Degradation Of Carbon Tetrachloride Research Articles

Influence of Riboflavin on Nanoscale Zero-Valent Iron Reactivity during the Degradation of Carbon Tetrachloride

Experiments were conducted to investigate the effect of riboflavin on the reactivity of nanoscale zerovalent iron (NZVI) during three reaction cycles of carbon tetrachloride (CT) degradation. The degradation kinetics of CT by NZVI without riboflavin (0.556 ± 0.044 h(-1)) was 1.5 times higher than that with riboflavin (0.370 ± 0.012 h(-1)) in the first cycle. Riboflavin was rapidly reduced (65.0 ± 7.0 h(-1)) by NZVI during CT degradation, resulting in the slow degradation kinetics of CT in the first cycle due to competition for electrons from NZVI between riboflavin and CT. These results indicate that riboflavin is not effective as an electron shuttle for reduction of CT by NZVI. On the other hand, the degradation kinetics of CT by NZVI without riboflavin decreased to 0.122 ± 0.033 h(-1) in the third cycle, while that with riboflavin was significantly enhanced (0.663 ± 0.005 h(-1)). The results from X-ray analyses and transmission electron microscopy suggest that the decline in reactivity of NZVI without riboflavin in the third cycle resulted from continuous Fe(0) oxidation to iron oxides on the NZVI surface. In contrast, riboflavin enhanced the reactivity of NZVI by reductive dissolution of passive iron oxides on NZVI surface by reduced riboflavin. The experimental results suggest that riboflavin can play a pivotal role in the prolongation of NZVI reactivity in long-term in situ and ex situ applications of NZVI.

Persulfate activation by iron oxide-immobilized MnO2 composite: Identification of iron oxide and the optimum pH for degradations

Iron oxide-immobilized manganese oxide (MnO2) composite was prepared and the reactivity of persulfate (PS) with the composite as activator was investigated for degradation of carbon tetrachloride and benzene at various pH levels. Brunauer–Emmett–Teller (BET) surface area of the composite was similar to that of pure MnO2 while the pore volume and diameter of composite was larger than those of MnO2. Scanning electron microscopy couples with energy dispersive spectroscopy (SEM-EDS) showed that Fe and Mn were detected on the surface of the composite, and X-ray diffraction (XRD) analysis indicated the possibilities of the existence of various iron oxides on the composite surface. Furthermore, the analyses of X-ray photoelectron (XPS) spectra revealed that the oxidation state of iron was identified as 1.74. In PS/composite system, the same pH for the highest degradation rates of both carbon tetrachloride and benzene were observed and the value of pH was 9. Scavenger test was suggested that both oxidants (i.e. hydroxyl radical, sulfate radical) and reductant (i.e. superoxide anion) were effectively produced when PS was activated with the iron-immobilized MnO2.

Investigation of design parameters in ultrasound reactors with confined channels

This paper presents a three-dimensional numercial simulation of sonochemical degradation upon cavitational activity. The model relates the simulation of the acoustic pressure distribution to the sonochemical reaction rate. As a case study, the thermal degradation of carbon tetrachloride during sonication is studied in a tubular milliscale reactor. The model is used to optimize the reactor diameter, ultrasound frequency and power dissipated to the ultrasound transducers. The results indicate that multiple transducers at a moderate power level are more efficient than one transducer with high power level. Furthermore, the average cavity volume fraction is proposed as a reaction independent parameter to estimate the optimal reactor design. Within the results obtained in this paper, it appears possible to optimise reactor design based on this parameter.

Carbon Tetrachloride Degradation by Alkaline Ascorbic Acid Solution

Ascorbic acid (AA) mediated electron transfer may induce reductive dechlorination of carbon tetrachloride (CCl(4)). This study investigated the role of AA in conjunction with the presence of iron minerals over a wide pH range for the reduction of CCl(4) in aqueous systems. The results indicate that CCl(4) was reduced by AA at a pH of 13 (>pKa(2, AA) of 11.79) and chloroform (CHCl3) was a transformation byproduct of CCl(4). When CCl(4) levels were reduced to near complete disappearance, the decrease of CHCl(3) was then observed. The degradation rate of CCl(4) and also the formation rate of CHCl(3) increased with increased AA concentrations. Analysis of reaction kinetics between CCl(4) and AA revealed an overall second-order reaction with a rate constant of 0.253 ± 0.018 M(-1) s(-1). Furthermore, the reduction rate of CCl(4) by AA at pH of 13 could be enhanced with the presence of iron minerals (Fe(3)O(4), Fe(2)O(3), FeOOH, and FeS2). In the absence or presence of iron minerals, the fraction of CCl(4) transformed to CHCl(3) was less than 1, indicating simultaneous one- and two-electron transfer processes. The end-products of AA at a pH of 13 included threonic acid and oxalic acid. This study highlights the potential of an alkaline AA solution for remediating chlorinated solvents.

