Batch Solution Research Articles

Citric acid functionalized chitosan hydrogel beads for enhanced Cr(VI) removal: Experimental assessment and COMSOL modelling of adsorption in a fixed-bed system

Chitosan hydrogel beads (CHB) and cross-linked CHB functionalized with tricarboxylic citric acid (CA-GLA-CHB) were synthesized and used for the removal of Cr(VI) from aqueous solutions in batch and dynamic adsorption systems. Applicability of COMSOL Multiphysics software as a tool for predictive modelling of column dynamics using a minimum set of experimental parameters was tested and compared with experimental results. Batch experiments demonstrated that CA-GLA-CHB showed almost 20% higher adsorption capacity and wider operational pH range compared to non-functionalized CHB. In a dynamic system, CA-GLA-CHB was used as column packing material and the column dynamics was investigated at different conditions. The breakthrough and exhaustion time of the column increased with an increase in bed height and a decrease in feed flow rate and initial Cr(VI) concentration. Computational modeling by COMSOL software with implemented Advection-Dispersion-Reaction (ADR) equation was used to simulate breakthrough curves for the applied dynamic system in order to validate the possibility of its application for process design in the scaled-up fixed-bed column systems for wastewater treatment. The simulated breakthrough curves of Cr(VI) adsorption matched well with the experimental, thus proving that COMSOL Multiphysics software can be used for scaling-up fixed-bed column systems packed with low-cost and effective CA-GLA-CHB bioadsorbent.

Urease-producing bacteria enhance the adsorption of Cd on organo-Fe hydroxide coprecipitates

Microorganisms, organic carbon, and iron oxides are important active components in soil that control the availability of heavy metals. In the extensive cultivation areas based on wheat–maize rotation, returning corn straw to the field increases the content of dissolved organic carbon (DOC) in the soil, affecting heavy metal adsorption by iron oxides and thereby threatening the safety of wheat. However, the effects and underlying mechanisms of maize straw-derived DOC on Cd adsorption by ferrihydrite (Fh) are unclear, and the effects of functional strains on Cd adsorption by organo-Fe hydroxide coprecipitates (OFCs) need further study. The effect of DOC on the adsorption of Cd by Fh was studied through batch solution adsorption experiments. Moreover, the mechanisms underlying the synergistic adsorption of Cd by the urease-producing bacterium Enterobacter sp. TJ6 and OFC were studied in adsorption experiments via scanning electron microscopy and X-ray photoelectron spectroscopy. The results showed that DOC inhibited the adsorption of Cd by OFC, while strain TJ6 enhanced the adsorption of Cd by OFC. Fe-OH and Fe-O bonds on the surface of Fh were important Cd adsorption sites. DOC affected the adsorption of Cd by Fe-OH and Fe-O, thereby inhibiting the adsorption of Cd by OFC. DOC also served as a reducing agent, reducing Fe2O3 on the surface of OFC to FeO and thus inhibiting OFC adsorption of Cd. The mechanisms by which strain TJ6 enhanced Cd adsorption by OFC included the following: 1) strain TJ6 utilized its own oxidation ability to oxidize FeO on the surface of OFC to Fe2O3, promoting the secondary precipitation of Cd during the redox process and enhancing the Cd adsorption capacity of OFC; and 2) strain TJ6 immobilized Cd2+ through ion exchange between Cd2+ and H+ in surface amino groups. In conclusion, this study has revealed the mechanism by which urease-producing bacteria regulate the adsorption of Cd by OFC and provides a theoretical basis for safe straw return to Cd-polluted farmland. This study also provides technical approaches and bacterial resources for the remediation of heavy metal-contaminated soil under straw return.

Sodium hydroxide supported cellulose for efficient removal of cationic dyes from aquatic solutions in batch and column modes: Adsorption characteristics and mechanism study

Sodium hydroxide supported cellulose for efficient removal of cationic dyes from aquatic solutions in batch and column modes: Adsorption characteristics and mechanism study

Removal of tetracycline by natural and iron-modified orange peel from aqueous solutions: processes in batch, column, and mechanism

