Availability Of Sorption Sites Research Articles

Kinetics and Dynamics of Sorption of the Glucose Target Molecule by a Molecularly Imprinted Polymer

The effect of imprinting of a polymer matrix based on ethylene glycol dimethacrylate on the kinetics and dynamics of binding of the glucose target molecule has been studied. The contribution of the adsorption act to the sorption kinetics of the target sorbate by the molecularly imprinted polymer was established. Mixed-diffusion limitation of mass transfer and cooperative adsorption of glucose molecules during sorption by both imprinted and nonimprinted polymer granules were revealed. The binding rate and accessibility of sorption sites in the imprinted polymer were shown to increase, and frontal sorption occurred in a regular mode.

The influence of partial chemical component removal on water state at high relative humidity and cell wall saturation state

Water sorption in wood is mostly determined by the cell wall pores and the availability of sorption sites. In this study, we partially removed hemicellulose and lignin to adjust hydroxyl accessibility and pore size distribution of the cell wall of beech (Fagus sylvatica). With the assistance of the two-dimensional time-domain nuclear magnetic resonance technique, the water state at high relative humidity (RH) regions and cell wall saturation state were investigated. Both hemicellulose removal and delignification brought newly created pore spaces, lowered the average pore size, and increased the specific surface area. At the same time, a decrease in hydroxyl accessibility was observed for the hemicellulose-removal samples, but an increase in delignified samples. Two cell wall waters (B-water and C-water) with different mobility and two cell lumen waters were categorized. At high RH regions, more water molecules accumulated in microfibril and its surrounding hemicellulose (the domain of B-water) with lower mobility after partial chemical components removal. In combination with the mobility change with the physiochemical environment of the water molecules, it may be established that the accumulation of B-water was affected more by the change in the physical environment. Furthermore, cell wall saturation may alter the matrix environment for both treated and untreated samples; following water saturation, the mobility of B-water increased in the delignified samples but decreased in the untreated and partially hemicellulose-removed samples.

Inhibiting wood-water interactions by hydrothermal hemicellulose extraction combined with furfurylation

Abstract Wood-water interactions affect durability and performance of wood products, such as dimensional stability and biodegradation. To upgrade wood, a combined modification via hemicellulose extraction and furfurylation was proposed to inhibit wood-water interactions. More intense hemicellulose extraction caused larger voids and led to higher pore volume. The increment of porosity resulted in more uniform distribution of polymerized furfural resin in cells, as indicated by scanning electron microscopic and confocal laser scanning microscopic observations. The combined modification greatly reduced surface wettability with an increase of water contact angle (CA) of over 134% at 100 s. With hemicellulose extraction, polymerized furfural resin partially occupied the accommodation initially for water molecules and reduced accessible sorption sites, causing water absorption (WA) of wood to decrease by over 30% after soaking in water for 768 h. Dynamic moisture sorption was weakened after combined modification, and the moderate hemicellulose extraction combined with furfurylation reduced the moisture content by over 50% due to incorporative changes of chemical sorption sites and physical porosity. The results confirmed the efficiency of the combined modification in inhibiting wood-water interactions and indicated the importance to accurately control hemicellulose content during modification. This study could provide useful information for sustainably enhancing wood performance and upgrading low-quality wood.

Hollow polyethyleneimine/carboxymethyl cellulose beads with abundant and accessible sorption sites for ultra-efficient chromium (VI) and phosphate removal

