Rpm Of Agitation Speed Research Articles

Co-immobilization of magnesium precursor and Candida rugosa lipase on alumina via covalent bonding for biodiesel production

Catalyst development is one of the most challenging aspects in biodiesel production due to the compatibility issue with the feedstocks and catalyst poisoning upon exposure to process conditions. In the present research, chemoenzymatic catalyst was prepared by impregnation of magnesium aluminate (MA) on alumina support, modifying the support using activating agent, and immobilization of Candida rugosa lipase (CRL) onto the support. The optimum immobilization condition was resulting in 85.07 % of activity recovery of immobilized lipase, equivalent to 30.53 % of immobilization efficiency. The catalysts were characterized through XRD, FTIR, FESEM-EDX, NAA and CO2-TPD confirming the mixture of AlO(OH), magnesium aluminate (MA), (MgNO3)2 and Mg2+ on the support. CRL/L-lysine/MA showed remarkable improvement in thermal stability (40 − 70℃), solvents tolerance (ethanol, methanol, isopropanol, tert-butanol), and storage stability at 30 ℃, as compared to free CRL. CRL/L-lysine/MA successfully produced biodiesel yield up to 87.10 % at 200.71 rpm of agitation speed, 13.58 % (w/w) of water content, 10 h reaction time, 15 % (w/w) of catalyst loading, at 50 ℃, using 1:12 of oil to methanol molar ratio, and retaining 46.60 % of biodiesel yield after six cycle. The CRL/L-lysine/MA demonstrated novel catalysts characteristics comprising chemical and biological active species on a single support for biodiesel production from waste cooking oil (WCO).

Efficient Removal of Heavy Metals from Crude Oil Using High Surface Area Adsorbent Media: Vanadium as a Case Study

Vanadium, one of the heavy metals present in crude oil, harmfully affects the equipment of oil refineries and the quality of petroleum products. As a result, it is important to innovate effective methods for reducing or removing its concentration. This paper aims to study removing vanadium metal from Iraqi crude oil using activated carbon as an effective adsorbent material. Different experimental factors, i.e., the activated carbon dose, contact time, and agitation speed, were regulatory varied to evaluate their impact on vanadium adsorption efficiency. The outcomes revealed an exceptionally good efficacy of activated carbon to eliminate vanadium. The results exhibited that the maximum remediation was 86.33%, recorded at optimum factors, i.e., 0.5 g of activated carbon, 400 rpm of agitation speed, 75 °C temperature, and time of 400 minutes. According to these findings, activated carbon has a great ability to adsorb vanadium from crude oil. Thus, it can be considered a sustainable material for treating petroleum. Furthermore, this approach will help the refineries by reducing costs by eliminating the heavy metals that lead to corrosion or poisoning catalysts.

Chitosan-coated coconut shell composite: A solution for treatment of Cr(III)-contaminated tannery wastewater

BackgroundTannery industry generates a large amount of Cr(III)-contaminated wastewater daily. Unless properly treated, not only this effluent contaminates the water body, but also damages the environment and threatens public health. This batch study investigates the feasibility of chitosan-coated coconut shells as a low-cost material for removing Cr(III) from tannery wastewater. Both chitosan and coconut shell (CS) waste are abundantly available from local agricultural and fishery industries. MethodsTo enhance its treatment performance for Cr(III) removal, the CS was coated with chitosan as a composite. To sustain its cost-effectiveness, the saturated composite was regenerated with HNO3. Its performance for Cr(III) removal was evaluated and compared to other low-cost adsorbents in previous work. FindingsAt the same initial concentration of 20 mg/L, it was found that the composite had a higher Cr(III) removal (97%) than the chitosan alone under the optimized conditions of 4 g/L of dose, pH 6.5, 200 rpm of agitation speed, and 1 h of reaction time. The isotherm of Cr(III) removal by the adsorbents followed the Langmuir model, while the pseudo-second order reaction was representative to simulate the adsorption data. The Cr(III) removal by the composite was based on attractive columbic forces between the negative charge of the adsorbent's surface and the positive charge of the metal cation. The negative value of ΔG thermodynamic parameter suggests the spontaneous nature of adsorption. The efficiency of machine learning regression (MLR) model was assessed in predicting the experimental data of adsorption. In spite of promising results, treated effluents still could not comply with the required limit of discharge standards of less than 0.5 mg/L mandated by local legislation. Therefore, a subsequent treatment using activated sludge is required. Overall, this work reveals a contribution of unused resources from the coconut and shrimp industries in the form of composite for protecting the aquatic environment.

