Contact Time Research Articles

Green synthesis of magnesium oxide nanoparticles using extracts of two brown seaweeds for removal of acid black 1 dye from aqueous environments

Water pollution by synthetic dyes, particularly acid black 1, poses a significant environmental challenge. The present study has addressed this issue by synthesizing novel magnesium oxide (MgO) nanocomposites using extracts from Padina sanctae crucis (Psc) and Sargassum hystrix (Sh) algae via a sol-gel process. The primary objective was to evaluate the efficacy of these nanocomposites in removing acid black 1 dye from aqueous solutions. The synthesized materials were characterized using Fourier transform infrared spectroscopy (FT-IR), energy dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) analysis, thermal gravimetric analysis (TGA), and dynamic light scattering (DLS). The results show the successful synthesis of MgONPs and MgO@Sh and MgO@Psc NPs with approximate sizes of 45.64–65.64, 52.14–59.09 and 39.19–58.30 nm. Batch mode experiments were conducted to assess the influence of contact time, pH, and adsorbent dosage on dye removal efficiency. The results demonstrated that at pH 6, increasing the adsorbent dosage from 0.5 to 2 g/L enhanced the dye removal efficiency from 41.6% to 59.1% for MgO@Psc and from 43.4% to 64.1% for MgO@Sh. The Sips isotherm model and intra-particle diffusion kinetic model provided the best fit to the experimental data. The negative values of ΔG° indicated, which the adsorption process is more spontaneous at higher temperatures. This study highlights the potential of MgO@Psc and MgO@Sh nanocomposites as effective adsorbents for acid black 1 removal, offering a promising solution for water purification.

Selecting the Most Sustainable Phosphorus Adsorbent for Lake Restoration: Effects on the Photosynthetic Activity of Chlorella sp.

To promote the conservation of aquatic ecosystems, it is essential to delve into restoration techniques for selecting the most sustainable option for combating eutrophication. Hence, we study the effects of novel phosphorus (P) adsorbents (magnetic carbonyl iron particles, HQ, and two non-magnetic P adsorbents: CFH-12® and Phoslock®) on the growth and photosynthetic activity of Chlorella sp. More specifically, the intrinsic photochemical efficiency of PSII (ΦPSII) and the nonphotochemical quenching (NPQ) were measured in Chlorella sp. after different contact times with different concentrations of these adsorbents. Our initial hypothesis was that non-magnetic P adsorbents have more effects on the organisms than magnetic ones. However, our results did not show strong evidence of inhibitory effects caused by HQ nor CFH-12® (no significant effect size on ΦPSII), while Phoslock® showed inhibitory effects on the photosynthetic activity of Chlorella sp. for any of its concentrations (NPQ = 0). Lastly, we compared the effect of the studied P adsorbents in a real application scenery (Honda wetland, Spain). For this study case, it is likely that CFH-12® and HQ doses would not cause any negative effects on photosynthetic efficiency while Phoslock®, by limiting light availability, will drastically reduce it.

Synthesis and application of MgCuAl-layered triple hydroxide/carboxylated carbon nanotubes/bentonite nanocomposite for the effective removal of lead from contaminated water

A novel multicomponent adsorbent nano-composite was synthesized by intercalating bentonite clay and carboxylated carbon nanotubes (CNT-COOH) into MgCuAl-layered triple hydroxide (MgCuAl-LTH), abbreviated as LTH/CNT-COOH/Bent. The produced nano-composite, its parental materials, and their binary combinations were characterized using various techniques. Pore filling was noted based on the BET analysis, hence, indicating effective component integration in the nano-composite structure. Further, distinct peaks appearing on the FTIR and XRD spectra of the single materials also appeared on the synthesized composites (including the binary combinations of the parental materials), hence, further indicating the successful synthesis of the targeted adsorbents. The effects of process parameters including pH, adsorbent dose, lead initial concentration and contact time on lead removal, were explored. In general, the application of LTH/CNT-COOH/Bent adsorbent yielded a significant improvement in lead adsorption capacity (∼260.8 mg/g) relative to all parental materials and their binary combinations. It was revealed that the adsorbent dose and lead initial concentration are the most significant factors affecting lead uptake onto the synthesized adsorbent and the adsorption kinetics was fast. The obtained results indicated that the Avrami kinetic and Redlich-Peterson isotherm models best fit the lead adsorption kinetics and isotherm experimental results, respectively. Furthermore, the response surface methodology (RSM) technique was employed for optimization of lead removal, achieving near complete removal (>99 %) at LTH/CNT-COOH/Bent dose of 0.5 g/L, lead initial concentration of 40 ppm and a time of 2 h. Additionally, the machine learning (ML) and the ANN based models for lead removal using LTH/CNT-COOH/Bent nano-composite yielded good predictions.

