Removal of organotin compounds and metals from Swedish marine sediment using Fenton’s reagent and electrochemical treatment

Metal and tributyltin (TBT) contaminated sediments are problematic for sediment managers and the environment. This study is the first to compare Fenton’s reagent and electrochemical treatment as remediation methods for the removal of TBT and metals using laboratory-scale experiments on contaminated dredged sediment. The costs and the applicability of the developed methods were also compared and discussed. Both methods removed > 98% TBT from TBT-spiked sediment samples, while Fenton’s reagent removed 64% of the TBT and electrolysis 58% of the TBT from non-spiked samples. TBT in water phase was effectively degraded in both experiments on spiked water and in leachates during the treatment of the sediment. Positive correlations were observed between TBT removal and the added amount of hydrogen peroxide and current density. Both methods removed metals from the sediment, but Fenton’s reagent was identified as the most potent option for effective removal of both metals and TBT, especially from highly metal-contaminated sediment. However, due to risks associated with the required chemicals and low pH level in the sediment residue following the Fenton treatment, electrochemical treatment could be a more sustainable option for treating larger quantities of contaminated sediment.

Enhanced Adsorption of Cooking Fume Pollutants By Loofah Carbon Modified By Fenton Reagents

In this study, natural loofah was used as a raw material to adsorb cooking fume pollutants after grinding into a powder (TGS), activation by phosphoric acid to generate activated loofah carbon (TGSC-0), and further modification by Fenton’s reagent (TGSC-1). SEM, GC-MS, FT-IR, and X-ray diffraction analyses, in addition to surface area and pore measurements, were used to characterize the adsorption performance of TGS, TGSC-0, and TGSC-1 toward cooking fume pollutants including oils, particulate matter, and non-methane hydrocarbon). TGSC-1 was the best adsorbent when compared against TGS and TGSC-0, and exhibited saturated adsorption capacities for oil, non-methane hydrocarbon (NMHC), PM2.5, and PM10 of 10.367 mg/g, 4.132 mg/g, 5.613 μg/g, and 16.486 μg/g, respectively. Microscopy indicated that the TGSC-1 surface was rougher than that of TGSC-0. In addition, the adsorption properties of TGSC-1 were enhanced due to abundant hydroxyl, carbonyl, and carboxyl groups on the material surfaces, while iron was also present in the amorphous form that was generated on TGSC-1 surfaces from Fenton’s reagent. As TGSC-1 mass increased, the adsorption breakthrough time and adsorption capacity for simulated cooking fumes (SCFs) gradually increased. Further, Langmuir models better fit the adsorption process based on the highest R2 values being observed for Langmuir model fitting curves of TGSC-1 adsorption of pollutants (i.e., oils, NMHC, PM2.5, and PM10) from SCF, suggesting that adsorption was primarily due to monolayer adsorption and that chemical adsorption plays a major role in this process. This study provides a theoretical basis for the application of TGSC adsorption technology in the treatment of cooking fumes.

Hydrocarbon treatability study of Antarctica soil with Fenton’s reagent

The study objectives were to determine the effectiveness of Fenton’s Reagent and Modified Fenton’s Reagent in reducing Total Petroleum Hydrocarbon (TPH) concentrations in petroleum-contaminated soil from McMurdo Station, Antarctica. Comparisons of the contaminated soils were made, and a treatability study was completed and documented. This material was presented at the Association for Environmental Health and Sciences Foundation (AEHS) 30th Annual International Conference on Soil, Water, Energy, and Air (Virtual) on March 25, 2021.

Kinetics and mechanism of oxidative decomposition of Congo red by Fenton’s reagent and its synergic effects on exposure to UV radiation

Congo red is a toxic azo dye which is used extensively in industries like textile, paper, pulp and paper. Very high amount of Congo red from these industrial sources is discharged into natural water bodies resulting environmental pollution. The present work reports the kinetics and mechanism of oxidative decomposition of Congo red by Fenton’s reagent in homogeneous medium and also under ultra violet light irradiation. Kinetic parameters like effect of [Fe2+], [H2O2], [Congo red] and temperature on the decomposition of Congo red were studied. The reaction is found to be fractional order with [Fe2+] and first order with [H2O2] and [Congo red]. The rate of oxidative decomposition of Congo red by Fenton’ reagent showed a rapid increase of three times when irradiated with ultra violet radiation and completion of reaction occurred within 5-6 minute. Various thermodynamic variables were determined and the presence of isosbestic points on sequential scanning of oxidation kinetics proves that the reaction is very smooth, spontaneous and endothermic. A suitable mechanism is suggested based on the experimental results obtained.

Modified Camellia oleifera Shell Carbon with Enhanced Performance for the Adsorption of Cooking Fumes

Using Camellia oleifera shell (COS) as a raw material and phosphoric acid as the activator, activated Camellia oleifera shell carbon (COSC-0) was prepared and then modified by Fenton’s reagent (named as COSC-1). SEM, GC-MS, FTIR, and specific surface area and pore analyzers were used to study the adsorption performance of COS, COSC-0, and COSC-1 on cooking fumes. Results showed that COSC-1 was the best adsorbent compared with COS and COSC-0. The adsorption quantity and penetrating time of COSC-1 were 44.04 mg/g and 4.1 h, respectively. Most aldehydes could be adsorbed by COSC-1, which was due to the large number of carbonyl and carboxyl groups generated on the surface of COSC-1 from the action of Fenton’s reagent. The adsorption effect of COSC-1 on different types of pollutants in cooking fumes was analyzed based on the similar compatibility principle. COSC-1 showed a much higher adsorption effect on the strong polarity functional groups than on weak polar groups. The results provide a theoretical basis for the application of Camellia oleifera shell carbon adsorption technology in the treatment of cooking fumes.

Intensification of advanced oxidation processes (AOPs) for the degradation of bisphenol-A

Bisphenol-A (BPA), a precursor for many polymers, is a harmful compound for living organisms if present beyond permissible limits in aqueous streams. The combinations of oxidation processes like Hydrodynamic Cavitation (HC), hydrogen peroxide (H2O2), and Fenton’s reagent (H2O2 + FeSO4) were examined for the degradation of BPA in the present study. The effects of operating parameters like inlet pressure, initial concentration of BPA, orifice geometry were investigated on BPA degradation. The degradation rates of BPA increased with inlet pressure up to 0.5 MPa and then showed a decreasing trend beyond 0.5 MPa. The initial concentration of BPA had an inverse relation with the degradation percentage. The multiple hole orifice plate showed better degradation of BPA compared to the single hole orifice plate. In the intensification studies, the addition of hydrogen peroxide to BPA in the cavitation reactor favored BPA degradation. A combination of HC + Fenton’s reagent (0.1 M H2O2 + 0.01 M FeSO4) significantly degraded BPA present in the aqueous streams.