Ferrous Sulfate Solution Research Articles

Mathematical modeling of ferrous sulfate oxidation in presence of air

In the present paper we studied the oxidation of ferrous sulfate salt with oxygen. ferric ammonium sulfate and ferrous sulfate were used to prepare standard solutions of Fe(III) and Fe(II) solutions. Oxidation experiments were carried out by mixing FeSO4·7 H2O in H2O. Air was supplied using a gas washing bottle in which air entered the bottle through the center tube, and exited into the bottom of the bottle. Samples were taken periodically and analyzed in the UV-Vis spectrophotometer. We consider that basic Fe(III) sulfate was one of the main compounds produced during the reaction and proposed a model to describe the process. We found solution to the differential equations that described the profile of FeSO4 and FwOHSO4 concentration in time and observed agreement between the experimental results and data predicted by the model. Moreover, we determined values of rate constants using the model and confirmed the determined values by means of experiments. This suggests that basic ferric sulfate was generated after aeration of ferrous sulfate solution.

Kinetics of zinc sulfide concentrate direct leaching in pilot plant scale and development of semi-empirical model

Abstract The direct leaching kinetics of an iron-poor zinc sulfide concentrate in the tubular reactor was examined. All tests were carried out in the pilot plant. To allow the execution of hydrostatic pressure condition, the slurry with ferrous sulfate and sulfuric acid solution was filled into a vertical tube (9 m in height) and air was blown from the bottom of the reactor. The effects of initial acid concentration, temperature, particle size, initial zinc sulfate concentration, pulp density and the concentration of Fe on the leaching kinetics were investigated. Results of the kinetic analysis indicate that direct leaching of zinc sulfide concentrate follows shrinking core model (SCM). This process was controlled by a chemical reaction with the apparent activation energy of 49.7 kJ/mol. Furthermore, a semi-empirical equation is obtained, showing that the order of the iron, sulfuric acid and zinc sulfate concentrations and particle radius are 0.982, 0.189, −0.097 and −0.992, respectively. Analysis of the unreacted and reacted sulfide particles by SEM–EDS shows that insensitive agitation in the reactor causes detachment of the sulfur layer from the particles surface in lower than 60% Zn conversion and lixiviant in the face with sphalerite particles.

Batch sorption\u2013desorption of As(III) from waste water by magnetic palm kernel shell activated carbon using optimized Box\u2013Behnken design

In this study, we converted activated carbon (AC) into magnetic activated carbon (MAC), which was established to have removed arsenic (III) from wastewater. Arsenic (III) is a toxic heavy metal which is readily soluble in water and can be detrimental to human health. The MAC was prepared by incorporating Fe3O4 into the AC by using Fe3O4 extracted from a ferrous sulfate solution, designated: magnetic palm kernel shell from iron suspension (MPKSF). Batch experiments were conducted using two methods: (1) one-factor-at-a-time and (2) Box–Behnken statistical analysis. Results showed that the optimum conditions resulted in 95% of As(III) removal in the wastewater sample. The adsorption data were best fitted to the Langmuir isotherm. The adsorption of As(III) onto the MPKSF was confirmed by energy dispersive X-ray spectrometry analysis which detected the presence of As(III) of 0.52% on the surface of the MPKSF. The Fourier transform infrared spectroscopy analysis of the MPKSF–As presented a peak at 573 cm−1, which was assigned to M–O (metal–oxygen) bending, indicating the coordination of As(III) with oxygen through the formation of inner-sphere complexation, thereby indicating a covalent bonding between the MPKSF functional groups and As(III). The findings suggested that the MPKSF exhibited a strong capacity to efficiently remove As(III) from wastewater, while the desorption studies showed that the As(III) was rigidly bound to the MPKSF thereby eliminating the possibility of secondary pollution.

The role of catalyst in the passivation of chalcopyrite during leaching

In this work, we present as investigation of chalcopyrite leaching under different leach conditions for how liquidation and surface of chalcopyrite study using Scanning Electron Microscopy (SEM) to determine the composition of the passivation layer in the surface of chalcopyrite. The study of chalcopyrite dissolution were in H2SO4 solution systems at pH of 1.2, with 5% chalcopyrite concentrate in redox potential of 460 mV at 90°C. The tests were directed to study on the leaching of chalcopyrite in ferric sulfate solution to extract copper with adding pyrite, silver and silver coated pyrite. In these approaches, achieved recoveries were different. The results showed that, in the present of pyrite, the presence of the elemental sulfur layer formed around the chalcopyrite particles which hindered the complete dissolution of copper in chalcopyrite. Also, in the presence of silver, no commercial process has been developed which successfully as a catalyst to recover copper from chalcopyrite. Because, the precipitation of argentojarosite, which forms during the leaching process, limits the availability of silver ion in solution which may act as a catalyst. But syndicate of silver and pyrite to form of silver coated pyrite, causes dissolution increase. However, in the presence of the pyrite coated by silver, leaching was very rapid for the duration of the test, and complete copper extraction was achieved within 10 hours.