• Novel hollow beads with abundantly accessible sorption sites were prepared. • Demonstration of excellent removal capability of hexavalent chromium and phosphate. • Excellent adsorption and recycling performance for two anionic pollutants. • Easy-to-handle preparation and recovery. Novel millimeter-scale hollow polyethyleneimine/carboxymethylcellulose beads were facilely prepared by simply adjusting the usage of polyethyleneimine for surface modification of preformed solid carboxymethylcellulose beads, which were gradually transformed into hollow beads during the glutaraldehyde mediated cross-linking process. Taking advantage of the hollow structure and porous shells which possess abundant, accessible sorption sites, this newly designed bead-like sorbent exhibited very high adsorption capacity for Cr(VI) and phosphates, for which the exceptional value of 535.39 mg/g and 150.65 mg/g was achieved under fitting conditions, respectively, and both of them much superior to most reported studies. Most importantly, the adsorption capacity for Cr(VI) and phosphate over the typical sorbent remained at high levels even after 6 and 22 cycles, respectively, which is another feature of the hollow bead-like sorbent. Based on various characterization results like SEM-EDX, FT-IR, TGA, zeta potential, XPS, etc., it showed that the adsorption mechanism of Cr(VI) over as-fabricated hollow bead-like sorbents could be mainly correlated to the electrostatic attraction and reduction manner, while the adsorption process of phosphate was mainly due to the electrostatic interaction. By its millimeter-sized shape with surface accessible sorption sites, the column adsorption testing revealed that the Thomas model fitted well with the phosphate adsorption process. Given its controllable fabrication process, excellent adsorption performance, and exceptional mechanical properties, this newly designed millimeter-scale hollow bead-like sorbent has promising applications in the field of anionic pollutant removal.

Nanopore-Level Wood-Water Interactions—A Molecular Simulation Study

The nanoscale wood-water interaction strength, accessible sorption sites, and cell wall pore sizes are important factors that drive water sorption and the hysteresis phenomenon in wood. In this work, these factors were quantitatively studied using molecular simulations based on a cell wall pore model, previously developed by the authors. Specifically, the wall-water interaction strength, the sorption sites network including their number, interaction range, strength, and spatial distributions were set at a series of theoretical values as simulation input parameters. The results revealed that most of the investigated parameters significantly affected both sorption isotherms and hysteresis. Water monolayers and clusters were observed on the simulated pore surface when the wood-water interaction and sorption site strength were set at unrealistically high values. Furthermore, multiple linear regression models suggested that wood-water interaction and sorption site parameters were coupled in determining sorption isotherms, but not in determining hysteresis.

Nanopore-Level Wood-Water Interactions—A Molecular Simulation Study

The nanoscale wood-water interaction strength, accessible sorption sites, and cell wall pore sizes are important factors that drive water sorption and the hysteresis phenomenon in wood. In this work, these factors were quantitatively studied using molecular simulations based on a cell wall pore model, previously developed by the authors. Specifically, the wall-water interaction strength, the sorption sites network including their number, interaction range, strength, and spatial distributions were set at a series of theoretical values as simulation input parameters. The results revealed that most of the investigated parameters significantly affected both sorption isotherms and hysteresis. Water monolayers and clusters were observed on the simulated pore surface when the wood-water interaction and sorption site strength were set at unrealistically high values. Furthermore, multiple linear regression models suggested that wood-water interaction and sorption site parameters were coupled in determining sorption isotherms, but not in determining hysteresis.

Facile preparation of cyclodextrin polymer materials with rigid spherical structure and flexible network for sorption of organic contaminants in water

Cross-linked cyclodextrin polymer (CDP) materials have high sorption capacity and selectivity toward organic contaminants in water, depending on the polymeric network. The network structure is difficult to predict, due to the exothermic nature of polymerization reactions for material preparation. Here, we prepared CDP composite materials with rigid bulk structure and flexible polymeric network through facile KMnO4 oxidation treatments of CDPs. These materials featured regular embedment of nanorod MnO2 particles in the polymeric matrix and had mechanical stability, associated with the oxidation of short chains of the polymeric network. The structure and properties of materials (e.g., the cross-linking degree, pore volume and CD unit content) were regulated by KMnO4 dosage, the majority of which were linearly increased or decreased with increasing oxidant doses. The cross-linking degree, pore volume and CD unit type/content of materials were found to pose important impacts on sorption capacity of CDP materials toward compounds. These property alterations accounted for a compromise of amounts and accessibility of sorption sites, consistent with the important sequence of sorption mechanisms of CDP materials (association complexation ≥ network meshing ≫ inclusion complexation). This compromise has practical interest in the preparation of CDP materials with more useful properties of sorbents. Reuse experiments of chosen CDP materials showed high removal efficiency and stability of materials toward pesticides in water. Removal efficiency of reused materials toward pesticides in water was increased by an average of 22.5%.

