Pickle Liquor Research Articles

Using waste to treat waste: Utilizing pickling liquor for detoxification and extraction of valuable elements from electroplating sludge

Addressing the urgent need for sustainable solutions in waste management, this study focuses on the pivotal task of recycling heavy metals from electroplating sludge (ES), a critical issue both environmentally and economically. The research introduces a novel leaching process utilizing pickling liquor as a reagent to extract valuable metals from the sludge. Key parameters such as agitation speed, solid to liquid ratio (S/L), temperature, and duration were examined to optimize the leaching rate. Results revealed impressive extraction rates, with 92.33 % Cr, 89.49 % Cu, and 89.59 % Ni extracted within 120 min from S/L 10 g/L, at 300 rpm, and 25 °C. However, it was noted that increasing temperature negatively impacted the leaching rate and led to the formation of undesirable compounds. X-ray diffraction (XRD) analysis identified gypsum and potassium jarosite as predominant compounds formed on the leaching residues at different temperatures of 25 °C and 45 °C. Field emission scanning electron microscopy (FE-SEM) illustrated significant morphological changes in the residues, indicating the influence of temperature on compound formation. Additionally, environmental risk assessment of the residues was conducted using synthetic precipitation leaching procedure (SPLP) and toxicology characteristic leaching procedure (TCLP) methods. In conclusion, this research underscores the promising potential of the developed leaching process using pickling liquor to reclaim valuable metals from ES. By optimizing parameters and assessing environmental risks, this study contributes to advancing environmentally sound practices in industrial waste management.

Thiazolium-Bearing Chitosan Polymer Mitigates Microbiologically and Acid-Induced Corrosion on Stainless Steel Dental Crowns and Pipeline Steel in Saliva and Pickle Liquor

Thiazolium-Bearing Chitosan Polymer Mitigates Microbiologically and Acid-Induced Corrosion on Stainless Steel Dental Crowns and Pipeline Steel in Saliva and Pickle Liquor

Extraction of zinc from spent pickle liquor using primary amine extraction system

Spent pickle liquor is a hazardous liquid containing zinc and iron ions, and other environmentally harmful elements. Therefore, its discharge is prohibited because of ecological and environmental issues. A novel cleaning process for the recovery of Zn from spent pickle liquor using solvent extraction was proposed. The extraction system comprised a secondary carbon primary amine (N1923), isooctanol, and sulfonated kerosene. Spent pickle liquor after ultrasonic enhanced reduction pretreatment was studied experimentally, and effective parameters such as the extractant concentration, organic phase composition, and phase ratio (O/A) on the extraction were investigated. The extractant N1923 was found to selectively extract Zn(II) from the spent pickle liquor and retain Fe(II) in the raffinate. The concentration of Zn(II) ions in raffinate obtained using three-stage counter-current extraction was only 0.01 g/L. The raffinate could be further used to prepare an iron salt water purifier. A solution of H2SO4 was used to strip Zn from the loaded organic phase, yielding a Zn-rich solution containing 5.39 mol/L Zn, which could be used to prepare ZnO. The unloaded organic phase was recycled, and no emulsification or scale accumulation was observed during the process. The structure of the extracted complex was determined using the slope and loading capacity methods, and combined with FT-IR analysis. The main reaction that occurs during the extraction process is the anion-exchange reaction, with a stoichiometric ratio of N1923 to zinc ions of 1, resulting in an extracted complex of RNH3ZnCl3. Overall, the process provided an efficient, low-consumption, convenient, safe, and sustainable method for recovering Zn from spent pickle liquor and laying the foundation for industrial applications.

Utilization of electrolytic manganese residue and bauxite to synthesize zeolite a for pickle liquor adsorption: Characterization, mechanisms and performance