Efficient physical delamination of Ti3C2Tx MXene under periodic and constant shear field of Taylor vortex flow

Employing Taylor vortex flow (TVF), we have devised an innovative technique for the delamination of MXene without using a chemical intercalant and demonstrated the enhanced optoelectronic characteristics of this delaminated MXene through their successful implementation in light emitting diode (LED). The pairwise toroidal fluid motion of TVF was induced by the rotation of the inner cylinder in the Couette-Taylor (CT) reactor. Due to periodic and constant shear field, TVF was highly efficient for the exfoliation of MXene. So, the continuous exfoliation process using CT reactor always showed 8.1 ∼ 12.5 times higher delaminated MXene (d-Ti3C2Tx) yield than that using a conventional mixing tank (MT) reactor which generated turbulent eddy flow (TEF) by impeller agitation. As such, 8.26 mgּ/mL (42.90 % of recovery ratio) of d-Ti3C2Tx was obtained in CT reactor at 1300 rpm of inner cylinder rotation speed and 24 min of mean residence time (MRT). In comparison, d-Ti3C2Tx in MT reactor at 3000 rpm of agitation speed and 24 min of MRT was 0.66 mgּ/mL (3.42 % of recovery ratio). In addition, d-Ti3C2Tx in TVF was thinner and wider than that in TEF. So, the d-Ti3C2Tx was homogeneously suspended without sedimentation and oxidation in aqueous suspension over 30 days. In addition, d-Ti3C2Tx in the TVF was applied to the transparent conducting electrode of inorganic CsPbBr3 perovskite light emitting diodes (PeLEDs). The transparent conducting oxide-free PeLED had 62.52 cd/A of maximum current efficiency and 14.48 % of maximum external quantum efficiency, which is comparable to the best performance of ITO-based inorganic CsPbBr3 PeLEDs.

A novel Lactiplantibacillus plantarum strain: probiotic properties and optimization of the growth conditions by response surface methodology

The objective of this study is to explore the probiotic properties and optimal growth conditions of Lactiplantibacillus plantarum BG24. L. plantarum BG24 exhibited a remarkable ability to utilize lactose, and to grow under acidic conditions and in the presence of high levels of bile salts. The strain showed the highest antibacterial activity against L. monocytogenes Scott A (zone of inhibition: 26 mm). L. plantarum BG24 was found to be resistant to 8 of the tested 19 antibiotics using the disc diffusion method.and its multiple antibiotic resistance (MAR) index was calculated as 0.421. The adhesion rate to human intestinal epithelial Caco-2 cells was determined as 37.51%. The enzyme profile of L. plantarum BG24 was investigated using API ZYM test kit and the highest enzymatic activities were found for Leucine arylamidase, β-glucosidase, Valine arylamidase, β-galactosidase and N-acetyl-β-glucosaminidase. L. plantarum BG24 strain showed higher microbial growth under static conditions (6.60 OD600) compared to 100 rpm (5.73 OD600) and 200 rpm (5.02 OD600) shaking speed due to its facultative anaerobic characteristic. However, different inoculation rates and glucose addition did not make a statistically significant difference on biomass formation (p > 0.05). The specific growth rate of L. plantarum BG24 was 0.416 h−1, the doubling time was 1.67 h, and the biomass productivity value was 0.14 gL−1 h−1 in the original MRS broth (pH 5.7) while higher values were found as 0.483 h−1, 1.43 h and 0.17 gL−1 h−1, respectively, in MRS broth (pH 6.5) medium enriched with 5 g/L yeast extract. The stirred tank bioreactor was used to optimise the growth of BG24 strain. The process variables was optimized at 0.05 vvm of aeration rate, 479 rpm of agitation speed, 3% of inoculation rate and 18 h of incubation time. The maximum biomass (g/L) production was obtained as 3.84 g/L at the optimized conditions.

