Removal of Phenolphthalein from Laboratory Wastewater Using Natural Clay and Activated Carbon

Activated carbon and natural clay are extremely promising for the removal of dyes in a water solution. Natural clay and activated carbon were characterized using X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) techniques, and the food dye was characterized by UV-Visible. The effects of various experimental parameters, such as initial carmine concentration, contact time, temperature and pH were studied. The removal of the dye increases with the decrease in the initial concentration of carmine and the contact time of the solution. The percentage of carmine removal increases accordingly, reaching 97% for activated carbon and 67% for natural clay. Langmuir and Freundlich adsorption models were used for the adsorption equilibrium descriptions. The data was very well corrected with these models. Monolayer adsorption capacities were equal to 31 mgg-1 at pH 8.0 and 27°C. Adsorption measurements show that the adsorption process is very fast and physical in nature. Thermodynamic parameters such as enthalpy ∆H°, ∆S° entropy and ∆G° free enthalpy were also evaluated to reveal the nature of adsorption. The results explain that the adsorption process is an exothermic, spontaneous physisorption.

Natural clay and activated carbon are extremely encouraging for the removal of colored indicators in an aqueous solution. The natural clay and activated carbon were analyzed by X-ray diffraction (XRD) and Fourier transformation (FTIR) and the colored indicator was characterized by UV-Visible. The effects of various experiments, such as initial phenolphthalein concentration, contact time, temperature, pH and decolorization were studied. Dye removal increases with the decrease in the initial concentration of phenolphthalein and the contact time of the solution. The phenolphthalein removal percentage increases accordingly, reaching 99% for activated carbon and 98% for natural clay. The Langmuir and Freundlich adsorption models were used for descriptions of the adsorption equilibrium. The data was very well corrected with these models. Monolayer adsorption capacities were equal to 35 mgg-1 at pH 8.0 and temperature 27°C. Adsorption Measurements show that the adsorption process is very rapid and physical in nature. The results explain that the adsorption process is an exothermic and spontaneous physisorption.

The natural clay is an abundant, accessible, and low-cost material that has the potential for use in the water and wastewater industry. In this paper, Iranian natural clay and clay/Fe-Mn composite were used to remove toxic arsenic from the liquid environment. The natural clay and clay/Fe-Mn composite were characterized by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), energy-dispersive X-ray (EDX), X-ray diffractometry (XRD), thermo-gravimetric analysis (TGA), and atomic force microscopy (AFM) techniques. The effects of parameters (initial pH, temperature, sorption dose, and contact time) on the efficiency and behavior of the arsenic(V) adsorption process were studied. Freundlich (R2 = 0.945 and 0.989), Langmuir (R2 = 0.922 and 0.931), modified Langmuir (R2 = 0.921 and 0.929), and Dubinin-Radushkevich (R2 = 0.706 and 0.723) models were fitted to evaluate the equilibrium data of arsenic(V) adsorption process by natural clay and clay/Fe-Mn composite, respectively. The Langmuir adsorption capacity of arsenic(V) by the natural clay and clay/Fe-Mn composite was determined to be 86.86 mg/g and 120.70 mg/g, respectively. The arsenic(V) adsorption process followed the pseudo-second-order model. Negative values of ΔG° and ΔH° showed that the arsenic(V) sorption by the studied materials is thermodynamically spontaneous and exothermic. According to the findings, the natural clay and clay/Fe-Mn are suitable and recyclable sorbents for arsenic(V) adsorption from aqueous solutions. Also, the composite of clay with iron and manganese can improve the efficiency of clay in the removal of arsenic.

Natural clay being locally abundant and cheap material in Algeria can be easily activated to become a promising adsorbent for phenol removal from aqueous solution. The natural clay before and after activation was characterized using XRD and IR techniques. The effects of various experimental parameters, such as initial phenol concentration, temperature, pH, contact time and adsorbent done on the adsorption extent were investigated. Langmuir adsorption model was used for the mathematical description of the adsorption equilibrium and the equilibrium data fitted very well with this model. The activated natural clay had the monolayer adsorption capacity equal to 15 mg/g at pH value of 5.0 and 23°C, adsorption measurements show that the process is very fast and physical in natural clay. The extent of the phenol removal increased with the decrease in the initial concentration of the phenol and contact time of solution. The results showed that as the amount of the adsorbent was increased, the percentage (%) of phenol removal increased accordingly. Thermodynamic parameters showed that the adsorption of phenol on activated natural clay was exothermic. Key words: Phenol, activated clay, adsorption isotherm, thermodynamic parameters, montmorillonites, adsorbent, x-ray diffraction.

