John Kwame Bediako

• Chemical Engineering PhD
• Researcher at Lappeenranta – Lahti University of Technology LUT

Water pollution poses a critical environmental challenge, necessitating effective wastewater treatment methodologies. In this regard, adsorption stands out as a common and efficient approach. Utilizing waste materials for adsorbent production provides an additional environmental benefit. This study focuses on converting refuse-derived fuel mixtures...

Industrial and mining wastewater, along with copper tailings, are typically highly acidic and contain copper and other heavy metals, which may contaminate and damage the environment. Copper (Cu) is, however, a valuable metal, making its removal and recovery from such wastewater and tailings environmentally and economically advantageous. Chelating i...

In recent years, polyelectrolyte-incorporated functional materials have emerged as novel adsorbents for effective remediation of pollutants in water and wastewater. Polyelectrolytes (PEs) are a special class of polymers with long chains of repeating charged moieties. Polyelectrolyte complexes (PECs) are obtained by mixing aqueous solutions of oppos...

To recover useful metals from waste PCBs, environmentally friendly bioleaching has recently attracted attention. Accordingly, distinct protocols are required to adequately recover the bioleached metals. Herewith, we present strategies to separate and recover copper and gold from a bioleached solution of waste PCBs. Polyethylenimine-polyacrylic acid...

In this paper, PEI-Alginate fibers were prepared using a more environmentally friendly method for the recovery of gold (Au (III)) from acidic wastewater. Adsorption results show that PEI plays a major role in the recovery of Au (III), and the maximum adsorption capacity of Au (III) was 644.92 ± 43.06 mg/g calculated by Langmuir model at pH 1, 25 °C...

For the first time, a polyethyleneimine-impregnated alginate capsule (PEIIAC) with a high adsorption capacity is developed for the recovery of monovalent and trivalent gold from an acidic solution. The strategy results in a new type of adsorbent, polyethyleneimine impregnated alginate capsule (PEIIAC) with a core–shell structure having a large numb...

The ion/molecular imprinting technique is an efficient method for developing materials with high adsorption selectivity. However, it is still difficult to obtain an imprinted adsorbent with desirably high selectivity when the preparation processes are not well designed and optimized. In this present work, a chitosan-based ion-imprinted adsorbent wa...

The disposal of bio-waste (e.g., Corynebacterium glutamicum) produced by the fermentation industry is a serious problem and has a negative impact on economic returns. Some fermentation waste can be recycled as livestock feed, but much cannot be used. Therefore, other recycling methods must be developed to increase its applications, for example, as...

An “ionic barrier” concept is proposed to introduce selectivity function to adsorbents towards precious metals (PMs) in the present study. As a model system, melamine-impregnated alginate capsule (MIAC) was prepared and used as a Pd(II) selective adsorbent from a binary metal solution containing Pt(IV) and Pd(II). The MIAC exhibited excellent Pd(II...

Waste printed circuit boards (WPCBs) contain high amounts and various types of precious metals; thus, it is necessary to efficiently and selectively recover these metals by eco-friendly and economic means. An in-situ microwave-assisted leaching and selective separation process employing biphasic aqua regia-ionic liquid systems was developed herein....

This study aimed to select a high-performance cation-exchange resin (CER) and estimate its uptake of positively ionized tricyclic antidepressants (TCAs), i.e., amitriptyline (AMI), imipramine (IMI), clomipramine (CLO), and desipramine (DES), which are frequently used, and detected in wastewater treatment systems. For the selection of the resin, the...

In this study, banana peel (BP) and its derivatives after sequential extraction of biochemical components were evaluated for selective recovery of gold. In-depth instrumental characterizations including XPS, FTIR, XRD and HR-TEM were performed to understand the adsorption mechanisms. The biomass after lipid extraction, BP-L, demonstrated very good...

Numerous studies have sought to address the extraction of metals from printed circuit boards by employing bioleaching process. However, separation and recovery of the bioleached metals have always been a bottleneck. Herein, we demonstrate effective recovery of bioleached Au and Cu via selective separation using ion exchange resins. pH-edge experime...

Metal-containing wastes in aquatic environments lead to public health hazards and valuable resource lose. Metal-bearing wastewater must be treated to remove heavy metals or recover precious metals. To achieve these, target-tunable adsorbents that bind cationic and anionic metal species were developed through facile polyelectrolyte complexation usin...

Dyes are colored compounds which are visible even at trace concentrations. Due to their recalcitrance and esthetic persistence, certain methods are unable to effectively eliminate them. So far, adsorptive treatment using activated carbons (ACs) is one of the most successful methods. In this study, we have employed orange peel (OP) as a cost-effecti...