Fluoride Removal in Water Using Kaolin and Eggshell Powder Blend Adsorbents

Fluoride contamination in water has emerged as a significant global concern due to its adverse health effects when consumed in excess. This study is focused on developing an eco-friendly, cost-effective adsorbent for fluoride removal using eggshells and kaolin. Adsorbent blends were prepared by mixing kaolin and eggshell powder in six different ratios, namely; 100:0, 80:20, 65:35, 50:50, 35:65, and 20:80. Cylindrical-shaped pellets were produced from each of the blends and subjected to the thermal treatment at 950 ◦C. Fluoride adsorption capacities of the pellets were investigated at different pH conditions (from pH 2 to pH 10) for a 5 mg/L fluoride solution with 1 g of adsorbent dosage and 60 min of contact time. Pellets with a 50:50 ratio (CKE3) were found to be the most effective adsorbent considering the adsorption capacity and stability at all the studied pH conditions. At pH 6, CKE3 showed an adsorption capacity of 0.06 mg/g compared to 0.02 mg/g of kaolin-only pellets. XRD, TGA-DSC, EDX and SEM analysis were used to characterize the adsorbent. XRD analysis showed that the raw adsorbent contained phases of CaCO3 and kaolinite, whereas the calcined material comprised Ca(OH)2 and metakaolinite. Batch experiments were carried out with CKE3 for adsorbent dosage, pH, contact time, and initial fluoride concentration. An adsorbent dosage of 4 g was capable of resulting in a 53% removal of fluoride for a 5 mg/L solution after 60 min of contact time. Pseudo-first-order and pseudo-second-order kinetic models were applied in the study, and pseudo-second-order exhibited the best fit. The isotherm data were studied for Langmuir and Freundlich models, and the results were satisfactorily fitted with Langmuir isotherm.

Eco-Friendly Carbon Nanotubes Reinforced with Sodium Alginate/Polyacrylic Acid for Enhanced Adsorption of Copper Ions: Kinetics, Isotherm, and Mechanism Adsorption Studies.

This study investigates the removal efficiency of Cu2+ from wastewater using a composite hydrogel made of carbon nanotubes (CNTs), sodium alginate (SA), and polyacrylic acid (PAA) prepared by free radical polymerization. The CNTs@SA/PAA hydrogel's structure and properties were characterized using SEM, TEM, FTIR, XRD, rheology, DSC, EDS, elemental mapping analysis, and swelling. The adsorption performance for Cu2+ was tested in batch adsorption experiments, considering the pH, dosage, initial concentration, and contact time. The optimal conditions for Cu2+ removal were pH 5.0, an adsorbent dosage of 500 mg/L, and a contact time of 360 min. The adsorption followed pseudo-second order kinetics. Isotherm analyses (Langmuir, Freundlich, Temkin, Dubinin-Radushkevich, Sips, Toth, and Khan) revealed that the Freundlich isotherm best described the adsorption, with a maximum capacity of 358.52 mg/g. A thermodynamic analysis indicated that physical adsorption was the main interaction, with the spontaneity of the process also demonstrated. This study highlights the high efficiency and environmental friendliness of CNT@SA/PAA composites for Cu2+ removal from wastewater, offering a promising approach for water treatment.