Electrolytic manganese residue (EMR) and its pickle liquor are extremely hazardous wastes that can cause significant environmental and biological hazards. In order to solve these problems, this paper used EMR and bauxite (BA) as the main raw materials to synthesize zeolite A (EMRZ), and carried out adsorption and purification of pickle liquor so as to realize the comprehensive utilization of EMR and BA. The study investigated the optimal parameters for the synthesis of zeolite and subsequently characterized the synthesized EMRZ. The characterization results revealed that the synthesized EMRZ exhibited notable attributes such as high purity, high crystallinity, and exceptional ion exchange capabilities. Subsequently, the synthesis mechanism of EMRZ was elucidated using XRD, FTIR, Raman spectroscopy, and MAS NMR techniques. The growth process of EMRZ involved three distinct stages, namely the growth induction period, rapid growth phase, and growth completion stage. More specifically, the transformation sequence was observed as follows: double four-membered rings (D4R) → β cages → α cages → zeolite A crystals. Besides, the migration and transformation of Si and Al in EMR were explored, and the mechanism was further expounded. In addition, the synthesis of EMRZ has been evaluated economically and compared with other zeolites synthesized by different methods. It was discovered that EMRZ has a higher economic value. Moreover, an investigation was conducted on the adsorption effect of EMRZ on impurity ions present in pickle liquor. It was discovered to be effective at removing impurity ions, suggesting that EMRZ is a feasible purification material for pickle liquor. Furthermore, the adsorption mechanism was ion exchange between impurity ions and Na ions, and EMRZ was successfully regenerated. The findings of the study validate the potential of EMRZ as a highly effective adsorbent for the treatment of pickle liquor, thereby offering a viable approach for the comprehensive utilization of EMR.

Insights into the adsorptive separation of iron from pickling waste acid: The overlooked role of FeCl3 species

Elucidating the dominant adsorption species of FeCln3−n is fundamental for precisely regulating the adsorption process and thus enhancing the management of waste pickling liquor. In this work, anion resin (D201) exhibits great adsorption for FeCl4−, also exhibits the unexpectedly high adsorption for neutral species FeCl3. The contribution of various iron species was quantitatively evaluated via Ion Species Contribution Evaluation (ISCE). The results illustrate that both FeCl3 and FeCl4− were the dominant species adsorbed by D201 resin and exhibited similar adsorption activities. Experimental and computational results indicate that the adsorption of FeCl4− is accompanied by the shedding of Cl on FeCl4− and FeCl3 recombines with the Cl on D201, which indicate that FeCl3 is an intermediate species in the FeCl4− adsorption process. Accordingly, FeCl3 was revealed to be critical species for iron adsorption in hydrochloric pickling liquor. The concentration of HCl (20 % w/w) required for FeCl3 was sufficient for the removal of iron compared with the higher concentration (25 % w/w) required for FeCl4−, which broadened the concentration boundary for HCl reuse. Our strategy serves for industrial iron removal from hydrochloric pickling liquor and results in 86 % reduction in the amount of hydrochloric acid during 100 days pilot-scale test.

Catalytic pyrolysis of lignite with clay catalyst activated with spent pickling liquor

AbstractSpent pickling liquor (SPL) is an acidic waste with rich iron content from the stainless steel production industry. Reusability of SPL as a catalytic activity promoter in bentonite clay is crucial for the catalytic pyrolysis of various materials like biomass, coal, and waste plastics. For this aim, the bentonite catalyst activated with the SPL nomenclatured as SPL‐treated bentonite (SPLAB) catalyst was employed in the catalytic pyrolysis of lignite for an oil product with high yield and quality. The SPL‐treated bentonite catalytic pyrolysis oil (SPLABO) for the conditions of the final temperature of 600°C, heating rate of 10°C/min, and catalyst ratio of 15 wt% had a yield of 26.35 ± 1.14 wt% and good fuel properties in view of the higher heating value of 35.23 MJ/kg and density of 1076.4 kg/m3 at 20°C. Moreover, it has a rich chemical content by means of monocyclic aromatics and shorter chain alkanes compared with that of the thermal activated bentonite oil (TABO). Based on the chemical structure analysis results of the SPLABO and TABO comparatively, it was concluded that the SPL agent used as a catalytic activity promoter led to a significant increase in the catalytic activity of bentonite catalyst.

Potentiodynamic Study of The Effects of Nickel on The Electrodeposition of Zinc from Chloride Media