A novel procedure for processing of the xenotime mineral concentrate of southwestern Sinai

A novel procedure for processing the xenotime mineral concentrate of southwestern Sinai (55.4% RE2O3 and 0.9% U3O8) has been studied. This procedure is based on leaching of uranium and rare earths from the xenotime concentrate using ferric sulfate solution by hydrolytic leaching with ferric ion, wherein ferric iron is precipitated to generate acid for the leaching step. The obtained slurry is washed by water and sulfuric acid. The relevant conditions of the ferric ion leaching of the concentrate and the washing step have been optimized. From the obtained sulfate liquor, rare earths are directly precipitated as oxalates. Uranium is extracted from the REE-free sulfate solution using ion exchange resin Amberlite IRA-400. Highly pure oxide products of the two interesting metal values, REEs and U, have properly been prepared.

The behaviour of the rare earth elements during the precipitation of ferrihydrite from sulphate media

The deportment of all the rare earth elements (REE) during the precipitation of ferrihydrite was investigated by pumping ferric sulphate solutions into a REE-containing solution at 75°C. At a pH of 3.5, controlled by NaOH additions, increasing concentrations of the light rare earths in the 0 to 4–5g/L range resulted in 2 to 3% REE adsorption on ferrihydrite. Light rare earth concentrations >4 or 5g/L generated Na-REE double sulphate salts and gave up to 15% REE contents in the precipitates. Heavy REE concentrations as high as 10g/L resulted in a near-linear increase in the adsorbed REE contents, up to 5–8% REE, and Na-REE double sulphate salts were not detected at the concentrations studied. Up to 70% REE precipitation occurs from <1g/L REE solutions but the extent of precipitation decreases sharply to ~15% in more concentrated REE media. Formation of Na-REE double sulphate salts significantly increased the overall precipitation of the light rare earths. Increasing solution pH greatly increased the extent of REE adsorption on ferrihydrite, and controlled ferrihydrite precipitation at pH <3.5 offers a potential means of reducing REE losses during iron precipitation. X-ray diffraction analysis and mineralogical examination of the products consistently identified dominant ferrihydrite, although the “crystallinity” of the ferrihydrite decreased as the REE concentration increased. The conclusion is that the rare earth elements adsorb on the surface of the fine grain ferrihydrite precipitates and the adsorption somehow impedes the “crystallization” of the ferrihydrite.

Ferric Sulphate Coagulant Obtained by Leaching from Coal Tailings

A ferric sulphate solution was produced from pyritic coal tailings for potential use as a coagulant for water and wastewater treatment. Laboratory-scale leaching experiments were carried out with four tailings with different concentrations of pyrite. The tailings were characterized for: total sulphur, pyritic sulphur, sulphate sulphur, organic sulphur, and elemental analysis of carbon, hydrogen, and nitrogen. X-ray diffraction analyses were also conducted to assess the mineral composition of the samples. The leaching was carried out using a laboratory column constructed as a packed bed reactor with a closed-circuit sprinkling system. After 4 weeks of leaching, the liquor was filtered and evaporated to reach an iron concentration of about 12% w/w, which is typical of most commercial FS coagulants in Brazil.

GREEN SYNTHESIS OF SUPERPARAMAGNETIC IRON OXIDE NANOPARTICLE FROM FICUS CARICA FRUIT EXTRACT, CHARACTERIZATION STUDIES AND ITS APPLICATION ON DYE DEGRADATION STUDIES

