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Solvent Extraction of Pentachlorophenol Associated with Humic Acids
Published in Gregory D. Boardman, Hazardous and Industrial Wastes, 2022
Cynthia E. Crane, John T. Novak
The oxidative coupling mechanism could also be used to explain the slow association with both dissolved and solid humic acids. However, under the experimental conditions, it is unlikely that this mechanism played a significant role. During the extraction process, soluble soil enzymes would have been denatured. It is possible that peroxidase active sites survived the acid/base extraction. This enzyme requires hydrogen peroxide (H2O2). In the experimental solutions, there was no biological activity to produce H2O2. H2O2 could have been present initially, and hydroxy radicals could have spontaneously formed during the study. The extremely small amount of H2O2 possibly present in solution can not account for the extent of association, in particular the long-term association, observed. Based on the observed association patterns, hydrophobic interactions, including attraction, absorption and diffusion within the organic material, dominated the association of PCP with humic acids.
A Study on the Cause and Effects of Paddy Straw Burning by Farmers in Fields and Proposal of Using Rice Husk as a Novel Ingredient in Pottery Industry
Published in Vikram Bali, Rajni Mohana, Ahmed A. Elngar, Sunil Kumar Chawla, Gurpreet Singh, Handbook of Sustainable Development through Green Engineering and Technology, 2022
Shikha Tuteja, Vinod Karar, Ravinder Tonk
To understand the reasons, we evaluate the adsorption isotherm of mesopore-free submicron silica debris. Mesopore-free submicron silica debris was organized from acid-base extraction of rice husk ash underneath a surfactant-free situation. The adsorption isotherm evaluation was accomplished within the borosilicate batch reactor gadget below, consistent pH condition in addition to room temperature and strain. Then, the results were compared to both Langmuir and Freund lich models. As a version of adsorbate, curcumin is utilized. To help the adsorption evaluation, numerous characterizations have been performed, including electron microscope, x-ray diffraction, and Fourier rework infrared (Ragadhita et al., 2019). The experimental results showed that the present mesopore-unfastened submicron silica particles have been efficiently adsorbing curcumin molecules. The adsorption isotherm confirmed that the equilibrium adsorption statistics of the present silica particles were fit to the Freund lich isotherm model, confirming the adsorption takes place on heterogeneous surfaces with multilayer adsorption. This informs molecule-molecule interaction at the adsorption layers. The low adsorption found is due to the lifestyles of mesopore-free shape on the silica adsorbent. This examination gives statistics for the importance of a variable influencing the adsorption capacity.
Aqueous Solvent Removal of Contaminants from Soils
Published in Donald L. Wise, Debra J. Trantolo, Edward J. Cichon, Hilary I. Inyang, Ulrich Stottmeister, Remediation Engineering of Contaminated Soils, 2000
James C. O'Shaughnessy, Frederic C. Blanc
Equipment is available for soil washing which can be transported and set up on-site. Such equipment utilizes unit operations such as screening, sedimentation, centrifugal separation, elutriation, filtration, acid/base extraction, mechanical shearing, flotation, Table 7 Soil Washing Equipment
A review on pretreatment methods for lipid extraction from microalgae biomass
Published in Preparative Biochemistry & Biotechnology, 2023
Muhammad Azreen Mat Husin, Nazlina Haiza Mohd Yasin, Mohd Sobri Takriff, Nur Hidayah Jamar
For the disruption of microalgal cell wall using acids, the acid selectivity, suitability, and efficiency are primarily based on the composition and features of the microalgal cell wall.[23] Sulfuric acid, for example, is comparatively low in terms of cost and efficiency compared to the other chemical agents. Table 1 shows that the acid treatment is usually coupled with heat treatment. For example, Lee et al.[36] studied the hydrothermal nitric acid treatment, while Park et al.[37] studied on the acid-catalyzed hot water extraction method. Both methods recovered about 24.4 and 96.7% lipid from N. salina and C. vulgaris, respectively. The hydrothermal-acid technique is commonly used for lignocellulosic biomass extraction. The strong acid catalyzes cell disruption, and the process is induced by heat.[36] In a study on the acid-catalysed hot water extraction method, high free fatty acids (FFA) were derived from C. vulgaris.[37]Table 2 shows the results from the treatment of C. vulgaris using different sulfuric acid concentrations and sodium dodecyl benzene sulfonate (SDBS). The mixture of methanol and sulfuric acid has been found to be the best for lipid extraction from C. vulgaris. Mixtures of acid and SDBS show different levels of effectiveness depending on the microalgal species. Acid-base extraction is typically used to separate organic compounds from each other based on their acid-base properties. The FAME content of the high-FFA type of microalgae lipid has been increased to 70.1% when using 1% (v/v) sulfuric acid. By combining acid and SDBS, much higher lipid recovery could be reached; however, the proportion used varies depending on species.[37]