Sonochemical Processes Research Articles

Understanding the Effect of Saturated Gases on Catalytic Performance of Graphitic Carbon Nitride (g‐C3N4) for H2O2 Generation and Dye Degradation in the Presence of Ultrasound

In this article, the effect of saturated gases on H2O2 generation and dye degradation is examined using graphitic carbon nitride (g‐C3N4) as a piezoelectric catalyst. A detailed catalytic evaluation is carried out using a double‐bath sono‐reactor, where the performance of g‐C3N4 for H2O2 production and degradation of rhodamine B and indigo carmine dyes is evaluated for a range of catalyst dosage levels and saturated gases. Specific gases are selected to understand their role in the sonochemical production of reactive oxygen species (ROS) and reactive nitrogen species (RNS) and to elucidate the catalytic mechanism. The use of an Ar–O2 gas mixture leads to the highest yield for H2O2 production and dye degradation due to the positive effect of argon and oxygen in the generation of H2O2 and ROS, respectively. The presence of nitrogen in both air and in an Ar–air mixture increases H2O2 generation since RNS improves the conversion of •OH into H2O2. In contrast, air and Ar–air negatively influences the generation of ROS, which results in a low rate of dye degradation. In this work, new insights of the mechanisms of sonochemical and piezocatalytic processes in the use of graphitic carbon nitride in catalytic applications are provided.

Sonication to remove organic dyes with the aid of NH2-MIL-125(Ti) and carbonization derivatives

Sonication provides a green and sustainable strategy to remove the organic dye pollutants in the environment. In this study, the NH2-MIL-125(Ti) and carbonization derivatives were prepared successfully, aiming to assist the sonochemical removal of organic dyes. By comparison, the NH2-MIL-125(Ti) had a structured cylinder while the carbonization derivatives were irregular in shape, and the NH2-MIL-125(Ti) had much larger specific surface area than the carbonization derivatives, even though the carbonization lowered the band gap. Moreover, the high-resolution XPS spectra showed that the NH2-MIL-125(Ti) had abundant Ti-Ox bonds and vigorous electron transfer, and the PL spectra suggested that the carbonization derivatives with narrow band gap caused the fast recombination of free electrons and holes. According to the observations on the dye removal experiments, the NH2-MIL-125(Ti) showed better catalytic activity under ultrasound irradiation, and the removal rate to Rhodamine B could reach about 80 % within 60 min, even almost 100 % in the presence of peroxydisulfate. Through the qualitative and quantitative analysis, an adsorption/degradation mechanism was proposed and demonstrated for the NH2-MIL-125(Ti)-mediated sonication. Thus, the catalyst-aided sonochemical processes will have attractive application prospect in the removal of industrial organic dyes.

General analytical solution expressions for analyzing Langmuir-type kinetics of sonochemical degradation of nonvolatile organic contaminants in water

Detailed kinetic studies of the ultrasonic decomposition of contaminants in water are scarce. Most of the work has used a pseudo-first order kinetics law, which is unrealistic. The model based on a Langmuir-type mechanism has been shown to fit the sonolytic decomposition data well, especially by using the non-linear technique. To avoid unrealistic assumptions, general analytical solutions to a time-dependent non-linear Langmuir-type equation may be the appropriate method. In this work, the sonolytic oxidation of organic contaminants, i.e., naphthol blue black and furosemide, in water was analyzed using two general analytical solution expressions of the Langmuir-type kinetics model, which describe the pollutant concentration in water. The validity of the two general analytical solution expressions was tested under a diversity of operating conditions, such as initial substrate concentration and varying ultrasonication frequency and intensity. As the initial substrate concentration increased, the sonolytic oxidation kinetics decreased, while the initial ultrasonic decomposition rate increased and then plateaued. Consequently, a heterogeneous kinetics equation based on a Langmuir-type mechanism can be used to simulate the sono-decomposition process. The decomposition yield increased with increasing sonication intensity and decreasing frequency. The two analytical solution expressions seem to be in excellent agreement with the experimental results of the sonochemical decomposition of the nonvolatile organic contaminants tested for the different operating conditions examined. These expressions provide a valuable tool for the analysis and simulation of advanced sonochemical oxidation processes under various experimental conditions.

The Properties of Microwave-Assisted Synthesis of Metal-Organic Frameworks and Their Applications.

