• A Novel Method for Cleaning Reaction Vessels.

      Cox, Jeffrey J.; Gibbons, M. N. N.; Hudson, I. D.; Williams, Craig D. (NISCAIR, 2002)
      The objective of zeolite synthesis is the production of pure phase material and a study by Lowe et al. showed that small and possibly significant amounts of template remaining in supposedly clean vessels could influence the crystallisation of subsequent gels. Two cleaning methods are widely used to clean the synthesis reaction vessels i.e. hydrofluoric acid or a solution of sodium hydroxide at reaction temperature, but their efficacy has not been tested. Zeolite omega was synthesized with both organic and inorganic templates and, following synthesis, the reaction vessels were cleaned by a novel method, described here, using hydrofluoric acid, crown ethers, and ultrapure water. This new method was compared to the standard methods by using a ‘scavenging gel’ to test the cleanliness of the vessels. The ‘scavenging gel’ produced some crystalline material when used following conventional cleaning whereas, when the vessels were cleaned using the method described here, the gel failed to crystallise. Conductivity measurements have proved a reliable index to the cleanliness of the reaction vessels.
    • A study of the chemistry of isomorphous substitution and characterisation of Al-ZSM-5 and Sc-ZSM-5 synthesised in fluoride media.

      Brigden, Clive T.; Williams, Craig D.; Apperley, David C. (MAIK Nauka/Interperiodica distributed exclusively by SpringerLink, 2007)
      Al-ZSM-5 and Sc-ZSM-5 samples have been synthesized using fluoride media at around neutral pH. The synthesis chemistry has been studied and it is shown how the lower tendency of scandium to undergo increased fluoro-complexation (compared with aluminum) coupled with its tendency to hydrolyze is conductive to its isomorphous substitution and framework incorporation into the MFI zeolite structure. Clear unit cell volume expansion, elongation of the c crystallographic axis with increased scandium content, and a strong positive linear correlation between the unit cell volume expansion and the calculated unit cell framework scandium content are shown. Chemical shifts are assigned to tetrahedral and octahedral scandium from 45Sc MAS NMR analysis. Shoulders and a peak at lower wavenumber on the main internal T-O asymmetric stretches in the FT-IR spectra indicate that an interaction exists between framework-incorporated scandium and the SiO4 tetrahedra. It is concluded from the experimental evidence that isomorphous substitution of scandium into the zeolite framework has been achieved.
    • A tin-lead alloy found in a zeolitic amygdale at Carsaig Bay on the Hebridean Isle of Mull.

      Dyer, Alan; Green, David I.; Taylor, Beryl; Williams, Craig D. (Russell Society, 2005)
    • CALCIUM ANALCIME FROM THE TOTHERICK AYRSHIRE, SCOTLAND: AN UNUSUAL CRYSTAL FORM WITH TRAPEZOIDAL FACES

      Dyer, Alan; Waughman, R.; Williams, Craig D. (The Russell Society, 2003)
    • Clinoptilolite and Heulandite from Wheal Hazard, St Just, Cornwall.

      Dyer, Alan; Green, David I.; Tindle, Andrew G.; Williams, Craig D. (Russell Society, 2006)
    • Efficient methane/nitrogen separation with low-sodium clinoptilolite.

      Guest, Jodie E.; Williams, Craig D. (Royal Society of Chemistry, 2002)
      The presence of sodium is shown to have a highly detrimental effect on the gas separation ability of clinoptilolite towards methane and nitrogen.
    • Ni-ZSM-5 and Cu-ZSM-5 Synthesized Directly from Aqueous Fluoride Gels.

