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- Niinipuu, Mirva, et al.
(författare)
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Influence of water matrix and hydrochar properties on removal of organic and inorganic contaminants
- 2020
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Ingår i: Environmental Science and Pollution Research. - : Springer. - 0944-1344 .- 1614-7499. ; 27, s. 30333-30341
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Tidskriftsartikel (refereegranskat)abstract
- The removal of contaminants from water using low-cost adsorbents has been widely studied, yet studies employing a realistic water matrix are still lacking. This study investigated the removal of organic compounds (trimethoprim, fluconazole, and perfluorooctanoic acid (PFOA)) and metals (As, Zn, and Cu) from landfill leachate. Additionally, tests in pure water, humic acid, and ion matrices were carried out to better understand how the water matrix affects adsorption. The hydrochars were produced from four feedstocks at three carbonization temperatures. The results show that the removal efficiencies for organic pollutants were low and metal removal by hydrochars was comparable with commercial activated carbon. The removal of all compounds from pure water was substantially lower. Tests with humic acid and ion-containing matrices could not fully explain the increased removal in the landfill leachate, which may be due to the combination of the water matrix and presence of soluble species from the hydrochars.
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| 2. |
- Niinipuu, Mirva, 1988-, et al.
(författare)
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The impact of hydrothermal carbonization on the surface functionalities of wet waste materials for water treatment applications
- 2020
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Ingår i: Environmental Science and Pollution Research. - : Springer. - 0944-1344 .- 1614-7499. ; 27:19, s. 24369-24379
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Tidskriftsartikel (refereegranskat)abstract
- Hydrothermal carbonization (HTC) is an energy-efficient thermochemical process for converting wet waste products into value added materials for water treatment. Understanding how HTC influences the physicochemical properties of the resultant materials is critical in optimizing the process for water treatment, where surface functionality and surface area play a major role. In this study, we have examined the HTC of four wet waste streams, sewage sludge, biosludge, fiber sludge, and horse manure at three different temperatures (180 degrees C, 220 degrees C, and 260 degrees C). The physicochemical properties of these materials were examined via FTIR, SEM and BET with their adsorption capacity were assessed using methylene blue. The yield of solid material after hydrothermal carbonization (hydrochar) decreased with increasing temperature for all samples, with the largest impact on horse manure and fiber sludge. These materials also lost the highest degree of oxygen, while HTC had minimal impact on biosludge and sewage sludge. The differences here were due to the varying compositions of each waste material, FTIR identified resonances related to cellulose in horse manure and fiber sludge, which were not detected in biosludge and sewage sludge. Adsorption capacities varied between 9.0 and 68 mg g(-1) with biosludge HTC at 220 degrees C adsorbing the highest amount. Adsorption also dropped drastically at the highest temperature (260 degrees C), indicating a correlation between adsorption capacity and HTC conditions. This was attributed to the loss of oxygen functional groups, which can contribute to adsorption. These results suggest that adsorption properties can be tailored both by selection of HTC temperature and feedstock.
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