Persulfate reactivity enhanced by Fe2O3–MnO and CaO–Fe2O3–MnO composite: Identification of composite and degradation of CCl4 at various levels of pH

The reactivity of persulfate (PS) was investigated when novel synthesized composites were used as activators. First, two types of composites were prepared by the mixing of an FeSO4 solution into a MnO-suspended solution with the addition of either NaOH (i.e. Composite I) or Ca(OH)2 (i.e. Composite II). SEM−EDS indicated that Fe and Mn were detected on Composite I while Fe and Ca were detected on Composite II. XPS analyses indicated that the crystalline form on the surface of Composite I was identified as maghemite (γ-Fe2O3), not jacobsite (MnFe2O4). On the other hand, the surface of Composite II was predominantly covered by lime (CaO) and maghemite. Based on these results, Composite I and Composite II were represented as Fe2O3–MnO and CaO–Fe2O3–MnO, respectively. BET surface area of MnO, Fe2O3–MnO, and CaO–Fe2O3–MnO were 0.4, 56, and 102m2g−1, and PZC of them were measured as 7.1, 8.2, and 12.2, respectively. The greater BET surface area and the higher PZC was due to CaO. Investigating the role of the composite as activator, PS/composite systems at various pH levels (i.e. 3, 7, 9 and 12) were applied for degradation of carbon tetrachloride (CT). The PS/Fe2O3–MnO system degraded CT effectively at pH 7 and 9, while PS/CaO–Fe2O3–MnO system showed effective degradation at pH 9 and 12. The optimum pH conditions in each PS/composite system implied that PS activation to produce reductant was possibly related to the surface charge of the composite. A mechanism to produce reductant, superoxide anion, from the PS/composite system was limitedly proposed.

Effects of Methanol and Carbon Tetrachloride on Sonolysis of 1,4-Dioxane in Relation to Temperature

The effects of methanol and carbon tetrachloride (CT) on the degradation of 1,4-dioxane via ultrasound irradiation were investigated by estimating the production rate of H2O2 and the degradation efficiency of the substrates. At 5 and 20 °C, the production rate of H2O2 significantly decreased as methanol concentration in pure water increased and during sonolysis of 1,4-dixoane. The sonolytic efficiency of 1,4-dioxane with methanol greatly decreased over 60 min at 5 °C and 90 min at 20 °C. Production of H2O2 increased during CT sonolysis at 5 °C but decreased at 20 and 40 °C, with efficiency greatest at 5 °C. Sonolysis of 1,4-dioxane with CT was enhanced from the beginning reaction at 5 °C and 40 min at 20 °C compared to the reactions without CT but was slightly lower at 40 °C. The results elucidate sonolytic mechanisms, such as pyrolysis and redox, in relation to reaction temperature, as well as suggest sonolytic conditions for the effective degradation of CT and 1,4-dioxane.

Enhanced reductive degradation of carbon tetrachloride by biogenic vivianite and Fe(II)

We demonstrated that reductive dechlorination of carbon tetrachloride (CT) can be enhanced by iron-bearing soil minerals (IBSMs) in the presence of Shewanella putrefaciens CN32 (CN32) due to the formation of biogenic vivianite and Fe(II). The bioreduction efficiency of magnetite was the highest (51.1%), followed by lepidocrocite (25.7%), goethite (3.6%), and hematite (1.8%). The dechlorination kinetic of CT by lepidocrocite (0.043d−1) in the presence of CN32 was three times faster than that by microbial transformation with CN32 (0.014d−1). Chloroform (16.1–29.4%), carbon monoxide (2.4–23.8%), and formate (0–58.0%) were measured as main products for the degradation of CT by magnetite and lepidocrocite in the presence of CN32. X-ray diffraction and electron microscope analyses revealed that the biogenic vivianite can form during the CT degradation in magnetite and lepidocrocite suspensions with CN32. The dechlorination kinetics of CT by chemogenic vivianite was much faster than that by magnetite and lepidocrocite with CN32. The highest formate production (84.2%) was observed during a full degradation of CT by the chemogenic vivianite. The experimental results showed that biogenic vivianite and sorbed Fe(II) formed during the bioreduction of IBSMs played a pivotal role for the reductive dechlorination of CT.

