Removal of dyes by Moringa oleifera seed extract. Study through response surface methodology

BACKGROUND: The effect of pH and initial dye concentration (IDC) on dye removal by coagulation/flocculation process with Moringa oleifera seed extract has been studied. The study was carried out by using the response surface methodology (RSM) in an orthogonal and rotatable design of experiments. Three types of dye were studied: anthraquinonic (Alizarin Violet 3R); indigoid (Indigo Carmine); and azoic (Palatine Fast Black WAN). RESULTS: The interaction level of the two variables studied is higher in the case of azo dye, while it is almost null in the case of anthraquinonic dye. Indigoid dye presents an intermediate situation. pH has a negative influence on dye removal, and by raising IDC q capacity tends to be higher. Polynomic regression of the surface plot was carried out and the adjusted r² found for each case, this being 0.99 in the case of anthraquinonic dye, 0.94 in the case of indigoid dye, and 0.74 in the case of azoic dye. CONCLUSIONS: Moringa oleifera is an interesting natural coagulation agent for use in dye removal. pH should be taken into account in the cases of indigoid and azo dyes, while its influence is rather small in the case of anthraquinonic dye. Copyright © 2009 Society of Chemical Industry     

Identification of Moringa oleifera protein responsible for the decolorization and pesticide removal from drinking water and industrial effluent – an in silico and in situ evaluation

Natural products are always in demand, especially in the food and water treatment industry, to reduce health hazards caused by the prolonged use of chemicals. Though crude seed extract of Moringa oleifera (MOCE) is used for decolouration, the protein responsible for such activity is not fully known. In this study, in silico analysis of Moringa oleifera coagulant protein (MOCP; a predominant oligomeric protein in MOCE) was undertaken to check its molecular interactions with water and soil pollutants, in order to identify the protein accountable for such activities. The molecular docking studies of MOCP with azo dyes like congo red, tartrazine) and a pesticide (dichlorodiphenyltrichloroethane) revealed a strong binding affinity (?5.66, ?5.33 and ?5.04, respectively, kJ mol^?1) between the protein and the pollutants through hydrogen bonding and electrostatic interactions. Further, these results were verified in situ with MOCP, a recombinant form of MOCP (MOCRP) and MOCE against congo red (100 mg L^?1) and revealed the dye removal efficiency of 63.8%, 65.7%, and 72.3%, respectively. While the jar test results of synthetic coloured water and industrial textile effluent containing congo red showed 51.6% and 58.3%. Hence, we believe that the MOCP is responsible for multiple activities of MOCE and suggest its prospective use for large‐scale treatment of drinking water and industrial effluents. © 2014 Society of Chemical Industry     

Removal of turbidity from drinking water using natural coagulants

The ability of three plant materials, seeds such as Moringa oleifera, Strychnos potatorum and Phaseolus vulgaris, to act as natural coagulants was tested using synthetic turbid water formulated to resemble the drinking water. An improved and alternative method for the extraction of the active coagulant agent M. oleifera, S. potatorum, P. vulgaris seeds was developed and compared with the conventional water extraction method. In the new method the seeds were extracted using different solvents of NaCl and NaOH to extract the active coagulant agent from natural coagulants. In addition, ultrasound was investigated as a potential method to assist the extraction process. Batch coagulation experiments were conducted to evaluate the performance of the extracted coagulant achieved through various schemes. The optimum turbidity removal at different values of initial synthetic wastewater turbidity from 100 to 500 NTU was investigated. Sodium chloride at 0.5 M was found to provide a high turbidity removal of >99% compared to NaOH and distilled water extract. Among these three coagulant M. oleifera seed extracts is the highest performance in turbidity removal. The optimum coagulant dosage showed the coagulation with blended coagulant M. oleifera, S. potatorum and P. vulgaris. The study was carried out for initial turbidity of the sample such as 100 NTU (low), 250 NTU (medium) and 500 NTU (high). For the natural coagulant dosage was found to be 250–1000 mg/L respectively. It was found that the percentage of removal is highest in M. oleifera.     

