Clean, safe and readily available water is very crucial in everyday life, especially for health, hygiene, and the productivity of the community. Unfortunately, increase in contaminants in water supplies from human activities and industrialization is very worrying. Conventional wastewater treatment includes the usage of alum that will affect health with prolonged consumption. This research was carried out to focus on the development of wastewater treatment system using adsorbent from Moringa oleifera seeds. Adsorbent was successfully synthesized from the seeds of Moringa oleifera. Characterization of the sample was made using X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscope (SEM), while the effectiveness of water treatment was analyzed using Turbidity Meter. Then, all samples were tested against kaolin wastewater. XRD results showed that all the adsorbent samples were amorphous in nature. FTIR results indicated that there were hydroxyl group and carboxylic group in the sample representing numerous oxygen-riddled functional groups on the surface. From SEM results, it was clearly shown that the pore structure and size of Moringa oleifera affected the capability of adsorption where the smaller the size, the more effective the sample. Turbidity test showed that the sample that worked best for wastewater treatment was adsorbent from Moringa oleifera seeds in size of 125µm that was heated for 4 hours with 93.76% turbidity removal. Therefore, this study proved that the adsorbent from Moringa oleifera seeds is very suitable for high turbidity wastewater treatment. Further studies investigating the combination of conventional activated carbon with adsorbent from Moringa oleifera seeds should be conducted before these samples are made available for further use so that we can compare which sample works best for wastewater treatment.
Multi-layer structure of functional materials often involves the integration of different crystalline phases. The film growth orientation thus frequently exhibits a transformation, owing to multiple possibilities caused by incompatible in-plane structural symmetry. Nevertheless, the detailed mechanism of the transformation has not yet been fully explored. Here we thoroughly probe the heteroepitaxially grown hexagonal zinc oxide (ZnO) films on cubic (001)-magnesium oxide (MgO) substrates using advanced scanning transition electron microscopy, X-ray diffraction and first principles calculations, revealing two distinct interface models of (001) ZnO/(001) MgO and (100) ZnO/(001) MgO. We have found that the structure alternatives are controlled thermodynamically by the nucleation, while kinetically by the enhanced Zn adsorption and O diffusion upon the phase transformation. This work not only provides a guideline for the interface fabrication with distinct crystalline phases but also shows how polar and non-polar hexagonal ZnO films might be manipulated on the same cubic substrate.
Mycelial pellets formed by Penicillium thomii ZJJ were applied as efficient biosorbents for the removal of polycyclic aromatic hydrocarbons (PAHs), which are a type of ubiquitous harmful hydrophobic pollutants. The live mycelial pellets were able to remove 93.48 % of pyrene at a concentration of 100 mg/L within 48 h, demonstrating a maximum adsorption capacity of 285.63 mg/g. Meanwhile, the heat-killed one also achieved a removal rate of 65.01 %. Among the six typical PAHs (pyrene, phenanthrene, fluorene, anthracene, fluoranthene, benzo[a]pyrene), the mycelial pellets preferentially adsorbed the high molecular weight PAHs, which also have higher toxicity, resulting in higher removal efficiency. The experimental results showed that the biosorption of mycelial pellets was mainly a spontaneous physical adsorption process that occurred as a monolayer on a homogeneous surface, with mass transfer being the key rate-limiting step. The main adsorption sites on the surface of mycelia were carboxyl and N-containing groups. Extracellular polymeric substances (EPS) produced by mycelial pellets could enhance adsorption, and its coupling with dead mycelia could achieve basically the same removal effect to that of living one. It can be concluded that biosorption by mycelial pellets occurred due to the influence of electrostatic and hydrophobic interactions, consisting of five steps. Furthermore, the potential applicability of mycelial pellets has been investigated considering diverse factors. The mycelia showed high environmental tolerance, which could effectively remove pyrene across a wide range of pH and salt concentration. And pellets diameters and humic acid concentration had a significant effect on microbial adsorption effect. Based on a cost-effectiveness analysis, mycelium pellets were found to be a low-cost adsorbent. The research outcomes facilitate a thorough comprehension of the adsorption process of pyrene by mycelial pellets and their relevant applications, proposing a cost-effective method without potential environmental issues (heat-killed mycelial pellets plus EPS) to removal PAHs.