A sponge-like material that can purify water has been developed by scientists in South Korea. Making water safe requires technologies that can remove almost any pollutant. This need is likely to increase as the world’s population grows and access to fresh water becomes scarcer. Nanomaterials offer one possible solution. Graphene-oxide membranes, fo...

High-capacity crosslinked polyethylenimine (PEI)/Ca²⁺-Alginate fibers were fabricated as fast-kinetics adsorbents for application in gold recovery from urban mines. The benign protocols include strategic blending of PEI and alginate and extrusion into a mixture of CaCl2 and glutaraldehyde (GA) for simultaneous ionotropic gelation between the algina...

Bediako, J.K. and Yun, Y.-S. (2018), "Adsorption of aurocyanide onto KOH-activated orange peel carbons: optimisation of the activated carbon yield and adsorption capacity through central composite design", 5 th UMaT Biennial International Mining and Mineral Conference, pp. MR62-67. Abstract Conventional gold mining involves cyanidation, leaching an...

After consumption of the inner fleshy fruit, the banana peel like many other fruit peels is usually disposed of unprocessed. For sustainable development, agro-wastes including banana peels need to be converted into valuable products that will be beneficial to human and the environment. In this study, biochemical components including lipids, protein...

Recovery of precious metal ions such as Pt(IV) from acidic media is very important owing to their increasing supply risks and environmental threats, nonetheless, it is a still challenging task. Metal-organic frameworks (MOFs) as a class of porous nano-materials, have attracted extensive attention for their sustainable and environmental applications...

Metal–Organic Framework (MOF)–polymer compatibility is a thorny issue in practical applications. In article number 1805242, Hak Yong Kim, Yeoung‐Sang Yun, and co‐workers investigate Zr(IV)‐based MOF membranes for precious metal recovery in a strongly acidic environment. The fibrous membranes show outstanding performances, and good stability attribu...

Precious metals such as palladium (Pd) and platinum (Pt) are marvelous materials in the fields of electronic and catalysis, but they are tapering day by day. Zr(IV)‐based metal–organic frameworks (MOFs) are competent for their recovery, notably in harsh environments, while the general powder form limits their practical application. Porous MOF‐based...

For sustainable development and environmental protection, “urban mining” for the recovery of critical metals, especially for precious metals (PMs), from urban solid wastes, has recently attracted substantial attention. Here, metal-organic frameworks (MOFs) of MOF-802, UiO-66 and MOF-808 with significantly different structures, such as various porou...

In this study, we performed modeling analysis based on isothermal experimental data to develop linear free energy relationship (LFER) model, which is a very useful concept for predicting the molecular interaction of an adsorbate in a certain system. Thirty compounds containing cationic, anionic, and neutral were used, and the effect of diverse inte...

In the present study, the relationship between the amount of anionic or cationic binding sites and adsorption capacities of biosorbents is discussed through potentiometric titration and mathematical model equations (proton-binding models). The poly(acrylic) acid-modified biomass (PAAB) and polyethylenimine-modified biomass (PEIB) derived from raw b...

We report the fabrication and application of high-performance and acid-tolerant fibers comprising polyethylenimine (PEI) and polyvinyl chloride (PVC) for platinum recovery from acidic waste solutions. The fibers were fabricated by amination of PVC with PEI and spin-extrusion via phase-inversion mechanism. Factors including the effects of chloride c...

The physico-mechanical properties of variable rubber blends including epoxide natural rubber (ENR), polybutadiene rubber (BR), and solution polymerized styrene-butadiene rubber (SBR) filled with silanized-silica and carbon black mixtures were explored. The tensile, hardness, resilience, abrasion and fatigue behavior were investigated. An optimized...

Due to high mobility and specific toxic actions of the ionizable pharmaceuticals in surface water with a normal range of pH, the pharmaceuticals should be removed before being discharged. Therefore, this study investigated the adsorptive interactions between cationic pharmaceuticals and a popular adsorbent (i.e., activated charcoal) frequently used...

Metal-organic frameworks (MOFs) have successfully employed as a class of adsorbents for selective separation of CO2 and some organics from gas and liquid phases; however, little attention has been paid to MOFs applications for selective adsorption of ionic targets from aqueous solutions. Besides, selective separation of precious metals is of great...

Facile fabrication of polyacrylic acid-polyvinyl chloride (PAA-PVC) composite adsorbents and their evaluation for Cd(II) adsorption is reported in this study. The sorbents were prepared via a simple phase inversion process by spinning PAA-PVC polymer blends into mixed solution of water and methanol. The prepared fibers were characterized by scannin...