Synthesis of hydrogels from fractionated proteins of Moringa oleifera Lam. seeds for the treatment of water contaminated with black reactive dye 5

As has been portrayed in the literature, the main proteins extracted from the seeds of Moringa oleifera Lam. have coagulant and clarifying potential in water treatment. However, when using them as coagulant agents, sludge formation occurs, which is an environmental problem. Thus, it was proposed to synthesize hydrogels from the main Moringa seeds proteins and use them as adsorbents. This work aimed to synthesize albumin hydrogels and globulin hydrogels and evaluate their efficiency as adsorbents to remove the reactive black 5 dye. Through FTIR spectrum it was possible to confirm that the synthesis of hydrogels occurred successfully. The kinetic data fit the pseudo-second order model for both hydrogels. The equilibrium isotherms showed that adsorption occurs in multilayers, due to Freundlich fitting. The maximum adsorption capacity occurred at 298 K and was 1.19 mg g⁻¹ for the albumin hydrogel and 10.06 mg g⁻¹ for the globulin hydrogel. Through the results it is possible to state that globulin hydrogel was more favourable for adsorption since it has a more porous morphology and requires less mass compared to albumin hydrogel.     

Biosorption of lac dye by the red marine alga Gracilaria tenuistipitata: biosorption kinetics,isotherms, and thermodynamic parameters

The hypothesis that the dried, ground biomass of the red marine alga Gracilaria tenuistipitata could be used for the efficient removal of lac dye from aqueous solution was assessed in this work. The effects of parameters such as initial pH, biosorbent dosage, contact time, initial dye concentration, and temperature on the biosorption capacity of the dye were investigated. Equilibrium data were analysed using Langmuir, Freundlich, and Temkin isotherm models, and the Freundlich model provided the highest coefficient of determination values. Biosorption kinetic data were successfully described with a pseudo‐second‐order model at initial dye concentrations of 50, 80, 100, and 120 mg l^?1. The thermodynamic parameters of biosorption – enthalpy change (?H° = ?30.64 kJ mol^?1), free energy change (?G° = 4.32 kJ mol^?1 at 303 K to 7.78 kJ mol^?1 at 333 K), and entropy change (?S° = ?115.38 J mol^?1 K^?1) – were determined. The negative value of the enthalpy change and positive values of the free energy change indicate that the biosorption process is exothermic and non‐spontaneous. The negative value of the entropy change is consistent with decreased randomness at the solid–liquid interface with dye biosorption. Attenuated total reflectance–Fourier transform infrared spectroscopic analysis confirmed the presence of lac dye on the G. tenuistipitata material. The efficiency of lac dye removal by this biomass material at 20 g l^?1 and with an initial dye concentration of 50 mg l^?1 in acidic solution was 71%, which indicated its potential usefulness as a new dye biosorbent.     

Palm oil mill effluent pretreatment using Moringa oleifera seeds as an environmentally friendly coagulant: laboratory and pilot plant studies

This research paper covers the suitability of the coagulation–flocculation process using Moringa oleifera seeds after oil extraction as a natural and environmentally friendly coagulant for palm oil mill effluent treatment. The performance of M. oleifera coagulant was studied along with the flocculant KP 9650 in removal of suspended solids, organic components and in increasing the floc size. The optimum values of the operating parameters obtained from the laboratory jar test were applied in a pilot‐scale treatment plant comprised of coagulation–flocculation and filtration processes. Pilot‐scale pretreatment resulted in 99.7% suspended solids removal, 71.5% COD reduction, 68.2% BOD reduction, 100% oil and grease removal and 91% TKN removal. In pilot plant pretreatment, the percentage recovery of water was 83.3%, and 99.7% sludge was recovered after dewatering in a filter press. Copyright © 2006 Society of Chemical Industry     

Application of magnetic iron oxide nanoparticles prepared from microemulsions for protein purification