Metal-organic frameworks (MOF) are a class of porous materials with various functions based on their host-guest chemistry. Their selectivity, diffusion kinetics, and catalytic activity are influenced by their design and synthetic procedure. The synthesis of different MOFs has been of considerable interest during the past decade thanks to their various applications in the arena of sensors, catalysts, adsorption, and electronic devices. Among the different techniques for the synthesis of MOFs, such as the solvothermal, sonochemical, ionothermal, and mechanochemical processes, microwave-assisted synthesis has clinched a significant place in MOF synthesis. The main assets of microwave-assisted synthesis are the short reaction time, the fast rate of nucleation, and the modified properties of MOFs. The review encompasses the development of the microwave-assisted synthesis of MOFs, their properties, and their applications in various fields.

A hydrogen-based technique for determining the number density of acoustic microreactors (actives bubbles) in sonicated solutions

In sonochemistry, acoustic bubbles are a population of microreactors where hydrogen and oxidants are produced. Optimizing the effectiveness of sonochemical processes and, as a result, designing ultrasonic reactors for diverse uses, including hydrogen generation, requires determining the number density of acoustic microreactors.The number density of micro-bubbles during water sonolysis was determined in this study using a novel semi-empirical method developed (for the first time) using hydrogen sono-production. The technique is based on relying on the overall molar production rate of hydrogen (i.e. resulted from the sonicated solution) to the amount of hydrogen produced per a single collapsing bubble, either from its internal gas phase reaction (pyrolysis) or from both the bubble inside and its liquid shell (via H•+H•→H2). The retrieved number density of bubbles varied between ∼108 to ∼1013 L−1 s−1 (depending on empirical conditions), showing an excellent order with that reported in the literature. As the frequency increased, the number of active bubbles increased, regardless of whether the number density is calculated through the amount of hydrogen formed inside the bubble or the total single-bubble yield (gas phase + liquid shell). However, a reduced number density was obtained as it was calculated via the total single-bubble yield, where this decrease goes up with the rise of ultrasound frequency (from 210 to 724 kHz) and the decrease of the liquid temperature. It has been deduced that hydrogen is mainly formed at the bubble's liquid shell (via H•+H•→H2), particularly at higher frequency and cold liquid.

Methods involved in the treatment of four representative pharmaceuticals in hospital wastewater using sonochemical and biological processes

A primary pollution source by pharmaceuticals is hospital wastewater (HWW). Herein, the methods involved in the action of a biological system (BS, aerobic activated sludge) or a sonochemical treatment (US, 375 kHz and 30.8 W), for degrading four relevant pharmaceuticals (azithromycin, ciprofloxacin, paracetamol, and valsartan) in HWW, are shown. Before treatment of HWW, the correct performance of BS was assessed using glucose as a reference substance, monitoring oxygen consumption, and organic carbon removal. Meanwhile, for US, a preliminary test using ciprofloxacin in distilled water was carried out. The determination of risk quotients (RQ) and theoretical analyses about reactive moieties on these target substances are also presented. For both, the degradation of the pharmaceuticals and the calculation of RQ, analyses were performed by LC-MS/MS. The BS action decreased the concentration of paracetamol and valsartan by ∼96 and 86%, respectively. However, a poor action on azithromycin (2% removal) was found, whereas ciprofloxacin concentration increased ∼20%; leading to an RQ value of 1.61 (high risk) for the pharmaceuticals mixture. The analyses using a biodegradation pathway predictor (EAWAG-BDD methodology) revealed that the amide group on paracetamol and alkyl moieties on valsartan could experience aerobic biotransformations. In turn, US action decreased the concentration of the four pharmaceuticals (removals > 60% for azithromycin, ciprofloxacin, and paracetamol), diminishing the environmental risk (RQ: 0.51 for the target pharmaceuticals mixture). Atomic charge analyses (based on the electronegativity equalization method) were performed, showing that the amino-sugar on azithromycin; piperazyl ring, and double bond close to the two carbonyls on ciprofloxacin, acetamide group on paracetamol, and the alkyl moieties bonded to the amide group of valsartan are the most susceptible moieties to attacks by sonogenerated radicals. The LC-MS/MS analytical methodology, RQ calculations, and theoretical analyses allowed for determining the degrading performance of BS and US toward the target pollutants in HWW.•Biological and sonochemical treatments as useful methods for degrading 4 representative pharmaceuticals are presented.•Sonochemical treatment had higher degrading action than the biological one on the target pharmaceuticals.•Methodologies for risk environmental calculation and identification of moieties on the pharmaceuticals susceptible to radical attacks are shown.

