most appropriate combination of the levels of controllable factors compared to uncontrollable factors. Results: It was evaluated the effects of parameters such as reaction temperature, solid-to liquid ratio, SO2/CO2 gas flow rate, particle size, stirring speed and reaction time. The optimum conditions determined to be reaction temperature of 45°C; a solid–liquid ratio of 0.083 g.mL−1; an SO2/CO2 ratio of 2/2 mL.s−1; a particle size of -0.354+0 .210 mm; a mixing speed of 750 rpm and a reaction time of 20 min. Conclusion: Under optimum operating conditions, 96.8% of colemanite was dissolved. It is thought that the industrial application of this study will have positive effects on the greenhouse effect by contributing to the reduction of CO2 and SO2 emissions that cause global warming.

scholarly journals Treatment of industrial electroplating wastewater for metals removal via electrocoagulation continous flow reactors

2022 ◽  
Author(s):  
Hussein I. Abdel-Shafy ◽  
Rehan M. M. Morsy ◽  
Mahmoud A. I. Hewehy ◽  
Taha M. A. Razek ◽  
Maamoun M. A. Hamid
Keyword(s):  
Stainless Steel ◽  
Ferric Chloride ◽  
Contact Time ◽  
Removal Rate ◽  
Operating Conditions ◽  
Synthetic Wastewater ◽  
Optimum Operating ◽  
Chemical Coagulation ◽  
Electroplating Wastewater ◽  
Metals Removal

Abstract A real industrial electroplating rinsing wastewater was collected and subjected the physical and chemical examination. The study showed that it can be categorized as high strength wastewater, at pH- 2, COD 1430 mg/l, and high level of metals above permissible limits namely: 150, 30, 25, and 2.9 for Ni, Cu, Zn, and Fe mg/l respectively. Therefore, metals must be adequately removed before discharging to avoid any hazardous impact on the environment. Similar synthetic wastewater was prepared to study effect of chemical coagulation for the precipitation of metals. The optimum removal rate was achieved by using a combination of lime and ferric chloride at 100 and 30 mg/l respectively. The chemically treated electroplating wastewater was subjected to an electrocoagulation study. A comparison between iron and stainless-steel electrodes for the removal of metals was investigated. Furthermore, the effect of different electric voltage, and the contact time on metals removal efficiency were also examined. It was found that the optimum removal capacity was achieved when stainless steel electrode was employed in the presence of ferric chloride as coagulant, at 10 volts, 30 min. contact time, and pH 9 for synthetic solution. In a batch treatment system, the real industrial wastewater was treated at the predetermined optimum operating conditions; the removal of metals was 92.1%, 87.8% and 82.9% for Ni. Zn, and Cu respectively. By employing a continuous flow reactor for the treatment of the same real wastewater and under the same operating conditions; metals removal rate increased to 98.9%, 97.4% and 96.6% for Ni. Zn, and Cu respectively. The level of metals in the final treated wastewater copes with Egyptian Environmental Regulation. The overall results confirmed that the electro-coagulation (EC) technology offers an effective alternative process in combination with the conventional chemical coagulation process for reaching high removal performance of toxic metals from the electroplating wastewater. The advantage of EC technique is achieving high treatment efficiency instead of expensive chemical reagents, high construction cost and/or other conventional processes. In addition, the final treated water can be reused for rinsing process in electroplating industry and/or discharging without any environmental hazard effect. It is also recommended to employ solar energy instead of electricity to reduce cost of operation.

Ceramic membranes for direct river water treatment applying coagulation and microfiltration

2006 ◽  
Vol 6 (4) ◽  
pp. 89-98 ◽  
Author(s):  
A. Loi-Brügger ◽  
S. Panglisch ◽  
P. Buchta ◽  
K. Hattori ◽  
H. Yonekawa ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Pilot Study ◽  
River Water ◽  
Membrane Filtration ◽  
Ceramic Membrane ◽  
Drinking Water Treatment ◽  
Ceramic Membranes ◽  
Operating Conditions ◽  
Optimum Operating

A new ceramic membrane has been designed by NGK Insulators Ltd., Japan, to compete in the drinking water treatment market. The IWW Water Centre, Germany, investigated the operational performance and economical feasibility of this ceramic membrane in a one year pilot study of direct river water treatment with the hybrid process of coagulation and microfiltration. The aim of this study was to investigate flux, recovery, and DOC retention performance and to determine optimum operating conditions of NGK's ceramic membrane filtration system with special regards to economical aspects. Temporarily, the performance of the ceramic membrane was challenged under adverse conditions. During pilot plant operation river water with turbidities between 3 and 100 FNU was treated. Membrane flux was increased stepwise from 80–300 l/m2h resulting in recoveries between 95.9 and 98.9%. A DOC removal between about 20–35% was achieved. The pilot study and the subsequent economical evaluation showed the potential to provide a reliable and cost competitive process option for water treatment. The robustness of the ceramic membrane filtration process makes it attractive for a broad range of water treatment applications and, due to low maintenance requirements, also suitable for drinking water treatment in developing countries.