Climate change caused by the greenhouse gases CO2 remains a topic of global concern. To mitigate the excessive levels of anthrophonic CO2 in the atmosphere, CO2 capture methods have been developed and among these, adsorption is an especially promising method. This paper presents a series of amine functionalized biochar obtained from desiccated coconut waste (amine-biochar@DCW) for use as CO2 adsorbent. They are ethylenediamine-functionalized biochar@DCW (EDA-biochar@DCW), diethylenetriamine-functionalized biochar@DCW (DETA-biochar@DCW), triethylenetetramine-functionalized biochar@DCW (TETA-biochar@DCW), tetraethylenepentamine-functionalized biochar@DCW (TEPA-biochar@DCW), and pentaethylenehexamine-functionalized biochar@DCW (PEHA-biochar@DCW). The adsorbents were obtained through amine functionalization of biochar and they are characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, Brunauer-Emmett-Teller (BET), and thermogravimetric analysis (TGA). The CO2 adsorption study was conducted isothermally and using a thermogravimetric analyzer. From the results of the characterization analyses, a series of amine-biochar@DCW adsorbents had larger specific surface area in the range of 16.2 m2/g-37.1 m2/g as compare to surface area of pristine DCW (1.34 m2/g). Furthermore, the results showed an increase in C and N contents as well as the appearance of NH stretching, NH bending, CN stretching, and CN bending, suggesting the presence of amine on the surface of biochar@DCW. The CO2 adsorption experiment shows that among the amine modified biochar adsorbents, TETA-biochar@DCW has the highest CO2 adsorption capacity (61.78 mg/g) when using a mass ratio (m:m) of biochar@DCW:TETA (1:2). The adsorption kinetics on the TETA-biochar@DCW was best fitted by the pseudo-second model (R2 = 0.9998), suggesting the adsorption process occurs through chemisorption. Additionally, TETA-biochar@DCW was found to have high selectivity toward CO2 gas and good reusability even after five CO2 adsorption-desorption cycles. The results demonstrate the potential of novel CO2 adsorbents based on amine functionalized on desiccated coconut waste biochar.
In this study, biochars derived from waste fiberboard biomass were applied in tetracycline (TC) removal in aqueous solution. Biochar samples were prepared by slow pyrolysis at 300, 500, and 800°C, and were characterized by ultimate analysis, Fourier transform infrared (FTIR), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET), etc. The effects of ionic strength (0-1.0 mol/L of NaCl), initial TC concentration (2.5-60 ppm), biochar dosage (1.5-2.5 g/L), and initial pH (2-10) were systemically determined. The results present that biochar prepared at 800°C (BC800) generally possesses the highest aromatization degree and surface area with abundant pyridinic N (N-6) and accordingly shows a better removal efficiency (68.6%) than the other two biochar samples. Adsorption isotherm data were better fitted by the Freundlich model (R2 is 0.94) than the Langmuir model (R2 is 0.85). Thermodynamic study showed that the adsorption process is endothermic and mainly physical in nature with the values of ΔH0 being 48.0 kJ/mol, ΔS0 being 157.1 J/mol/K, and ΔG0 varying from 1.02 to -2.14 kJ/mol. The graphite-like structure in biochar enables the π-π interactions with a ring structure in the TC molecule, which, together with the N-6 acting as electron donor, is the main driving force of the adsorption process.
The nanoenvironment of nanobiocatalysts, such as local hydrophobicity, pH and charge density, plays a significant role in optimizing the enzymatic selectivity and specificity. In this study, Kluyveromyces lactis β-galactosidase (Gal) was assembled onto polystyrene nanofibers (PSNFs) to form PSNF-Gal nanobiocatalysts. We proposed that local hydrophobicity on the nanofiber surface could expel water molecules so that the transgalactosylation would be preferable over hydrolysis during the bioconversion of lactose, thus improve the galacto-oligosaccharides (GOS) yield. PSNFs were fabricated by electro-spinning and the operational parameters were optimized to obtain the nanofibers with uniform size and ordered alignment. The resulting nanofibers were functionalized for enzyme immobilization through a chemical oxidation method. The functionalized PSNF improved the enzyme adsorption capacity up to 3100mg/g nanofiber as well as enhanced the enzyme stability with 80% of its original activity. Importantly, the functionalized PSNF-Gal significantly improved the GOS yield and the production rate was up to 110g/l/h in comparison with 37g/l/h by free β-galactosidase. Our research findings demonstrate that the localized nanoenvironment of the PSNF-Gal nanobiocatalysts favour transgalactosylation over hydrolysis in lactose bioconversion.