      Round, Catherine I.; Williams, Craig D.; Latham, Kay; Duke, Catherine V. A. (ACS Publications, 2001)
      Ni-ZSM-5 and Cu-ZSM-5 have been synthesized in a slightly acidic fluoride medium. A low water H-ZSM-5 formula was used to synthesize the metal-substituted systems using bis(tetraethylammonium) tetrachloronickelate(II) [N(CH2CH3)4]2[NiCl4] and bis(tetraethylammonium) tetrachlorocuprate(II) [N(CH2CH3)4]2[CuCl4] as the tetrahedrally coordinated metal species. X-ray diffraction analysis established the presence of highly crystalline and thermally stable material. Unit cell dimensions increased with increasing levels of metal substitution. X-ray fluorescence (XRF) bulk analysis showed increasing levels of metals in the material and corresponding decreases in the moles of silica. The maximum levels of substitution achieved were Ni 3.93 and Cu 4.38 (in wt %). Analysis by scanning electron microscopy (SEM) showed a crystal morphology similar to that of H-ZSM-5 but with smaller crystals having an increasing aspect ratio in the substituted materials. There was evidence of twinned crystals and the appearance of raised faces in all substituted samples. Thermogravimetric and derivative thermogravimetric analysis showed anomalous losses, which could be explained by Jahn-Teller distortions. Fourier transform infrared analysis of the materials showed an increasing level of distortion in significant regions of the spectra. Analysis of the filtrate, from EDTA-exchanged material, by atomic absorbance spectroscopy (AAS) showed that there were tetrahedrally coordinated M2+ species in the material and relatively small amounts were removed by ion exchange.
    • Nucleation and growth history of zeolite LTA synthesized from kaolinite by two different methods.

      Rios, Carlos A.; Williams, Craig D.; Fullen, Michael A. (Amsterdam: Elsevier, 2009)
      The synthesis of zeolite Linde Type A (LTA) from kaolinite by two different routes: (1) conventional hydrothermal alkaline activation and (2) alkaline fusion prior to hydrothermal reaction, as well as its nucleation and growth history, were investigated. Using the first method, co-crystallization of sodalite and cancrinite, probably via an unstable zeolite LTA intermediate, was observed during treatment of kaolinite in NaOH solutions. The addition of a SiO2 source promoted the co-precipitation of several zeolite phases, including zeolites LTA, X and P, with traces of sodalite and cancrinite. By fusion with NaOH followed by hydrothermal reaction, kaolinite was converted into zeolite LTA. Synthesized materials appeared stable thermodynamically under the experimental conditions. The synthesis products have been characterized by X-ray diffraction, scanning electron microscopy and Fourier Transform Infrared Spectroscopy.
    • Preparation of isomorphously substituted scandium ZSM-5 using aqueous fluoride gels.

      Brigden, Clive T.; Thompsett, David; Williams, Craig D. (RSC Publishing, 2004)
      Sc-ZSM-5 zeolite is synthesised using a hydrothermal fluoride based synthesis medium and evidence, viz. XRF, NMR, XRD, TGA and FT-IR shows that scandium (Sc3+) has been isomorphously substituted into the zeolite framework.
    • Production of silver-loaded zeolites and investigation of their antimicrobial activity

      Radecka, Izabela; Williams, Craig D.; Kenward, M. A.; Kibble, Kevin A.; Kwakye-Awuah, Bright (University of Wolverhampton, 2008)
      The production of silver-loaded zeolites either by ion exchange method or by isomorphous substitution of silver ions into zeolites frameworks and their antimicrobial activity is presented. Silver-loaded zeolites produced by ion-exchange in this work include silver-exchanged zeolite X, silver-exchanged zeolite A and silver-exchanged high-alumina Phillipsite. Silver-doped Analcime was produced by isomorphous substitution of silver ions into the Analcime framework. The silver-loaded zeolites were characterized by X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis, particle size analysis and Fourier transformed infrared (FTIR) spectroscopy. Studies showed that the amount of silver ions loaded into the zeolites frameworks differed for each zeolite. XRD analysis showed little or no changes in the phase purity of all zeolites before and after ion exchange or before and after substitution of silver ions. SEM analysis and particle size analysis showed that the morphology of each zeolite particles was closely related before and after ion exchanged or before and after substitution of silver ions. The antimicrobial activity of these silver-loaded zeolites was investigated by exposing Escherichia coli K12W-T, Staphylococcus aureus NCIMB6571 and Pseudomonas aeruginosa NCIMB8295 suspended in tryptone soya broth (TSB) to the silver-loaded zeolites. The first stage of the investigation involved the exposure of the strains to silver-loaded zeolites in TSB for a duration of 24 hours at different concentration of silver-loaded zeolites. The second stage involved the exposure of the strains to silver-loaded zeolites in TSB over a period of two hours. The persistency of antimicrobial activity of silver-loaded zeolites was investigated by retrieving each silver-loaded zeolite from the first exposure cultures, washed copiously with de-ionised water and adding to fresh bacterial suspensions. To understand the mode of antimicrobial activity of the silver-loaded zeolites, the uptake of silver ions by the strains, composition of fatty acid, as well as the DNA content of Escherichia coli K12W-T was studied. The results obtained showed silver ions appeared to elute from the zeolites frameworks into the TSB in anomalous trend. All three microorganisms were completely inhibited within one hour with the silver-loaded zeolites retaining their antimicrobial activity. The release of silver ions from the zeolites frameworks followed first-order kinetics with varying rate constants and half-lives. The fatty acid composition of all strains as well as the DNA content of Escherichia coli K12W-T were affected by the action of silver ions.
    • Remediation of oil spills using zeolites