SORPTION AND LEACHING OF METALS IN THE SOIL DUE TO APPLICATION OF DISSOLVED ORGANIC MATTER

Agriculture is one of the most important nonpoint sources of soil contamination by heavy metals, and the presence of dissolved organic matter (DOM) in soil can influence the movement of metals. The objective of this research was to evaluate the effect of DOM on the sorption and leaching of copper (Cu) and zinc (Zn) in the soil. Clay soil samples collected at a 0-30 cm depth were used to conduct the experiments, and DOM was extracted from dairy cow manure. Soil tests to evaluaye sorption were carried out in the batch method, two treatments being considered: without the presence of DOM (control) and with the presence of DOM, in different concentrations of Cu and Zn. Experimental results were adjusted to models of the of Langmuir and Freundlich isotherms. In the leaching experiment, columns were filled with soil previously contaminated with Cu and Zn and the distilled water was passed through them; afterwards, the leachate was collected. The sorption of copper and zinc in the soil was greater in the presence of DOM, possibly by the availability of sorption sites and interactions of metals with the DOM structure. The leaching of copper in soil was facilitated by the application of DOM, which can enable large-scale contamination of groundwater. No differences were found in zinc leaching considering water or DOM, however this metal has high mobility in the soil under study.

Sulfhydryl functionalized covalent organic framework as an efficient adsorbent for selective Pb (II) removal

A key challenge in environmental remediation is the design of adsorbents with appropriate pore size and accessible sorption sites to achieve the rapid uptake and high capacity for the removal of their target pollutants. Covalent organic framework (COF) materials with adjustable pore size and designed skeleton structure are a new class of adsorbent materials for environmental remediation. Here, a novel COF was synthesized by a mild solvothermal solution-suspension method for efficient Pb (II) removal from aqueous solution. The prepared COF material displayed a typical lamellar structure, and the sulfhydryl groups on the COFs skeleton were confirmed to behave as active adsorption sites for Pb (II) capture. Sulfhydryl functionalized COF (COF-SH) reached adsorption equilibriums within 48 h and had a maximum adsorption capacity for Pb (II) of 239 mg/g based on Langmuir fitting. The adsorption capacity of COF-SH for Pb (II) removal is much higher than that of other conventional adsorbents, such as shell activated carbon and resin. Moreover, the selective adsorption performance of COF-SH to Pb (II) in the presence of coexisting heavy metal is superior, and its unique properties are derived from its soft sulfur-based chelating groups allowing selective capture of soft or relatively soft metal ions. The results presented here reveal the exceptional potential of COFs for high performance in environmental remediation.

Characteristic and mechanism of sorption and desorption of benzene on humic acid.

The sorption/desorption behaviors of benzene, toluene, ethylbenzene, and xylene (BTEX) on soil organic matter (SOM) have a significant influence on their fate and bioavailability in soil. Humic acid (HA) is a major fraction of SOM. And due to its various structural properties and chemical composition, the sorption/desorption characteristics and mechanisms of HA are diverse for organic contaminants. In this study, batch experiments were conducted to investigate the sorption/desorption behavior of benzene on HA at different conditions (temperature, pH, and ionic strength). The particle size of HA increased at lower initial pH which promoted sorption capacity for benzene, illustrating that HA with larger particle size may develop preferential chemical conformation for benzene sorption at lower pH. Sorption isotherms indicated that the sorption of benzene on HA is an exothermic and spontaneous physical process. And kinetic studies showed that the sorption of benzene on HA is controlled by the diffusion process and the availability of sorption sites. Meanwhile, weak sorbent-sorbate interaction is presented in the desorption experiment. There was no obvious effect of ionic strength on benzene sorption, suggesting that the sorption process is not controlled by ion-exchange or electrostatic interaction. Combined with FTIR analysis, the hydrophobic partitioning and π-π conjugative interaction are the possible sorption mechanisms of benzene on HA.