ABSTRACT Natural (OP) and iron modified orange peel (Fe-OP) were used for the removal of tetracycline from aqueous solutions in batch and fixed bed column systems. The adsorbents were characterized by infrared spectroscopy (IR) and the morphologies of the surfaces before and after tetracycline removal were determined by scanning electron microscope and the elemental analysis was performed by X-ray dispersive spectroscopy (EDS). The kinetic behaviour showed that the equilibrium was reached in 24 and 10 h for OP and Fe-OP respectively, the data were adjusted to both the pseudo second order and intraparticle diffusion models which indicate a chemisorption mechanism and the adsorption process is controlled by the intraparticle diffusion process. The isotherms showed that the adsorption capacity was eight times higher for Fe-OP than OP and the data were best fitted to the Freundlich model indicating that the materials are heterogeneous. The effect of flow rate, influent concentration and adsorbent mass were determined in the column system. The data were adjusted to the Thomas, Adams–Bohart and Yoon-Nelson models, and the best adjustment of data was with the first one. The adsorption capacities in the column system were about half of those obtained in the batch system. These adsorbents show good properties for the removal of tetracycline from water.

An improved solution for total least squares collocation in the EIV-model with random effects

The total least squares (TLS) method within the Errors-In-Variables (EIV) model has been comprehensively investigated in measurement and its relevant fields. However, when prior information is considered, existing solutions in the EIV model with random effects (EIV-REM) have many shortcomings, which limit the application of this approach. We have developed the total least squares collocation (TLSC) solution based on general adjustment, where prior information is added to the functional model in the form of pseudo-observations. The accuracy of the estimated parameters is evaluated, and our TLSC solution is converted into a recursive form. The proposed methodology is applied to a 3D datum transformation and an autoregression model. The results for the datum transformation show that our proposed TLSC solution provides more precise estimates than the traditional least squares (LS) and TLS methods. The results for the autoregression model show that TLSC yields similar performance to the batch solution of TLS, but has advantages in terms of computational complexity.

Assessment of waste hop (Humulus Lupulus) stems as a biosorbent for the removal of malachite green, methylene blue, and crystal violet from aqueous solution in batch and fixed-bed column systems: Biosorption process and mechanism

The discharge of industrial textile waters into water bodies leads to the accumulation of pollutants which are a serious threat to humans and the environment. The development of an efficient adsorbent for the removal of toxic organic dyes from water is of crucial importance. For that reason, this work aimed to elaborate on the potential application of a biosorbent obtained from waste Humulus lupulus stems (Hlup-BA) for the elimination of malachite green, methylene blue, and crystal violet from aqueous solution in batch and fixed-bed column systems. The Hlup-BA was characterized using chemical composition analysis, by determination of particle size distribution, the point of zero charge (pHpzc), SEM, BET, EDS, XRD, and FTIR. Comprehensive analysis of Hlup-BA adsorption efficiency in a batch study showed that at the optimal conditions (e.g. contact time, 120 min; biosorbent dose, 2 g/L; dye concentration, 100 g/L; pH, 8 and temperature, 298 K), even 98.4 %, 98.8 %, and 98.5 % of MG, MB, and CV were removed, respectively. The results showed that the biosorption process followed pseudo-second-order kinetics. The equilibrium data were modeled using Langmuir, Freundlich, Sips, and Dubinnin-Radushkevich biosorption isotherms. High values of Hlup-BA biosorption capacities obtained from Langmuir isotherm were 398.9 mg g−1, 209.8 mg g−1, and 133.2 mg g−1 for MG, MB, and CV, thus proving Hlup-BA as an excellent biosorbent for removal of the tested dyes. The thermodynamic study indicated that the biosorption of these three dyes on Hlup-BA from aqueous solution is an endothermic, spontaneous, and thermodynamically stable process. The proposed mechanism of the biosorption process covers π-π interactions, electrostatic interactions, and hydrogen bonding. Furthermore, the data obtained by modeling in the fixed-bed column were also successfully correlated with the Thomas, Bohart-Adams, and Yoon–Nelson models. The very good fit of the results obtained in this way will greatly contribute to optimizing the pilot-scale operations for future wastewater treatment. Consequently, Hlup-BA can be an effective, cheap, and environmentally friendly biosorbent to eliminate methylene blue, malachite green, and crystal violet dyes from the aqueous solution in batch and column systems.