Abstract. The potentiodynamic experiments of the nickel effects on the zinc electrodeposition have been done to understand the impact of Ni impurities on the electrowinning of Zn from spent pickling liquor. The nickel chloride solutions of Ni concentrations 90 and 1 g/dm3 were used as the electrolytes. The latter was also mixed with 90 g/dm3 Zn in the experiments. All the runs were carried out at room temperature with 40 mV/s continuous polarization speed and with 1/s sampling rate. It was observed that nickel electrodeposition from chloride media containing 90 g/dm3 Ni started with the generation of hydrogen bubbles, entirely blocking the cathode surface. Only a slight current development was observed until the polarization potential ~ -0,8 V. The visual observation showed bubbles also formed at the anode, which may represent chlorine and/or oxygen evolution. While, in the electrodeposition of nickel with only 1 g/dm3 Ni concentration in the electrolyte, metal deposition was hardly observed, but visible hydrogen bubbles constantly blocked the cathode surface. A similar tendency was observed in the mixed-solution electrolysis cell; the initial tiny bubbles accumulated at the cathode surface more than in the pure Zn solution. The enhancement of H2 evolution indicates how nickel deposition may contribute to the loss of useful current in the process of Zn electrodeposition. The mass of nickel deposited from the mixed solutions significantly decreases as the Ni concentration decreases in the electrolyte, while the mass of deposited zinc is relatively constant. It means that the purity of the produced Zn is appreciably higher – with respect to Ni – if nickel is efficiently eliminated from the solution before electrowinning.

(Digital Presentation) The Role of Iron in the Zinc Electrodeposition from Chloride Media for Recovering Zinc from Spent Pickling Liquors

Electrodeposition of Zn from chloride media had been studied by potentiodynamic method to understand the characteristics of Zn recovery from spent pickling liquor (SPL). Various concentration, pH, agitation speed and impurities contamination were examined in the series of experiments. The influence of Zn concentration in the range of 30-150 g/dm3 relevant to the real SPL were studied along with acidity level change (pH 1.5-5.5). It was found that the cathodic deposition started with the uniform patern followed by sponge-like deposit and as the concentration of the electrolyte near the cathode surface decreased, the dendritic deposition start to grow, especially at the edge of the cathodes.It was found that the effect of iron concentration on the polarization curves of zinc from SPL is complex. Initially it has a negative effect on the generated cathodic current because of the enhancement of hydrogen bubble formation. At a higher concentration range, however, iron deposits at a relatively higher rate. Further increased iron concentrations may make the composition of the Zn-Fe deposit dominantly in favor of iron, resulting in a hydrogen dominated cathodic mechanism. It is also characterised by the loss of the dendritic structure – attributed mostly of zinc deposition when hydrogen bubbles are not blocking the cathode. As the gas evolution becomes more characteristic, the deposit tends to become more powdery. Under such conditions the cathode becomes smoother and the active surface is reduced. Increasing the stirring speed, the powder was easily detached from the cathode surface. Iron, however can enhance the cathodic deposition process of zinc. With 30 – 60 g/dm3 iron in the 90 g/dm3 Zn solution, an increased iron concentration resulted in a significant increase in the mass of the deposited zinc. This may be interpreted by a beneficial effect of the increased hydrogen evolution enhancing the zinc ion transport to the electrode surface. However further increments of iron had a contrary effect, possibly by the locally increased – and generally detected – pH of the solution indirectly causing a superficial precipitation of hydroxides. Technically pure zinc could be deposited from only low-iron (< < 30 g/dm3) zinc solutions (of 90 g/dm3 Zn) at relatively vigorous stirring speeds. High iron concentration in the solution is definitely unsuitable for obtaining the aimed quality of cathode zinc.

Recovery of zinc and iron from hot-dip galvanizing spent pickle liquor using solvent extraction

The disposal of spent pickle liquor from the hot-dip galvanizing process is of serious environmental concern that demands development of safe and economical methods. The present work attempts to extract zinc and iron utilizing a mixture of trialkyl-phosphine oxide (Cyanex 923) as the extractant. Isooctanol and sulfonated kerosene was mixed with the extractant to improve the mass transfer as well as to suppress emulsification. The effect of the extractant concentration, organic phase composition, contact duration, temperature, phase ratio (O/A) were assessed to identify the optimal process conditions. A thorough analysis of the zinc extraction mechanism was carried out utilizing FT-IR, Raman spectroscopy, and ESI-MS analysis. The structures of extractant and extraction complex were simulated using density functional theory (DFT), the overall situation and the local activity index were calculated. The extraction mechanism is proposed based on theoretical simulation and characterization, supported by the experimental results. The extraction process was identified to be exothermic in nature with the extraction efficiency of zinc as high as 95.57% under the optimal conditions. The extraction efficiency of 99.99% for zinc and 1.90% for iron could be achieved in a three-stage countercurrent extraction process. The single stage stripping efficiency of zinc was 95.25% with 0.8 mol/L HNO3. The extraction efficiency of zinc was 92.50% after five extraction and stripping cycles.