Stationary Phases Based on PIM-1 Polymer of Intrinsic Microporosity for Gas Chromatography

Polyimide PIM-1, which forms a porous polymer layer on the walls of a capillary column, exhibits high thermal stability. It is studied as a stationary phase for gas chromatography. A column with the PIM-1 stationary phase displays a drastic difference in efficiency, depending on the molecular size of the analyte: 2500–3000 theoretical plates per meter for methane and ethane and fewer than 1000 plates for larger molecules. This behavior of the column is attributed to the poor accessibility of sorption sites, as is apparent from the high loss of entropy during the sorption of light hydrocarbons and the low diffusion coefficients for these sorbates. The effect the physical aging of PIM-1 has on the separating properties of a column is studied in the accelerated thermal aging mode using the example of separation of a model C1–C4 hydrocarbon mixture. It is shown that upon heating the stationary phase to 200°C, sorbate retention and column efficiency fall monotonously. When the temperature is raised to 300°C, an unexpected increase in the analyte retention is observed, though the column’s efficiency continues to fall with respect to all sorbates except isobutane, for which this parameter increases. The causes of these unexpected effects have yet to be revealed.

Imidazolyl derivative of chitosan with high substitution degree: Synthesis, characterization and sorption properties

A method of synthesis of chitosan imidazolyl derivative – N-(5-methyl-4-imidazolyl)methylchitosan (IM-chitosan) with high degree of substitution (DS) via reaction with 5-methyl-4-imidazolylmethanol has been developed. This method enables one to obtain polymers with the DS up to 1.35 with simultaneous cross-linkage of the matrix. The chemical structure of the obtained IM-chitosan was characterized by FT-IR, 13C and 15N NMR spectroscopies. It was shown that cross-linkage of IM-chitosans occurred due to formation of N-glucoside derivatives. Sorption capacities of IM-chitosans toward transition metal ions have an extremal dependence on DS, which is less pronounced for Ag(I) ions in comparison with Cu(II) and Ni(II) ions. The decrease of sorption capacities for derivatives with DS 0.5–1.0 is attributed to steric hindrances for ion-binding due to increased stiffness of the polymer matrix at high DS as a result of cross-linking. Sorption capacities of IM-chitosans toward noble metal ions in 0.1M HCl gradually increase with DS, since higher swelling polymers in acidic media eliminates negative effect of cross-linking on availability of sorption sites.

Adsorption Characteristics of Norfloxacin by Biochar Prepared by Cassava Dreg: Kinetics, Isotherms, and Thermodynamic Analysis

Biochars (BC) generated from biomass residues have been recognized as effective sorbents for organic compounds. In this study, biochars as adsorbents for the removal of norfloxacin (NOR) from aqueous solutions were evaluated. Biochars were prepared from cassava dregs at 350 °C, 450 °C, 550 °C, 650 °C, and 750 °C, respectively (labeled as BC350, BC450, BC550, BC650, and BC750). The results showed that the kinetic data were best fitted to the pseudo second-order model, indicating that the sorption was governed by the availability of sorption sites on the biochar surfaces rather than the NOR concentration in the solution. Sorption isotherms of NOR were well described by the Freundlich model, and the Freundlich coefficients (lgkF) increased with the pyrolysis temperature of biochars. Thermodynamic analysis indicated the feasibility and spontaneity of the NOR adsorption process. The NOR adsorption on BC450, BC550, BC650, and BC750 was an endothermic process, while an exothermic process occurred for BC350. FTIR studies further suggested that the adsorption mechanism was possibly attributable to H-bond and π-π interactions between NOR and biochars. Overall, this work constitutes a basis for further research considering the bioavailability and toxicity of antibiotics in the presence of biochar.

