Journal of the European Ceramic Society

Green tire technology: Effect of rice husk derived nanocellulose (RHNC) in replacing carbon black (CB) in natural rubber (NR) compounding.

Extraction, characterization, and catalytic potential of amorphous silica from corn cobs by sol-gel method

In this work, waste coconut husk was explored as potential raw material for silica production. Coconut husk was burned in controlled environment inside electrical furnace at 500, 600 and 700 °C. These ashes were treated by using two different chemical treatments to extract the highest percentage of silica. XRF analysis of coconut husk ash (CHA) revealed that the content of SiO2 varies between 8 and 11% and increased up to 90% after chemical treatment. Based on the XRD spectrum, silica obtained was in crystalline form after acid treatment but was in amorphous form after the alkali treatment. The CHA morphology on FESEM images observed to be rod-like structure but changed to irregular shapes and started to agglomerate together after the chemical treatments. EDX results show good agreement with XRF data as the same elements detected during both analysis. Alternative source of high purity silica can be obtained from CHA and it has high potential in optoelectronic application.

Synthesis and structural properties of coconut husk as potential silica source

The bioavailability of pollen bioactive compounds for humans is limited. In this study, our aim was to enhance the health-related benefits of pollen by fermentation with a Kombucha/SCOBY (symbiotic culture of bacteria and yeasts) consortium. We performed the fermentation of pollen suspended from the beginning with SCOBY on sweetened green tea or on Kombucha vinegar, by adding pollen after 20 days of Kombucha fermentation. We analyzed: formation of bioactive compounds (anti-oxidant polyphenols, soluble silicon, hydroxy-acids, short chain fatty acids—SCFA); parameters related to Kombucha fermentation (dynamics of lactic acid bacteria—LAB, formation of organic acids, soluble sugar evolution on Kombucha vinegar); the influence of Kombucha fermentation on pollen morphology and ultrastructure; in vitro cytotoxic and antitumoral effects of the Kombucha fermented pollen. The pollen addition increases LAB proportion in the total number of SCOBY microbial strains. SEM images highlight the adhesion of the SCOBY bacteria to pollen. Ultrastructural analysis reveals the release of the pollen content. The content of bioactive compounds (polyphenols, soluble silicon species and SCFA) is higher in the fermented pollen and the product shows a moderate antitumoral effect on Caco-2 cells. The health benefits of pollen are enhanced by fermentation with a Kombucha consortium.

https://www.mdpi.com/2072-6643/10/10/1365/pdf/1

Bee Collected Pollen with Enhanced Health Benefits, Produced by Fermentation with a Kombucha Consortium.

Large quantities of agricultural wastes such as palm ash and rice husk are found in Malaysia, have a large possibility to be employed as usefully renewable to produce energy and silica (SiO2). Extensive researches have been carried out to extract silica from agricultural wastes such rice husk, because silica is useful raw material for industrial application. In the previous studies, the strong acid leaching treatment was carried out on rice husk to remove metallic impurities and organics contained in them. Leaching treatment is a proper route to extract the silica. Sulphuric acid (H2SO4), hydrochloric acid (HCl) and nitric acid (HNO3) solutions are conventionally used in leaching treatment to prepare silica materials [. A strong acid leaching treatment, however, is significantly hazardous to the environment and humans. This paper reviews the common extraction method used and the latest research trends in extraction of silica.

Review of Extraction of Silica from Agricultural Wastes Using Acid Leaching Treatment

). Extensive researches have been carried out to extract silica from agricultural wastes such as rice husk, due to silica as a useful raw material for industrial application. In the previous studies, the strong acid leaching treatment was carried out to remove metallic impurities and organics contained in rice husk. A strong acid leaching treatment, however, is significantly hazardous to the environment and people [1].In this study, the environmentally benign and economically effective process to produce SiO

Extraction of silica from palm ashvia citric acid leaching treatment

Large quantities of agricultural wastes such as palm ash and rice husk are found throughout Malaysia, have a possibility to be used as a usefully renewable source for production of energy and silica (SiO2). Extensive researches have been carried out to extract silica from agricultural wastes such as rice husk, due to silica as a useful raw material for industrial application. In the previous studies, the strong acid leaching treatment was carried out to remove metallic impurities and organics contained in rice husk. Since leaching treatment is a proper route to extract the silica, sulphuric acid (H2SO4), hydrochloric acid (HCl) and nitric acid (HNO3) solutions are currently used in leaching treatment to prepare silica materials [. A strong acid leaching treatment, however, is significantly hazardous to the environment and people. In this study, the weaker acid, citric acid solutions were used to replace strong acid in leaching processes. Preliminary results showed that silica can be extracted from palm ash using citric acid leaching treatment under the optimum extracting conditions with 70°C of solution temperature, 60 minutes of reaction time and concentration of citric acid of more than 2%. The purity of silica extracted is more than 90%.

Extraction of Silica from Palm Ash Using Citric Acid Leaching Treatment: Preliminary Result

Al-doped ZnO thin films were prepared by ink-jet printing and their electrical and thermal properties with different amounts of Al doping and sintering atmosphere were investigated. The XRD traces of films show the doped materials did not form additional crystalline phases with increasing amounts of Al doping. Electrical conductivity of film increased from 4.86 S/cm to 120.94 S/cm as the amounts of Al doping increased from 0 wt% to 4 wt%. However, the thermal conductivity decreased from 24 W/mK to 13 W/mK with increasing the Al doping from 0 wt% to 4 wt%. The electrical conductivity of film shows higher values sintered in vacuum (120.94 S/cm) compared to film sintered in air (114.1 S/cm).

Effect of Sintering Atmosphere on the Electrical and Thermal Properties of Al-Doped ZnO Thin Films Prepared Using Inkjet Printing Method

In this study, the ability of treated oil palm ash aided with kaolin powder to produce zeolites is studied. The use of treated oil palm ash in the zeolites conversion seems to be an option for waste materials management. Characterization of treated oil palm ash from Malaysia’s palm oil plantation has been acquitted. The treated oil palm ash and kaolin powder are used as the starting material for the synthesis of zeolites materials. The method chose for the zeolites conversion is alkaline hydrothermal treatment. The chemical composition, crystalline phases and elemental composition of treated oil palm ash and as-synthesized samples were characterized and studied. From the analysis, the treated oil palm ash was a fertile source of silica and exists as quartz phase. The outcomes have significant motivation for the production of zeolites by using low cost material such as treated oil palm ash.

C. Abdullah

Papers

Review of Extraction of Silica from Agricultural Wastes Using Acid Leaching Treatment

Extraction of silica from palm ashvia citric acid leaching treatment

Extraction of Silica from Palm Ash Using Citric Acid Leaching Treatment: Preliminary Result

Effect of Sintering Atmosphere on the Electrical and Thermal Properties of Al-Doped ZnO Thin Films Prepared Using Inkjet Printing Method

Synthesis of Zeolites from Treated Oil Palm Ash