Synthesizing pectin-crosslinked gum ghatti hydrogel for efficient adsorptive removal of malachite green

Pectin-crosslinked gum ghatti hydrogel (PGH) has been synthesized utilizing pectin and gum ghatti through an uncomplicated and inexpensive copolymerization method. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM-elemental mapping), Brunauer-Emmett-Teller (BET), and X-ray photoelectron spectroscopy (XPS) characterization techniques have been employed to determine various structural, chemical and compositional characteristics of fabricated PGH. Three different weight ratios (1:1, 2:1, or 1:2 for pectin and gum ghatti, respectively) were employed to synthesize three distinct types of PGH. Swelling studies has been done to determine the best ratios for PGH fabrication. PGH has been assessed as an adsorbent for the removal of malachite green dye from aqueous solutions. The effects of PGH dosage (100–400 mg/L), dye concentration (10–160 mg/L), pH (2–9 pH), adsorption time (0–480 min), and temperature (25–55 °C) has been examined through batch solutions. According to Langmuir isotherm analysis, the maximum adsorption capacity is 658.1 mg/g. By using pseudo-second-order kinetics and the Freundlich adsorption isotherm, the adsorption process could be well explained. After five consecutive cycles, PGH had an adsorption percentage of 86.917 % for the malachite green dye. It is safe for the environment and may be used to remove malachite green (MG) dye from aqueous solutions.

Conversion of seaweed waste to biochar for the removal of heavy metal ions from aqueous solution: A sustainable method to address eutrophication problem in water bodies

The present study investigated the sustainable approach for wastewater treatment using waste algal blooms. The current study investigated the removal of toxic metals namely chromium (Cr), nickel (Ni), and zinc (Zn) from aqueous solutions in batch and column studies using biochar produced by the marine algae Ulva reticulata. SEM/EDX, FTIR, and XRD were used to examine the adsorbents' properties and stability. The removal efficiency of toxic metals in batch operations was investigated by varying the parameters, which included pH, biochar dose, initial metal ion concentration, and contact time. Similarly, in the column study, the removal efficiency of heavy metal ions was investigated by varying bed height, flow rate, and initial metal ion concentration. Response Surface Methodology (Central Composite Design (CCD)) was used to confirm the linearity between the observed and estimated values of the adsorption quantity. The packed bed column demonstrated successful removal rates of 90.38% for Cr, 91.23% for Ni, and 89.92% for Zn heavy metals from aqueous solutions, under a controlled environment. The breakthrough analysis also shows that the Thomas and Adams-Bohart models best fit the regression values, allowing prior breakthroughs in the packed bed column to be predicted. Desorption studies were conducted to understand sorption and elution during different regeneration cycles. Adding 0.3 N sulfuric acid over 40 min resulted in the highest desorption rate of the column and adsorbent used for all three metal ions.

Multi-GNSS ultra-rapid orbit determination through epoch-parallel processing

High-precision Global Navigation Satellite Systems (GNSS) orbits are critical for real-time clock estimation and precise positioning service; however, the prediction error grows gradually with the increasing prediction session. In this study, we present a new efficient precise orbit determination (POD) strategy referred to as the epoch-parallel processing to reduce the orbit update latency, in which a 24-h processing job is split into several sub-sessions that are processed in parallel and then stacked to solve and recover parameters subsequently. With a delicate handling of parameters crossing different sub-sessions, such as ambiguities, the method is rigorously equivalent to the one-session batch solution, but is much more efficient, halving the time-consuming roughly. Together with paralleling other procedures such as orbit integration and using open multi-processing (openMP), the multi-GNSS POD of 120 satellites using 90 stations can be fulfilled within 30 min. The lower update latency enables users to access orbits closer to the estimation part, that is, 30–60-min prediction with a 30-min update latency, which significantly improves the orbit quality. Compared to the hourly updated orbit, the averaged 1D RMS values of predicted orbit in terms of overlap for GPS, GLONASS, Galileo, and BDS MEO are improved by 39%, 35%, 41%, and 37%, respectively, and that of BDS GEO and IGSO satellites is improved by 47%. We also demonstrate that the boundary discontinuities of half-hourly orbit are within 2 cm for the GPS, GLONASS, and Galileo satellites, and for BDS the values are 2.6, 15.5, and 9.8 cm for MEO, GEO, and IGSO satellites, respectively. This method can also be implemented for any batch-based GNSS processing to improve the efficiency.