Facile synthesis of zeolitic‐imidazole framework‐67 (ZIF‐67) for the adsorption of indigo carmine dye

AbstractThis study aims to synthesize ZIF‐67 for the adsorption of indigo carmine (I.C.) dye. ZIF‐67 materials were synthesized under different conditions and the synthesis condition of ZIF‐67 giving the best adsorption efficiency was obtained. In batch adsorption studies, pH, adsorbent amount, contact time, initial dye concentration, and temperature effects were investigated. Adsorption data were applied to Langmuir, Freundlich, and Temkin isotherm models. The best correlation value was obtained in Langmuir isotherm (R2 = 0.999). The adsorption of I.C. dye with ZIF‐67 occurred in a monolayer with a homogeneous surface according to Langmuir isotherm. The highest adsorption capacity value of ZIF‐67 metal–organic framework for I.C. dye was found as 370 mg/g. Kinetic model studies were also performed and pseudo first‐order, pseudo second‐order, and intraparticle diffusion models were used. Pseudo second‐order was the best fitting kinetic model to the data (R2 = 0.997). Adsorption mechanisms of ZIF‐67 for I.C. dye include electrostatic interaction, π–π interaction, and hydrogen bonding. Thermodynamic studies showed that I.C. removal by ZIF‐67 is an exothermic and spontaneous process. ZIF‐67 was characterized by X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FT‐IR), field emission scanning electron microscope (FE‐SEM), and N2 adsorption–desorption. The surface area of synthesized ZIF‐67 was found 1493 m2 g−1. The salt concentration effect on I.C. adsorption by ZIF‐67 was also investigated, showing an increase in adsorption capacities with increasing salt concentration. The regeneration study was carried out and after 5 cycles, the reduction in efficiency was 21%.

Carbon Dots Derived from Waste Fish Scale for Enhanced Removal of Levofloxacin Drug: Parametric Optimization, Isotherm and Kinetic Studies

The public health and environmental protection have been facing a great challenge for efficient antibiotics' adsorption from aqueous solution. In this work, a carbon dots nanoparticle from biomass (fish scale) was synthesized and employed for antibiotic adsorption. The synthesized fish scale carbon dots (FCD) were characterized by means of the X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Fourier transform infrared (FTIR) analyses. Experiments on adsorption were performed to examine the capability of the synthesized adsorbent for adsorption of Levofloxacin. The optimum conditions were ascertained through the use of Response Surface Methodology (RSM) design to increase the effectiveness of levofloxacin removal, and there was 96.03% removal efficiency of 60 minutes contact time, 10 mg/L levofloxacin concentration and FCD dosage of 0.2 g/L. Also, the adsorption experiments indicated that at the lowest concentration of 10 mg/L, at time 45 min and 0.15 mg dosage the adsorption rate was high. For the kinetics data, the pseudo-second order model best fit the data. Furthermore, the Redlich-Peterson model fit isothermal data the best.

Wettability and Interfacial Reaction between the K492M Alloy and an Al2O3 Shell.

In this study, wettability behavior and the interaction between the K492M alloy and an Al2O3 shell were investigated at 1430 °C for 2~5 min. The microstructural characterization of the alloy-shell interface was carried out by optical microscopy (OM) and scanning electron microscopy (SEM). The results indicated that the interaction could cause a sand adhesion phenomenon affecting the alloy, and the attached products were Al2O3 particles. In addition, the wetting angles of the alloys located on the shell were 125.2°, 109.4°, 97.0°, and 95.0°, respectively, as the contact time was increased from 2 to 5 min. Apparently, the wettability of the alloy in relation to the shell had a relationship with the contact time, where a longer contact time was beneficial to the permeation of the alloy into the shell and the interaction between the two components. No significant chemical products could be detected in the interaction layer, indicating that only the occurrence of the physical dissolution of the shell took place in the alloy melt.