ABSTRACTObjective: The synthesis of nanoparticles (NPs) has become a matter of great interest in recent times due to their various advantageous propertiesand applications in a variety of fields. Metal NPs are being increasingly used in many sectors, and there is growing interest in the biological andenvironmental safety of their production.Methods: In this study, iron oxide NPs (Fe3O4-NPs) were synthesized from fruits of Ficus carica using a rapid, single step and completely greenbiosynthetic method by reduction of ferrous sulfate solution with F. carica ethanolic extract. The prepared Fe3O4-NPs were investigated by X-raydiffraction, Fourier transform infrared spectroscopy, and ultraviolet-visible spectroscopy.Results: The report emphasizes the effect of superparamagnetic Fe3O4-NPs on the degradation rate of hazardous dyes acid blue.Conclusion: To conclude, Fe3O4-NPs were prepared from fruits of F. carica using a rapid, single step and completely green biosynthetic method byreduction of ferrous sulfate solution with F. carica ethanolic extract.Keywords: Ficus carica, Ethanolic extract, Reduction, Ferrous sulfate, Superparamagnetic iron oxide nano particles, Dye degradation.

Fricke Gel Dosimeters

Fricke gel dosimeters are based on the aqueous ferrous sulfate solution that has been used as a reliable chemical dosimeter for more than 90 years. The amount of radiation-induced oxidation of ferrous ions to ferric ions could be evaluated three-dimensionally via optical computed tomography (OCT) or magnetic resonance imaging (MRI). Three-dimensional dosimetry is expected to be a useful tool, in particular, for the verification of complex radiation dose planning in advanced radiation cancer therapy. Compared with other 3D gel dosimeters, there are several problems such as retention of dose distribution or dose sensitivity; however, they can easily be prepared in a chemistry laboratory. In addition, a unique gel dosimeter was also reported for heavy-ion beam irradiation. In this review, recent papers concerning the Fricke gel dosimeter and its application in 3D dosimetry are summarized.

Oxidative weathering of a copper sulphide ore and its influence on pulp chemistry and flotation

The influence of grinding chemistry on the flotation behaviour of sulphides minerals has been widely studied. However, its influence on partially oxidised sulphide ores is not well documented. Various oxidation events can affect a sulphide ore, either during in situ weathering of an ore body or during the different extraction and processing stages (mining operations, stockpiling, crushing, milling and flotation). In this study, a hypogene copper sulphide ore was artificially oxidised to various lengths of time by percolating a small quantity of acidic ferric sulphate solution inoculated with a mixed bacterial culture through packed columns. For each time interval a series of grinding-flotation tests using different grinding media alloys was completed. The grinding and flotation chemistry were compared and linked to the flotation behaviour of the ore samples.The results reveal that as oxidation progressed the copper metallurgy deteriorated. However, the deleterious effects of oxidation could be partially overcome through the application of the right grinding chemistry.

Electrochemical Behaviors of Various Alloys in Ferric Sulfate Solution

The effects of alloying elements on the electrochemical behaviors in ferric sulfate solution at 25 oC were investigated using A508III low alloy steel, pure Fe, Cr, Ni, 316L SS, 430 SS and Alloy 690. The electrochemical behaviors of A508III steel and iron are similar, showing no active-passivation transition on the anodic polarization curves and no mass-transport-controlled region on the cathodic polarization curves. Active-passivation transition appears on the anodic polarization curves of 316L and 430 steel. Mass-transport-controlled region appears on the cathodic polarization curves of the alloys with certain contents of Cr and Ni. Certain contents of Cr and Ni in alloys increases the open circuit potential, decreases the current density, and increases the electrochemical impedance spectroscopy value. A higher Cr content results in a higher EIS value.

Low dose characterization of Fricke gel dosimeters by optical absorbance and MR relaxation methods

Introduction Fricke gel dosimeters allow measurements of 3D dose distributions and can be an effective tool for dosimetry verifications in radiotherapy. Various authors have reported drawbacks of the gels affecting the accuracy in case of low dose measurements. Purpose This study aims at investigating such drawbacks and at establishing the conditions for an optimal use of the gels. Materials and methods Our dosimeters consist of gels infused with a Fricke ferrous sulphate solution combined with xylenol orange (XO). Two kinds of xylenol orange (XO) and two different gelling agents (gelatin from porcine skin and Agarose) were utilized. Gels are red out by light absorption techniques: images of absorbance in two wavelength regions (around 430 nm and 585 nm) are acquired with a CCD camera. Absorbance spectrum measurements were done with a compact spectrometry based on optical fibres. Magnetic resonance (MR) measurements of Longitudinal Relaxation Time (T1) were also performed. Results Different trends characterized the absorbance spectra of dosimeters obtained with different gelling agents or different XOs. Moreover, the trends were different for different absorbed doses and varied over a few hours after irradiation. Conclusion The variation of the absorbance spectra is consistent with various previously unexplained effects reported in literature and may explain them. The results are a valid aid for a better use of these dosimeters and warrant further studies of the changes in the Fricke gel matrices after irradiation. Disclosure Authors declare no relationship that may bias the presentation.