Laboratory waste water is categorized as a toxic and hazardous waste. Research on laboratory waste water treatment which is resulted from COD analysis by applying coagulation, filration, adsorption and ion exchange in one step intergrated method has been done, in a laboratory scale of 1 liter volume of laboratory waste water. The purpose of this research is to get the optimum condition of treatment by variation the kind and concentration of coagulant, and the contact time in the adsorption process. Percentage decrease of pollutant has been observed through the measurement of some parameters such as: Total Dissolved Solid (TDS); Heavy metals such as iron (Fe), Manganese (Mn), and chromium (Cr), ammoniac and acidity (pH). The resultof this research that the best coagulant was 1 g/L Alum sulphate (AL 2 (SO 4 ) 3 ) and contact time was 2,5-5 minute. The result of analysis integrated laboratory waste water had been treated with batch system able to reduced total dissolved solution (TDS) 78,61 – 91,23%. Heavy metals Fe 97,61% - 99,99%, Mn 45,53% - 99,88%, Cr 92,54% - 99,98% and ammoniac 22,54% - 91,82%. Acidity (pH) of final laboratory waste water was 8,93.

In this study, natural clay (NC) was collected from Saudi Arabia and modified by cocamidopropyl betaine (CAPB) at different conditions (CAPB concentration, reaction time, and reaction temperature). NC and modified clay (CAPB-NC) were characterized using X-ray diffraction, thermogravimetric analysis, Fourier transform infrared spectroscopy, field-emission scanning electron microscopy, and N2 adsorption at 77 K. The adsorption efficiency of NC and CAPB-NC toward Pb2+ and reactive yellow 160 dye (RY160) was evaluated. The adsorption process was optimized in terms of solution initial pH and adsorbent dosage. Finally, the adsorption kinetics and isotherms were studied. The results indicated that NC consists of agglomerated nonporous particles composed of quartz and kaolinite. CAPB modification reduced the specific surface area and introduced new functional groups by adsorbing on the NC surface. The concentration of CAPB affects the adsorption of RY160 tremendously; the optimum concentration was 2 times the cation exchange capacity of NC. The equilibrium adsorption capacity of CAPB-NC toward RY160 was about 6 times that of NC and was similar for Pb2+. The adsorption process followed the pseudo-second-order kinetics for both adsorptive. RY160 adsorption on CAPB-NC occurs via multilayer formation while Pb2+ adsorption on NC occurs via monolayer formation..

In this work, we study the elimination of three bivalent metal ions (Cd2+, Cu2+, and Pb2+) by adsorption onto natural illitic clay (AM) collected from Marrakech region in Morocco. The characterization of the adsorbent was carried out by X-ray fluorescence, Fourier transform infrared spectroscopy and X-ray diffraction. The influence of physicochemical parameters on the clay adsorption capacity for ions Cd2+, Cu2+, and Pb2+, namely the adsorbent dose, the contact time, the initial pH imposed on the aqueous solution, the initial concentration of the metal solution and the temperature, was studied. The adsorption process is evaluated by different kinetic models such as the pseudo-first-order, pseudo-second-order, and Elovich. The adsorption mechanism was determined by the use of adsorption isotherms such as Langmuir, Freundlich, and Temkin models. Experiments have shown that heavy metals adsorption kinetics onto clay follows the same order, the pseudo-second order. The isotherms of adsorption of metal cations by AM clay are satisfactorily described by the Langmuir model and the maximum adsorption capacities obtained from the natural clay, using the Langmuir isotherm model equation, are 5.25, 13.41, and 15.90 mg/g, respectively for Cd(II), Cu(II), and Pb(II) ions. Adsorption of heavy metals on clay is a spontaneous and endothermic process characterized by a disorder of the medium. The values of ΔH are greater than 40 kJ/mol, which means that the interactions between clay and heavy metals are chemical in nature.

The current work investigates the adsorption behavior of methylene blue (MB) from aqueous solution using natural Saudi Red Clay (SRC) adsorbent. The surface characteristics of the adsorbent were investigated using surface area measurements (SBET), Scanning Electron Microscopy (SEM), X-ray florescence (XRF) and Fourier-Transform Infrared Spectroscopy (FTIR) and x-ray diffraction (XRD). Various process parameters such as pH, adsorbent dosage, initial dye concentration, contact time and temperature were investigated. MB removal efficiency was noticed to increase with increasing adsorbent dosage while the effect of pH was noticed to be insignificant for the pH range studied. Applying the Langmuir isotherm fitting to the experimental data, a maximum adsorption capacity was found to be 50.25 mg g−1 of clay at 298 K. Pseudo-first-order and pseudo-second-order models were applied to the experimental data to study the kinetics of the process. Pseudo-second-order model fitted well with the experimental as compared to the pseudo-first order model. The spontaneous and endothermic nature of the adsorption process was revealed by studying the thermodynamic parameters of the system. The positive ΔS° value indicates the affinity of MB molecules to the adsorbent surface. Re-usability/recycling study showed that this material can be successfully reused at least four times in this study without significant loss in the adsorption capabilities.