Degradation of carbon tetrachloride in modified Fenton reaction

We showed that the dechlorination of carbon tetrachloride (CT) can be significantly enhanced at nearneutral pH by modified Fenton reaction in the presence of Fe(II) chelated by cross-linked chitosan (CS) with glutaraldehyde (GLA). CT dechlorination was verified by monitoring the release of chloride and detection of intermediates such as trichloromethane and dichloromethane in the modified Fenton system with Fe(II) chelated by cross-linked CS with GLA (Fe(II)-CS/GLA). Measured chlorine mass balance of each sample was greater than 91% of total chlorine mass corresponding to initial CT concentration throughout the reaction. Addition of hydroxyl radical scavenger (2-propanol) enhanced the CT degradation in 5 h at near-neutral pH (removal efficiency from 57.2% to 92.4%), while the addition significantly inhibited trichloroethylene (TCE) degradation at the same condition (74.7% to 19.9%). This implies that, in contrast to the dechlorination of TCE, that of CT did not follow an oxidative dechlorination pathway but a reductive dechlorination pathway in the modified Fenton system with Fe(II)-CS/GLA. Dechlorination kinetics of CT in the modified Fenton system was affected by the concentrations of H2O2, Fe(II), and CT. The formation of surface Fe(II)-CS/GLA complex and its valence change from Fe(II) to Fe(III) observed during the modified Fenton reaction gave a clue to identify the proposed reaction mechanism properly.

Dechlorination of Environmental Contaminants Using a Hybrid Nanocatalyst: Palladium Nanoparticles Supported on Hierarchical Carbon Nanostructures

This paper demonstrates the effectiveness of a new type of hybrid nanocatalyst material that combines the high surface area of nanoparticles and nanotubes with the structural robustness and ease of handling larger supports. The hybrid material is made by fabricating palladium nanoparticles on two types of carbon supports: as-received microcellular foam (Foam) and foam with carbon nanotubes anchored on the pore walls (CNT/Foam). Catalytic reductive dechlorination of carbon tetrachloride with these materials has been investigated using gas chromatography. It is seen that while both palladium-functionalized carbon supports are highly effective in the degradation of carbon tetrachloride, the rate of degradation is significantly increased with palladium on CNT/Foam. However, there is scope to increase this rate further if the wettability of these structures can be enhanced in the future. Microstructural and spectroscopic analyses of the fresh and used catalysts have been compared which indicates that there is no change in density or surface chemical states of the catalyst after prolonged use in dechlorination test. This implies that these materials can be used repeatedly and hence provide a simple, powerful, and cost-effective approach for dechlorination of water.

Photocatalytic reduction of carbon tetrachloride by natural sphalerite under visible light irradiation

The photoreductive degradation of carbon tetrachloride (CT) in natural sphalerite ((Zn, Fe)S mineral) suspensions irradiated by visible light (VL) is studied in this paper. 92% of CT is degraded in N,N-dimethylformamide (DMF) organic solvent system after 8 h of VL irradiation. The effects of light source, sphalerite dosage, electron donors, dissolved oxygen and CT initial concentration on CT photocatalytic degradation efficiency are discussed. The degradation products are analyzed by gas chromatography–mass spectrometry (GC–MS), and the photocatalytic degradation mechanism is then proposed.

Ligand-assisted degradation of carbon tetrachloride by microscale zero-valent iron

Degradation of carbon tetrachloride (CT) by microscale zero-valent iron (ZVI) was investigated in batch systems with or without organic ligands (ethylenediaminetetraacetic acid (EDTA), citric acid, tartaric acid, malic acid and oxalic acid) at pHs from 3.5 to 7.5. The results demonstrated that at 25°C, the dechlorination of CT by microscale ZVI is slow in the absence of organic ligands, with a pseudo-first-order rate constant of 0.0217h−1 at pH 3.5 and being further dropped to 0.0052h−1 at pH 7.5. However, addition of organic ligands significantly enhanced the rates and the extents of CT removal, as indicated by the rate constant increases of 39, 31, 32, 28 and 18 times in the presence of EDTA, citric acid, tartaric acid, malic acid and oxalic acid, respectively, at pH 3.5 and 25°C. The effect of EDTA was most significant; the dechlorination of CT at an initial concentration of 20mgl−1 increased from 16.3% (no ligands) to 89.1% (with EDTA) at the end of 8h reaction. The enhanced CT degradation in the presence of organic ligands was primarily attributed to the elimination of a surface passivation layer of Fe(III) (hydr)oxides on the microscale ZVI through chelating of organic ligands with Fe(III), which maintained the exposure of active sites on ZVI surface to CT.