      Fullen, Michael A.; Kelay, Asha; Williams, Craig D. (2011)
      Current research is testing the hypothesis that zeolites can efficiently and cost effectively adsorb oil spills. To date, this aspect of zeolites science has received little attention. A series of five Master of Science (M.Sc.) Projects at the University of Wolverhampton have shown that the zeolite clinoptilolite can effectively adsorb oil. Various sand-clinoptilolite mixes were tested in replicated laboratory analyses in terms of their ability to adsorb engine oil. Adsorption increased with clinoptilolite amount. The relationship between percentage clinoptilolite and oil adsorption was asymptotic. Thus, on a cost-effective basis, a 20% clinoptilolite: 80% sand mix seems the most costeffective mix. However, a particularly exciting finding was that it was possible to burn the oil-sand-zeolite mix and reuse the ignited mix for further oil adsorption. Experiments are ongoing, but to date the ignition and adsorption cycle has been repeated, on a replicated basis, seven times. Still, the ignited mix adsorbs significantly more oil than the sand control. Initial results suggest that the temperature of ignition is critical, as high temperatures can destroy the crystal and micro-pore structure of zeolites. Thus, low temperature ignition (~400oC) seems to allow the retention of structural integrity. Similar results were obtained using the zeolite chabazite and experiments are in progress on phillipsite, which is the third major zeolite mineral. If the hypotheses can be proven, there are potentially immense benefits. Sand-zeolite mixtures could be used to effectively adsorb terrestrial oil spills (i.e. at oil refinery plants, road accidents, beach spills from oil tankers and spills at petrol stations) and thus remediate oil-contaminated soils. The contaminated mix could be ignited and, given the appropriate infrastructure, the energy emission of combustion could be used as a source for electrical power. Then, the ignited mix could be reused in subsequent oil spills. This offers enormous potential for an environmentally-friendly sustainable ‘green’ technology. It would also represent intelligent use of zeolite resources. On a global scale, including Europe, clinoptilolite is the most common and inexpensive zeolite resource.
    • Removal of heavy metals from acid mine drainage (AMD) using coal fly ash, natural clinker and synthetic zeolites.

      Rios, Carlos A.; Williams, Craig D.; Roberts, Clive L. (Amsterdam: Elsevier, 2008)
      Acid mine drainage (AMD) is a widespread environmental problem associated with both working and abandoned mining operations, resulting from the microbial oxidation of pyrite in presence of water and air, affording an acidic solution that contains toxic metal ions. The generation of AMD and release of dissolved heavy metals is an important concern facing the mining industry. The present study aimed at evaluating the use of low-cost sorbents like coal fly ash, natural clinker and synthetic zeolites to clean-up AMD generated at the Parys Mountain copper-lead-zinc deposit, Anglesey (North Wales), and to remove heavy metals and ammonium from AMD. pH played a very important role in the sorption/removal of the contaminants and a higher adsorbent ratio in the treatment of AMD promoted the increase of the pH, particularly using natural clinker-based faujasite (7.70-9.43) and the reduction of metal concentration. Na-phillipsite showed a lower efficiency as compared to that of faujasite. Selectivity of faujasite for metal removal was, in decreasing order, Fe>As>Pb>Zn>Cu>Ni>Cr. Based on these results, the use of these materials has the potential to provide improved methods for the treatment of AMD.
    • Shape selective catalysis using zeolites.

      Williams, Craig D. (Italy: Teknoscienze SRL, 2002)
    • Study of some inorganic oxyanion-loaded ODA and Ag Clinoptilolite-rich tuff by HR TEM, SEM and XRD spectral analytical techniques.