Anion exchange separations to produce a suitable electrolyte for the electrodeposition of pure zinc

Anion exchange separations have been devised to purify model solutions of the usual pickling liquor (SPL) obtained from hot dip galvanization to produce a suitable ZnCl2 electrolyte for electrodepositing pure Zn. The method was based on the established anion-exchange distribution functions in chloride media. Both the simple batch and the more accurate chromatographic methods of separation were examined. The loaded solutions contained Zn, Fe, Mn, Ni and Pb of different concentrations with 1.8 - 2 M NaCl or HCl as the background. The resin bed primarily retained Zn while divalent Fe, Mn and Ni were removed in the loading and the continued rinsing steps with the mobile phase at the initial level of Cl- ion concentration. The elution of Zn was carried out by a significantly reduced Cl- ion concentration. The preliminary reduction of the iron to its divalent state was found of utmost importance. The only difficulty arises from the separation of Pb, which has an equilibrium distribution function comparable to the anion exchange of Zn, however in Europe this minor impurity should not be present at disturbing levels. Kinetic examination of the batch process revealed that Zn sorption is virtually complete within 20 minutes, however despite the low distribution coefficients, some 10 % of iron is also sorbed. Almost 90 % of the retained iron could be in the Fe(III) state caused by aerial oxidation. It was also found that the elution of Zn in the batch technique was not possible by just lowering the Cl- ion concentration. Therefore, the chromatographic method is the only possible way if only chloride media are to be applied.

Processing waste sulphate pickle liquor by acid retardation on a strong basic anion exchanger

Processing waste sulphate pickle liquor by acid retardation on a strong basic anion exchanger

Synthesis of nanosized nickel zinc ferrite using electric arc furnace dust and ferrous pickle liquor

Electric arc furnace dust (EAFD) and waste pickle liquor (WPL); two major side products of the steel industry with negative environmental impact were used for the synthesis of nickel zinc ferrite (NZF); the important magnetic ceramic material of versatile industrial applications. The structural and magnetic properties of the prepared material were examined which showed good magnetic properties (high saturation magnetization and low coercivity) compared with those synthesized from pure reagents. In the applied process, nano sized nickel zinc ferrite (NZF) with a composition of Nix(Zn + impurities)1−xFe2O4 (where x = 0, 0.25, 0.5, 0.75 and impurities of manganese, magnesium, and calcium were prepared using zinc-containing electric arc furnace dust (EAFD) and waste pickle liquor (WPL). The chemical compositions of the prepared samples were determined using X-ray fluorescence (XRF) analysis. The optimum acetic acid concentration for EAFD treatment was found 2% v/v that decreased Ca content of EAFD by 70.6% without loss of Fe and Zn. The structural and morphological characterization was done by X-ray diffraction (XRD), Fourier transform infrared (FTIR) and Field Emission Scanning Electron Microscope (FESEM) to confirm the formation of Ni–Zn ferrite nanoparticles and estimate the particle sizes. The maximum saturation magnetization (Ms) of 73.89 emu/g was achieved at 0.5 Ni content and the minimum coercivity of 2.55 Oe was obtained at 0.25 Ni content.

Obtention and Characterization of Ferrous Chloride FeCl2·4H2O from Water Pickling Liquors

As a hazardous waste, water pickling liquors must be properly treated. An alternative consists of promoting the formation of ferrous salts from this residue due to their higher ferrous content. Since FeCl2·4H2O is widely used in several applications, obtaining pure crystals of this material appears to be an interesting prospect. However, this compound has scarcely been investigated. In the present work, FeCl2·4H2O crystals were obtained from water pickling liquors. Their structural and morphological characteristics were investigated by X-ray diffraction, scanning electron microscopy as well as Mössbauer spectroscopy. In addition, the photoluminescence study of the obtained samples was also assessed. It was observed that after some aging time, the obtained crystals changed in colour from green to more yellowish. As such, the aged sample was also evaluated, and their structural characteristics were compared with the original crystals. Despite this, the obtained crystals exhibit a FeCl2·4H2O structure, which is not modified with the aging of the sample.