Selective redox degradation of chlorinated aliphatic compounds by Fenton reaction in pyrite suspension

Selective redox degradation of chlorinated aliphatics by Fenton reaction in pyrite suspension was investigated in a closed system. Carbon tetrachloride (CT) was used as a representative target of perchlorinated alkanes and trichloroethylene (TCE) was used as one of highly chlorinated alkenes. Degradation of CT in Fenton reaction was significantly enhanced by pyrite used as an iron source instead of soluble Fe. Pyrite Fenton showed 93% of CT removal in 140 min, while Fenton reaction with soluble Fe(II) showed 52% and that with Fe(III) 15%. Addition of 2-propanol to the pyrite Fenton system significantly inhibited degradation of TCE (99% to 44% of TCE removal), while degradation of CT was slightly improved by the 2-propanol addition (80–91% of CT removal). The result suggests that, unlike oxidative degradation of TCE by hydroxyl radical in pyrite Fenton system, an oxidation by the hydroxyl radical is not a main degradation mechanism for the degradation of CT in pyrite Fenton system but a reductive dechlorination by superoxide can rather be the one for the CT degradation. The degradation kinetics of CT in the pyrite Fenton system was decelerated (0.13–0.03 min −1), as initial suspension pH decreased from 3 to 2. The formation of superoxide during the CT degradation in the pyrite Fenton system was observed by electron spin resonance spectroscopy. The formation at initial pH 3 was greater than that at initial pH 2, which supported that superoxide was a main reductant for degradation of CT in the pyrite Fenton system.

Rapid degradation of carbon tetrachloride by commercial micro-scale zinc powder assisted by citric acid

We developed an effective method for degradation of carbon tetrachloride (CT) in contaminated water. Zinc metal as a reducing agent for CT in aqueous solutions has been previously studied in some detail, but the rapid corrosion of zinc surface usually reduces its efficiency in removing CT. We assumed that citric acid could enhance the degradation of CT by zinc powder due to the elimination of a passivation layer of Zn(II) (hydr)oxides on the surface of zinc powder through chelating of organic ligands with Zn(II) produced from the reaction and keeping the exposure of active sites to targets. Here the influence of citric acid on the decomposing of CT by commercial micro-scale zinc powder was investigated in a pH range of 3.5–7.5 at 25°C in batch experiments. Reaction mixtures were analysed by gas chromatography/headspace analysis, and Cl− concentration was determined by turbidimetry. The results demonstrate that the degradation of CT by zinc metal alone is very weak, but the addition of citric acid can assist zinc powder to decompose CT more completely and rapidly at all pHs. Degradation of CT took place mainly in the first 10 min of reaction, coupled with 75–95% of CT removal. Maximum dechlorination percentage (82.4%) of CT was obtained at pH 5.5. In that case, chloroform and dichloromethane, as main intermediates, were found at low levels during the whole reaction, suggesting that CT may be sequentially and multiply degraded so quickly that methane is yielded before the intermediates can be desorbed and released to aqueous solution. When compared with the current methods of nano-scale zinc and bimetallic systems, the application of commercial micro-scale zinc particles assisted by organic ligands is of environmental significance since it allows decontamination of aqueous chlorinated organic compounds at low cost and with high efficiency.

Trimetallic Pd/Fe/Al particles for catalytic dechlorination of chlorinated organic contaminants

Zero-valent aluminum based trimetallic particles comprising a combination of catalytically effective amounts (1 wt%) of palladium and zero-valent iron on the aluminum surface were synthesized and tested for the dechlorination of chlorinated methanes in batch reactors. XRD analysis indicated the trimetallic particles present in zero-valent form of all three components. Trimetallic Pd/Fe/Al particles showed a very rapid degradation of carbon tetrachloride leading to a surface normalized rate constant (k(SA)) of approximately 0.03 L/h/m(2), two orders of magnitude higher than that of reported data on zero-valent iron particles under near neutral pH conditions. Hydrocarbons including methane and ethane were the major products that accounted for about 38% and 27% of the carbon tetrachloride lost, respectively. Repetitive addition of carbon tetrachloride showed no loss of activity of Pd/Fe/Al particles for more than 20 cycles. In the absence of palladium, the degradation rate decreased by a factor of 10 suggesting palladium serves as a catalyst. Analysis of anions in the solution revealed that the chloride accounted for 75% of the carbon tetrachloride lost. Metallic ions for aluminum and iron were determined to be about 0.02 and 20 mg/L, respectively at the end of the experiment. No palladium ion was measured.