Cationic and anionic dyes adsorption from wastewater by clay-chitosan composite: An integrated experimental and modeling study

Water contamination with organic dyes is a significant environmental concern because it results in serious problems that threaten public health. In this study, a clay-based composite from Safi City, coated with chitosan (Cs), was used as an adsorbent (SRC/Cs) to remove co-existing dyes (methylene blue (MB) and congo red (CR)) from aqueous solution. Characterization methods such as Fourier infrared transform spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM) coupled with EDX, and zero charge point determination were performed to understand the adsorption mechanisms of the co-pollutants in the adsorbent’s surface. The effects of pertinent parameters, such as initial dye concentration, adsorbent's dose, reaction time, pH, and temperature, were optimized to maximize the adsorption of both anionic and cationic dyes. The Langmuir, Freundlich, and Temkin isotherm models were applied to simulate experimental data. The DFT method was used to identify the key mechanism for MB and CR adsorption. It was found that the composite with 30% (w/w) CS and 70% (w/w) clay showed a complete removal of the target dye with an initial dye concentration of 20 mg/L at optimized pH 2 (CR) and pH 4 (MB), 60 min of reaction time, and 600 rpm of agitation speed. The Langmuir model was suitable for modeling the MB dye adsorption, while the Temkin isotherm was representative to describe CR adsorption. The adsorption capacities of both MB and CR dyes were 97.08 mg/g and 80.9 mg/g, respectively. The kinetic study showed that their adsorption process followed the pseudo-second-order. Thermodynamic parameters such as ΔH0, ΔG0, and ΔS0 imply that the adsorption reaction was spontaneous and endothermic. Overall, this study implies the potential of the composite as a novel adsorbent for removing MB and CR in single and binary systems.

A composite based on hydroxyapatite biocrystal and poly(aniline-o-phenylenediamine) copolymer for efficient removal of anionic dyes from wastewater

BackgroundAcid dyes in any water source strongly impact its color, blocking sunlight and harming aquatic life. Herein, the technical applicability of a novel composite based on hydroxyapatite and poly(aniline-o-phenylenediamine) for removing dyes from synthetic wastewater was investigated using a batch method. MethodsIn this work, camel bones were used as a source of hydroxyapatite. Camel bones were pretreated in an alkali environment before extracting hydroxyapatite biocrystal (HAP). Subsequently, the extracted HAP was mixed with the poly(aniline-o-phenylenediamine) (PANI@PoPD) co-polymer. Different formulation methods were designed to optimize the tested composite samples' shape, size, structure and composition. Then, the optimized composite was further used as an adsorbent to remove orange G (OG) and thymol blue (TB) dyes from synthetic wastewater. The effects of the composite's dose, pH, dyes’ initial concentration and temperature on the overall performance of the composite were assessed. Statistical tests were then used to test the best experimental conditions to remove target dyes from wastewater. Significant findingsBy keeping the dye concentration constant at 50 mg/L for both OG and TB in wastewater at 25 °C, pH = 2 and 800 rpm of agitation speed in a batch reactor, it was found that the synthesized composite efficiently removes 99% of each dye at optimum dose of 0.5 or 1 g/L with a reaction time close to 30 or to 80 min for OG or TB, respectively. The predictive capacity of two-parameter models, including the Langmuir, Freundlich, Temkin and Dubinin-Radushkevich models, and three-parameter models such as the Redlich-Peterson, Sips and Toth models, was assessed to estimate the collected adsorption data. It was found that the statistical analysis was slightly better when the Temkin model was applied. This indicates that this equation was better suited to represent the experimental data of the adsorption of the OG dye. In contrast, the Redlich-Peterson and Toth models were in better agreement with the experimental results of the TB dye adsorption. Furthermore, thermodynamic parameters associated with each dye adsorption demonstrated its feasibility, while the adsorption kinetic data were found to be better described with the pseudo-second-order kinetics. In addition, the regenerability performances of the tested composite were successfully assessed by reusing the spent composite five consecutive times.