Sonochemical processes for antibiotics removal from water and wastewater: A systematic review

Nowadays the removal of antibiotics in wastewater has become a matter of considerable interest due to their extensive usage and resistance to natural biodegradation. Among various wastewater treatment technologies, sonolysis as an advanced oxidation process has received considerable attention for the elimination and destruction of antibiotics due to its safety, operational simplicity, and environmental-friendly properties. The aim of this review is to organize the scattered available information relating to the sonochemical degradation of antibiotics for the last two decades. For this purpose, the operational variables, the degradation pathway, by-products, mineralization, the kinetics of the sonochemical antibiotic degradation as well as the mechanism of the synergistic effects in sono-based oxidation processes were critically reviewed. According to findings, most of the optimized sonolytic processes can obtain maximum removal efficiency with low antibiotic concentrations (i.e., 0.1–100 µM) and low US frequencies (i.e., 20–200 kHz) over a temperature range of 20–40 °C, though the exact recommended values vary depending on antibiotic characteristics and the sono-reactor geometry. Based on the literature, sono-based oxidation processes under optimized conditions yield significant benefits as compared to the individual processes; however, their applications at pilot and full-scale wastewater treatment are still incipient.

Ultrasound assisted synthesis of 5–7 membered heterocyclic rings in organic molecules

AbstractUltrasound synthesis is a powerful technique that is being used increasingly to accelerate organic reactions as a green synthetic approach. Ultrasonication has offered advantages over conventional methods in terms of enhanced yields, shorter reaction time, high selectivity and minimal side reaction. The current investigation is the review of papers published from 2016 to 2022 for the synthesis of organic heterocycles under the effect of ultrasound irradiation. It is a comprehensive compilation of sonochemical processes as a versatile technique to achieve synthesis of numerous organic scaffolds from simple carbocyclic compounds to complex and biologically active heterocyclic structural molecules. This review encompasses the examples of ultrasound supported synthetic reactions of multicomponent one pot processes as well as different steps flow synthesis. Ultrasound assisted synthesis have been proved as an eco‐friendly and benign approach for the synthesis of 5–7 membered heterocyclic rings, with one to three hetero atoms. Moreover Ultrasound synthesis has offered excellent yield in a vast majority of reactions under mild conditions without involving complicated purification procedures.

Sonochemistry of actinides: from ions to nanoparticles and beyond

AbstractSonochemistry studies chemical and physical effects in liquids submitted to power ultrasound. These effects arise not from a direct interaction of molecules with sound waves, but rather from the acoustic cavitation: the nucleation, growth, and implosive collapse of microbubbles in liquids submitted to power ultrasound. The violent implosion of bubbles leads to the formation of chemically reactive species. In principle, each cavitation bubble can be considered as a microreactor initiating chemical reactions at mild conditions. In addition, microjets and shock waves accompanied bubble collapse produce fragmentation, dispersion and erosion of solid surfaces or particles. Microbubbles oscillating in liquids also enable nucleation and precipitation of nanosized actinide compounds with specific morphology. This review focuses on the versatile sonochemical processes with actinide ions and particles in homogenous solutions and heterogenous systems. The redox reactions in aqueous solutions, dissolution or precipitation of refractory solids, synthesis of actinide nanoparticles, and ultrasonically driving decontamination are considered. The guideline for further research is also discussed.

Study of Photochemical and Sonochemical Processes Efficiency for Degradation of Acibenzolar-S-Methyl Fungicide in Aqueous Solution

Study of Photochemical and Sonochemical Processes Efficiency for Degradation of Acibenzolar-S-Methyl Fungicide in Aqueous Solution

Simultaneous H/D and 13C/12C Anomalous Kinetic Isotope Effects during the Sonolysis of Water in the Presence of Carbon Monoxide.

Splitting of water molecules driven by ultrasound plays a central role in sonochemistry. While studies of sonoluminescence revealed the formation of a plasma inside the cavitation bubble, much less is known about the contribution of plasma chemical processes to the sonochemical mechanisms. Herein, we report for the first time sonochemical processes in water saturated with pure CO. The presence of CO causes a large increase in the H/D kinetic isotope effect (KIE) to αH = 14.6 ± 1.8 in a 10% H2O/D2O mixture under 20 kHz ultrasound. The anomalous H/D KIE is attributed to electron quantum tunneling in the plasma produced by cavitation. In addition, CO2 formed simultaneously with hydrogen during the sonochemical process is enriched with the 13C isotope, which indicates a V-V pumping mechanism typical for non-equilibrium plasma. Both observed KIEs unambiguously point to the contribution of quantum effects in sonochemical mechanisms.