Kinetic study of the dissolution of metallic nickel in sulphuric acid solutions in the presence of different oxidants

AbstractThe dissolution of metallic nickel particles in sulphuric acid solutions has been studied in this work. The effect of temperature, sulphuric acid concentration, and oxidant type has been assessed. In the presence of hydrogen peroxide or dissolved oxygen the dissolution of nickel was fast.A shrinking particle model was used to fit the experimental data and estimate kinetic parameters. The apparent reaction rate constants calculated at 55 °C when dissolved oxygen, ferric sulphate, and hydrogen peroxide were used as oxidants were, respectively, 0.17, 0.02, and 7.13 ms−1. The dissolution of Ni in the presence of ferric sulphate occurred under surface chemical control, with an activation energy of 82.3 kJ/mol, while in the presence of hydrogen peroxide and dissolved oxygen the reaction seemed to have been mass transfer controlled. The dissolution of Ni in ferric sulphate solutions was also pH sensitive, possibly due to the formation of NiFe2O4 or NiO that was prevented when sulphuric acid concentration was 1 mol/L. The dissolution rate in ferric sulphate‐free solutions was affected negatively by temperature due to a decrease in O2 solubility.

Effect of purification pretreatment on the recovery of magnetite from waste ferrous sulfate

The present study was conducted to elucidate the influence of impurities in waste ferrous sulfate on its recovery of magnetite. Ferrous sulfate solution was purified by the addition of NaOH solution to precipitate impurities, and magnetite was recovered from ferrous sulfate solution without and with purification pretreatment. Calcium hydroxide was added to the solution of ferrous sulfate as a precipitator. A mixed product of magnetite and gypsum was subsequently obtained by air oxidation and heating. Wet-milling was performed prior to magnetic separation to recover magnetite from the mixed products. The results show that with the purification pretreatment, the grade of iron in magnetite concentrate increased from 62.05% to 65.58% and the recovery rate of iron decreased from 85.35% to 80.35%. The purification pretreatment reduced the conglutination between magnetite and gypsum, which favors their subsequent magnetic separation. In summary, a higher-grade magnetite with a better crystallinity and a larger particle size of 2.35 μm was obtained with the purification pretreatment.

Iron‐encapsulated cold‐set whey protein isolate gel powder ‐ Part 2: Effect of iron fortification on sensory and storage qualities of Yoghurt

Iron was incorporated at 20–60 mg/kg of yoghurt using iron‐encapsulated cold‐set whey protein isolate gel powder (WPI‐Fe) and by direct addition of ferrous sulphate solution. The changes in physicochemical and sensory qualities of the yoghurt samples were determined over 14 days of storage. Quality attributes of the yoghurt fortified using WPI‐Fe particles at up to 60 mg iron/kg were similar to those of unfortified control samples, especially in terms of colour and flavour, while the samples fortified by direct addition of ferrous sulphate exhibited noticeable adverse effects even at 20 mg iron/kg.

Milk protein composition and stability changes affected by iron in water sources

Water makes up more than 80% of the total weight of milk. However, the influence of water chemistry on the milk proteome has not been extensively studied. The objective was to evaluate interaction of water-sourced iron (low, medium, and high levels) on milk proteome and implications on milk oxidative state and mineral content. Protein composition, oxidative stability, and mineral composition of milk were investigated under conditions of iron ingestion through bovine drinking water (infused) as well as direct iron addition to commercial milk in 2 studies. Four ruminally cannulated cows each received aqueous infusions (based on water consumption of 100L) of 0, 2, 5, and 12.5mg/L Fe2+ as ferrous lactate, resulting in doses of 0, 200, 500 or 1,250mg of Fe/d, in a 4×4Latin square design for a 14-d period. For comparison, ferrous sulfate solution was directly added into commercial retail milk at the same concentrations: control (0mg of Fe/L), low (2mg of Fe/L), medium (5mg of Fe/L), and high (12.5mg of Fe/L). Two-dimensional electrophoresis coupled with matrix-assisted laser desorption/ionization–tandem time-of-flight (MALDI-TOF/TOF) high-resolution tandem mass spectrometry analysis was applied to characterize milk protein composition. Oxidative stability of milk was evaluated by the thiobarbituric acid reactive substances (TBARS) assay for malondialdehyde, and mineral content was measured by inductively coupled plasma mass spectrometry. For milk from both abomasal infusion of ferrous lactate and direct addition of ferrous sulfate, an iron concentration as low as 2mg of Fe/L was able to cause oxidative stress in dairy cattle and infused milk, respectively. Abomasal infusion affected both caseins and whey proteins in the milk, whereas direct addition mainly influenced caseins. Although abomasal iron infusion did not significantly affect oxidation state and mineral balance (except iron), it induced oxidized off-flavor and partial degradation of whey proteins. Direct iron addition to milk led to lipid oxidation during storage at 4°C. Oxidation level was positively associated with the concentration of added iron. Minerals (Mg, P, Na, K, Ca, Zn) in milk were not affected by the added iron in milk. This study indicated that a small amount of iron contamination in bovine drinking water at the farm or incidental iron addition from potable water sources causes oxidation, affects milk protein composition and stability, and affects final milk quality.