BACKGROUND: Magnetic nanoparticles are of immense interest for their applications in biotechnology. This paper reports the synthesis of magnetic iron oxide nanoparticles from two different water‐in‐oil microemulsion systems (ME‐MIONs), their characterization and also their use in purification of coagulant protein. RESULTS: ME‐MIONs have demonstrated to be an efficient binder in the purification of Moringa oleifera protein when compared with the superparamagnetic iron oxide nanoparticles prepared from coprecipitation in aqueous media. The size and morphology of the ME‐MIONs were studied by transmission electron microscopy (TEM) while the structural characteristics were studied by X‐ray diffraction (XRD). The microemulsion magnetic iron oxide nanoparticles (ME 1‐MION and ME 2‐MION) obtained have a size range 7–10 nm. The protein and ME‐MIONs interaction was investigated by Fourier transform infrared spectroscopy (FT‐IR); the presence of three peaks at 2970, 2910 and 2870 cm^?1 respectively, confirms the binding of the protein. The purification and molecular weight of the coagulant protein was 6.5 kDa as analyzed by SDS‐PAGE. CONCLUSION: The ME‐MIONs have the advantage of being easily tailored in size, are highly efficient as well as magnetic, cost effective and versatile; they are, thus, very suitable for use in a novel purification technique for protein or biomolecules that possess similar characteristics to the Moringa oleifera coagulant protein. Copyright © 2011 Society of Chemical Industry     

Biosorption of Cu(II) onto agricultural materials from tropical regions

BACKGROUND: In Ghana, the discharge of untreated gold mine wastewater contaminates the aquatic systems with heavy metals such as copper (Cu), threatening ecosystem and human health. The undesirable effects of these pollutants can be avoided by treatment of the mining wastewater prior to discharge. In this work, the sorption properties of agricultural materials, namely coconut shell, coconut husk, sawdust and Moringa oleifera seeds for Cu(II) were investigated. RESULTS: The Freundlich isotherm model described the Cu(II) removal by coconut husk (R² = 0.999) and sawdust (R² = 0.993) very well and the Cu(II) removal by Moringa oleifera seeds (R² = 0.960) well. The model only reasonably described the Cu(II) removal by coconut shell (R² = 0.932). A maximum Cu(II) uptake of 53.9 mg g^?1 was achieved using the coconut shell. The sorption of Cu(II) onto coconut shell followed pseudo‐second‐order kinetics (R² = 0.997). FTIR spectroscopy indicated the presence of functional groups in the biosorbents, some of which were involved in the sorption process. SEM‐EDX analysis confirmed an exchange of Mg(II) and K(I) for Cu(II) on Moringa oleifera seeds and K(I) for Cu(II) on coconut shell. CONCLUSION: This study shows that coconut shell can be an important low‐cost biosorbent for Cu(II) removal. The results indicate that ion exchange, precipitation and electrostatic forces were involved in the Cu(II) removal by the biosorbents investigated. Copyright © 2011 Society of Chemical Industry     

Experimental Modeling and Simulation of Supercritical Fluid Extraction of Moringa oleifera Seed Oil by Carbon Dioxide

Moringa oleifera seed is an important source of high oleic acid in vegetable oil. In the present work, supercritical extraction of Moringa seed oil has been carried out to study the influence of operating temperature, pressure, particle size, carbon dioxide flow rate, and co-solvent addition by performing experiments in the range of 333–373?K, 20–40?MPa, 0.50–1.00?mm, 0.83?×?10^?4–2.50?×?10^?4?kg/s, and 0–10% ethanol. The extraction data have been successfully modeled by extended Lack’s model and fitting parameters are optimized by the Box global optimization technique. The results showed that pressure has a significant effect followed by temperature, co-solvent, solvent flow rate, and particle size.     

Biocorrosion inhibition of mild steel in crude oil-water environment using extracts of Musa paradisiaca peels,Moringa oleifera leaves,and Carica papaya peels as biocidal-green inhibitors: kinetics and adsorption studies