Sonoprocessing: From Concepts to Large-Scale Reactors.

Intensification of ultrasonic processes for diversified applications, including environmental remediation, extractions, food processes, and synthesis of materials, has received attention from the scientific community and industry. The mechanistic pathways involved in intensification of ultrasonic processes that include the ultrasonic generation of cavitation bubbles, radical formation upon their collapse, and the possibility of fine-tuning operating parameters for specific applications are all well documented in the literature. However, the scale-up of ultrasonic processes with large-scale sonochemical reactors for industrial applications remains a challenge. In this context, this review provides a complete overview of the current understanding of the role of operating parameters and reactor configuration on the sonochemical processes. Experimental and theoretical techniques to characterize the intensity and distribution of cavitation activity within sonoreactors are compared. Classes of laboratory and large-scale sonoreactors are reviewed, highlighting recent advances in batch and flow-through reactors. Finally, examples of large-scale sonoprocessing applications have been reviewed, discussing the major scale-up and sustainability challenges.

Photocatalytic and Sonocatalytic Degradation of EDTA and Rhodamine B over Ti0 and Ti@TiO2 Nanoparticles

Herein, we report a comparative study of photocatalytic (Xe-lamp) and sonocatalytic (345 kHz power ultrasound) degradation of Ethylenediaminetetraacetic acid (EDTA) and Rhodamine B (RhB) in the presence of Ti0 and Ti@TiO2 core-shell nanoparticles (NPs). Ti@TiO2 NPs have been obtained by sonohydrothermal treatment (20 kHz, 200 °C) of commercially available Ti0 NPs in pure water. The obtained material is composed of quasi-spherical Ti0 particles (30–150 nm) coated by 5–15 nm crystals of anatase. In contrast to pristine TiO2, the Ti@TiO2 NPs exhibit the extend photo response from UV to NIR light region due to the light absorption by nonplasmonic Ti core. EDTA can be oxidized effectively by photocatalysis in the presence of Ti@TiO2 NPs. By contrast, air passivated Ti0 nanoparticles was found to be inactive in the photocatalytic process for both EDTA and RhB. Photocatalytic degradation of EDTA over Ti@TiO2 NPs exhibits strong photothermal effect, which has been attributed to the higher yield of oxidizing radicals produced by light at higher bulk temperature. The efficiency of RhB photocatalytic degradation depends strongly on RhB concentration. At [RhB] ≥ 1 × 10−3 M, its photocatalytic degradation is not feasible due to a strong self-absorption. At lower concentrations, RhB photocatalytic degradation is observed, but at lower efficiency compared to EDTA. We found that the efficient sonochemical degradation of RhB does not require the presence of any catalysts. For both processes, EDTA and RhB, sonochemical and photocatalytic processes are more effective in the presence of Ar/O2 gas mixture compared to pure Ar. The obtained results suggest that the choice of the optimal technology for organic pollutants degradation can be determined by their optical and complexing properties.

Electrochemical and sonochemical advanced oxidation processes applied to tartrazine removal. Influence of operational conditions and aqueous matrix

Tartrazine degradation was investigated by electrochemical and sonochemical oxidation processes. Anodic oxidation was carried out using boron-doped diamond (BDD) electrodes. The influence of current density and dye initial concentration on the removal of tartrazine from water was analyzed. The experimental results indicate that total removal of tartrazine was obtained, and Chemical Oxygen Demand (COD) and Total Organic Carbon (TOC) removals of up to 94.4% and 72.8% were achieved, respectively. To optimize the process, the pollutant removal percentage, the kinetic rate constant, and the TOC removal efficiency were chosen as target variables. Moreover, sonochemical oxidation experiments at a high-frequency range of cavitation (up to 1 MHz) were performed to establish the influence of three different operating variables, namely ultrasound frequency (0.5–1.1 MHz), ultrasound power (2.0–26.6 W ⋅L−1), and pulse-stop ratio (5:1–1:1). The process was also analyzed in terms of kinetics and energy costs. The kinetics resulted to be three times faster for the electrochemical process. However, the calculated energy costs were very similar, at least at long treatment times. Finally, the influence of three aqueous matrices was investigated. According to the experimental results, the natural occurrence of chloride and/or nitrate ions in water strongly conditions the rate of the process, although at least 90% of tartrazine removal was achieved within the first 50 min of treatment.