Metal adsorption equilibrium response of iron oxide nanoparticles embedded on Acacia (Vachellia nilotica) wood waste under different parametric conditions

The present study reveals cost-effective, environmentally approachable, and efficient adsorbent for the elimination of heavy metals by utilizing the biological synthesis route of nanoparticles (NPs). IONPs (hematite) synthesized from Vachellia nilotica wood waste. Raw wood waste and IONPs were characterized by SEM and FTIR. A batch adsorption process was conducted to study the adsorption of lead (Pb+2) and (Cu+2) ions by raw wood waste and IONPs synthesized from wood waste. Parameters like pH change, temperature, dosage of sorbent, and contact time were performed to provide information about optimal conditions for adsorption. It was found that an adsorbent dosage of 4 g, pH = 7, temperature = 120 °C, and time of 20 min provided high removal efficiency of both metals. With Langmuir and Freundlich adsorption isotherm, experimental data matched well with a high adsorption capacity of 7.5 mg/L for Cu (II) and 0.83 mg/L for Pb (II). Kinetics study shows that equilibrium data supports with pseudo-second-order model with the highest R 2=0.99. Thermodynamics study (ΔGo, ΔHo, and ΔSo) shows that the process is feasible and has an endothermic nature. IONPs provide high removal efficiency with R 2=0.99 with both metals. IONPs proved as efficient adsorbents with high removal efficacy of studied metal as paralleled to raw wood waste.

UV-radiation manufacturing of natural macromolecular products salecan and tannic acid-based functional gel material as superadsorbent for toluidine blue remediation

Adsorbent materials constructed from natural macromolecular products are favored because of their wide range of sources, biodegradability, and environmental friendliness. Salecan is a novel extracellular polysaccharide with ideal physicochemical and biological activities. Here, we have designed a polymer gel through UV-initiated polymerization of [2-(Methacryloyloxy) ethyl] dimethyl-(3-sulfopropyl) ammonium hydroxide (SBMA) in the mixture of salecan and tannic acid. Photopatterned polymerization process allowed in situ formation of gel adsorbent in a mild reaction condition with energy-efficient manner. Batch experiments for toluidine blue (TB) adsorption were carried out as a function of initial dye concentration, solution pH, contact time, and gel dosage to examine the adsorption capacity, potential mechanism, and removal efficiency. Adsorption behavior exhibited a pH-dependence pattern, which was closely related to their swelling and morphological properties. Adsorption process was in conformity to pseudo-second-order kinetic and Langmuir isotherm models, unlocking a chemical adsorption behavior and monolayer-type removal. The maximum adsorption was 490.2 mg/g, which could be considered a superiorly competing value. Additionally, the UV-gel still showed desirable recyclability and maintained the adsorption effectiveness over 95 % after five regeneration cycles. This study opened up new prospects in preparing high performance adsorbent for TB decontamination and laid the foundation for polysaccharide-based adsorption material research.

Application of sewage sludge derived hydrochar as an adsorbent for removal of methylene blue

Hydrothermal pretreatment (HTP) is used to convert biomass into hydrochar (HC) through the application of heat and pressure in a water-based medium. The HC has emerged as a promising material for various environmental applications including wastewater treatment, soil amendment, and carbon sequestration. In this study, the applicability of sewage sludge (SS) derived HC was tested as an adsorbent for methylene blue (MB) dye removal from wastewater. The HC was also subjected to chemical activation with KOH before the adsorption study. The HC samples were characterized for structural morphology and molecular functionalities using instrumental analysis. All the HC samples exhibited almost similar adsorption capacity (∼190 mg/g) for MB after 24 h of contact time (MB concentration = 200 mg/L, solution pH = 7 and adsorbent dose = 1 g/L). The equilibrium data could be adequately fit in Langmuir model equation. The negative value of free energy indicated favorable MB adsorption process. The study demonstrated that the SS derived HC can be recycled as adsorbent in wastewater treatment plant which is not only an environment-friendly approach but also may reduce cost of tertiary treatment at sewage treatment plant often required to remove emerging contaminants.

A rosin-functionalized plastic surface inactivates African swine fever virus.