Extraction of cadmium from aqueous solutions by emulsion liquid membrane (ELM) using three different carriers dissolved in a 70:30 ratio of sunflower oil to kerosene

This study explores the use of novel green emulation liquid membranes (GELMs) for the simultaneous extraction and stripping of Cd (II) from aqueous solutions. A solute is transported through the membrane due to the presence of the carrier and then concentrated in the internal phase. Soybean, sunflower, corn, and canola oils were used to form green substitutes to petroleum-based organic diluents for use as GELMs. Bis-(2-ethylhexyl) phosphate (D2EHPA), tri-butyl- phosphate (TBP), and trioctylamine (TOA) were the extractants, span 80 was the emulsifier, and HCl or H2SO4 was used as the stripping agent. The best conditions for maximum extraction efficiency (98.68%), stripping efficiency (97.14%), and lowest membrane breakage (0.9%) were achieved using a mixture of sunflower oil and kerosene in the ratio of 70:30. The other optimum values of the variables were: 2% (v/v) Span 80, 10 min emulsification time, 12700 rpm emulsification speed, 400 rpm of agitation speed, 5% (v/v) D2EHPA, an external phase pH was 3.5, an internal phase of 0.25 M HCl, and 5:1 of the treat ratio (external phase to emulsion) at 10 min contact time. The synthesized membrane was reused eight times, with approximately the same efficiency and no significant breakage during the first seven cycles.

Applicability of magnetic biochar derived from Fe-enriched sewage sludge for chromate removal from aqueous solution

In this work, inexpensive biochar derived from different feedstock was synthesized, characterized, and tested for Cr(VI) removal from synthetic wastewater. The physical properties of the sludge-based magnetic biochars (SSB) were analyzed using FT-IR, XRD, BET surface area, SEM-EDS, and XPS techniques. The effects of pyrolysis temperature (300–900 ℃), initial Cr(VI) concentration (2–30 mg/L), rotation speed (50–200 rpm), pH (3–11), and co-ions (Na+, Ca2+, Mg2+, K+, Cl−, HCO3− and SO42−) on Cr(VI) removal by the SSB were determined in batch modes. It was found that the SSB had the highest Cr(VI) removal (43.7%), as compared to the other feedstock-derived biochars (p ≤ 0.05; Anova test). The characterization data indicated that with an increasing pyrolysis temperature from 300 to 900℃, the surface area, pore volume, and pore size decreased, while the Fe3O4 on SSB was gradually reduced to α-Fe0. With respect to Cr(VI) removal, under the optimized conditions of 900℃ of pyrolysis temperature, 2 mg/L of Cr(VI) concentration, 200 rpm of agitation speed, and pH 6.8, a complete Cr(VI) removal could be attained by the SSB900. Its treated effluents could comply with the required Cr(VI) discharge limit of <0.01 mg/L (GB3838-2002) mandated by local legislation. Therefore, further treatment was not required, avoiding additional cost. Coexisting ions experiments showed that all of them inhibited the Cr(VI) removal by the adsorbent after 1 h of reaction. The Cr(VI) removal followed the pseudo-second-order kinetics and the Langmuir isotherm model. The removal mechanism was based on the reduction of Cr(VI) by nZVI on the SSB900 and the Fe leakage might have facilitated the Cr(VI) removal. Overall, iron-enriched sewage sludge biochar is promising and cost-effective for treatment of low-level Cr(VI)-contaminated wastewater.

Fluoride removal from drinking water (Metlaoui, Tunisia) using untreated and treated natural clays

AbstractBACKGROUNDFluorosis is an endemic disease due to an excess of fluoride intake via drinking water. In some regions of the world, removing fluoride from drinking water is a severe problem that is still to be solved. The present study focuses on the use of a natural clay to reduce fluoride concentration in Tunisian contaminated drinking water under relevant working conditions.RESULTSAdsorption experiments were performed in batches using a fluoride aqueous solution. The Box–Behnken model design was used to define the working conditions in which three factors were controlled: clay dosage, contact time and agitation speed. The fixed parameters were the initial fluoride concentration and water pH as observed in Metlaoui, Tunisia in 2021, and experiments were performed at room temperature. Results show that 4 g(50 mL)−1 of clay dosage, 10 min of contact time and 280 rpm of agitation speed could provide 51% fluoride removal using an untreated natural clay. Then, various adsorbents based on this clay were synthesized (chitosan–clay, C6H17NO3Si–clay and thermally treated clays purified using different methods) and tested using the same approach. Among the adsorbents tested, the thermally treated purified clays were the most effective in removing fluoride under ambient conditions with a fluoride removal of 97.5%. Tests performed on drinking water showed that the safety fluoride concentration could be achieved without modifications of the water pH.CONCLUSIONSThe thermally treated clays investigated in this study were effective for fluoride removal under relevant conditions, which can pave the way for future field applications. © 2023 Society of Chemical Industry (SCI).