Highly efficient sono-piezo-photo synergistic catalysis in bismuth layered ferroelectrics via finely distinguishing sonochemical and electromechanochemical processes

Ultrasonic stimulation induced polarization behaviors in ferroelectric materials have been extensively explored in catalytic degradations. However, the ultrasonic wave similarly can realize dye degradation by the sonocatalysis behavior, which is always neglected in most reports on in-situ ultrasound-induced piezoelectric catalysis, so that people might overestimate piezocatalytic contributions. For this, we designed a series of visible light sensitive bismuth layered ferroelectric materials (BLFMs), M0.5Bi2.5Nb2O9 (MBN, M = Li, Na, and K). It is found that the cavitation-induced degradation rates of Rhodamine B (RhB) strongly depend mechanical stirring speeds under a fixed ultrasonic power, which gradually increases with it, and reaches 77.9% (500 rpm and 3 h). Under lower stirring speed and reaction time (<50 rpm and 2 h), the cavitation effect is almost negligible, only piezocatalysis behavior occurs, which can be used as a key condition to distinguish the piezocatalysis and sonocatalysis. In particular, the degradation rate constant of Na0.5Bi2.5Nb2O9 catalyst reaches up to 4.943 × 10−2 min−1 by the coupling of sonocatalysis, piezocatalysis and photocatalysis, which is much higher than that of single photocatalysis (0.491 × 10−2 min−1), piezocatalytic (1.6 × 10−3 min−1), and sonocatalysis (0.756 × 10−2 min−1). These results may provide a feasible strategy of further improving catalytic degradation efficiency, and accurately determining the sonocatalysis and piezocatalysis contribution.

Integrated technique of pulsed laser irradiation and sonochemical processes for the production of highly surface-active NiPd spheres

The development of highly surface-active nano-sized and submicron particles with well-defined features is a promising approach in regulating various physicochemical properties of materials for different applications. A new hybrid technique involving pulsed laser irradiation and sonochemical processes for the production of Pd nanoparticles, NiPd alloys, and ZnO and Ag/graphene oxide (GO) composites was developed herein. An unfocused pulsed laser (neodymium-doped yttrium aluminum garnet [Nd:YAG] laser pulse with a wavelength of 532 nm) was used to irradiate a mixture of colloidal Ni solution obtained by ablation and PdCl2, resulting in the formation of highly surface-active NiPd under continuous sonication at 40 kHz. The physicochemical properties of the synthesized materials were analyzed by X-ray diffraction (XRD), ultraviolet–visible (UV–vis) spectroscopy, field-emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), high-resolution transmission electron microscopy (HR-TEM), and dynamic light scattering (DLS). To investigate their potential uses, the alloys were employed as electrocatalysts in the hydrogen evolution reaction (HER). Notably, the NiPd synthesized by the integrated process exhibited higher HER activity in a 1 M KOH solution (overpotential of 38 mV at 1 mA/cm2) than the material obtained via pulsed laser irradiation alone (44 mV). The enhanced HER performance of the NiPd alloy was attributed to the synergistic effects of the integrated pulsed laser irradiation and sonochemical processes, affording NiPd particles displaying active surface defects and shape homogeneity. These features resulted in high electronic conductivity and low internal resistance of the material. The proposed hybrid technique could be utilized in the upscaling production of various functional materials with controlled properties.

Degradation of Losartan in Fresh Urine by Sonochemical and Photochemical Advanced Oxidation Processes

In this work, the degradation of the pharmaceutical losartan, in simulated fresh urine (which was considered because urine is the main excretion route for this compound) by sonochemistry and UVC/H2O2 individually, was studied. Initially, special attention was paid to the degrading action of the processes. Then, theoretical analyses on Fukui function indices, to determine electron-rich regions on the pharmaceutical susceptible to attacks by the hydroxyl radical, were performed. Afterward, the ability of the processes to mineralize losartan and remove the phyto-toxicity was tested. It was found that in the sonochemical treatment, hydroxyl radicals played the main degrading role. In turn, in UVC/H2O2, both the light and hydroxyl radical eliminated the target contaminant. The sonochemical system showed the lowest interference for the elimination of losartan in the fresh urine. It was established that atoms in the imidazole of the contaminant were the moieties most prone to primary transformations by radicals. This was coincident with the initial degradation products coming from the processes action. Although both processes exhibited low mineralizing ability toward losartan, the sonochemical treatment converted losartan into nonphytotoxic products. This research presents relevant results on the elimination of a representative pharmaceutical in fresh urine by two advanced oxidation processes.