scholarly journals Removal of Arsenic from Wet Scrubbing Wastewater

2016 ◽  
Vol 5 (2) ◽  
pp. 255
Author(s):  
Francesco Ferella ◽  
Ida De Michelis ◽  
Francesco Veglio
Keyword(s):  
Arsenic Removal ◽  
Operating Conditions ◽  
Iron Chloride ◽  
Optimum Operating ◽  
Optimum Process ◽  
Process Conditions ◽  
Calcium Arsenate ◽  
Wet Scrubbing ◽  
Negative Effect ◽  
Removal Of Arsenic

<p class="emsd-body"><span lang="EN-GB">Arsenic removal is hindered by its valence state. Addition of lime into wastewater containing arsenic gives benefits through the formation of low-soluble calcium arsenate, but the mechanism involved in the reduction of arsenic dissolution is not well known yet. Hence, in the present work different Ca/As ratios from 0 to 70% w/w were tested with the aim of finding the best conditions for removal of As from water (neutral tests) or solution (acid tests) containing sulphate ions. These solutions simulated aqueous streams coming from a wet scrubber for treatment of flue gas. Moreover, 5 g L<sup>-1</sup> of iron chloride were tested as additive in the acid tests. </span></p><p class="emsd-body"><span lang="EN-GB">In the optimum operating conditions, nearly 99% precipitation yield was obtained for both As(III) and As(V) in less than 1 h; the optimum process conditions were 10 g L<sup>-1</sup> of CaO without FeCl<sub>3</sub> for As(III) and 9 g L<sup>-1</sup> of CaO and 5 g <sup>-1</sup> FeCl<sub>3</sub> for As(V) in acid solutions. As regards neutral solutions, 1 g L<sup>-1</sup> of CaO is enough to precipitate around 99% of As(III) whereas the same result for As(V) is achieved by a higher CaO concentration (40 g L<sup>-1</sup>). Iron chloride had a negative effect on As(III) precipitation.</span></p>

scholarly journals Recrystallization and Micronization of p-Toluenesulfonamide Using the Rapid Expansion of Supercritical Solution (RESS) Process

Crystals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 449 ◽  
Author(s):  
Tsung-Mao Yang ◽  
Chie-Shaan Su ◽  
Jin-Shuh Li ◽  
Kai-Tai Lu ◽  
Tsao-Fa Yeh
Keyword(s):  
Operating Conditions ◽  
Rapid Expansion ◽  
Optimum Operating ◽  
Control Factor ◽  
Process Conditions ◽  
Extraction Temperature ◽  
Control Factors ◽  
Supercritical Solution ◽  
Average Size ◽  
Expansion Temperature

This study is focused on the micronization of p-toluenesulfonamide (p-TSA) using the rapid expansion of supercritical solution (RESS) process. Taguchi’s experimental design method was applied to determine the optimum operating conditions. L9(34) orthogonal array with four control factors and three levels of each control factor was used to design nine experimental conditions. Four control factors were selected, including extraction temperature, extraction pressure, pre-expansion temperature, and post-expansion temperature. The particle size and morphology of the prepared samples were observed by scanning electron microscopy (SEM). In addition, Fourier transform infrared spectrometer (FTIR), X-ray diffraction (XRD), and differential scanning calorimetry (DSC) were employed to compare the differences between the raw and micronized p-TSA particles. The experimental and analytical results indicated that the extraction temperature was the most significant factor for the micronization of p-TSA in the RESS process, and the optimal operating conditions were at an extraction temperature of 50 °C, an extraction pressure of 220 MPa, a pre-expansion temperature of 220 °C, and a post-expansion temperature of 30 °C. The p-TSA particles were micronized from the original average size of 294.8 μm to the smallest average size of 1.1 μm at the optimal RESS process conditions. Furthermore, the physicochemical characteristics of p-TSA did not differ significantly before and after recrystallization.