RAW OYSTER SHELL SORBENT FOR REMOVAL OF CONGO RED DYE

Raw oyster shell was successfully prepared as an adsorbent for removing Congo Red (C.R.) dye in an aqueous solution using an adsorption technique. The various parameters influencing this adsorption process, such as adsorbent size, adsorbent dosage, initial dye concentration, contact time, pH, agitation speed and agitation time, were studied. The maximum percentage of dye removal of 96.3% was obtained at the optimised conditions of 75 μm of adsorbent size, 1.0 g of adsorbent dosage, 30 mg/L of initial dye concentration, pH 3, 110 rpm of agitation speed and 75 min of agitation time. The experimental data were analysed using two adsorption models, the Langmuir isotherm model and the Freundlich isotherm model. The adsorption data obtained well fitted for the Langmuir isotherm model indicate a monolayer adsorption reaction involved during the adsorption process. The result shows that raw oyster shells could be employed as a suitable alternative adsorbent to remove Congo red dye in an aqueous solution.Keywords: raw oyster shell, adsorption, congo red

A cost-effective and eco-friendly biosorption technology for complete removal of nickel ions from an aqueous solution: Optimization of process variables

Abstract The enormous industrial usage of nickel during its manufacture and recycling has led to widespread environmental pollution. This study was designed to examine the ability of Gelidium amansii biomass to biosorb Ni2+ ions from an aqueous solution. Six independent variables, including contact time (1.0 and 3.0 h), pH (4 and 7), Ni2+ concentration (25 and 200 mg·L−1), temperature (25°C and 50°C), G. amansii biomass (1.0 and 4.0 g·L−1), and agitation mode (agitation or static), were investigated to detect the significance of each factor using a Plackett–Burman design. The analysis of variance for the Ni2+ biosorption percentage indicated that three independent variables (contact time, temperature, and agitation–static mode) exhibited a high level of significance in the Ni2+ biosorption process. Twenty experiments were conducted containing six axial, eight factorial, and six replicates points at center points. The resulting face-centered central composite design analysis data for the biosorption of Ni2+ exhibited a very large variation in the removal percentage of Ni2+, which ranged from 29.73 to 100.00%. The maximum Ni2+ biosorption percentage was achieved in the 16th run with an experimental percentage quantified as 100.00% under the experimental conditions of 3 h of incubation time and 45°C with 100 rpm for agitation speed.

Optimization of Electrodeposited Ni-Cr Composite Coatings by using Taguchi Design and Grey Relational Method

In this investigation, the Nickel (Ni) – Chromium (Cr) composite deposits was developed from conductive type nickel plating bath through electrodeposition technique. The Cr particles concentration in bath were taken in three different proportions such as 10 g/l,20 g/l and 30 g/l and got deposited on the Ni plate. The design of experiment technique, L27 orthogonal array of Taguchi method was employed for conducting experiments with different combination of parameters and its level. The parameters taken into consideration were current density level, pH range, bath temperature, Cr concentration in bath and stirrer speed. The experiment includes the measurement of micro hardness, area fraction of Cr, mass of deposit and coating thickness of coated samples with variable input parameters. The main effects of process parameters and their influences on the responses were analyzed. The outcomes shows that Cr concentration in bath and pH range are the most significant parameters for better enhanced responses measured. Microstructure examinations were conducted to analyze Cr deposition in prepared Ni plates using optical metallurgical microscope, scanning electron microscope (SEM) micro images and Energy Dispersive X-Ray (EDX) spectroscopy studies. Furthermore, the decision-making procedure was carried out for maximization of multi-performance measured responses using grey relational analysis (GRA). The optimized plating parameters levels are found to be 4 A/dm2 for Current density, 2.5 for pH, 45˚C for bath temperature, 30 g/l for bath concentration and 300 rpm for agitation speed to have the maximum micro hardness of 1037 HV, 370 mg of mass of deposit, 42% of Cr particle area fractions and 112 µm of coating thickness. Subsequently the obtained optimal combination of process parameters was validated through confirmation experiment. The results shows that the confirmation test responses are well associated with predicted response values on the Ni-Cr coatings.

