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Green products from herbal medicine wastes by subcritical water treatment

Jouyandeh, M ; Sharif University of Technology | 2022

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  1. Type of Document: Article
  2. DOI: 10.1016/j.jhazmat.2021.127294
  3. Publisher: Elsevier B.V , 2022
  4. Abstract:
  5. Herbal medicine wastes (HMWs) are byproducts of medicine factories, which are mainly landfilled for their environmental problems. Only bearing in mind the contamination and concerns caused by the COVID-19 pandemic and environmental emissions, the worth of herbal medicine wastes management and conversion to green products can be understood. In this work, subcritical water treatment was carried out batch-wise in a stainless tube reactor in the pressure range of 0.792–30.0 MPa, varying the temperature (127–327 °C) and time (1–60 min) of extraction. This resulted in new and green material sources, including organic acids, amino acids, and sugars. Amazingly, at very low extraction times (below 5 min) and high temperatures (above 277 °C), about 99% of HMWs were efficaciously converted to clean products by subcritical hydrothermal treatment. The results of hydrothermal extraction after 5 min indicated that at low temperatures (127–227 °C), the total organic carbon in the aqueous phase increased as the residual solid phase decreased, reaching a peak around 220 °C. Acetone soluble extracts or fat phase appeared above 227 °C and reached a maximum yield of 21% at 357 °C. Aspartic acid, threonine, and glycine were the primary amino acids; glycolic acid, formic acid, lactic acid, and acetic acid were obtained as the main organic acids, glucose, fructose, and cellobiose were substantial sugars produced from the aqueous phase after 5 min of hydrothermal subcritical hydrolysis extraction. © 2021 Elsevier B.V
  6. Keywords:
  7. Organic acids ; Acetone ; Amino acids ; Extraction ; Medicine ; Organic carbon ; Plant extracts ; Sugars ; Waste treatment ; Water treatment ; Amino-acids ; Aqueous phasis ; Batch-wise ; Environmental emissions ; Environmental problems ; Green products ; Herbal medicine waste ; Herbal medicines ; Subcritical extraction ; Subcritical water treatment ; Alanine ; Asparagine ; Aspartic acid ; Carbohydrate ; Carboxylic acid ; Cellobiose ; Disaccharide ; Fat ; Formic acid ; Fructose ; Glucose ; Glutamic acid ; Glycolic acid ; Isoleucine ; Lactic acid ; Leucine ; Monosaccharide ; Organic compound ; Peppermint ; Serine ; Threonine ; Valine ; Acetic acid ; Chemical compound ; Concentration (composition) ; Extraction method ; Temperature effect ; Aqueous solution ; Carrot ; Extraction temperature ; Extraction time ; Ginger ; Green chemistry ; High temperature ; Liquefaction ; Low temperature ; Solid ; Total organic carbon ; Waste ; Waste water management ; Water content ; Hospital waste ; Human ; Pandemic ; Water management ; COVID-19 ; Herbal Medicine ; Humans ; Hydrolysis ; Medical Waste ; Pandemics ; SARS-CoV-2 ; Temperature ; Water Purification
  8. Source: Journal of Hazardous Materials ; Volume 424 , 2022 ; 03043894 (ISSN)
  9. URL: https://www.sciencedirect.com/science/article/abs/pii/S0304389421022627