Electrochemical Behaviors of Various Alloys in Ferric Sulfate Solution

A508III low alloy steels (LAS) are often used as reactor pressure vessel materials in nuclear power plants. LAS could be exposed to primary water of nuclear power plants when stainless steel or Ni-based alloy corrosion resistant layers failed or as a result of small leaks in flanged joints valves, fittings, etc. Primary water contains boric acid and lithium hydroxide. Under leaking conditions, the primary water could be concentrated due to evaporation and become aerated as the results of contacting with the environment, producing varying degrees of external corrosion. There could be corrosion product such as rust or ferric ions at the leaking sites. Previous work has conformed that the corrosion rates of A508III steel increased dramatically when ferric sulfate was added in boric acid solution. While in the ferric sulfate solution, adding boric acid had no significant effect on the electrochemical behavior and corrosion rates, suggesting that ferric ions promoted the subsequent corrosion process. A508III LAS contains about ~97 wt.% Fe, with Cr, Ni, Mn and other elements added to improve the corrosion resistance, mechanical properties and processing performance, etc. The present work investigated the electrochemical behavior of various alloys and their main alloying elements in 0.05 mol/L Fe2(SO4)3 solution at 25 oC. Pure iron, Cr, Ni, A508III LAS, 430 steel, 316L steel, and Alloy 690 were used as working electrodes. Open circuit potential (OCP), electrochemical impedance spectroscopy and anodic polarization curve were measured. OCP values of A508III steel and iron in 0.05 mol/L Fe2(SO4)3 solution were lower than -0.52 V(SCE). The OCP of A508III steel is a little higher than that of iron. OCP values of the other materials were stable at relatively higher values that range from 0.37 V(SCE) to 0.56 V(SCE), and the ascending order was that 316L steel, 430 steel, Cr, Alloy 690, and Ni. The anodic polarization curves for various materials in 0.05 mol/L Fe2(SO4)3 solution are shown in Figure 1. Anodic polarization curves for A508III and iron were nearly the same, and neither current peak nor dissolution/passivation transition could be observed. Active-passivation transition appeared and single current peak were observed on the curves for 316L and 430 steel. The anodic polarization curves for Cr, 690 alloy and Ni showed different trends at different potential ranges. The EIS Nyquist plots of various materials in 0.05 mol/L Fe2(SO4)3 solution are shown in Figure 2. The Nyquist plots of A508III steel and iron exhibited two capacitive loops at higher and intermediate frequencies, and one inductive loop at low frequencies. The second capacitive loop was smaller than the first which suggest that the protectiveness of surface film is not good. The second capacitive loop of iron was a little larger than that of A508III steel and this suggest that protectiveness of iron was slightly better. The Nyquist plots of Cr, 316L steel, 430 steel and Alloy 690 exhibited two capacitive loops. The second capacitive loop was far greater than the first one, suggesting that the high protectiveness of the surface films. The size of second capacitive loop decreased in the order as 316L steel, Alloy 690, 430 steel, and Cr. This suggests that when immersed in 0.05 mol/L Fe2(SO4)3 solution, the surface film protectiveness of Cr was good. The Nyquist plots of Ni exhibited two capacitive loops at high and intermediate frequencies, and Warburg characteristics at low frequencies. The first capacitive loops were nearly the same for all materials in this context. The second capacitive loop of Ni was significantly greater than those of A508III steel and iron, but far smaller than those of 316L steel, Alloy 690, 430 steel and Cr. The amounts of Cr and Ni in A508III LAS were not enough to significantly affect the electrochemical behavior in the Fe2(SO4)3 solution. The electrochemical behaviors of A508III steel and iron were nearly the same. Protective films could form on the electrode surfaces at OCPs in 0.05 mol/L Fe2(SO4)3 solution if there was a certain Cr content in alloys. The reactivity of materials with certain Cr element was higher than that with certain nickel element under anodic polarization. Figure 1

Evaluation of Safety of Iron-Fortified Soybean Sprouts, a Potential Component of Functional Food, in Rat.