Rapid industrialization has significantly boosted economic growth but has also introduced severe environmental challenges, particularly in water pollution. This study evaluates the effectiveness of a nanocomposite composed of Rumex Abyssinicus Activated Carbon/Acid Activated Bentonite Clay/Graphene Oxide, and Iron Oxide (RAAC/AABC/GO/Fe3O4) for chromium removal from aqueous solutions. The preparation of the nanocomposite involved precise methods, and its characterization was performed using Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Brunauer–Emmett–Teller (BET) surface area analysis, and the point of zero charge (pHpzc). Batch adsorption experiments were designed using Design Expert software with a central composite design under response surface methodology. The factors investigated included pH (3, 6, and 9), initial Cr (VI) concentration (40, 70, and 100 mg/L), adsorbent dose (0.5, 0.75, 1 g/200 mL), and contact time (60, 90, and 120 min). Adsorption isotherms were analyzed using nonlinearized Langmuir, Freundlich, and Temkin models, while pseudo-first-order and pseudo-second-order models were applied to adsorption kinetics. Characterization revealed a pHpzc of 8.25, a porous and heterogeneous surface (SEM), diverse functional groups (FTIR), an amorphous structure (XRD), and a significant surface area of 1201.23 m2/g (BET). The highest removal efficiency of 99.91% was achieved at pH 6, with an initial Cr (VI) concentration of 70 mg/L, a 90 min contact time, and an adsorbent dose of 1 g/200 mL. Optimization of the adsorption process identified optimal parameters as pH 5.84, initial Cr (VI) concentration of 88.94 mg/L, contact time of 60 min, and adsorbent dose of 0.52 g/200 mL. The Langmuir isotherm model, with an R2 value of 0.92836, best described the adsorption process, indicating a monolayer adsorption mechanism. The pseudo-second-order kinetics model provided the best fit with an R2 value of 0.988. Overall, the nanocomposite demonstrates significant potential as a cost-effective and environmentally friendly solution for chromium removal from wastewater.

This study investigates the synthesis, characterisation, and application of titanium dioxide nanoparticles (TNP) as an adsorbent for effectively removing Methylene Blue (MB) dye from aqueous solutions. The TNP was synthesised through a biogenic route using Pseudomonas aeruginosa as a bio-reducing and stabilising agent. The synthesised nanoparticles were characterised using various analytical techniques, including X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDX). The UV–visible spectrophotometer was used to monitor nanoparticle formation at a wavelength of 393 nm. Results from the study showed that XRD confirmed the nanostructured and amorphous nature of TNP, while SEM–EDX analysis indicated a coarse and rough surface of the nanoparticles. TEM analysis revealed their uniform spherical morphology, and FTIR spectroscopy identified the presence of O–H, C-O, and N–H functional groups likely responsible for MB adsorption. The adsorption experiments examined factors such as initial dye concentration, adsorbent dosage, contact time, solution pH, and temperature via batch adsorption methods. Kinetic studies demonstrated that the pseudo-second-order model accurately described the complex dynamics of the adsorption process. The Langmuir isotherm model was found to be the best fit for the experimental data, indicating monolayer adsorption on the TNP surface. Thermodynamic studies provided insights into the energetics of the adsorption process, with positive ∆H (12.75 kJ) indicating an endothermic reaction, while positive ∆S (62.27 J/mol) suggested increased disorderliness between adsorbent and adsorbate. Negative values of ∆G (− 8.522 and − 13.967 kJ/mol) confirmed the feasibility and spontaneity of the adsorption system, demonstrating a strong affinity for MB. After five cycles of adsorption and desorption, the regeneration study revealed that TNP maintained an MB removal capacity of over 80%. Highlights from this research underscore the excellent potential of green-synthesised TNP as a promising adsorbent for the efficient removal of MB dye from aqueous solutions and for potential application in other wastewater treatments.