African swine fever virus (ASFV) causes a severe hemorrhagic disease in pigs, leading to up to 100% case fatality. The virus May persist on solid surfaces for long periods; thus, fomites, such as contaminated clothing, footwear, farming tools, equipment, and transport vehicles, May contribute to the indirect transmission of the virus. Here, a plastic surface functionalized with tall oil rosin was tested against ASFV. The rosin-functionalized plastic reduced ASFV infectious virus titers by 1.3 log10 after 60 min of contact time and killed all detectable viruses after 120 min, leading to a ~ 6 log10 reduction. In contrast, the infectious virus titer of ASFV in contact with low-density polyethylene (LDPE) plastic reduced <1 log10 after 120 min. Transmission electron microscopy (TEM) showed significant morphological changes in the virus after 2 h of contact with the rosin-functionalized plastic surface, but no changes were observed with the LDPE plastic. The use of antiviral plastic in the farming sector could reduce the spread of ASFV through fomites and could thus be part of an integrated program to control ASFV.

Fluoride Removal from Aqueous Solutions by Using Super-Adsorbents of Chitosan/Orange Peels/Activated Carbon@MgO: Synthesis, Characterization, and Adsorption Evaluation

Exposure to excessive concentrations of fluoride in potable water is harmful to human health; therefore, its limitation is deemed necessary. Among the commonly applied technologies, adsorption is selected, as it is a highly effective, simple, and economically efficient treatment. In the present study, several combinations of chitosan (CS), orange peels (OP), activated carbon (AC), and MgO were synthesized and tested as adsorbents in order to find the most effective derivative for fluoride extraction. The impact of the adsorbent dosage, pH level, contact time, and initial concentration was investigated to assess the feasibility of the chitosan/orange peels/activated carbon@MgO composite. According to the results, the modification of chitosan with AC, OP, and MgO in a unique adsorbent (CS/OP/AC@MgO), especially in acidic conditions (pH 3.0 ± 0.1) by using 1.0 g/L of the adsorbent, demonstrated the highest efficiency in F removal, up to 97%. The pseudo-second (PSO) order model and Langmuir isotherm model fit better to the experimental results, especially for CS/OP/AC@MgO, providing a Qm = 26.92 mg/g. Thermodynamic analysis confirmed the spontaneous nature of the adsorption process. The structure and morphology of the modified OP/CS@AC-Mg were extensively characterized using BET, XRD, FTIR, and SEM techniques.

Visualization study on the dynamic behavior of shear thinning droplets impacting superhydrophobic spheres

The surface and droplet characteristics significantly affect the dynamic of droplet impact on solid surfaces. In present work, a platform is utilized to experimentally study the dynamic behavior of shear thinning fluid droplets impacting superhydrophobic spheres, where the effects of different concentrations, Weber numbers (We), particle size ratios on droplets impact are studied. The results showed that on the superhydrophobic sphere, as the shear thinning droplet concentration increases, the diffusion diameter increases, and the contact time decreases. For the same curvature, the contact time between the droplet and the sphere decreases with the increase of the We. When the We reaches 75 or above, the contact time remains constant with an increase in the We. For various curvature conditions, the contact time increases as the curvature increasing. When the diameter ratio of the sphere to the droplet is D∗≥6, the maximum diffusion coefficient remains almost constant. However, when D∗<6, the maximum diffusion dimensionless diameter significantly increases as the particle size ratio decreases. More importantly, a theoretical model considering gravity effect is presented to predict the maximum dimensionless diameter of shear thinning droplets on superhydrophobic spheres according to energy conservation. The predicted results are rationally agreement with experiments with the deviation within ±10 %.

