a b s t r a c tIn this work, an indirect method for estimating the total amount and concentration of oxidative radicals in aqueous and slurry-phase Fenton's systems was developed. This method, based on the use of benzoic acid as probe compound, was applied for evaluating the effect of the operating conditions on the radicals amount produced, their production efficiency (i.e. moles of radicals generated per mole H 2 O 2 ) and their concentration. A Rotatable Central Composite design (RCC) was used to select the operating conditions in order to get a statistically meaningful data set. Hydrogen peroxide and ferrous ion concentrations ranged between 0.2-1 mM and 0.2-0.5 mM, respectively; humic acid concentration between 0 and 15 mg/L, whereas the soil/water weight ratio in slurry-phase systems between 1:10 and 9:10. The probe compound concentration was 9 or 0.1 mM in experiments aimed to evaluate the total amount or concentration of oxidative radicals, respectively. The obtained results indicated that the amount of radicals generated in both aqueous and soil slurry Fenton's system increased with higher H 2 O 2 concentration and, more specifically, that their production efficiency increased with increasing Fe(II):H 2 O 2 molar ratio. Addition of dissolved organic compounds as humic acid did not notably affect the oxidative radicals amount and concentration. On the contrary, a one order of magnitude reduction in both radicals amount generated and concentration was observed when soil was added to the reaction environment.
Criteria for the design of In-Situ Fenton Oxidation (ISFO) is proposed and applied to the development of a pilot-scale treatment of a former refinery site contaminated by hydrocarbons. The proposed criteria takes in account both the regulatory and technical constraints that typically characterize the application of in situ remediation technologies. The proposed design strategy of the ISFO treatment is based on coupling experimental and numerical modelling of the ISFO treatment in an iterative way. Batch tests are performed first, allowing to select the optimal operating conditions and the data on hydrogen peroxide decomposition kinetics. These data, together with the hydro-geological information collected in the field, are then used for the numerical modelling of the ISFO treatment, which allows to define the pilot plant layout and operating conditions and to evaluate the effective delivery of the oxidant and the hydraulic gradient developed in the field. These data are then used to design column scale tests aimed to evaluate the effective hydrogen peroxide longevity, the process performance and the extent of gas production from hydrogen peroxide decomposition.
Microplastic (MP) contamination is a globally recognised issue in aquatic environments, and recently, there has been an increase in investigations focusing on lake contamination, revealing significant amounts of dispersed MPs. However, our understanding of the ingestion and effects of MPs on organisms living in lake ecosystems remains limited. This study aims to develop an effective protocol for assessing the ingestion of MPs by the talitrid amphipod Cryptorchestia garbinii, with the goal of verifying and evaluating the biological effects following ingestion. Individuals sampled from the shores of Lake Albano were exposed to four different polymers, namely low-density polyethylene (PE), polyethylene terephthalate (PET), polyester (PES), and polypropylene (PP), under laboratory conditions. To deliver MPs through the diet, we decided to employ DECOTABs (DEcomposition and COnsumption TABlets) which have been successfully used as a food source in aquatic toxicity tests. At the end of the experiments, we employed the solvatochromic and fluorescent dye Nile red to detect and quantify the MPs present in the digestive tube contents of the animals. The results clearly demonstrate the ingestion of the supplied polymers through the tabs, validating this method of exposure as effective. Furthermore, the measurement of glucose, glycogen, and lipid levels reveals that within 24 h of ingestion, MPs had an impact on the macromolecules involved in the energy metabolism of C. garbinii. This research underscores the suitability of this species as a model organism for studying MP uptake and its effects.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.