      Chmielewska, E.; Bogdanchikova, Nina; Williams, Craig D. (Wroclaw University of Technology, 2004)
    • Synthesis and characterization of zeotype ANA framework by hydrothermal reaction of natural clinker.

      Sandoval, M.V.; Henao, J.A.; Rios, Carlos A.; Williams, Craig D.; Apperley, David C. (Amsterdam: Elsevier, 2009)
      The zeotype ANA framework was successfully synthesized for the first time by conventional hydrothermal alkaline activation of natural clinker. The synthesis process was investigated as a function of the starting material, reaction temperature, reaction time and mineralizer concentration. The as-synthesized products were characterized by X-ray powder diffraction (XRPD) analysis, scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, magic-angle spinning nuclear magnetic resonance (MAS NMR) and thermogravimetric analyses (TGA). The results of this study indicate that ANA with a low quantity of impurities can be synthesized using natural clinker as starting material.
    • Synthesis of zeolites and their application as soil amendments to increase crop yield and potentially act as controlled release fertilizers.

      Williams, Craig D.; Fullen, Michael A.; Hocking, Trevor J.; Jakkula, Vijay S. (University of Wolverhampton, 2005)
      Zeolites have been used in agriculture since the 1960s, due to the effectiveness of these crystalline microporous solids as soil amendments for plant growth, their cation exchange capacity (CEC) and slow-release fertilizer properties. Most work on slow-release fertilizers has focused on natural Clinoptilolite, Phillipsite and Chabazite. The aim of this study was to synthesize zeolites, study their effectiveness as soil amendments and their ability to act as controlled release fertilizers to decrease nitrate leaching. Nitrate pollution of groundwater is a major agro-environmental concern. The zeolites Phillipsite and Linde-type F were synthesized from aluminosilicate gels; ion exchanged to introduce ammonium and characterized using X-ray diffraction (XRD), X-ray fluorescence (XRF), Thermo-gravimetric analysis (TGA) and Scanning electron microscopy (SEM) techniques, both before and after ion exchange. Ammoniumexchanged Phillipsites (natural and synthetic), ammonium-exchanged synthetic Linde-type F (the zeolite having highest affinity towards ammonium) and ammonium exchanged Phillipsites (high crystalline and high aluminium) were compared with conventional NPK fertilizer.Three glasshouse experiments were performed to study the effects of zeolite-amended soils on maize growth. Ion exchanged synthetic and natural Phillipsites were first used as soil amendments (w/w 2, 4, 8% zeolite to soil). Synthetic Phillipsite, at 2% loading, resulted in the most significant improvement in both plant growth and phased ammonium release. The synthetic ammonium-exchanged zeolites Phillipsite and Linde-type F (at w/w 1, 2, 4%) were then compared; synthetic Phillipsite, at 2% loading, again resulted in the most significant plant growth response with an increase (≥15%) in shoot dry weight and a decrease (≥30%) in nitrate leaching. Experiments using unexchanged synthetic Phillipsite (at w/w 2%), but with added NPK fertilizer, showed increased plant growth and decreased nitrate leaching, compared with parallel experiments containing unexchanged synthetic Linde-type F (at w/w 2%) and a conventional fertilizer amended soil. This revealed the beneficial effect of Phillipsite for soil amendment, even without ion exchange to the ammonium form. To study the physico-chemical properties affecting the release of ammonium from the Phillipsite framework; high crystalline/low aluminium and low crystalline/high aluminium forms were synthesized and ion exchanged. Both forms were introduced as soil amendments (at w/w 1 and 2%) and experiments showed that the lower zeolite crystallinity decreased cation exchange and therefore decreased nitrate leaching. Experimental results from the glasshouse experiments and cation exchange capacity (CEC) experiments suggest that synthetic Phillipsite, at lower loadings (1 and 2% w/w zeolite to soil) have most potential as soil amendments for both plant growth and controlled-release applications. This conclusion is supported by soil leachate and shoots dry weight analysis. Furthermore, Phillipsite, synthesized in a low crystalline and low ammonium form, may be an even better soil amendment for controlled release of ammonium, which will thereby further decrease nitrate pollution.
    • Synthesis of Zeolites and Zeotypes by Hydrothermal transformation of Kaolinite and Metakaolinite.