In this work, graphene oxide (GO) and its reduced graphene oxide-zinc oxide nanocomposite (rGO-ZnO) was used for the removal of Cr (VI) from aqueous medium. By employing a variety of characterization techniques, morphological and structural properties of the adsorbents were determined. The adsorption study was done by varying concentration, temperature, pH, time, and amount of adsorbent. The results obtained confirmed that rGO-ZnO is a more economical and promising adsorbent for removing Cr (VI) as compared to GO. Kinetic study was also performed, which suggested that sorption of Cr (VI) follows the pseudo-first-order model. For equilibrium study, non-linear Langmuir was found a better fitted model than its linearized form. The maximum adsorption capacity calculated for GO and rGO-ZnO nanocomposite were 19.49 mg/g and 25.45 mg/g, respectively. Endothermic and spontaneous nature of adsorption was detected with positive values of ΔS (change in entropy), which reflects the structural changes happening at the liquid/solid interface.
Herein, it was aimed to optimize, model, and forecast the biosorption of Congo Red onto biomass-derived biosorbent. Therefore, the waste-orange-peels were processed to fabricate biomass-derived carbon, which was activated by ZnCl2 and modified with cetyltrimethylammonium bromide. The physicochemical properties of the biosorbents were explored by scanning electron microscopy and N2 adsorption/desorption isotherms. The effects of pH, initial dye concentration, temperature, and contact duration on the biosorption capacity were investigated and optimized by batch experimental process, followed by the kinetics, equilibrium, and thermodynamics of biosorption were modeled. Furthermore, various artificial neural network (ANN) architectures were applied to experimental data to optimize the ANN model. The kinetic modeling of the biosorption offered that biosorption was in accordance both with the pseudo-second-order and saturation-type kinetic model, and the monolayer biosorption capacity was calculated as 666.67 mg g-1 at 25 °C according to Langmuir isotherm model. According to equilibrium modeling, the Freundlich isotherm model was better fitted to the experimental data than the Langmuir isotherm model. Moreover, the thermodynamic modeling revealed biosorption took place spontaneously as an exothermic process. The findings revealed that the best ANN architecture trained with trainlm as the backpropagation algorithm, with tansig-purelin transfer functions, and 14 neurons in the single hidden layer with the highest coefficient of determination (R2 = 0.9996) and the lowest mean-squared-error (MSE = 0.0002). The well-agreement between the experimental and ANN-forecasted data demonstrated that the optimized ANN model can predict the behavior of the anionic dye biosorption onto biomass-derived modified carbon materials under various operation conditions.
Water contamination can be detrimental to the human health due to higher concentration of carcinogenic heavy metals such as chromium (Cr) in the wastewater. Many traditional methods are being employed in wastewater treatment plants for Cr removal to control the environmental impacts. Such methods include ion exchange, coagulation, membrane filtration, and chemical precipitation and microbial degradation. Recent advances in materials science and green chemistry have led to the development of nanomaterial that possess high specific surface areas and multiple functions, making them suitable for removing metals such as Cr from wastewater. Literature shows that the most efficient, effective, clean, and long-lasting approach for removing heavy metals from wastewater involves adsorbing heavy metals onto the surface of nanomaterial. This review assesses the removal methods of Cr from wastewater, advantages and disadvantages of using nanomaterial to remove Cr from wastewater and potential negative impacts on human health. The latest trends and developments in Cr removal strategies using nanomaterial adsorption are also explored in the present review.
Palm oil mill wastes (palm kernel shell (PKS)) were used to prepare activated carbons, which were tested in the removal of colorants from water. The adsorbents were prepared by 1-h impregnation of PKS with ZnCl2 as the activating agent (PKS:ZnCl2 mass ratios of 1:1 and 2:1), followed by carbonization in autogenous atmosphere at 500 and 550 °C during 1 h. The characterization of the activated carbons included textural properties (porosity), surface chemistry (functional groups), and surface morphology. The dye removal performance of the different activated carbons was investigated by means of the uptake of methylene blue (MB) in solutions with various initial concentrations (25-400 mg/L of MB) at 30 °C, using a 0.05-g carbon/50-mL solution relationship. The sample prepared with 1:1 PKS:ZnCl2 and carbonized at 550 °C showed the highest MB adsorption capacity (maximum uptake at the equilibrium, q max = 225.3 mg MB / g adsorbent), resulting from its elevated specific surface area (BET, 1058 m2/g) and microporosity (micropore surface area, 721 m2/g). The kinetic experiments showed that removals over 90% of the equilibrium adsorptions were achieved after 4-h contact time in all the cases. The study showed that palm oil mill waste biomass could be used in the preparation of adsorbents efficient in the removal of colorants in wastewaters.