Characterization and Reactivity of Iron Nanoparticles prepared with added Cu, Pd, and Ni

The association of a secondary metal with iron particles affects redox reactivity in engineered remediation systems. However, the structural characteristics of the metal additives and mechanism responsible for changes in reactivity have not been fully elucidated. Here, we synthesized iron nanoparticles with Cu, Pd, and Ni content ranging from 0-2 mol % via a solution deposition process (SDP), hydrogen reduction process (HRP), or hydrogen reduction of ferrihydrite coprecipitated with the metal cations (HRCO). Results from solid-state characterization show that the synthesis methods produced similar iron core/magnetite shell particles but produced substantial differences in terms of the distribution of the metal additives. In SDP, the metal additives were heterogeneously distributed on the surface of the particles. The metal additives were clearly discernible in TEM images as spherical nanoparticles (5-20 nm) on the HRP and HRCO particles. Because the metals were integral to the synthesis process, we hypothesize that the metal additive is present as solute within the iron core of the HRCO particles. Kinetic batch experiments of carbon tetrachloride (CT) degradation were performed to quantitatively compare the redox reactivity of the particles. Overall, metal additives resulted in enhanced pseudo-first-order rate constants of CT degradation (k(O,CT)) compared to that of the iron nanoparticles. For the bimetallic iron nanoparticles prepared by SDP and HRP, k(O,CT) increased with the concentration of metal additives. The values of chloroform yield (Y(CF)) were independent of the identity and amount of metal additives. However, both k(O,CT) and Y(CF) of the HRCO iron particles were significantly increased. Results suggest that it is the distribution of the metal additives that most strongly impacts reactivity and product distribution. For example, for materials with ca. 0.9 mol % Ni, reactivity and Y(CF) varied substantially (HRCO > SDP > HRP), and HRCO-NiFe resulted in the lowest final chloroform concentration because chloroform was rapidly dechlorinated. In addition, sequential spike experiments for long-term reactivity demonstrated that the presence of the metal additives facilitated reduction by enabling greater utilization of Fe(0).

The Impact of Carbon Tetrachloride on an Anaerobic Methanol-Degrading Microbial Community

The evolution of microbial communities with increasing carbon tetrachloride concentrations was studied in two anaerobic columns containing sand and two different clay soils, one of which contained high levels of iron. Microbial communities were characterized through analysis of column effluents with denaturing gradient gel electrophoresis and quantitative polymerase chain reaction for archaea and eubacteria as inlet carbon tetrachloride concentrations were increased from 0.8 to 29 μM. Inhibition of microbial activity was observed in both columns, and was associated with the accumulation of chloroform at concentrations of 0.2 to 0.4 μM as inlet CT concentrations were increased to 2.4–3.0 μM in the low-iron clay column and approximately 16 μM in the iron rich clay column. Inhibition was indicated by decreasing rates of methanol and carbon tetrachloride degradation, decreases in effluent levels of DNA, and shifts in microbial communities of the columns. Even with the inhibition observed, in the iron-rich clay column CT degradation continued to the end of the study with inlet CT concentrations of 29 μM, in contrast to the low-iron clay column in which minimal CT degradation occurred once CT inlet concentrations exceeded 3 μM. The greater capacity for CT degradation in the column containing the iron-rich clay was hypothesized to be the result of reaction with biogenic ferrous iron produced by biological dissimilatory iron reduction.