Removal of Methyl Red using Adsorbent Produced from Empty Fruit Bunches by Taguchi Approach

Contamination of anionic dye in the water streams may cause harm to human being and aquatic species. The conventional adsorbent used in the adsorption process is normally produced using expensive and unsustainable precursor such as coal. In this work, activated carbon was produced through carbonization and activation of raw oil palm empty fruit bunches (EFBs). Taguchi approach was employed to determine the optimum dye removal parameters. The percentages of contribution of each factor in the removal of Methyl Red (MR) by raw EFB and EFB based activated carbon (AC) were determined using analysis of variance (ANOVA). According to ANOVA, for raw EFB, agitation speed has the highest percentage of contribution. As for EFB based AC, the amount of adsorbent is the most significant factor. The optimum parameters for both adsorbents were obtained from mean and S/N ratio. The optimum operating parameters for raw EFB were 25 ppm of initial dye concentration, 0.01 g of adsorbent and 200 rpm of agitation speed whereas the optimum operating parameters for EFB based AC were 20 ppm of initial dye concentration, 0.06 g of adsorbent and 120 rpm of agitation speed. The predicted percentages of dye removal for raw EFB (55.54%) and EFB based AC (86.72%) were in good agreement with the experimental values for raw EFB (50.5%) and EFB based AC (84.61%), respectively. This study provides a useful insight into the practicability of using the Taguchi method in the removal of anionic dye using raw EFB and EFB based AC as adsorbents.

Statistical Optimization of Adsorption Processes for The Removal of Phenol by Activated Carbon Derived from Baobab Fruit Shell

Baobab fruit shell (BFS) biomass was used as an alternative precursor for producing high surface area and microporous baobab fruit shell activated carbon (BFS-AC) by chemical activation using KOH. Scanning electron microscope (SEM) was performed for the characterization of baobab fruit shell activated carbon. The adsorption property of BFS-AC for the removal of phenol from aqueous solution was evaluated. The effect of key adsorption parameters such as the contact time (10-20 min), BFS-AC dose (2.5-3.5 g/L), pH (1-3), and agitation speed (150-250 rpm) were optimized using a response surface methodology (RSM) with faced centered central composite design (FCCCD). Consequently, a maximum adsorption capacity (196.86 mg/g) was achieved at 15 min of contact time, 2 of pH, 3 g/L of adsorbent dosage, and 250 rpm of agitation speed. The results reveal that BFS-AC has an efficient performance for the removal of phenol from aqueous media.

Protein-based nanoparticles synthesized at a high shear rate and optimized for drug delivery applications

This study aims to establish a method for the preparation of protein-based nanoparticles with uniform-sized nanoparticles less than 100 nm. For this, the conventional desolvation method was enhanced by applying a high shear rate. Molecular bovine serum albumin (BSA) was exploited in the modified method. The synthesis condition was optimized by the Taguchi approach. For this, an orthogonal array of L16 was used for four parameters each at four levels. Temperature, pH, agitation speed, and the volume fraction of organic solvents (ethanol/acetone) were selected as affecting parameters. The smallest size of BSA nanoparticles was obtained at pH 8, 8 °C, 66.7% (v/v) ethanol to acetone, and 7000 rpm of agitation speed (shear rate ~73304 s−1). The nanoparticles were characterized using dynamic light scattering (DLS), scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy (FTIR). The BSA nanoparticles with the smallest size of 76 nm were used for the controlled release of cefazolin (Cef) as one of the most commonly used antibiotics for the treatment of bacterial infections. Also, the loading capacity and in vitro drug release kinetic behavior of the BSA nanoparticles were investigated. Amongst the adsorption equilibrium isotherms fitted to the experimental data, the Freundlich isotherm was the best isotherm with R2 = 0.97. The release kinetics of Cef was followed by the Korsmeyer-Peppas model (R2 = 0.99) revealing that the drug release is controlled by the non-Fickian diffusion-based mechanism along with polymer erosion. The kinetic data showed that about 99% of the drug is released within 42 h. According to the result of this study, BSA nano-formulation could be an encouraging carrier for antibiotics delivery.

