Biowaste Valorization Using Hydrothermal Carbonization for Potential Wastewater Treatment Applications

Abstract

In today’s world, due to population increase, there are many alarming and potential catastrophic problems like climate change, environmental pollution and an enormous mass of wastes constantly produced by humankind to find innovative solutions for the management, recycling, and valorization of biowaste from agricultural production, food processing, and organic household residues. The search for sustainable and efficient wastewater treatment technologies has gained scientific interest recently; particular focus is on using biowaste to produce hydrochars (HCs) via the hydrothermal carbonization (HTC) process used as adsorbent materials for dye, heavy metal, and emerging pollutant removal. HTC materials derived from renewable resources are an environmentally friendly and adequate way to adsorb pollutants such as organic and inorganic molecules from wastewaters. This review focuses on the advantages of the HTC process which lead to improved properties of the materials obtained, making them highly efficient in wastewater treatment. The information presented in this paper was derived from the most recent publications in the field. Future perspectives of HC materials should consider the possibilities of scale-up, pretreatment of biowastes, and the optimal parameters of the HTC process to produce HCs applied for pollutant removal from wastewaters.

Carbon dots: Types, preparation, and their boosted antibacterial activity by photoactivation. Current status and future perspectives

“…Besides, reactions such as: decarbonylation, decarboxylation, dehydration, hydrolysis polymerization, re‐condensation, and aromatization, can occur. It depends on the nature of the precursor, temperature, pressure, time, and pH (Ţurcanu et al, 2022). Usually, temperature ranges of 50°C–240°C are used, with time intervals of 5–24 h. Higher temperatures also improve the diffusion of dissolved molecules of the precursors and the present ions, upgrading the polymerization rate or self‐assembly.…”

“…It is usually employed times of 5 min to 20 h (Sanni et al, 2022; Han et al, 2022; W. Liu, Gu, et al, 2022; Ma et al, 2019; Miao et al, 2018). In the solid‐phase pyrolysis carried out in open systems, the volatiles components are lost, reducing the amount of carbon to form CDs (Ţurcanu et al, 2022).…”

Hydrothermal carbonization of vegetable-tanned leather shavings (HTC-VTS) for environmental remediation: optimization of process conditions

“…The HTC has several advantages; just to cite one: many organic materials are found in aqueous medium and which obviously have a high water content, make the HTC process ideally suitable for the carbonization of such material. Since no drying process is required, the HTC method offers a 50% energy saving compared with other methods which require drying beforehand [15][16][17][18][19][20]. The HTC equally enables the washing of inorganic elemental compositions into the liquid phase and reduces significantly the ash content.…”

Ferrous Industrial Wastes—Valuable Resources for Water and Wastewater Decontamination

“…The main challenge was the lack of data in recent years regarding ferrous waste potential applications; thus, the research was extended to 1992. If agri-food wastes (e.g., biomass are well-known for their efficient applications in environmental remediation, especially for water decontamination and compost use [ 25 , 26 , 27 , 28 ], iron as the main component of ferrous waste was still partially reused; today, the main challenge is the transition from the linear concept of disposal to the circular concept of secondary products conversion into raw materials [ 1 , 29 , 30 ]. The use of wastes with iron content as raw materials integrated into the circular economy concept was intensively studied for the sintering process, pig iron production, ferroalloys or other steel products, or pigment and cement industry [ 31 ].…”