The Effect of Pyrolysis Conditions on the Preparation of Fe2O3 Particles Using Simulated Pickling Liquor in a Venturi Reactor

Large amounts of pickling liquor are produced during the pickling of iron and steel. The Venturi reactor is used during the pyrolysis of pickling liquor to prepare high-purity Fe2O3 particles. Changing the pyrolysis conditions will affect the purity and concentration of Fe2O3 particles. In this paper, physical experiments and numerical simulations were carried out to study the effect of pyrolysis conditions on the Fe2O3 particles, including the pyrolysis temperature, the FeCl2/FeCl3 ratio in the pickling liquor, and the citric acid ratio. The results showed that a product with a higher purity, better crystallinity, and greater concentration was obtained at 923 K. Further increasing the temperature did not change the concentration of Fe2O3 particles. When the ratio of FeCl2/FeCl3 in the pickling liquor was 1:1.5, the maximum concentration of Fe2O3 particles at the outlet was obtained. When the added proportion of citric acid was 1:1, the particle size distribution was more uniform, and when the added proportion was 1:2.5, the maximum concentration of Fe2O3 particles at the outlet was achieved.

Valorization of secondary resources into silica-based adsorbents: Preparation, characterization and application in dye removal from wastewater

Low-cost silica, magnetite, and magnetic silica were prepared using corn cob and spent pickle liquor. To enhance the adsorption characteristics, the extracted silica was heat-treated and the ratio of silica:magnetite was optimized. A detailed characterization of the prepared materials was conducted and the adsorption characteristics were also inclusively assessed.The characterization study disclosed that the prepared materials were nanosized, nonporous, and forms large aggregates with inter-particles voids. The prepared silica was amorphous and heat treatment of extracted silica increased the specific surface area greatly. The superparamagnetism and consequent magnetic separability is an advantage of magnetic silica. The adsorption study showed that the optimum silica:magnetite ratio, solution initial pH, and adsorbent dosage were 1:10, 3 and 2 g/L, respectively. The adsorption kinetics obeyed the pseudo-second-order equation while the adsorption isotherm was best described by Langmuir model. Magnetic silica provides a balance between the adsorption capacity (19 mg/g) and magnetic separation possibility after wastewater treatment. Amongst the different prepared materials, heat-treated silica achieved the highest adsorption capacity (44 mg/g) toward RhB and was better than many other adsorbents reported in the literature.

Efficient metals removal from waste pickling liquor using novel task specific ionic liquids - classical manner and encapsulation in polymer shell

In the presented studies, extractant N′-(2-ethylhexyloxy)pyridine-4-carboximidamide (EH4IA), and its quaternary salts (4-[1-amine(2-ethylhexyloxyimine)]-1-propylpyridinium chloride (EH4IA-Cl) and 4-[1-amine(2-ethylhexyloxyimine)]-1-propylpyridinium bromide (EH4IA-Br)) were tested as the selective extractants of Zn(II) from waste pickling liquor, as well as after encapsulation, as sorbents enabling separation of Fe(II) and (III), Zn(II), and Pb(II). In the extraction study various factors affecting zinc(II) extraction, and its separation from Fe(II), such as NaCl, HCl, and the metals ions concentration in the aqueous feed solution, as well as structure and concentration of the extractant were analyzed. The metals sorption with the encapsulated extractants was found to be affected by the structure of the encapsulated ionic liquid, pH of the aqueous phase, shaking time, concentration of the metals ions, NaCl, HCl, and temperature of the process. The obtained results enabled to propose the scheme of waste pickling liquor treatment, and laboratory tests confirmed very high potential of the method and the selected to extraction and sorption stages extractant - EH4IA-Br.

Effect of HNO3 and FeCl3 Additives on the Pickling Ability of Fayalite-Containing Oxide Film from Si-Containing Steels

The present work discusses the morphology and pickling behavior of tertiary oxide scale formed on 4 types of hot-rolled steels (0.008 Si-0.019 Cr, 0.43 Si-0.017 Cr, 0.35 Si-0.525 Cr and 0.034 Si-0.72 Cr (wt.% basis)) in four successive tanks of acid containing 4, 6, 8 and 12% HCl solution, respectively, with the addition of strong oxidizer like FeCl3 and HNO3 along with inhibitor. The presence of fayalite (Fe2SiO4) in oxide scale of 0.43 Si-0.017 Cr and 0.35 Si-0.525 Cr steels was confirmed. This fayalite layer is difficult to be removed by pickling. Therefore, pickling was done at room temperature and at 80 ± 3 °C with different strong oxidants, such as FeCl3 and HNO3 added to the pickling liquor and it was found that even at room temperature, the addition of 0.1N FeCl3 and 0.1N HNO3 could remove the oxide scale completely for the high Si-containing steel too. However, only the addition of 0.1N FeCl3 was sufficient to remove the fayalite layer when pickled at 80 ± 3 °C. Additionally, an inhibitor helped to restrict the over-pickling.