The power of power: Electrokinetic control of PAH interactions with exfoliated graphite

Exfoliated graphite (EG) exhibits exceptional sorption capacity for petroleum and dissolved hydrocarbons owing to its highly hydrophobic surface and wide pore size distribution. The high price of preparing EG, however, restricts its application. Methods which increase the rate or extent of sorption to EG even further are thus longed for. Here, we assess the effects of weak direct current (DC) fields on the sorption of the polycyclic aromatic hydrocarbon phenanthrene (PHE) to EG. DC applied to an ionic solution in a solid matrix invokes electroosmotic flow (EOF), i.e., the surface charge-induced movement of the solution. EG was exposed to weak DC fields in the presence of dissolved PHE to test if EOF increases transport of PHE to poorly accessible sorption sites. DC fields increased PHE sorption rates in EG sevenfold and reduced the desorption rate of sorbed PHE by >99%. EOF thus appeared to be highly effective in translocating PHE into pores, which contribute most of the sorption sites, but are difficult to access in the absence of EOF by molecular diffusion only. The observed ‘power of power’ may be used to kinetically regulate the interaction of sorbates with EG or other porous sorbents in environmental (bio-) technology.

Three-dimensional molecular basket sorbents for CO2 capture: Effects of pore structure of supports and loading level of polyethylenimine

Three-dimensional (3-D) mesoporous materials including mesocellular siliceous foam (MCF), MSU-J and hexagonal mesoporous silica (HMS) were examined as supports of “molecular basket” sorbents (3-D MBS) by loading CO2-philic polyethylenimine (PEI). The CO2 sorption performance of the 3-D MBS was evaluated in comparison with the MBS by using MCM-41, SBA-15 and carbon black (CB) as the supports. The effect of PEI loading on the sorption capacity is associated with the sorption temperature and pore structure of the support. At 30wt% PEI loading, the increase in temperature from 30 to 75°C has a slight and even negative effect on the sorption capacity; while at 65wt% PEI loading, it has a significant, positive effect. Superior CO2 sorption capacity and sorption rate of 3-D MBS over 2-D and 1-D MBS were observed. MCF-based MBS with 65wt% PEI loading (PEI(65)/MCF) gave the highest CO2 sorption capacity of 201mg-CO2/g-sorb. The maximum PEI loading for MCF was up to 80wt%, which is the largest among the support materials studied in this work, and is related to its largest pore volume. The highest sorption capacity and sorption rate of PEI(65)/MCF are ascribed to its largest pore size and unique 3-D pore structure, which facilitate the CO2 diffusion, promote mass transfer and offer more accessible sorption sites. The present work demonstrates that the 3-D mesoporous solid amine sorbents are more effective for CO2 capture in comparison with 1-D and 2-D materials in terms of higher sorption capacity and faster sorption rate. The pore structure (pore dimension, pore size, pore volume) of the support, PEI loading and temperature are the three key factors that determine the sorption capacity and sorption rate.

The water vapor sorption mechanism and its hysteresis in wood: the water/void mixture postulate