Biocorrosion inhibition of mild steel in the crude oil-water environment was investigated in the absence and presence of Carica papaya peel extract, Musa paradisiaca peel extract, and Moringa oleifera leaf extract as potential biocidal-green inhibitors using gravimetric, polarization, and surface analysis (Inverted metallurgical microscope and Fourier transform infra-red spectroscopy) methods. Kinetics and adsorption behaviors of the extracts were determined and evaluated. Results revealed that each of the extracts functioned as biocidal-green inhibitors in the crude oil-water environment and that biocorrosion inhibition efficiency (IE%) of each extract increased with increase in extract concentration and exposure time. Maximum IE% of 97.7, 96.5, and 99.2% was achieved with Musa paradisiaca peel extract, Moringa oleifera leaf extract, and Carica papaya peel extract, respectively, at 4000?mg/l extract concentration and 35 d exposure time. Polarization studies indicated that each of the extracts acts as a mixed-type inhibitor. Mild steel susceptibility to biocorrosion was significantly reduced by each of the extracts through biofilm development suppression and extract adsorption onto the mild steel surface which obeyed Langmuir, Freundlich, Temkin, and Flory-Huggins isotherm models. Kinetics of mild steel biocorrosion inhibition followed a Monod form of kinetics (Type A). Gibbs free energy of adsorption values for Musa paradisiaca peel extract (?9.65?kJ/mol), Moringa oleifera leaf extract (?9.57?kJ/mol), and Carica papaya peel extract (?9.71?kJ/mol) showed that each extract adsorption was spontaneous and of physical adsorption.     

Decolorisation of aqueous reactive dye Remazol Red 3B by electrocoagulation

The present study demonstrated the applicability of the electrocoagulation method for the removal of reactive dye, Remazol Red 3B, in a batch study. Iron electrode material was used as a sacrificial electrode in monopolar parallel mode in this study. The effects of the initial pH, current density, conductivity, initial concentration of dye and electrolysis time on the removal of Remazol Red 3B were investigated to determine optimum operating conditions. High decolorisation efficiency (>99%) for Remazol Red 3B dye solution was obtained with optimal value of process parameters, such as 15 mA cm^?2 of current density, 10 min of electrolysis time, pH 6 and 500 mg l^?1 dye concentration. The energy consumption, electrode consumption and operating costs under optimum operating conditions were calculated as 3.3 kW h kg dye^?1, 1.2 kg Fe kg dye^?1 and 0.6 € m^?3, respectively.     

THE EFFECT OF ENVIRONMENTALLY BENIGN FRUIT EXTRACT OF SHAHJAN (MORINGA OLEIFERA) ON THE CORROSION OF MILD STEEL IN HYDROCHLORIC ACID SOLUTION

The inhibition of the corrosion of mild steel in hydrochloric acid solution by the fruit extract of shahjan (Moringa oleifera) was studied using weight loss, electrochemical impedance spectroscopy (EIS), linear polarization, and potentiodynamic polarization techniques (Tafel). Inhibition was found to increase with increasing concentration of the extract. The effect of temperature, immersion time, and acid concentration on the corrosion behavior of mild steel in hydrochloric acid solutions with addition of extract was also studied. The inhibition occurred via adsorption of the inhibitor molecules on the mild steel surface obeying the Langmuir adsorption isotherm. Thermodynamic activation parameters such as activation energy, enthalpy (ΔH*), and entropy (ΔS*) of activation for corrosion process were calculated and discussed. The results obtained show that both chemical and physical adsorption of inhibitor molecules occur simultaneously and the fruit extract of shahjan (Moringa oleifera) could serve as an effective inhibitor of the corrosion of mild steel in hydrochloric acid media.     

Ozone treatment of textile effluents and dyes: effect of applied ozone dose,pH and dye concentration

The ozonation of wastewater supplied from a treatment plant (Samples A and B) and dye‐bath effluent (Sample C) from a dyeing and finishing mill and acid dye solutions in a semi‐batch reactor has been examined to explore the impact of ozone dose, pH, and initial dye concentration. Results revealed that the apparent rate constants were raised with increases in applied ozone dose and pH, and decreases in initial dye concentration. While the color removal efficiencies of both wastewater Samples A and C for 15 min ozonation at high ozone dosage were 95 and 97%, respectively, these were 81 and 87%, respectively at low ozone dosage. The chemical oxygen demand (COD) and dissolved organic carbon (DOC) removal efficiencies at several ozone dose applications for a 15 min ozonation time were in the ranges of 15–46% and 10–20%, respectively for Sample A and 15–33% and 9–19% respectively for Sample C. Ozone consumption per unit color, COD and DOC removal at any time was found to be almost the same while the applied ozone dose was different. Ozonation could improve the BOD₅ (biological oxygen demand) COD ratio of Sample A by 1.6 times with 300 mg dm^?3 ozone consumption. Ozonation of acid dyes was a pseudo‐first order reaction with respect to dye. Increases in dye concentration increased specific ozone consumption. Specific ozone consumption for Acid Red 183 (AR‐183) dye solution with a concentration of 50 mg dm^?3 rose from 0.32 to 0.72 mg‐O₃ per mg dye decomposed as the dye concentration was increased to 500 mg dm^?3. © 2002 Society of Chemical Industry     