Elevated levels of nutrients in agroindustry wastewaters, and higher reliance on chlorination pose health threats due to formation of chlorinated organics as well as increased chlorination costs. Removals of ammonium and nitrate compounds were studied using activated carbon from palm shells, as adsorbent and support media. Experiments were carried out at several loadings, F:M from 0.31 to 0.58, and hydraulic residence times (HRT) of 24 h, 12 h and 8 h. Results show that the wastewater treatment process achieved removals of over 90% for COD and 62% for Total-N. Studies on removals from river water were carried out in sequencing batch reactor (SBR) and activated carbon biofilm (ACB) reactor. Removals achieved by the SBR adsorption-biodegradation combination were 67.0% for COD, 58.8% for NH3-N and 25.5% for NO3-N while for adsorption alone the removals were only 37.0% for COD, 35.2% for NH3-N and 13.8% for NO3-N. In the ACB reactor, at HRT of 1.5 to 6 h, removals ranged from 12.5 to 100% for COD, 16.7 to 100% for NO3-N and 13.5 to 100% for NH3-N. Significant decrease in removals was shown at lower HRT. The studies have shown that substantial removals of COD, NO3-N and NH3-N from both wastewater and river water may be achieved via adsorption-biodegradation by biofilm on activated carbon processes.
The present work was aimed at evaluating the multi-metals column adsorption of lead(II), cadmium(II) and manganese(II) ions onto natural bentonite. The bentonite clay adsorbent was characterized for physical and chemical properties using X-ray diffraction, X-ray fluorescence, Brunauer-Emmett-Teller surface area and cation exchange capacity. The column performance was evaluated using adsorbent bed height of 5.0 cm, with varying influent concentrations (10 mg/L and 50 mg/L) and flow rates (1.4 mL/min and 2.4 mL/min). The result shows that the breakthrough time for all metal ions ranged from 50 to 480 minutes. The maximum adsorption capacity was obtained at initial concentration of 10 mg/L and flow rate of 1.4 mL/min, with 2.22 mg/g of lead(II), 1.71 mg/g of cadmium(II) and 0.37 mg/g of manganese(II). The order of metal ions removal by natural bentonite is lead(II) > cadmium(II) > manganese(II). The sorption performance and the dynamic behaviour of the column were predicted using Adams-Bohart, Thomas, and Yoon-Nelson models. The linear regression analysis demonstrated that the Thomas and Yoon-Nelson models fitted well with the column adsorption data for all metal ions. The natural bentonite was effective for the treatment of wastewater laden with multi-metals, and the process parameters obtained from this work can be used at the industrial scale.
The current status of silver nanoparticles (AgNPs) in the water environment in Malaysia was examined and reported. For inspection, two rivers and two sewage treatment plants (STPs) were selected. Two activated carbons derived from oil palm (ACfOPS) and coconut (ACfCS) shells were proposed as the adsorbent to remove AgNPs. It was found that the concentrations of AgNPs in the rivers and STPs are in the ranges of 0.13 to 10.16 mg L-1 and 0.13 to 20.02 mg L-1, respectively, with the highest concentration measured in July. ACfOPS and ACfCS removed up to 99.6 and 99.9% of AgNPs, respectively, from the water. The interaction mechanism between AgNPs and the activated carbon surface employed in this work was mainly the electrostatic force interaction via binding Ag+ with O- presented in the activated carbon to form AgO. Fifteen kinetic models were compared statistically to describe the removal of AgNPs. It was found that the experimental adsorption data can be best described using the mixed 1,2-order model. Therefore, this model has the potential to be a candidate for a general model to describe AgNPs adsorption using numerous materials, its validation of which has been confirmed with other material data from previous works.