The effect of dual-frequency ultrasound waves on B16F10 melanoma cells: Sonodynamic therapy using nanoliposomes containing methylene blue.

We investigated the effect of dual-frequency sonication on the viability of B16F10 melanoma cells in the presence of methylene blue (MB) encapsulated in nanoliposomes. Treatment protocols were studied: sonication groups (40kHz, 1MHz and dual-frequency), the same sonication groups with nanoliposomes containing MB, MB free and nanoliposomes containing MB groups, and so sham and control groups. The nanoliposomes were prepared by the lipid film hydration method. The cell viability of the different treatment groups was evaluated by the MTT assay. The dual-frequency protocols caused higher viability losses compared to the kHz and MHz sonications (P<.05). In presence of the nanoliposomes containing MB, dual frequency led to 6% and 3% viability for 600 and 1200seconds, respectively, while the corresponding values were 10% and 4% for the 40kHz protocols and 22% and 9% for the 1MHz, as compared to the control group (100%). The result of KI dosimetry showed that the cavitation activity of the dual-frequency protocol was about 1.23, as compared to sonication at 40kHz and 1MHz. Enhancement of inertial cavitation induction by dual-frequency sonication may be the primary effective mechanism, which causes increased sonochemical processes and drug release from nanocarriers.

The application of flow to an ultrasonic horn system: Phenol degradation and sonoluminescence

Sonochemical (SC) processes can be increased with the application of fluid flow due to changes in bubble characteristics. In this work, a novel flow through set-up was applied to an ultrasonic horn system to investigate the effects of flow on the degradation of phenol. KI dosimetry and sonochemiluminescence (SCL) were also analysed, under the same conditions, to provide comparison of degradation to other SC processes. Further, sonoluminescence (SL) in water and different concentrations of potassium iodide (KI) and phenol solutions was studied to determine the effect of flow on processes inside the bubble that result in SL. The degradation of 0.1 mM phenol solutions, KI dosimetry and SL from phenol (0.1, 20 and 60 mM) and KI (0.1, 1 and 2 M) solutions were analysed under flow rates of 0, 24, 228 and 626 mL/min. For an ultrasonic horn system, all flow rates could augment phenol degradation beyond that of the systems without flow. At the lowest applied power, the amount of degradation was significantly increased with flow, becoming greater than degradation observed at the highest power. A strong correlation between phenol degradation and SC processes indicated that degradation followed an oxidative process. SL intensity from water, KI, and phenol solutions could also be increased with flow beyond the no flow system. For water this occurred most readily at higher powers, then for the solutes there was varied behaviour dependent upon the solute concentration. It was theorised that flow may increase the transfer of radical species to solution to enhance SC processes. An increase in SL, with flow, indicates that flow is acting to change the properties of the bubbles and/or the bubble field such that the active bubbles present collapse with greater total intensity.

Hazardous wastes treatment technologies.

A review of the literature published in 2019 on topics related to hazardous waste management in water, soils, sediments, and air. The review covered treatment technologies applying physical, chemical, and biological principles for the remediation of contaminated water, soils, sediments, and air. PRACTICAL POINTS: This report provides a review of technologies for the management of waters, wastewaters, air, sediments, and soils contaminated by various hazardous chemicals including inorganic (e.g., oxyanions, salts, and heavy metals), organic (e.g., halogenated, pharmaceuticals and personal care products, pesticides, and persistent organic chemicals) in three scientific areas of physical, chemical, and biological methods. Physical methods for the management of hazardous wastes including general adsorption, sand filtration, coagulation/flocculation, electrodialysis, electrokinetics, electro-sorption ( capacitive deionization, CDI), membrane (RO, NF, MF), photocatalysis, photoelectrochemical oxidation, sonochemical, non-thermal plasma, supercritical fluid, electrochemical oxidation, and electrochemical reduction processes were reviewed. Chemical methods including ozone-based, hydrogen peroxide-based, potassium permanganate processes, and Fenton and Fenton-like process were reviewed. Biological methods such as aerobic, anoxic, anaerobic, bioreactors, constructed wetlands, soil bioremediation and biofilter processes for the management of hazardous wastes, in mode of consortium and pure culture were reviewed. Case histories were reviewed in four areas including contaminated sediments, contaminated soils, mixed industrial solid wastes and radioactive wastes.