Removal of Cr (III) from industrial wastewater using coconut shell carbon and limestone as adsorbent

Agricultural waste materials gained attention among researchers to study the effectiveness of adsorbent media in heavy metal treatment. In this study, application of coconut shell carbon and limestone as modified adsorbent was used to remove Cr (III) from industrial wastewater. Synthetic industrial wastewater sample containing 2 mg/L of Cr (III) was prepared using distilled water and standard solution of Cr (III). Batch adsorption study was conducted to determine the effect of varied contact time (0 to 120 minutes) and pH (pH3 to pH7). The result shows that at 60 minutes of contact hour, the removal of Cr (III) from the synthetic industrial wastewater is about 98% with optimum adsorption capacity is 0.000019 mg/g at 250 rpm of agitation speed in pH5 as optimum pH. The kinetic data obtained specified that the data follow closely the pseudo-second-order. Thus, this indicates that mixing coconut shell carbon and limestone as a modified adsorbent has a potential in reducing Cr (III) concentration in industrial wastewater.

Evaluation of cadmium biosorption property of de-oiled palm kernel cake

Cadmium contamination is a global concern because of its widespread nature of polluting both biotic and abiotic components of ecosystem. Though many natural, chemical/synthetic components have been researched for remediation of cadmium, development of an eco-friendly, economic biosorbent still remains a challenge. Deoiled palm kernel cake (DOPC), a byproduct from palm-oil mills was investigated in the present study for its cadmium remediating capacity. DOPC was immobilized using sodium alginate polymer and biosorption studies were carried out using DOPC as adsorbent for removal of cadmium. Research revealed biosorption potential of DOPC and the optimum conditions for maximum biosorption of cadmium have been identified as 120 min of contact time, 150 rpm of agitation speed, pH 6 and 15 mg/L of initial cadmium concentration. Maximum percentage of adsorption was 99% by using 1.5 g/100 ml of adsorbent. The adsorption equilibrium data Biosorbent was characterized before and after adsorption by FTIR which showed the involvement of carboxyl, hydroxyl and amino-groups. Statement of novelty Cadmium pollution and the leading environmental problems is a global concern. Despite various attempts for development of different matrices for remediation of cadmium from contaminated samples, application of deoiled palm kernel cake (DOPC) as a biosorbent is not being explored. Present study provides quantitative data relating the richness of phytochemical repertoire DOPC possess, its resulting radical scavenging potential and its applications as an efficient, eco-friendly and economic alternative as a biosorbent matrix material for cadmium bio-remediation.

Stability Study of Emulsion Liquid Membrane via Emulsion Size and Membrane Breakage on Acetaminophen Removal from Aqueous Solution Using TOA.

The purpose of this study is to explore the emulsion liquid membrane stability for acetaminophen (ACTP) removal from aqueous solution. In this work, the membrane phase was prepared by dissolving trioctylamine (TOA) with kerosene and Span80. The stability of the emulsion in terms of emulsion size, membrane breakage, and its efficiency in removing ACTP was considered for the optimization of parameters. Investigation on the stability of emulsion was carried out by manipulating the concentration of stripping agent, agitation speed, extraction time, and treat ratio. The best condition to produce a very stable emulsion was achieved at 0.1 M of stripping agent concentration, with 300 rpm of agitation speed for 3 min of extraction time with a treat ratio of 3:1. Eighty-five percent of ACTP successfully stripped into the emulsion with minimum membrane breakage of 0.17% through this experiment.

Optimization of Extraction Parameters of Polyphenols from Mango Seed Kernel through Response Surface Methodology

Phenolic compounds constitute an essential part of the human diet, and are of considerable interest due to their antioxidant properties. The traditional maceration method has been used for the extraction of polyphenols from mango seed kernel (Mangifera indica L.). Highlight the effects of different extraction parameters is useful to optimize the process, as well as to predict the extraction yield within the experimental domain with enough precision and confidence. The purpose of this work is to probe the influence of extraction time, extraction temperature and agitation speed on the extraction yield of phenolic compounds, and the total reducing power of the extract. The Surface Methodology (RSM), using the Doehlert design, have been applied. Optimal values of extraction yield and total reducing power was 36.99 mg Gallic acid equivalent/g and 61.08 mg Ascorbic Acid Equivalent/g respectively. The optimal conditions are 60 minutes of extraction time, 68.7°C extraction temperature and 424 rpm for agitation speed. Under optimized conditions the experimental values well agreed with the values predicted by the model equations proposed.