Ferritin-iron is currently considered as one of the most promising iron forms to prevent iron deficiency anaemia. We found that the cultivation of soybean seeds in a solution of ferrous sulfate results in material with extremely high iron content - 560.6 mg Fe/100 g of dry matter, while ferritin iron content was 420.5 mg/100 g dry matter. To assess the potential adverse effects of a preparation containing such a high concentration of iron, male and female Wistar rats were exposed via diet to 10, 30, 60 g soybean sprouts powder/kg feed for 90 days. There were no differences in final body weight and mean food consumption between controls and rats administered sprouts. No statistically significant differences in haematology and clinical chemistry parameters were found between controls and treated rats. Microscopic examination of 22 tissues did not reveal any pathology due to soybean sprouts intake. Long term administration of the test material did not cause oxidative damage to DNA and protein in the liver as evidenced by the unchanged basal levels of DNA damage as well as carbonyl groups content. Lipid peroxidation was slightly increased only in females. The activity of several antioxidant enzymes: superoxide dismutase, glutathione peroxidase and glutathione S-transferase was increased, which substantially enhanced the antioxidant status in the liver from the rats treated with soybean sprouts. Hence, the material tested can be recommended as a component of food supplements for individuals with iron deficiency anaemia and inflammatory bowel diseases.Electronic supplementary materialThe online version of this article (doi:10.1007/s11130-016-0535-8) contains supplementary material, which is available to authorized users.

Green synthesis of iron oxide nanoparticles from Mimosa pudica root extract

An aqueous root extract of Mimosa pudica was used to synthesise iron oxide nanoparticles. The formation of iron oxide nanoparticles was observed on exposure of the aqueous root extract with the ferrous sulphate solution. The iron oxide nanoparticles were characterised using UV-Visible spectroscopy, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), particle size analyser (PDA) and vibrating sample magnetometer (VSM). UV-Vis is a spectrum of iron oxide nanoparticles showed a sharp peak at 294 nm due to the surface plasmon resonance. FTIR spectroscopy confirmed the attachment of bioactive molecules of plant on the iron oxide nanoparticle surfaces. The phase and crystal structure were determined through XRD. The scanning electron microscopy (SEM) illustrated that the iron oxide nanoparticles were spherical in shape with 67 nm of surface volume mean diameter. Magnetisation measurements indicates that the synthesised iron oxide nanoparticles exhibited superparamagnetic behaviour at room temperature.

Investigations into the Correction of Iron Deficiency in Second Generation Oil Palm Replants in Mature Organic Soils in Indonesia

Scattered to localised pockets of iron (Fe) deficiency were observed in young second generation oil palm replants on deep and mature organic soils in North Sumatra, Indonesia. Opportunity was taken to establish four trials to evaluate the efficacy of various treatments in correcting the deficiency and their results are reported here. Of the various treatments evaluated, foliar spraying with 1 per cent ferrous sulphate (FeSO4) solution produced the fastest response but as translocation of Fe from older to younger fronds is minimal, multiple rounds at monthly intervals was required to sustain the re-greening effect. Foliar spraying at monthly intervals (12 rounds per year) or in three campaigns per annum (one campaign = 4 rounds x 2 weekly intervals) was superior to eight rounds of spraying conducted in two campaigns per year. Soil application with chelated iron fertiliser (Fe-EDTA) was equally effective but the correction was not permanent lasting only four to six months, necessitating re-application every six months. Optimum dosage varied with palm age. Root infusion of FeSO4 even at a dosage as low as 2 g per palm was phytotoxic to the young palms. Application of iron via incorporation into clay balls or as iron rods buried next to palm boles was generally less effective. A combination of foliar spraying followed by soil application of Fe-EDTA fertiliser is advocated for a quick re-greening response and longer term management of the deficiency. Keywords: Iron deficiency, oil palm, peat.