Activated Carbon Based on Borassus aethiopum Shells, Hulls, Kernels and Fruits for Removal of Phenol and 2-Chlorophenol from Water

This study aimed at developing activated carbons from Borassus aethiopum shells (BaS), hulls (BaH), kernels (BaK) and fruits (BaF) for removing phenol (Ph) and 2-chlorophenol (2-CP) from aqueous solution. The preparation of the activated carbons involved carbonization of the starting materials at 500 ºC followed by chemical activation at 600 ºC using 0.5 M H3PO4 acid. The prepared activated carbons were found to be mesoporous having pore sizes and surface areas in the range of 3.2 to 3.5 nm and 644 to 740 m2/g, respectively. Thermogravimetric analysis (TGA) thermograms showed that the prepared activated carbons can be applied in the batch solution with a temperature not greater than 500 ºC as above this temperature, the materials decompose. Adsorption experiments showed that the uptake of 100 mg/L of Ph and 2-CP from water is favourable using an adsorbent dose of 0.5 g and a contact time of 6 hours. On the other hand, the batch solution of pH 8 and 6 favoured the adsorption of Ph and 2-CP, respectively. Moreover, the adsorption of the aforementioned adsorbates strongly depended on their initial concentrations and temperature of the batch solution. Equilibrium adsorption isotherms fitted into both Langmuir and Freundlich isotherms, but the Freundlich adsorption model was found to have the highest regression value, hence the best fit.

Investigation of Mechanochemical Sonogashira Couplings─From Batch Solution to Continuous Reactive Extrusion through Ball-Milling Optimization

Investigation of Mechanochemical Sonogashira Couplings─From Batch Solution to Continuous Reactive Extrusion through Ball-Milling Optimization

Valorization of Peanut and Walnut Shells through Utilisation as Biosorbents for the Removal of Textile Dyes from Water

The present research focuses on the application of peanut and walnut shells, in their natural state, for the removal of methylene blue (MB) from water solutions in batch and dynamic (flow-through) conditions. Under batch conditions, at a 100 mg/L MB concentration of aqueous solution, the optimum dose of the studied biosorbents was determined to be 2.5 g/L, reaching about 95–97% efficiency of MB removal for both materials. Langmuir and Freundlich isotherms were used to model and evaluate the experimental data under different initial concentrations of MB (25 to 100 mg/L). The determined maximum adsorption capacities are 41.50 mg/g for walnut shells and 46.80 mg/g for peanut shells. Under flow-through conditions, breakthrough curves are determined for three sizes of fractions (<0.25 mm, 0.315–0.5 mm, and 0.8–1.6 mm). For peanut shells, the smaller the particle size, the higher the adsorption capacity and the column breakthrough time. For walnut shells, however, the particle size seems to have a more complex influence on the adsorption process parameters, and this phenomenon deserves future investigation. The adsorption capacity for one and the same fraction size of 0.315–0.5 mm and initial MB concentration of 50 mg/L is higher under dynamic flow conditions, i.e., 51 mg/g compared to 20 mg/g for walnut shells and 46 mg/g compared to 17.5 mg/g for peanut shells.

Removal of Copper Ions onto Walnut Shells by Using Batch and Continuous Fluidized Bed

An agricultural waste (walnut shell) was undertaken to remove Cu(II) from aqueous solutions in batch and continuous fluidized bed processes. Walnut shell was found to be effective in batch reaching 75.55% at 20 and 200 rpm, when pH of the solution adjusted to 7. The equilibrium was achieved after 6 h of contacting time. The maximum uptake was 11.94mg/g. The isotherm models indicated that the highest determination coefficient belongs to Langmuir model. Cu (II) uptake process in kinetic rate model followed the pseudo-second-order with determination coefficient of 0.9972. More than 95% of the Cu(II) were adsorbed on the walnut shells within 6 h at optimum agitation speed of 800 rpm. The main functional groups responsible for biosorption of Cu(II) onto walnut shell were hydroxyl, carbonyl,carboxylate, carboxylic acids, alcohols groups, and aromatic compounds. In continuous system, fluidized bed column at 20 , and pH 7 was carried out to study the effects of various parameters like (flow rate,bed depth, and initial concentration). The time of breakthrough was 97 min when the initial concentration (Co= 20mg/l), bed depth (L=10cm), and flowrate (Q=10l/h)

Insights into influence of aging processes on zero-valent iron modified biochar in copper(II) immobilization: from batch solution to pilot-scale investigation

Insights into influence of aging processes on zero-valent iron modified biochar in copper(II) immobilization: from batch solution to pilot-scale investigation

Synthesis of Cellulose-Poly(Acrylic Acid) Using Sugarcane Bagasse Extracted Cellulose Fibres for the Removal of Heavy Metal Ions.