Influences of Process Conditions on Ni-P Electroless Plating on PVC Plastic

2010 ◽  
Vol 154-155 ◽  
pp. 1771-1774
Author(s):  
Xi Ran Wang ◽  
Ying Wei Zhang
Keyword(s):  
Surface Morphology ◽  
Ph Value ◽  
Optimum Operating ◽  
Process Conditions ◽  
Optimum Operating Condition ◽  
X Ray ◽  
Optimum Ph ◽  
The Matrix ◽  
One Step ◽  
Electroless Ni

In this work, one step for sensitization and activation in pretreatment process is adopted. The influences of the temperature, pH value on electroless Ni-P plating on PVC plastic were discussed. The components and surface morphology of the coating were studied by using SEM and EDS. The results show that the optimum operating condition is temperature being 50～55 , the optimum pH value being 8.5. Under the optimal technical conditions, the deposits is smooth and uniformity. The adhesion between the deposits and the matrix is better, The deposit contains 97.68% (wt) Ni and 2.32% (wt)P by the analyses of energy disperse X-ray.

scholarly journals Reduction crystallization of heavy metals from acid treated phosphogypsum effluent utilizing hydrazine as a reducing reagent

2019 ◽  
Vol 96 ◽  
pp. 01002
Author(s):  
Tebogo Mashifan ◽  
Nastassia Sithole
Keyword(s):  
South African ◽  
Nickel Powder ◽  
Negative Impact ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Optimum Ph ◽  
Powder Particles ◽  
Seeding Material ◽  
Iron Manganese ◽  
Base Substrate

Phosphogypsum is a by-product generated from phosphoric acid production processes. Due to the negative impact posed to the environment by the material, a chemical treatment process was developed to reduce the hazardous constituents in the material and render the final product useful for other applications. The treatment of phosphogypsum produced an effluent laden with contaminants such as copper, iron, manganese and thallium. This study was conducted to investigate the use of hydrazine as a reducing agent to remove and reduce Cu, Fe, Mn and TI from effluent, applying a reduction crystallization process. Nickel powder a base substrate was utilised as a seeding material. A feasibility study was carried out to test the efficiency and find the optimum operating conditions for the process. The predominant detected components in the feedstock were 71% Fe, 14% Tl, 5.1% Mn, 4.12% Cu and 2.4% Zn. The results obtained indicate that hydrazine can effectively remove up to 99.8% of metals from the effluent at the optimum pH of 10.5. Growth of the nickel powder particles was evident indicating a reduction and adsorption of contaminants on the surface of the powder. The treated solution was within South African acceptable limits for effluent discharge, which stipulates a concentration of 20 mg/l of copper, iron, manganese and thulium.

scholarly journals Adsorption Capacities of Iron Hydroxide for Arsenate and Arsenite Removal from Water by Chemical Coagulation: Kinetics, Thermodynamics and Equilibrium Studies

Molecules ◽  
2021 ◽  
Vol 26 (22) ◽  
pp. 7046
Author(s):  
Muhammad Ali Inam ◽  
Rizwan Khan ◽  
Kang Hoon Lee ◽  
Muhammad Akram ◽  
Zameer Ahmed ◽  
...  
Keyword(s):  
Iron Hydroxide ◽  
Point Of Zero Charge ◽  
Infrared Spectrometry ◽  
Equilibrium Studies ◽  
Chemical Coagulation ◽  
Ζ Potential ◽  
Maximum Sorption Capacity ◽  
As Species ◽  
Adsorption Affinity ◽  
Ft Ir

Arsenic (As)-laden wastewater may pose a threat to biodiversity when released into soil and water bodies without treatment. The current study investigated the sorption properties of both As(III, V) oxyanions onto iron hydroxide (FHO) by chemical coagulation. The potential mechanisms were identified using the adsorption models, ζ-potential, X-ray diffraction (XRD) and Fourier Transform Infrared Spectrometry (FT-IR) analysis. The results indicate that the sorption kinetics of pentavalent and trivalent As species closely followed the pseudo-second-order model, and the adsorption rates of both toxicants were remarkably governed by pH as well as the quantity of FHO in suspension. Notably, the FHO formation was directly related to the amount of ferric chloride (FC) coagulant added in the solution. The sorption isotherm results show a better maximum sorption capacity for pentavalent As ions than trivalent species, with the same amount of FHO in the suspensions. The thermodynamic study suggests that the sorption process was spontaneously exothermic with increased randomness. The ζ-potential, FT-IR and XRD analyses confirm that a strong Fe-O bond with As(V) and the closeness of the surface potential of the bonded complex to the point of zero charge (pHzpc) resulted in the higher adsorption affinity of pentavalent As species than trivalent ions in most aquatic conditions. Moreover, the presence of sulfates, phosphates, and humic and salicylic acid significantly affected the As(III, V) sorption performance by altering the surface properties of Fe precipitates. The combined effect of charge neutralization, complexation, oxidation and multilayer chemisorption was identified as a major removal mechanism. These findings may provide some understanding regarding the fate, transport and adsorption properties onto FHO of As oxyanions in a complex water environment.

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