This work was aimed to evaluate the feasibility of castor bean residue based activated carbons prepared through metals chloride activation. The activated carbons were characterized for textural properties and surface chemistry, and the adsorption data of rhodamine B were established to investigate the removal performance. Zinc chloride-activated carbon with specific surface area of 395 m(2)/g displayed a higher adsorption capacity of 175 mg/g. Magnesium chloride and iron(III) chloride are less toxic and promising agents for composite chemical activation. The adsorption data obeyed Langmuir isotherm and pseudo-second-order kinetics model. The rate-limiting step in the adsorption of rhodamine B is film diffusion. The positive values of enthalpy and entropy indicate that the adsorption is endothermic and spontaneous at high temperature.
Multi-walled carbon nanotubes (MWCNTs) were prepared via chemical vapor deposition (CVD) using a series of different catalysts, derived from FeCoNiAl, CoNiAl and FeNiAl layered double hydroxides (LDHs). Catalyst-active particles were obtained by calcination of LDHs at 800 °C for 5 h. Nitrogen and hexane were used as the carrier gas and carbon source respectively, for preparation of MWCNTs using CVD methods at 800 °C. MWCNTs were allowed to grow for 30 min on the catalyst spread on an alumina boat in a quartz tube. The materials were subsequently characterized through X-ray diffraction, Fourier transform infrared spectroscopy, surface area analysis, field emission scanning electron microscopy and transmission electron microscopy. It was determined that size and yield of MWCNTs varied depending on the type of LDH catalyst precursor that is used during synthesis. MWCNTs obtained using CoNiAl-LDH as the catalyst precursor showed smaller diameter and higher yield compared to FeCoNiAl and FeNiAl LDHs.
The sorption characteristics of Cr(VI) and Cu(II) by ethylenediamine modified rice hull from single and binary metal ion solutions were evaluated under various experimental conditions. Optimal Cr(VI) and Cu(II) removal from single metal ion solutions occurred at pH 2.0 and 5.5, respectively. Simultaneous removal of Cr(VI) and Cu(II) occurred at pH greater than 3.0. The sorption kinetics of Cr(VI) and Cu(II) from single and binary metal ion solutions were studied with reference to metal concentration, agitation rate and particle size. Sorption of Cr(VI) was more rapid than Cu(II). The kinetics of metal ion sorption fitted a pseudo-second order expression. The variation in the initial uptake rates was very small at an agitation rate beyond 150 rpm and sorption was generally independent of particle size. Equilibrium sorption data could be fitted into the Langmuir isotherm equation. Maximum sorption capacities of ethylenediamine modified rice hull for Cr(VI) at pH 2 and Cu(II) at pH 4 in single metal solutions were 0.45 and 0.06 mmol g(-1), respectively. This corresponds to an enhancement factor of 2.6 and 3 fold for Cr(VI) and Cu(II), respectively, compared to natural rice hull. A synergistic effect was observed for sorption of these ions in binary metal solutions.
The removal of methyl orange (MO) dye has been studied using TiO2/chitosan-montmorillonite (TiO2/Cs-MT) bilayer photocatalyst which also functions as an adsorbent. The dye removal experiments were conducted in the dark and under UV-Vis light irradiation via adsorption and photocatalysis-adsorption processes, respectively. The adsorption modelings were employed on the dark experimental data and compared with the immobilized and suspended Cs-Mt counterparts. It was found that the bilayer photocatalyst closely followed the adsorption properties of immobilized Cs-Mt which obeyed the pseudo-second-order kinetic and film diffusion models. Fluorescent analysis revealed that the charge separation was enhanced in the presence of Cs-Mt as a sub-layer of TiO2. Under light irradiation, the photocatalytic activity of TiO2/Cs-MT corresponded to its adsorption counterpart trend and was optimized at pH 6.5 and 20 mg L-1 of MO dye solution. High removal efficiency and synergism of MO by TiO2/Cs-MT over TiO2 single layer were observed throughout the 10 cycles of application due to contribution of adsorption of Cs-Mt sub-layer and photocatalysis by TiO2 top layer.