Preparation of Low-Carbon and Low-Sulfur Fe-Cr-Ni-Si Alloy by Using CaSO4-Containing Stainless Steel Pickling Sludge

Stainless steel pickling sludge is the precipitate from the neutralization process of stainless steel pickling liquor. Until now, many methods about the harmless treatments of pickling sludge have been developed, and among them the most effective one is to produce Fe-Cr-Ni alloy by carbothermic reduction process. However, the carbon and sulfur (harmful elements for steel) contents of the produced Fe-Cr-Ni alloy are difficult to be controlled, especially for the high-CaSO4 sludge. The current paper proposed a new method to produce the low-carbon and low-sulfur Fe-Cr-Ni-Si alloy by using the high-CaSO4 stainless steel pickling sludge. Firstly, the sludge was pre-reduced by carbon at 1100 °C. Then, the pre-reduced sludge was mixed with silicon powder and reacted at 1550 °C for the deep reduction, separation, and desulfurization. By the current method, the Fe-Cr-Ni-Si alloy with a carbon content of 0.513 wt pct and a sulfur content of 0.003 wt pct was produced. Meanwhile, the Fe, Cr, and Ni contents in alloys were 59.600, 15.440, and 13.570 wt pct, with recovery rates of 97.99, 97.61, and 98.65 pct, respectively. Such an alloy can be used as the alloy additive for stainless steel production.

Hierarchical bead chain ZnFe2O4-PEDOT composites with enhanced Li-ion storage properties as anode materials for lithium-ion batteries

In this study, we synthesized hierarchical bead chain ZnFe2O4-PEDOT composites with network of macroporous channels. For the first time, a ZnFe2(C2O4)3 precursor was prepared by co-precipitation using steel waste pickling liquor as a raw material, which was then sintered in air at 800 °C to yield monolithic ZnFe2O4. PEDOT was coated on the surface of ZnFe2O4 via in-situ polymerization of 3,4-ethylenedioxythiophene (EDOT). Electrochemical measurements showed that the 15 wt% PEDOT coated ZnFe2O4 composites (ZFPE-15) delivered a discharge capacity of 1510.5 mAh g−1 at 100 mA g−1 after 200 cycles, which was much larger than that of pure ZnFe2O4 (1055.9 mAh g−1), 10 wt% PEDOT coated ZnFe2O4 composites (ZFPE-10, 1264.2 mAh g−1), and 20 wt% coated ZnFe2O4 composites (ZFPE-20, 900.1 mAh g−1). Additionally, the ZFPE-15 composite exhibited a reversible capacity of 1004.7 mAh g−1, even at a large current density of 1 A g−1 after 200 cycles. These more desirable electrochemical properties can be attributed to the interconnected macroporous channels in the hierarchical bead chain skeleton, which can buffer volume expansion during circulation and inhibit particle agglomeration. Furthermore, the PEDOT nanoparticle coating produces a composite with greater mechanical strength and higher electrical conductivity, which provides higher electron transfer during the charge/discharge processes.

FeCl3 coagulant production from waste pickle liquor using electrolysis

Pickling is a typical method used in a cold milling plant to remove impurities from hot rolled coil by immersing the coil in strong acidic solution. The spent acidic solution or waste pickle liquor (WPL) requires certain waste treatment before it can be disposed to environment because of its metallic ion and acid content. WPL contains a number of metallic ions that can be utilized as ferric chloride coagulant. The purpose of this paper is to evaluate the kinetics of Fe2+ oxidation into FeCl3 and the performance of the ferric chloride coagulant using the proposed electrolysis configuration. The electrolysis process was conducted in ambient condition with voltage 3 & 6 V, electrolysis time of 120 minutes, and addition of excess NaCl or HCl. The result shows that metal impurities in WPL and excess chlorine do not significantly affect the Fe2+ conversion. It can also be concluded that the optimum condition for electrolysis is using 6V of voltage, 90 minutes of electrolysis time, and excess chlorine at 0% stoichiometry which gave 60% conversion of Fe2+ in WPL. Due to the equilibrium between the Fe2+ dan Fe3+ which is formed during electrolysis process, the full conversion of Fe2+ is not possible yet, and the maximum conversion of Fe2+ is 60%. The presence of impurities in WPL is proven not affecting the Fe2+ conversion during the electrolysis process.