      Rios, Carlos A.; Williams, Craig D.; Maple, Martin J. (Bucaramanga, Colombia: Universidad de Pamplona, 2007)
      The synthesis of zeolitic materials by hydrothermal transformation of kaolinite and metakaolinite in NaOH solutions of various concentrations was investigated between 100 and 200 degrees C, over different reaction times, using in some cases precipitated SiO2 or organic templates. Materials were obtained, including clathrasils: cancrinite (CAN), sodalite (SOD), and Linde Type A (LTA), faujasite (FAU), NaP1 (GIS), analcime (ANA) and nepheline hydrate I (JBW) zeolites. In general, co-crystallization of CAN and SOD, likely via an unstable LTA zeolite intermediate, was observed after dissolution of kaolinite at low temperature; although the feldspathoids tend to be unstable at high temperature. LTA zeolite was synthesized after metakaolinite reaction, with minor amount of FAU zeolite, ANA and SOD. Solids were characterized by powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA).
    • Synthesis of zeolites from geological materials and industrial wastes for potential application in environmental problems

      Williams, Craig D.; Roberts, Clive L.; Fullen, Michael A.; Rios Reyes, Carlos A. (University of WolverhamptonSchool of Applied Sciences, University of Wolverhampton, 2008)
      Zeolites are among the least-known products for environmental pollution control, separation science and technology. Due to their unique porous properties, they are used in various applications in petrochemical cracking, ion-exchange and separation and removal of gases and solvents. The preparation of synthetic zeolites from chemical reagents is expensive. Therefore, in order to reduce costs, zeolite researchers are seeking cheaper aluminosilicate bearing raw materials, such as clay minerals, to produce synthetic zeolites. This research concerns the synthesis of zeolites and zeotypes derived from low-cost materials like kaolinite (KAO), natural clinker (NC) and fly ash (FA). The motivation for using these sources as the starting materials in zeolite synthesis is driven by factors, such as they are cheap and available in bulk quantities, are currently under-utilized, have high workability, and require less water (or solution) for activation. The raw materials were activated by two different routes: (1) classic alkaline hydrothermal synthesis and (2) alkaline fusion prior to hydrothermal synthesis. In the first method, the synthesis of zeolitic materials was carried out generally in alkaline media, although KAO or its calcination product, metakaolinite (MTK), was also activated in the presence or absence of structure directing agents (SDAs) and additional silica (precipitated SiO2), with the last one determining the SiO2/Al2O3 ratio of the reaction mixture and the time given for zeolitization. Synthesis in fluoride- and calcium-bearing media was also used to activate kaolinite. The process of synthesis was optimized by applying a wide range of experimental conditions with a wide range of reaction temperature, time, mineralizer concentration and solid/solution ratio. In the second approach, an alkaline fusion step was conducted prior to hydrothermal treatment, because it plays an important role in enhancing the hydrothermal conditions for zeolite synthesis. On the other hand, this approach was adopted because it can dissolve more aluminosilicates. The main synthesis products obtained after activation of KAO in NaOH solutions included zeolite LTA (LTA), sodalite (SOD), cancrinite (CAN), faujasite (FAU), zeolite Na-P1 (GIS), JBW-type zeolite (JBW), analcime (ANA), whereas the activation of KAO in KOH solutions produced chabazite (CHA), zeolite Barrer-KF, phillipsite (PHI) and K-feldspar. The hydrothermal conversion of kaolinite in fluoride media did not produce successful results, although traces of FAU, GIS, CHA, SOD and CAN crystallized. The activation of KAO in the system CaO-SiO2-Al2O3-H2O promoted the formation of different calcium silicate hydrate (C-S-H) phases, including hydrogarnet (HYD) and tobermorite (TOB). Following the fusion approach, the main zeolitic phases obtained using NaOH as mineralizer were LTA and CAN. The main as-synthesized zeolites obtained from NC by the conventional hydrothermal treatment method include PHI, SOD and CAN. Using the fusion approach, FAU and LTA were obtained with NaOH as an activator, whereas non-zeolitic material crystallized when KOH was used. The main as-synthesized zeolitic materials obtained by hydrothermal reaction of FA include PHI, zeolite Barrer-KF, CHA and SOD with traces of TOB, ANA, zeolite LTF (LTF) and herschelite (HER), appearing occasionally. By the fusion approach, FAU was obtained with NaOH as activator, whereas no zeolitic material crystallized using KOH. Experimental results indicate that the method, mineralizer, concentration and time have strong effects on the type and degree of crystallinity of the synthesis products. On the other hand, the type and chemical composition of the as-synthesized products are strongly dependent on the chemical composition of the starting material. The chemistry of zeolite synthesis was subject to perturbations caused by the presence of impurities in the raw materials, which may remain insoluble during crystallization and cause undesired species to nucleate, developing mixtures of different types of zeolites. However, other physicochemical factors may play a very important role in the thermodynamics and kinetics of zeolite formation. The raw materials have very high contents of SiO2 and Al2O3, with SiO2/Al2O3 ratios appropriate for the synthesis of low-Si zeolitic materials with high crystallinity and cation exchange capacity (CEC). However, although zeolites’ CEC represents a very important characteristic quality in the removal of undesired species from polluted effluents, it is not the deciding factor in determining zeolite performance during ion exchange processes, since numerous other factors also need to be considered. Finally, the potential application of the raw materials and their as-synthesized products as low-cost sorbents in the remediation of metal ions and ammonium from wastewater effluents was investigated. PHI showed a lower efficiency than FAU. Selectivity of FAU for metal removal was, in decreasing order, Fe>As>Pb>Zn>Cu>Ni>Cr. Based on these results, the use of these materials has the potential to provide improved methods for the treatment of contaminated effluents.
    • Synthesis of zeolitic materials from natural clinker: A new alternative for recycling coal combustion by-products.