Herein, a new approach was proposed to produce reduced graphene oxide (rGO) from graphene oxide (GO) using various oil palm wastes: oil palm leaves (OPL), palm kernel shells (PKS) and empty fruit bunches (EFB). The effect of heating temperature on the formation of graphitic carbon and the yield was examined prior to the GO and rGO synthesis. Carbonization of the starting materials was conducted in a furnace under nitrogen gas for 3 h at temperatures ranging from 400 to 900 °C and a constant heating rate of 10 °C/min. The GO was further synthesized from the as-carbonized materials using the 'improved synthesis of graphene oxide' method. Subsequently, the GO was reduced by low-temperature annealing reduction at 300 °C in a furnace under nitrogen gas for 1 h. The IG/ID ratio calculated from the Raman study increases with the increasing of the degree of the graphitization in the order of rGO from oil palm leaves (rGOOPL) < rGO palm kernel shells (rGOPKS) < rGO commercial graphite (rGOCG) < rGO empty fruit bunches (rGOEFB) with the IG/ID values of 1.06, 1.14, 1.16 and 1.20, respectively. The surface area and pore volume analyses of the as-prepared materials were performed using the Brunauer Emmett Teller-Nitrogen (BET-N₂) adsorption-desorption isotherms method. The lower BET surface area of 8 and 15 m2 g-1 observed for rGOCG and rGOOPL, respectively could be due to partial restacking of GO layers and locally-blocked pores. Relatively, this lower BET surface area is inconsequential when compared to rGOPKS and rGOEFB, which have a surface area of 114 and 117 m² g-1, respectively.
This study examines the feasibility of catalytically pretreated biochar derived from the dried exocarp or fruit peel of mangostene with Group I alkali metal hydroxide (KOH). The pretreated char was activated in the presence of carbon dioxide gas flow at high temperature to upgrade its physiochemical properties for the removal of copper, Cu(II) cations in single solute system. The effect of three independent variables, including temperature, agitation time and concentration, on sorption performance were carried out. Reaction kinetics parameters were determined by using linear regression analysis of the pseudo first, pseudo second, Elovich and intra-particle diffusion models. The regression co-efficient, R² values were best for the pseudo second order kinetic model for all the concentration ranges under investigation. This implied that Cu(II) cations were adsorbed mainly by chemical interactions with the surface active sites of the activated biochar. Langmuir, Freundlich and Temkin isotherm models were used to interpret the equilibrium data at different temperature. Thermodynamic studies revealed that the sorption process was spontaneous and endothermic. The surface area of the activated sample was 367.10 m²/g, whereas before base activation, it was only 1.22 m²/g. The results elucidated that the base pretreatment was efficient enough to yield porous carbon with an enlarged surface area, which can successfully eliminate Cu(II) cations from waste water.
The non-ionic silicone surfactant (OFX 0309) has been applied in cloud point extraction for the extraction of triazine herbicides in food samples. Evidence has shown that the non-ionic silicone surfactant demonstrated a good performance as an extractor toward triazine herbicides. In this present study, OFX 0309 surfactant was combined with activated charcoal (AC) due to their valuable properties. Activated charcoal modified with non-ionic silicone surfactant coated with magnetic nanoparticles (AC-OFX MNPs) was synthesized and characterized by FT-IR, VSM, SEM, TEM and BET. This novel material was applied as a magnetic adsorbent for the pre-concentration and separation of triazine herbicides due to hydrophobic interaction between polysiloxane polyether of OFX 0309 surfactant and triazine herbicides. Under optimal conditions, the proposed magnetic solid phase extraction method using AC-OFX MNPs adsorbent was applied to extract triazine herbicides from selected milk and rice samples using high performance liquid chromatography coupled with diode array detector. The validation method revealed a good linearity (1 - 500 μg L-1) with the coefficient of determination (R2) in the range of 0.992-0.998 for the samples. The limits of detection (LOD) of the developed method were 0.04 - 0.05 µg L-1 (milk sample) and 0.02 - 0.05 µg L-1 (rice sample). The limits of quantification (LOQ) were 0.134 - 0.176 µg L-1 (milk sample) and 0.075 - 0.159 µg L-1 (rice sample). The recoveries of the triazine compounds ranged from 81% to 109% in spiked milk samples and from 81% to 111% in spiked rice samples, with relative standard deviations (RSD) values lower than 13.5% and 12.1% for milk and rice samples, respectively. To the best of our knowledge, this is the first study that have investigated the use of magnetic nanoparticles coated activated charcoal modified with OFX 0309 surfactant for pretreatment of triazine herbicides in food samples analysis for simultaneous separation of organic pollutants.