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Comparative Evaluation of Biogas Yield and Physicochemical Properties of Three-Phase and Traditional Olive Oil Mill Wastes – The Most Suitable Choice for Efficient Anaerobic Digestion

Hamdi Inass, El Asri Ouahid, Lihi Khadija, Hamdaoui Hajar, Auajjar Nabila, Chafi Abdelhafid, Attarassi Benaissa

Ecological Engineering & Environmental Technology

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2023

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Vol. 24, iss. 5

76--83

EN

Olive oil mill waste is characterized by its high organic matter content, especially fatty acids, polyphenols, sugars, and proteins. These nutrients can be used as a source of energy for biogas production. However, olive oil mill waste can also contain heavy metals such as lead, cadmium, copper, and zinc that can be absorbed by plants. In addition, very high concentrations of heavy metals can also inhibit the anaerobic digestion process by affecting the methanogenic bacteria involved in biogas production The aim of this research is to determine the composition of solid and liquid rejections from traditional and continuous three-phase crushing systems, by analyzing samples from different oil mills in the eastern region of Morocco. We also applied the technology of anaerobic digestion of solid and liquid waste forms of oil mills, to make a link between the biogas yield and the physicochemical characteristics of these wastes. The results suggest that traditional oil mill wastewater (Discontinuous OMWW) has high organic matter, nutrients, and heavy metals content and a low concentration of phenolic compounds, which can increase its biogas production potential with a production of 10.02 Nml/g VS, while three-phase wastewater (Continuous OMWW) has limited biogas production potential (3.83 Nml/g VS) due to the low organic matter and nutrients content, and high concentration of phenolic compounds. Three-phase olive pomace (Continuous OMSW) has a higher biogas production (9.28 Nml/ g VS) than traditional olive pomace (Discontinuous OMSW) with 5.91 Nml/g VS. In fact, the lower content of phenolic compounds and volatile fatty acids favors their anaerobic digestion and improves their biogas production. In conclusion, the selection of the type of waste adapted for biogas production must be based on the physicochemical and microbiological characteristics of these wastes.

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Evolution of Physicochemical Structure of Waste Cotton Fiber (Hydrochar) During Hydrothermal Carbonation

Sheng Shi, Meiling Zhang, Suying Zhang, Wensheng Hou, Zhifeng Yan

Autex Research Journal

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2020

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Vol. 20, no. 3

319--326

EN

To study the hydrothermal behavior of cotton fiber, the carbonization process and structural evolution of discarded or waste cotton fiber (WCF) under hydrothermal conditions were investigated using microcrystalline cellulose (MCC), and glucose was used as a model compound. Results showed that high temperature was beneficial for the hydrolysis of discarded cotton fiber, and the yield of sugar was 4.5%, which was lower than that of MCC (6.51%). WCF and MCC were carbonized at 240–~260°C and 220–~240°C, respectively, whereas the carbonization temperature of glucose was lower than 220°C. The C/O ratios of WCF and glucose hydrothermal products were 5.79 and 5.85, respectively. The three kinds of hydrothermal carbonization products had similar crystal structures and oxygen-containing functional groups. The carbonized products of WCF contained many irregular particles, while the main products of glucose carbonization were 0.5-mm-sized carbon microspheres (CMSs). Results showed that glucose was an important intermediate in WCF carbonization and that there were two main pathways of hydrothermal carbonization of cotton fibers: some cotton fibers were completely hydrolyzed into glucose accompanied by nucleation and then the growth of CMSs. For the other part, the glucose ring of the oligosaccharide, formed by the incomplete hydrolysis of cotton fibers under hydrothermal conditions of high temperature and pressure, breaks and then forms particulate matter.

3

The similarity of selected statins - a comparative analysis

Dreyer C., Placha W., Zgajewski J., Dygut J., Stangel-Wójcikiewicz K., Piwowar M.

Bio-Algorithms and Med-Systems

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2018

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Vol. 14, no. 4

art. no. 20180034

EN

The paper presents the physicochemical and structural characteristics as well as the comparison of selected statins. Statins are relatively popular compounds used in modern medicine. They are increasingly often combined with other medications to improve the effectiveness of therapy. We analyzed the characteristics of pravastatin, simvastatin, atorvastatin, pitavastatin, lovastatin, mevastatin, fluvastatin, and rosuvastatin obtained from the PubChem Substance database. On the basis of data related to chemical structure and physicochemical properties, the statins were grouped into more and less similar ones. Statins are not homogeneous in terms of physicochemical properties and structure. Three groups of statins were identified. Mevastatin, lovastatin, and simvastatin are the most similar to each other, while pravastatin shows a slightly lower similarity to them. Pitavastatin and fluvastatin are also highly similar, while atorvastatin and rosuvastatin, because of their properties, are the most different from other statin groups.

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Physicochemical characteristics of land waters in the Bellsund region (Spitsbergen)

Chmiel S., Bartoszewski S., Gluza A., Siwek K., Zagórski P.

Landform Analysis

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2007

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Vol. 5

13--15