Electro-Fenton treatment of synthetic organic dyes: Influence of operational parameters and kinetic study

This work investigates oxidative decolorization of two different dyes, Methylene blue and Titan yellow in aqueous solution using an environmentally friendly advanced electro-chemical oxidation (electro-Fenton) process. The effect of operating conditions like H₂O₂ concentration, current density, initial dye concentration was studied in a batch stirred cell. Individual decolorization decay kinetics for both dyes was investigated. The second-order absolute rate constants (L mol^?1 s^?1) between hydroxyl radical and dye have been calculated from experimental data by fitting it to the decolorization model. The apparent kinetic constants, k _app (s^?1) for Methylene blue and Titan yellow dye decolorization were also determined. The experimental data showed a good fit to the theoretical model, which can predict data in a wide range of % dye decolorization. This process also reduces COD of the dye solution, and the unit energy demand (UED) in kWh/kg COD removed for different electrical current has been reported.     

Adsorption of phenazine dyes using poly(hydroxamic acid) hydrogels from aqueous solutions

Swelling and adsorption properties of poly(hydroxamic acid), (PHA) hydrogels in aqueous solutions of some phenazine dyes such as Neutral Red, Safranin T, and Janus Green have been investigated. PHA hydrogels containing N,N′ methylenebisacrylamide or ethyleneglycoldimethacrylate were used in experiments on swelling, diffusion and adsorption of the dyes. The equilibrium swelling (S_eq) values of PHA hydrogels in aqueous solutions of the phenazine dyes were calculated as 2.16–33.25 g g^?1. Swelling kinetic parameters such as initial swelling rate, swelling rate constant, and maximum swelling were found. Dye diffusion into hydrogels was found to be non‐Fickian in character. Diffusion coefficients are ranged 1.32 × 10^?6 cm² s^?1 ? 44.70 × 10^?6 cm² s^?1. Adsorption of the phenazine dyes onto PHA hydrogels was studied by batch technique. PHA hydrogels in the phenazine dye solutions showed the dark coloration. The data was found that Freundlich isotherm model fits. According the Freundlich constants, the adsorption isotherms are of S‐type in Giles classification. All swelling and binding parameters for PHA‐EGDMA were found to be higher than those for PHA‐NNMBA. The type of crosslinker influenced the swelling, binding, and sorption more than the type of dye. Finally, it can be said that PHA hydrogels may be used a sorbent for removal of dyes. POLYM. ENG. SCI., 58:310–318, 2018. © 2017 Society of Plastics Engineers     

Application of polypyrrole coated onto wood sawdust for the removal of carmoisine dye from aqueous solutions

In this research, the removal of carmoisine dye from aqueous solutions using polypyrrole coated onto sawdust (PPy/SD) has been investigated. The sorption experiments were performed using both batch and column systems. The effects of some important parameters such as pH, initial concentration, sorbent dosage, exposure time, and temperature on uptake of carmoisine dye were investigated. Based on the data obtained in batch system, it was found that maximum adsorption is occurred under acidic conditions. Complete removal was observed when a dye solution with the initial concentration of 100 mg L^?1 was treated by 1.0 g of the used adsorbent (PPy/SD) at pH value of 4 and room temperature. However, higher sorption was observed at elevated temperature. According to the kinetics study, it was found that the experimental data fitted very well the pseudo‐second‐order kinetic model (k₂ = 0.184 g mg^?1 min^?1). It was found that polypyrrole chemically coated on SD is an efficient system for the removal of carmoisine dye from aqueous solutions. Desorption of the dye‐loaded column was also possible by using dilute NaOH solution with high efficiency (～ 80%). © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Synthesis of acrylamide/acrylic acid‐based aluminum flocculant for dye reduction and textile wastewater treatment