Hydrothermal fabrication of composite chitosan grafted salicylaldehyde/coal fly ash/algae for malachite green dye removal: A statistical optimization

In this study, chitosan grafted salicylaldehyde/coal fly ash/algae (Chi-SL/CFA/Alg) was synthesized by assistance of hydrothermal process to be an effective adsorbent to remove cationic dye (malachite green: MG) from water. The physicochemical properties of the Chi-SL/CFA/Alg biomaterial were examined using SEM-EDX, pHpzc, specific surface area (BET), and FTIR analyses. The optimization process of the adsorption operation parameters for MG removal by Chi-SL/CFA/Alg were optimized using a Box-Behnken design (BBD). The selected adsorption operation parameters Chi-SL/CFA/Alg dosage (A: 0.02–0.1 g/100 mL), solution pH (B: 4–8), and contact time (C: 20–360 min). Analysis of variance (ANOVA) test was applied to determine the significant interaction between the adsorption operation parameters and to validate BBD output. The adsorption kinetics and isotherms of MG dye by Chi-SL/CFA/Alg were well described by pseudo-second order (PSO) kinetic and Freundlich isotherm model respectively. Thus, the maximum adsorption capacity (qmax) of MG dye by Chi-SL/CFA/Alg was found to be 493.7 mg/g at basic pH environment (pH = 8) and working temperature 25 °C. The adsorption mechanism can be ascribed to various interactions, including hydrogen bonding, π-π interactions, electrostatic attraction, and n-π interactions. Thus, Chi-SL/CFA/Alg can be considered as preferable and potential adsorbent for removing cationic dye from aqueous environment.

Measurement of ethanol concentration for monitoring the solvent exchange during the alcogel preparation

A crucial and time-consuming stage in aerogel production is the solvent exchange process for alcogel formation. This process involves multiple steps, exposing the hydrogel to ethanol solutions with increasing concentration until the equilibrium in each step. Currently, the determination of contact time between phases (hydrogel and liquid solution) is either arbitrary or based on prior studies. However, considering the unique physicochemical characteristics of each system, as well as the solid-liquid interactions and the liquid diffusion within the matrix, the required time may vary. Monitoring this step can lead to a reduction in the time needed for alcogel production and the optimization of the entire process. The refractive index serves as a tool to assess ethanol concentration in the liquid solution over time, providing immediate information about the status of the solvent exchange. Alongside, differential scanning calorimetry can be employed to evaluate ethanol content in the alcogel (solid phase), confirming the attainment of equilibrium between phases.•This research introduces a technique for monitoring solvent exchange.•Refractive index measurement of the liquid solvent offers immediate concentration information into the status of the solvent exchange.•Differential scanning calorimetry is applicable for measuring the ethanol content within the alcogel and validating refractive index findings.

Peat Water Treatment Using Modified Red mud

Red mud is an alumina refinery waste residue that has been used to develop an effective adsorbent for wastewater treatment, one of which can be applied to peat water. Peat water treatment is carried out using the adsorption method. This study sought to ascertain the impact of the acid types of acid HCl and H2SO4 solution on dealumination process to the characteristics of the red mud adsorbent based on the analysis of XRF and BET instruments. In addition, this study was to determine the effect of the effect of mass variations of the red mud adsorbent on the effectiveness of peat water treatment. This research was conducted on a laboratory scale using variations in the adsorbent mass of 1 g; 3 g ; 5 g and 7 g and variation of contact time used was 15, 30, 60, and 90 minutes . The results showed an increase in the Si/Al ratio from 1.064% to 1.697% for HCl, while for H2SO41.565%. Increasing of surface area with HCl was 179.574% while using H2SO4 was 162.891%. The results of research on the adsorption process with variations in the mass of the adsorbent 1, 3, 5, and 7 grams obtained the results of peat water pH respectively were 6.6; 7.0; 7.0; and 7,1. In the Fe metal there were removal of 73.39%; 37.09%; 24.19% and -141.93%. Then for the organic matter removal efficiency were 53.07%; 50%; 44.30% and -17.98% respectively. In variation of contact time for the parameter Fe, there were removals of 29,03%, 27,41%, and 24,19% respectively. Then for organic matter the removal efficiencies were 32,46%, 54,82%, 48,25%, and 44,29%. The optimum condition based on the result obtained are the 5 g for the mass adsorbent and 30 minute for contact time. Keywords: adsorbent; dealumination; H2SO4; HCl; peat water; red mud.