High-capacity polyethylenimine (PEI)/Ca-alginate blended hydrogel fibers were fabricated via three steps, viz. electrostatic blending of PEI and alginate, ionotropic gelation of alginate and CaCl2, and fixing of PEI into the Ca-alginate matrix, using glutaraldehyde (GA) as a crosslinker. Two crosslinking approaches resulted in different stabilities...

Magnetic MnFe2O4 nanoparticles (MNPs) were fabricated and entrapped in amine-rich chitosan (CS) sorbents containing multi-walled carbon nanotubes (MWCNTs) or polyethyleneimine (PEI). Magnetic polymer composite sponges (MPCSs) and magnetic polymer composite fibers (MPCFs) were prepared through mixing each of MWCNT and PEI with MNPs-CS solution. The...

Separation of precious metal ions from acidic solutions is of great importance due to their cumulative supply risk and environmental concern. However, their separation is still challenging as they are often present in extremely low pH solutions. Metal-organic frameworks (MOFs) have attracted a myriad curiosity for adsorption owing to their fascinat...

A facile modification of waste textile cellulose Lyocell fibers with tripolyphosphate and application of the adsorbent thereof to the treatment of Pb(II)-contaminated wastewater was investigated. Characterization and batch adsorption studies were conducted to understand the characteristics of the prepared adsorbent and its metal binding mechanisms....

Fibrous adsorbents were prepared by carboxymethylation of waste textile fibers and were used for Cd(II) sorption in comparison with Dowex Mac-3 (DM-3). The prepared sorbents were designated carboxymethyl cellulose-Lyocell strands (CMC-LS) and carboxymethyl cellulose-Lyocell fabrics (CMC-LF). Kinetic and isotherm studies indicated that CMC-LS had th...

Poly(styrenesulfonic acid)-impregnated alginate capsule (PSSA-AC) was prepared using a simple fabrication process, and used for selective separation of Pd(II) and Pt(IV) from their mixture. Evaluation of the pH effect revealed that PSSA-AC had good Pd(II) selectivity especially when the pH was between 3 and 5 at which neutral species Pd(OH)2 are pr...

Low-cost renewable adsorbent was developed from waste textile Lyocell via simple carboxymethylation and crosslinking reactions. The success of chemical modification was confirmed by scanning electron microscopy, energy disperse X-ray spectroscopy and Fourier transforms infra-red spectroscopy studies. Response surface methodology was employed to opt...

Adsorptive separation of Pb(II) and Cu(II) using modified waste Lyocell fiber adsorbent was investigated in this research. The waste Lyocell fiber was functionalized through carboxymethylation of the hydroxyl moieties using sodium chloroacetate as modifying agent and was crosslinked with epichlorohydrin to provide water stability. The maximum equil...

In this study, a capsule type sorbent of poly(styrenesulfonic acid)-impregnated alginate capsule (PSSA-AC) was developed by using a simple and moderate method. PSSA was used as a model encapsulated material because of its large number of sulfonic acid groups which have high affinity toward Cd(II). PSSA-AC was prepared by dropping solution A (mixtur...

This study investigates the possibility of applying textile fiber waste coated with carboxymethyl cellulose (CMC) as a feasible adsorbent for treating toxic heavy metals contained in wastewaters. The soluble CMC was successfully coated on Lyocell fiber and cross-linked with epichlorohydrin to give mechanical and water stability as well as to enhanc...

Aliquat-336-impregnated alginate capsule (Aliquat-336-AC) was fabricated using a facile method. Ionic liquid Aliquat-336 was used as a model extractant owing to its good extraction performance toward precious metals (PMs). Aliquat-336-AC was prepared by dropping the mixture solution (Aliquat-336 + Tween 80 + CaCl2) into the alginate solution. CaCl2...

This study investigated the possibility of applying textile fiber waste coated with carboxymethyl cellulose (CMC) as a feasible adsorbent for treating toxic heavy metals contained in wastewaters. The soluble CMC was successfully coated on Lyocell fiber and cross-linked with epichlorohydrin to give mechanical and water stability as well as to enhanc...

In this study, an outstanding performance of chemically modified waste Lyocell for heavy metals treatment is reported. The sorbent, which was prepared by a simple and concise method, was able to bind heavy metals such as Pb(II), Cu(II) and Cd(II), with very high efficiencies. The binding mechanisms were studied through adsorption and standard chara...

In this study, a fast kinetic sorbent, epichlorohydrin cross-linked carboxymethyl cellulose fiber (ECMCF), was developed by using a simple synthetic method. SEM images showed that the ECMCF has a thin fibrous shape (20–90 µm of diameter) with a rough and porous surface, which is beneficial for the purpose of sorption. Cadmium metal ion (Cd(II)) was...