Self-Assembled Behavior of Ultralightweight Aerogel from a Mixture of CNC/CNF from Oil Palm Empty Fruit Bunches

This study aims to explore the use of cellulose nanocrystals (CNC) and cellulose nanofiber (CNF), obtained from unbleached fiber of oil palm empty fruit bunches (EFB), as raw materials in fabricating aerogel, using the facile technique without solvent displacement. The CNC was isolated from sulfuric acid hydrolysis, and the CNF was fibrillated using Ultra Turrax. The CNC and CNF were mixed by ultrasonication in different ratios to produce aerogel using slow freezing (−20 °C), followed by freeze-drying. The obtained aerogel was characterized as ultralightweight and highly porous material, at the density range of 0.0227 to 0.0364 g/cm3 and porosity of 98.027 to 98.667%. Interestingly, the ratio of CNC and CNF significantly affected the characteristics of the obtained aerogel. The mixed aerogel exhibited a higher specific surface area than pure CNC or CNF, with the highest value of 202.72 m2/g for the ratio of 1:3 (CNC/CNF). In addition, the crystallinity degree of obtained aerogel showed a higher value in the range of 76.49 to 69.02%, with the highest value being obtained for higher CNC content. This study is expected to provide insight into nanocellulose-based aerogel, with a promising potential for various applications.

Revisiting Soil Aquifer Treatment: Improving Biodegradation and Filtration Efficiency Using a Highly Porous Material

Soil aquifer treatment (SAT) is an established and sustainable wastewater treatment approach for water reuse that has been gaining increased attention in various countries around the world. Increasing volumes of domestic wastewater and escalating real estate prices around urban areas emphasize the urgent need to maximize the treatment efficiency by revisiting the SAT setup. In this study, a novel approach was examined to increase biodegradation rates and improve the quality of SAT topsoil effluent. Experiments with midscale, custom-made columns were carried out with sand collected from an operational SAT and a highly permeable natural material with high internal porosity, tuff, which was maturated (i.e., buried in the SAT infiltration basin) for 3 months. The filtration efficiency, biodegradation rates of organic material, microbial diversity, and outflow quality were compared between the operational SAT sand and the tuff using state-of-the-art approaches. The results of this study indicate that biodegradation rates (9.2 µg C g−1d−1) and filtration efficiency were up to 2.5-fold higher within the tuff than the SAT sand. Furthermore, the biofilm community was markedly different between the two media, giving additional insights into the bacterial phyla responsible for biodegradation. The results highlight the advantage of using highly porous material to enhance the SAT filtration efficiency without extending the topsoil volume. Hence, infusing a permeable medium, comprising highly porous material, into the SAT topsoil could offer a simple approach to upgrade an already advantageous SAT in both developed and developing countries.

Study of the Influence of the Add оf Micropores on Filtering Characteristics of High Porous Structures

In this work we carried out a numerical study of the gas flow through an open cell foam material with solid-state partitions and partitions containing micropores. The effect of a geometry change by adding micropores on the pressure drop, particle deposition efficiency, and filter quality factor is estimated. The results showed that the addition of micropores positively affects the filtering and hydrodynamic properties of the highly porous material for the same macroporosity of the medium, and for the case of total porosity of the medium, the material with micropores allows one to obtain an increased value of the deposition efficiency and filter quality factor for small particles.

Study of H2S Removal Capability from Simulated Biogas by Using Waste-Derived Adsorbent Materials

Three waste-derived adsorbent materials (wood-derived biochar, sludge-derived activated carbon and activated ash) were pre-activated at the laboratory scale to apply them for the removal of H2S from a biogas stream. The H2S removal capabilities of each material were measured by a mass spectrometer, to detect the H2S concentration after the adsorption in an ambient environment. The activated ash adsorbent has the highest removal capacity at 3.22 mgH2S g−1, while wood-derived biochar has slightly lower H2S removal capability (2.2 mgH2S g−1). The physicochemical properties of pristine and spent materials were characterized by the thermogravimetric analyzer, elemental analysis, X-ray fluorescence spectroscopy and N2 adsorption and desorption. Wood-derived biochar is a highly porous material that adsorbs H2S by physical adsorption of the mesoporous structure. Activated ash is a non-porous material which adsorbs H2S by the reaction between the alkaline compositions and H2S. This study shows the great potential to apply waste-derived adsorbent materials to purify a biogas stream by removing H2S.

Sintering Temperature and Applied Pressure Effect on Manufacturing Ni-Cr Based Composite Material.

Mechanical Property of Nickel-Chromium composite investigated with different parameters. Green pallets (composite) were manufactured under the different pressure (220MPa, 275MPa and 330MPa) and such pallet sintering in two different temperatures (9000C and 10000C). The result indicate that the properties of the composite increases with increasing pressure and also with increasing sintering temperature for Ni-Cr based composite. Porosity plays a vital role in mechanical properties of composite and it present between maximum 4.304% to minimum 1.865%. For highly porous material, mechanical properties are minimum than lower porous composite material. The result of the study reveals that the properties of Ni-Cr based composite improved for 330MPa pressure and 1000oC temperature. Thus there is need to consider these aspect while manufacturing the composite material to have a good mechanical or Tribological properties.

Activated Carbon from Almond Shells for Water Treatment: A Mini Review

Activated carbon is a highly porous material that is gaining interest nowadays in different sectors due to its strong adsorption capacity. Although it can be manufactured from very diverse feedstock, vegetable carbon and coal have been the most widely used raw materials. The increasing market demand and the encouragement of practices for the transition to the circular economy have promoted the use of wastes for the manufacturing of activated carbon. A significant part of the activated carbon currently in the market is produced from coconut shells, but wastes from a variety of sources are the subject of intense research. The number and variety of agricultural wastes tested as precursors of activated carbon is enormous, especially due to their high lignocellulose content. This review is focused on the use of almond shells as feedstock for the production of high-quality activated carbon.

Hierarchically structured, highly porous nickel synthesized in sintering–evaporation process from a metal nanopowder and a space holder

This paper reports on the creation of a highly porous material with a hierarchical structure using powder metallurgy methods based on nickel nanopowder and ammonium bicarbonate NH4HCO3 as a space holder.

Adsorption of Cu(II) from aqueous solution using raw peat: preliminary results

Peat is a polar, highly porous material that could have significant applications as an adsorbent for removal of heavy metals from aqueous solutions. Various functional groups in lignin allow such compounds to bind on active sites of peat. The adsorption of Cu (II) from aqueous solutions on peat from the West Siberia was studied in the concentration range of 10–150 mg/L and time variations of 0.25-12 hours. The pH of the solutions varied over a range of 3.2–4.3. The adsorption data could be fitted to a Freundlich adsorption isotherm and the maximum adsorption capacity of peat was determined to be 2.5⋅10-3 mmol/g when the initial concentration for Cu2+ was at its minimum (0.05 mmol/L), and the time of adsorption was 30 minutes.