The Application of Wood Biowaste Chemically Modified by Bi2O3 as a Sorbent Material for Wastewater Treatment

Textile dyes discharged into aquatic systems can have significant environmental impacts, causing water pollution and toxicity to aquatic life, and constituting a human health risk. To manage these effects, the sorption ability of wood biowaste chemically modified by Bi2O3 for textile dye removal was investigated. Sorbent characterization was performed using scanning electron microscopy, and elemental analysis by energy dispersive X-ray spectroscopy (SEM-EDX), X-ray diffraction (XRD), the Brunauer–Emmett–Teller (BET) method for the specific surface area, and Fourier transform infrared spectroscopy–attenuated total reflectance (FTIR-ATR). The optimization of the sorption process was carried out, and optimal parameters, such as contact time, pH, the dose of sorbent, the concentration of dye, and temperature, were defined. Also, desorption studies were conducted. Kinetics and isotherms studies were carried out, and the data fits to a pseudo-second order model (r2 ≥ 0.99) and Langmuir model (r2 ≥ 0.99), indicating that the process occurs in the monolayer form and the dye sorption depends on the active sites of the sorbent surface. The maximal sorption capacity of the sorbent was 434.75 mg/g.

Appraisal of Characterization and Adsorption Isotherm in the Bioremediation of Cu and Zn Ions from Aqueous Solutions Exploiting Unmodified Corn and Coconut Husk

Environment is contaminated by heavymetals has emerged as a substantial globaly. Conventional remediation methods have proven inadequate and costly in addressing this issue. Hence, there is a pressing need to discover bio-remediation as a cost effective, effectual, and environmentally, a substitute for heavymetal removal. This work investigates the adsorption behaviour of Corn Husk (CH) and Coconut Husk (CCH), an inexpensive adsorbent, towards Cu and Zn ions for potential application in wastewater treatment. The physico-chemical variables of unmodified CH and CCH were appraised, and batch experimental methods were employed to study variables like pH, contact time, size of particle, and preliminary content of metals. The impact of solution pH on metals uptake by the adsorbent was investigated on the pH range of 3 to 8, revealing optimal removal efficiencies at pH 6 for Cu and pH 5 for Zn. Equilibrium adsorption times were determined to be 80 minutes for Cu and 60 minutes for Zn ions onto CH and CCH. adsorption volumes is conforming to mono-layer coverage, attained from the Langmuir plots were 4.792 mg/g and 4.594 mg/g respectively for Cu and Zn metals onto the CH and 4.771 mg/g and 4.400 mg/g for their adsorption onto CCH. Experimental values were confirmed to the Langmuir model and Freundlich model, with the Langmuir model providing the best fit. The CH based adsorbent was generally found to have an increased capacity of adsorption of the metal contents than Coconut husk (CCH). These findings underscore the strength of Corn husk as an active adsorbent to extract cationic heavymetal contents from industrial effluents.

Performance Assessment of Biomass-derived Urea-Furfuraldehyde Resins as Oilfield Scale Inhibitors

Oilfield-scale formation is a persistent challenge in the oil industry. While numerous scale inhibitors have been in use for decades, there is a significant research gap in discovering renewable, cost-effective, ecologically friendly, and efficient inhibitors. This study sets out to fill this gap by investigating the potential of scale inhibitors (SIs) made from bio-resin derivatives of red onion skin; ROF and ROFU, in reducing CaCO3 and CaSO4 scales. The scale inhibition performance of ROF and ROFU was rigorously evaluated using the NACE standard static bottle test method. The data revealed that increasing scale-inhibitor contact time, concentration, and temperature enhances inhibitor efficacy, with the best inhibition efficiencies found for ROF and ROFU on the CaSO4 scale compared to the CaCO3 scale across all studied parameters. A comparison of the prepared SIs with a commercial scale inhibitor (CSI) showed a high inhibition rate of over 90% at minimal dosage of 60ppm in both scales studied. Despite having a lower inhibition rate (IE) than CSI, ROF and ROFU demonstrate significant potential as green oilfield SIs. This sustainable technique, which transforms agro-waste into a valuable oilfield chemical via a one-pot chemical process, could have profound economic and societal benefits, offering hope for a more sustainable future in the oil industry.