A new method of wood moisture sorption analysis is presented using sorption isotherms of a series of mildly heat-treated specimens with varied and known elemental composition. This method allows the determination of the occupancy of accessible sorption sites in wood as a function of relative humidity h, θ(h) ≈ h, found in agreement with the literature data on the non-freezing water occupancy of hydroxyl groups for h < 0.9. Complementary sorption isotherm shape analysis identifies an empirical power law occupancy function, θ(h) = h α , α ≈ 0.73, which is close to the former two determinations in the same humidity range. The validity of widely accepted surface sorption theories for wood with a strongly bound primary layer and loosely bound secondary layers is disproven. To explain the found occupancy function, θ(h) ≈ h, a near-ideal liquid mixture of moisture and polar dynamic microvoids in the cell wall substance is postulated. The power law occupancy function is used to calculate the humidity-dependent number of sorption sites in adsorption/desorption isotherms to show that (1) the number of sorption sites from the adsorption line monotonically increases with increasing humidity—argued to represent the equilibrium number of sorption sites at each humidity, and (2) the number of sorption sites from the desorption line fails to fully return to that of the (equilibrium) adsorption line. Hysteresis is quantitatively explained as the result of non-equilibrium excess sorption sites being occupied according to the occupancy law. The relaxation of non-equilibrium excess sorption sites is satisfactorily modeled by a first-order rate equation. Applying the analysis to study mild thermal modification of moisture sorption isotherms revealed that (1) moisture contents decrease directly linear to the removed amount of sorption sites at all humidity <0.95, and (2) the absolute hysteresis is nearly unaffected as a result of counter-acting effects of the reduced number of sorption sites and reduced amount of relaxation.

Effect of multivalent cations, temperature and aging on soil organic matter interfacial properties

Environmental context The supramolecular structure and resulting physicochemical properties of soil organic matter (SOM) significantly control storage and buffer functions of soils, e.g. for nutrients, organic molecules and water. Multivalent cations, able to form complexes, are suggested to form inter- and intramolecular cross-links in SOM. At present, specific effects of the valence and type of cation on SOM properties are incompletely understood. We investigated changes in SOM interfacial properties, its ability to release mobile colloids in aqueous solutions and its sorption affinity towards organic chemicals in dependence on cation–SOM interactions, temperature and aging time. Abstract The present study aims to improve our understanding on the effect of multivalent cations, temperature treatment and isothermal aging time on interfacial soil organic matter (SOM) properties as major factors that modify its supramolecular structures. A sandy topsoil (LW) and a peat soil (SP) were enriched with Na, Ca or Al, or desalinated in a batch experiment, treated at 25, 40, 60 and 105°C and aged at constant temperature and humidity (20°C, 31% relative humidity). After aging for different periods, contact angles (CAs), sorption properties towards xenobiotics and properties of water dispersible colloids were determined. With increasing valence of the dominant cations fewer and larger colloids were observed, probably attributable to cation cross-links or enhanced aggregation caused by reduced surface charge. Al-enrichment of LW resulted in more abundant or more accessible sorption sites for hydrophobic xenobiotics. But in contrast to expectations, hydrophilic sorption as well as wettability was not significantly affected by the type of adsorbed cation. Increasing the temperature had a major effect on surface properties resulting in rising surface hydrophobisation with increasing solid–water CAs, decreasing surface O/C ratio and decreasing sorption of hydrophilic substances; whereas systematic temperature effects on water dispersible colloids and on hydrophobic sorption were not detected. Aging was found to increase the initial CA of the 25°C treatment and to increase the sorption of phenanthrene to LW for all treatment temperatures. We conclude that aging of SOM is a process that changes surface properties and approaches a new equilibrium state after a disturbance. The aging process may be significantly accelerated for samples treated at elevated temperatures.

Cation treatment and drying‐temperature effects on nonylphenol and phenanthrene sorption to a sandy soil