      Rios, Carlos A.; Williams, Craig D. (Amsterdam: Elsevier, 2008)
      In this study, we report an innovative process of zeolite synthesis through transforming of natural raw clinker (NRC) via (1) conventional hydrothermal alkaline activation and (2) alkaline fusion prior to hydrothermal reaction. Both methods were evaluated at 100 °C as a function of the alkaline agent, although in the first method other variables such as concentration of the activation solution and reaction time were selected, whereas in the second method similar ratios of alkaline activator/NRC and H2O/alkali fused product during different reaction times were used. Experimental results indicate that the method, alkali activator, concentration and time have a strong effect on the type and degree of crystallinity of the synthesized zeolite. Low-silica sodium or potassium zeolitic materials were synthesized, which include Na-phillipsite, hydroxysodalite and hydroxycancrinite, K-chabazite, zeolite K-F, faujasite and zeolite Linde Type A. The use of a recycling process of NRC in zeolite synthesis could become an area of important interest and research, playing an active role in encouraging and promoting technological advances, research and technology transfer related to the use and disposal of mining wastes, remaining after the natural and spontaneous combustion of coal seams. NRC-based zeolites (NRCZs) synthesized under well-optimized experimental conditions could be used in applications for environmental waste treatment.
    • Synthetic faujasite based on coal by-products for the treatment of acid mine drainage (AMD).

      Rios, Carlos A.; Williams, Craig D.; Roberts, Clive L.; Fullen, Michael A. (Greece: University of Patras, 2008)
      Acid mine drainage (AMD) has long been a significant environmental problem associated to mining operations at the Parys Mountain copper-lead-zinc deposit of Anglesey (North Wales), a volcanogenic massive sulphide district of major metallogenic importance. AMD is a natural occurrence resulting from the microbial oxidation of sulphide minerals, especially pyrite (FeS2), pyrite in presence of water and air, which produces polluted waters strongly acidic containing high concentrations of Fe, sulphate and toxic metals. The treatment of AMD has traditionally been conducted by neutralization with lime or similar materials. However, liming is often temporary and produces secondary wastes, such as metal hydroxide sludges and gypsum, which are highly regulated and have costly disposal requirements. Several methods for AMD treatment have been developed, although adsorption being the preferred method for heavy metal removal due to its effectiveness. AMD remediation can be very costly and difficult, due to the high costs of activated carbon production and regeneration for water treatment. Therefore, alternative low-cost liming materials are constantly sought. Such adsorbents should be readily available, economically viable and easily regenerated. The aim of this study is to investigate the efficiency of synthetic faujasite obtained from coal by-products as adsorbent in removing heavy metals from AMD generated at the Parys Mountain copper-lead-zinc deposit.