In this study, sugarcane bagasse (SCB) was treated with sodium hydroxide and bleached to separate the non-cellulose components to obtain cellulose (CE) fibres. Cross-linked cellulose-poly(sodium acrylic acid) hydrogel (CE-PAANa) was successfully synthesised via simple free-radical graft-polymerisation to remove heavy metal ions. The structure and morphology of the hydrogel display an open interconnected porous structure on the surface of the hydrogel. Various factors influencing batch adsorption capacity, including pH, contact time, and solution concentration, were investigated. The results showed that the adsorption kinetics were in good agreement with the pseudo-second-order kinetic model and that the adsorption isotherms followed the Langmuir model. The maximum adsorption capacities calculated by the Langmuir model are 106.3, 333.3, and 163.9 mg/g for Cu(II), Pb(II), and Cd(II), respectively. Furthermore, X-ray photoelectron spectroscopy (XPS) and energy-dispersive X-ray spectrometry (EDS) results demonstrated that cationic exchange and electrostatic interaction were the main heavy metal ions adsorption mechanisms. These results demonstrate that CE-PAANa graft copolymer sorbents from cellulose-rich SCB can potentially be used for the removal of heavy metal ions.

Ostwald Rule of Stages─Myth or Reality?

In 1897, following a number of crystallization studies, Ostwald suggested that if a system has a number of metastable states open to it then it proceeds sequentially by means of the nearest thermodynamic state and so on. This conjecture, which is known as Ostwald’s Rule of Stages (ORS), has gained traction with many researchers in many different fields. However, there has been no general proof of its validity. In this paper the specific case of batch solution crystallization of a polymorphic compound using classical nucleation and growth theory is examined in some detail and the ORS conjecture is found wanting. Classical nucleation theory presents not a sequential process, as in ORS, but a parallel process of multiphase nucleation and growth development of all metastable phases. What is observed is not the appearance of metastable phases sequentially but the disappearance of phases sequentially in the order of their metastability. If the crystallization kinetics of the metastable phases are suitably differentiated and advantageous the system might appear to be sequential under suitable conditions. This analysis does not exclude ORS from being applicable in other transformation cases. For instance, it is possible that systems where the subsequent phase changes are governed by solid-state transformations then the sequential model proposed by Ostwald might be appropriate but whether this covers all available metastable states is an open question.

Preparation of magnetic poly(ethylene glycol dimethacrylate-N-Methacryloyl-(L)-glutamic acid) particles for thrombin purification

In this study, magnetic poly(ethylene glycol dimethacrylate-N-methacryloyl-(L)-glutamic acid) (mPEGDMA-MAGA) particles were prepared by the dispersion polymerization in order to purify thrombin effectively. mPEGDMA-MAGA particles were synthesized by adding different ratios of magnetite (Fe3O4) to the medium in addition to the monomer phases EGDMA and MAGA. The characterization studies of mPEGDMA-MAGA particles were used by fourier transform infrared spectroscopy, zeta size measurement, scanning electron microscopy and electron spin resonance. mPEGDMA-MAGA particles were used in thrombin adsorption studies from aqueous thrombin solutions in both batch and magnetically stabilized fluidized bed (MSFB) system. Maximum adsorption capacity in pH 7.4 phosphate buffer solution is 964 IU/g polymer and 134 IU/g polymer in MSFB system and batch system, respectively. The developed magnetic affinity particles enabled the separation of thrombin from different patient serum samples in one step. It has also been observed that magnetic particles can be used repeatedly without significant reduction in adsorption capacity.

Collision-Free Motion Algorithms for Sensors Automated Deployment to Enable a Smart Environmental Sensing-Net