AbstractThe objective of this study was to investigate the effects of mono‐ and polyvalent cations on sorption of the two hydrophobic compounds nonylphenol (NP) and phenanthrene (Phe). To this end, exchange sites of a sandy soil were saturated with either Na+, Ca2+, or Al3+ and excess salts were removed by washing. The samples were then sterilized and either stored moist, dried at room temperature, or at 20°C, 60°C, or 105°C in a vented oven. Saturation with Na+ led to an increase of dissolved organic C (DOC) concentration in the soil water extracts, whereas the polyvalent cations Ca2+ and Al3+ decreased it. The 1H‐NMR relaxometry analyses showed that Al3+ restricted the mobility of water molecules that are confined within the SOM structure to a higher extent than Ca2+ or Na+. According to contact‐angle (CA) analyses, cation treatment did not significantly change the wetting properties of the samples. Batch sorption–desorption experiments showed no clear salt‐treatment effects on the sorption and desorption equilibria or kinetics of NP and Phe. Instead, the sorption coefficients and sorption hysteresis of NP and Phe increased in dry soil. With increasing drying temperature the CA of the soils and the sorption of both xenobiotics increased significantly. We conclude that structural modifications of SOM due to incorporation of polyvalent cations into the interphase structure do not modify the sorption characteristics of the soil for hydrophobic compounds. Instead, increasing hydrophobization of organic soil constituents due to heat treatment significantly increased the accessible sorption sites for nonpolar organic compounds in this soil.

Modeling Sorption of Neutral Organic Compound Mixtures to Simulated Aquifer Sorbents with Pseudocompounds

The feasibility of the ideal adsorbed solution theory (IAST) in reducing the complexity associated with predicting the sorption behaviors of 12 neutral organic compounds (NOCs) contained in complex mixtures as a fewer number (four to six) of pseudocompounds (groups of compounds) to simulated aquifer sorbents was investigated. All sorption isotherms from individual- and multiple-pseudocompound systems were fit reasonably well ( ≥ 0.953) by the Freundlich sorption model over the range of aqueous concentrations evaluated (i.e., ≤200 μmol L). The presence and magnitude of mutual competition among pseudocompounds varied depending on the composition of the mixtures (i.e., concentrations and polarities of pseudocompounds) and the properties of sorbents (i.e., the fraction of organic carbon and the availability of hydrophilic specific sorption sites). Finally, comparisons between the IAST-based predictions with individual-pseudocompound sorption parameters and experimentally measured data revealed that the accuracy in predicting the sorption behaviors of several NOCs in terms of a fewer number of pseudocompounds decreased with increasing deviations from the assumption of equal and ideal competition in the IAST (i.e., differential availability of sorption sites and nonideal competitions among pseudocompounds).

Impact of long-term wastewater irrigation on sorption and transport of atrazine in Mexican agricultural soils

In the Mezquital Valley, Mexico, crops have been irrigated with untreated municipal wastewater for more than a century. Atrazine has been applied to maize and alfalfa grown in the area for weed control for 15 years. Our objectives were to analyse (i) how wastewater irrigation affects the filtering of atrazine, and (ii) if the length of irrigation has a significant impact. We compared atrazine sorption to Phaeozems that have been irrigated with raw wastewater for 35 (P35) and 85 (P85) years with sorption to a non-irrigated (P0) Phaeozem soil under rainfed agriculture. The use of bromide as an inert water tracer in column experiments and the subsequent analysis of the tracers’ breakthrough curves allowed the calibration of the hydrodynamic parameters of a two-site non equilibrium convection-dispersion model. The quality of the irrigation water significantly altered the soils’ hydrodynamic properties (hydraulic conductivity, dispersivity and the size of pores that are hydraulically active). The impacts on soil chemical properties (total organic carbon content and pH) were not significant, while the sodium adsorption ratio was significantly increased. Sorption and desorption isotherms, determined in batch and column experiments, showed enhanced atrazine sorption and reduced and slower desorption in wastewater-irrigated soils. These effects increased with the length of irrigation. The intensified sorption-desorption hysteresis in wastewater-irrigated soils indicated that the soil organic matter developed in these soils had fewer high-energy, easily accessible sorption sites available, leading to lower and slower atrazine desorption rates. This study leads to the conclusion that wastewater irrigation decreases atrazine mobility in the Mezquital valley Phaeozems by decreasing the hydraulic conductivity and increasing the soil's sorption capacity.