Degradation of carbon tetrachloride in the presence of zero-valent iron

Efforts to achieve the decomposition of carbon tetrachloride through anaerobic and aerobic bioremediation and chemical transformation have met with limited success because of the conditions required and the formation of hazardous intermediates. Recently, particles of zero-valent iron (ZVI) have been used with limited success for in situ remediation of carbon tetrachloride. We studied a modified microparticulate product that combines controlled-release carbon with ZVI for stimulation of in situ chemical reduction of persistent organic compounds in groundwater. With this product, a number of physical, chemical, and microbiological processes were combined to create very strongly reducing conditions that stimulate rapid, complete dechlorination of organic solvents. In principle, the organic component of ZVI microparticles is nutrient rich and hydrophilic and has high surface area capable of supporting the growth of bacteria in the groundwater environment. In our experiments, we found that as the bacteria grew, oxygen was consumed, and the redox potential decreased to values reaching -600 mV. The small modified ZVI particles provide substantial reactive surface area that, in these conditions, directly stimulates chemical dechlorination and cleanup of the contaminated area without accumulation of undesirable breakdown products. The objective of this work was to evaluate the effectiveness of ZVI microparticles in reducing carbon tetrachloride under laboratory and field conditions. Changes in concentrations and in chemical and physical parameters were monitored to determine the role of the organic products in the reductive dechlorination reaction. Laboratory and field studies are presented.

Bimetallic iron–aluminum particles for dechlorination of carbon tetrachloride

Bimetallic iron–aluminum (Fe/Al) particles were synthesized and tested for their reactivity toward carbon tetrachloride using batch reactors and a flow-through column at near neutral pH. Preparation of bimetallic Fe/Al particles was conducted under acidic conditions under which iron was readily deposited onto the aluminum surface. The SEM image showed clusters of iron on the aluminum surface at the measured Fe:Al molar ratio of about 2:3. Results showed that the presence of zero-valent aluminum successfully prevented the formation of a passive layer at the iron surface and maintained the reactivity of iron. The dechlorination of carbon tetrachloride by bimetallic Fe/Al particles produced chloroform (9%), dichloromethane (17%) and methane (38%). Kinetic analysis suggests that bimetallic Fe/Al particles increased the reactivity toward carbon tetrachloride degradation by a factor of 10 compared to zero-valent iron and possessed a comparable reactivity with nano-sized Fe. The effectiveness of bimetallic Fe/Al particles was further confirmed by the continuous flow column study from which an ageing of bimetallic particles was also observed.

Influence of Aluminum Substitution on the Reactivity of Magnetite Nanoparticles

Magnetite is an iron oxide that commonly forms in soils under reducing conditions. It is an important material in natural and engineered remediation systems because it can affect the reductive degradation of environmental toxins such as halogenated hydrocarbons. To examine the influence of redox-inactive dopants and particle size on the reactivity of magnetite nanoparticles, samples with varying size and amounts of aluminum cation substitution (0-8.07 mol %) were synthesized. These materials were characterized, and their reactivity was examined using the organic molecules benzoquinone and carbon tetrachloride. Activation energies and frequency factors for the reaction of magnetite with benzoquinone were determined from a series of variable temperature kinetic studies. The ratio of products formed during the degradation of carbon tetrachloride was also studied to assess the influence of aluminum doping on the mechanism of reaction. The activation energy and frequency factor both initially decreased with increasing aluminum substitution, then increased as the aluminum content increased from 2.14% to 8.07%. Overall, the reactivity of magnetite nanoparticles decreased as a function of aluminum substitution in both systems, while the ratio of products resulting from the reaction with carbon tetrachloride seemed to be unaffected.

Degradation of Chlorocarbons Driven by Hydrodynamic Cavitation

AbstractTo provide an efficient lab‐scale device for the investigation of the degradation of organic pollutants driven by hydrodynamic cavitation, the degradation kinetics of chloroform and carbon tetrachloride and the increase of conductivity in aqueous solutions were measured. These are values which were not previously available. Under hydrodynamic cavitation conditions, the degradation kinetics for chlorocarbons was found to be pseudo first‐order. Meanwhile, C‐H and C‐Cl bonds are broken, and Cl2, Cl., Cl– and other ions released can increase the conductivity and enhance the oxidation of KI in aqueous solutions. The upstream pressures of the orifice plate, the cavitation number, and the solution temperature have substantial effects on the degradation kinetics. A decreased cavitation number can result in more cavitation events and enhances the degradation of chlorocarbons and/or the oxidation of KI. A decrease in temperature is generally favorable to the cavitation chemistry. Organic products from the degradation of carbon tetrachloride and chloroform have demonstrated the formation and recombination of free radicals, e.g., CCl4, C2Cl4, and C2Cl6 are produced from the degradation of CHCl3. CHCl3 and C2Cl6 are produced from the degradation of CCl4. Both the chemical mechanism and the reaction kinetics of the degradation of chlorocarbons induced by hydrodynamic cavitation are consistent with those obtained from the acoustic cavitation. Therefore, the technology of hydrodynamic cavitation should be a good candidate for the removal of organic pollutants from water.