As natural habitats protection has become a global priority, smart sensing-nets are ever-increasingly needed for effective environmental observation. In a practical monitoring network, it is critical to deploy sensors with sufficient automated intelligence and motion flexibility. Recent advances in robotics and sensors technology have enabled automated mobile sensors deployment in a smart sensing-net. Existing deployment algorithms can be employed to calculate adequate destinations (goals) for sensors to perform respective monitoring tasks. However, given the calculated goal positions, the problem of how to actually coordinate a fleet of robots and schedule moving paths from random initials to reach their goals safely, without collisions, remains largely unaddressed in the wireless sensor networking (WSN) literature. In this paper, we investigate this problem and propose polynomial-time collision-free motion algorithms based on batched movements to ensure all the mobile sensors reach their goals successfully without incurring collisions. We observe that the grouping (batching) strategy is similar to the coloring procedure in graph theory. By constructing a conflict graph, we model the collision-free path scheduling as the well-known k-coloring problem, from which we reduce to our k-batching problem (determining the minimum number of required batches for a successful deployment) and prove its NP completeness. Since the k-batching problem is intractable, we develop CFMA (collision-free motion algorithm), a simple yet effective batching (coloring) heuristic mechanism, to approximate the optimal solution. Performance results show that our motion algorithms outperform other existing path-scheduling mechanisms by producing 100% sensors reachability (success probability of goals reaching), time-bounded deployment latency with low computation complexity, and reduced energy consumption. Note to Practitioners— This research was originally motivated by an oceanography project, which studied marine microbes by sending a team of tiny robots (sensors) randomly scattered on the ocean floor. For hard-to-access habitats like deserts or oceans, where manual placement of sensors is costly or impossible, automatically scheduling robots movements to calculated positions from random initials is essential for an effective monitoring. Our contribution is unique in two ways. First, traditional path-planning research focuses more on independent robots navigating the environment, whereas we target on the network automation problem, coordinating a fleet of robots working together to perform an environmental sensing task. Second, we observe that existing movement methods are too complicated and energy-consuming due to the calculation on-the-go nature. To provide a practical solution, we suggest and design our motion algorithms from a new perspective: pre-scheduled batched movements. Our approach requires a central server for grouping (batching) calculations, but can effectively reduce computation complexity and save significant energy expenditure exerted on resource-limited sensors. The proposed collision-free motion algorithm (CFMA) is a suboptimal yet efficient batching solution, which can be easily applied in real-life open-space monitoring networks. Insights from this foundational research will facilitate future opportunities to implement and verify our method in operational monitoring testbeds.

Adsorption mechanisms of inositol hexakisphosphate in the presence of phosphate at the amorphous aluminum oxyhydroxide-water interface.

Myo-inositol hexakisphosphate (myo-IHP) is one of the most common soil organic phosphorus (P) species in soil. Its retention in soil is often competed by phosphate, making bioavailability of P species difficult. In this study, the adsorption mechanism of myo-IHP at the amorphous aluminum (oxyhydr)oxide (AAH)-water interface was investigated at pH 6.5 in the presence of phosphate using batch adsorption experiments and solution 31P NMR spectroscopy. The ratio of [myo-IHP]i/[phosphate]i (Ri) was kept 0.33-3 while ligand addition was varied. In the absence of phosphate, myo-IHP forms inner-sphere surface complexes in AAH via P1,3, P2, P4,6, and P5 functional group coordination. When two ligands were simultaneously added, fewer P functional groups of myo-IHP coordinated to AAH and the surface complexes were altered with the coordination of mainly P1,3 and P2 functional groups. When phosphate was pre-adsorbed, myo-IHP adsorption decreased by 8.0-44% compared to the respective simultaneous addition system. P2 or P5 functional group was predominantly coordinated to the AAH surfaces at Ri = 0.33. Myo-IHP pre-adsorption resulted in an increase in the final myo-IHP adsorption compared to that in the simultaneous addition system under the respective Ri values (0.33-3). In this system, P1,3, P2, P4,6, and P5 functional groups were coordinated to form inner-sphere surface complexes regardless of Ri. The study revealed that the functional group specific adsorption mechanism of myo-IHP at the AAH-water interface was affected by addition sequence and Ri of two ligands. The competitive adsorption between organic P and phosphate plays an important role in the fate of P in soils.

Molybdenum Release Triggered by Dolomite Dissolution: Experimental Evidence and Conceptual Model.

The injection of oxygenated water into anoxic aquifers during managed aquifer recharge (MAR) can cause the mobilization of metal(loid)s. Here, we study the processes controlling MAR-induced molybdenum (Mo) release in dolomitic aquifers. Sequential chemical extractions and energy dispersive X-ray spectroscopy combined with scanning electron microscopy point to an association of Mo with easily soluble sulfurized organic matter present in intercrystalline spaces of dolomites or directly incorporated within dolomite crystals. The easily soluble character was confirmed by a batch experiment that demonstrated the rapid mobilization of Mo, dissolved organic carbon, and sulfur. The type and time of batch solution contact with the sulfurized organic matter impacted the release of Mo, as demonstrated by a 36% increase in Mo concentrations when shaking was intensified. Based on the experimental results, a conceptual model for the release of Mo was formulated, where (i) the injection of oxygenated water causes the oxidation of pyrite in the aquifer matrix, and (ii) the associated release of protons (H+) induces the dissolution of dolomite as a buffering reaction, which (iii) enhances the accessibility of the injectant to intercrystalline and incorporated sulfurized organic matter within dolomite, causing the release of Mo.