Aluminum hydroxide‐poly[acrylamide‐co‐(acrylic acid)], AHAMAA, was synthesized with a redox initiator by solution polymerization in which the effects of reactant contents were optimized. The effects of pH, temperature, and initial dye concentration on Congo red reduction were investigated. A mixture of Congo red and direct blue 71, and the composite textile dye wastewater were investigated. Adsorptions of both dyes were more effective in the nonbuffered solution than those in the buffered solution, and Congo red adsorbed more than direct blue 71 at all pHs. The adsorption of Congo red increased with increasing temperature and its initial concentration. Both dyes obeyed the Freundlich adsorption isotherm. The maximum adsorptions in 100 mg dm^?3 solution were 109 ± 0.5 mg g^?1 and 62 ± 6.6 mg g^?1 for Congo red and direct blue 71, respectively. At 150 mg dm^?3 of the mixed Congo red and direct blue 71, the adsorption was 142 ± 2 mg g^?1 by 643 ± 3 mg dm^?3 AHAMAA. The 40 mg g^?1 dyes of the textile effluent wastewater were adsorbed by 500 mg dm^?3 AHAMAA. AHAMAA could decrease turbidity of the composite wastewater containing a mixture of reactive and direct dyes from 405 to 23 NTU. POLYM. ENG. SCI., 50:1535–1546, 2010. © 2010 Society of Plastics Engineers     

Uptake of anionic and cationic dyes by highly effective porous carbon adsorber based on industrial processing residues

In this work, we investigated the performance of porous carbon prepared from carob (Ceratonia siliqua L.) processing residues at optimized conditions for the removal of the Basic Green 4 (BG4) and Direct Red 28 (DR28) dyes from aqueous solutions. The influence of several parameters such as adsorbent dose, initial dye concentration, contact time and temperature was evaluated in batch adsorption experiments. Maximum adsorption capacities were observed as 769 mg g^?1 and 323 mg g^?1 for BG4 and DR28, respectively. These results suggest that BG4 and DR28 could be removed using a novel porous carbon from carob processing residues.     

Reductive decolourization and total organic carbon reduction of the diazo dye CI Acid Black 24 by zero‐valent iron powder

In this study, wastewater contaminated by colour and total organic carbon from the diazo dye CI Acid Black 24 was successfully removed by reductive decolourization with zero‐valent iron powder. The effects on decolourization of experimental variables such as iron dosage, initial dye concentration, pH and dissolved oxygen level were evaluated. The best removal efficiencies for decolourization of 99.7% and total organic carbon of 57.4% were obtained with an initial dye concentration of 25.0 mg L^?1 and iron dosage of 200.0 g L^?1. Moreover, the decolourization rates followed pseudo‐first‐order kinetic equations with respect to dye concentration. The colour removal efficiency was simultaneously dependent on iron dosage and various initial dye concentrations, although the colour and total organic carbon removal efficiencies linearly increased with increased iron dosage, reaching a maximum at 100.0 g L^?1. A contour plot was developed to illustrate the 3D relation of removal efficiencies with initial dye concentration and iron dosage. For wastewater with a concentration range from 25 to 100 mg L^?1 CI Acid Black 24 the suggested ideal operation conditions are 100.0 g L^?1 iron dosage, pH 2‐4, normal oxygen concentration of 5‐7 mg L^?1 and reaction time of 30‐60 min. Copyright © 2006 Society of Chemical Industry     

Optimum Coagulant from Acacia mearnsii de Wild for Wastewater Treatment

A novel coagulant agent from Acacia mearnsii de Wild tannin extract was characterized for removal of the anthraquinonic colorant Alizarin Violet 3R and the anionic surfactant sodium dodecylbenzene sulfonate. This coagulant is the result of a previous optimization study. The influence of operative variables such as temperature, coagulant dosage, initial pollutant content, and pH was investigated. The new coagulant demonstrates a high affinity for dye and surfactant and is efficient within a wide range of working conditions. While the temperature does not affect the coagulant ability, an acidic pH seems to increase the contaminant removal from aqueous solutions. Implementation in a pilot plant confirms the feasibility of this coagulant not only at lab scale, but also at higher level.