The comparative study of the adsorption of three red dyes (phenolphthalein, Eosin B and carmine) on activated carbon and natural clay was carried out in a static régime. We used different physico-chemical techniques to know the crystalline structure of the DRX device, to do this a clear idea of the chemical bond by the FTIR analysis and finally to know the maximum absorbance λmax of the dyes it is by the method of analysis UV-Visible. The tree dyes removal percentage increases accordingly, reaching 99% for activated carbon and 98% for natural clay .The Langmuir and Freundlich adsorption models were used for descriptions of the adsorption equilibrium. The data was very well corrected with these models. Monolayer adsorption capacities were equal to 30 mgg-1 at which is in the range 5 - pH -8 in temperatures 25°C and time in rang 2 - hour - 30. Adsorption Measurements show that the adsorption process is very rapid and physical in nature. The results explain that the adsorption process is an exothermic and spontaneous physisorption and that the red color of three red dyes in three media (acid, neutral, base) does not influence the adsorption phenomenon

Kaolinite (K)-based matrices modified with manganese ferrite nanoparticles (MnFe₂O₄) were synthesized via a microwave-assisted route and evaluated as magnetically recoverable adsorbents for methylene blue (MB) removal from aqueous solutions. Structural, morphological, and compositional characteristics were investigated using X-ray diffraction (XRD), X-ray fluorescence (XRF), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and Brunauer–Emmett–Teller (BET) surface area analysis. XRD confirmed the presence of inverse spinel MnFe₂O₄, while XRF revealed a significant increase in iron oxide content, indicating successful incorporation of manganese ferrite into the kaolinite matrix. FTIR and SEM analyses supported surface modification through changes in functional groups and morphology. Batch adsorption studies demonstrated that MB removal efficiency was influenced by solution pH, adsorbent dosage, initial dye concentration, contact time, and temperature. Optimal adsorption performance was achieved at pH 5, an initial MB concentration of 40 mg/L, and an adsorbent dosage of 0.6 g/L, attaining approximately 91% removal efficiency. Adsorption equilibrium was best described by the Langmuir isotherm, indicating monolayer adsorption on a homogeneous surface. Kinetic data followed the pseudo-second-order model, suggesting that the adsorption rate was governed by surface interaction mechanisms rather than diffusion control. Thermodynamic analysis revealed that the adsorption process was spontaneous and weakly exothermic, with enhanced adsorption at elevated temperatures attributed to improved mass transfer rather than thermodynamic favorability. The MnFe₂O₄-modified kaolinite exhibited superior adsorption capacity and magnetic separability compared with natural kaolinite, along with good regeneration performance over multiple cycles. These findings demonstrate that MnFe₂O₄-embedded kaolinite matrices are promising, low-cost, and reusable adsorbents for dye-contaminated wastewater treatment.

Natural clay being locally abundant and cheap material in Algeria can be easily activated to become a promising adsorbent for phenol removal from aqueous solution. The natural clay before and after activation was characterized using XRD and IR techniques. The effects of various experimental parameters, such as initial phenol concentration, temperature, pH, contact time, and adsorbent dose on the adsorption extent were investigated. Langmuir adsorption model was used for the mathematical description of the adsorption equilibrium and the equilibrium data fixed very well with this model. The activated natural clay had the monolayer adsorption capacity equal to 15 mg/g at pH value of 5.0 and 23°C; adsorption measurements show that the process is very fast and physical in nature. The extent of the phenol removal increased with decrease in the initial concentration of the phenol and contact time of solution. The results showed that as the amount of the adsorbent was increased, the percentage of phenol removal increased accordingly. Thermodynamic parameters showed that the adsorption of phenol on activated natural clay was exothermic.

The adsorption properties of layered double hydroxide (Mg/Al-CO3) for the removal of Congo Red (CR) dye from aqueous solution were studied. The layered double hydroxide was synthesized by co-precipitation method and characterized by X-ray diffraction (XRD), Fourier Transform Infrared spectroscopic (FTIR) and Energy-Dispersive X-ray Spectroscopic (EDX). The effects of various experimental parameters such as contact time, dye concentrations and temperature variation were investigated. The results show that the amount of Congo Red adsorbed increases with increase in temperature but decreases with increase in initial dye concentration and contact time. The data were also fitted to several kinetic models: zero-order kinetic model, first-order kinetic model, second-order kinetic model, pseudo-second-order kinetic model and third-order kinetic model respectively. The adsorption process was best defined by zero-order-kinetic model (R2 = 1). Langmuir, Freundich, Temkin and Dubinin-kaganer-Radushkevich (DPK) adsorption isotherm models were applied to analyze adsorption data with Temkin isotherm being the most applicable to the adsorption process. Thermodynamic parameters e.g. △Go, △So, △Ho and △Hx of the adsorption process were found to be endothermic, spontaneous and feasible.

Removal of phenolphthalein and methyl orange from laboratory wastewater using tetraethylammonium modified kaolinite clay