Preparation of biochar and activated carbon from cocoa pod husk by using microwave as ammonium carrier in urea-based fertilizer

Biochar (CPH_BCHAR) and activated carbon was prepared from Cocoa pod husk (CPH_AC) under microwave activation. The optimization of carbonization and activation step was performed at different microwave input power and irradiation time. Porous texture, surface and functional characteristics were analysed by N2 adsorption, scanning electron microscopy and Fourier transform infrared spectroscopy. Please click on the file below for full content of the abstract

Controlled Carbonization Heating Rate for Enhancing CO2 Separation Based on Single Gas Studies

Concerns about the impact of greenhouse gas have driven the development of new separation technology to meet CO2 emission reduction targets. Membrane-based technologies using carbon membranes that are able to separate CO2 efficiently appears to be a competitive method. This research was focused on the development of carbon membranes derived from polymer blend of polyetherimide and polyethylene glycol to separate CO2 rendering it suitable to be used in many applications such as landfill gas purification, CO2 removal from natural gas or flue gas streams. Carbonization process was conducted at temperature of 923 K and 2 h of soaking time. To enhance membrane separation properties, pore structure was tailored by varying the carbonization heating rates to 1, 3, 5, and 7 K / min. The effect of carbonization heating rate on the separation performance was investigated by single gas permeabilities using CO2 , N2 , and CH4 at room temperature. Carbonization heating rate of 1 K / min produced carbon membrane with the most CO2 / N2 and CO2 / CH4 selectivity of 38 and 64, respectively, with the CO2 permeability of 211 barrer. Therefore, carbonization needs to be carried out at sufficiently slow heating rates to avoid significant loss of selectivity of the derived carbon membranes

Removal of bisphenol S from aqueous solution using activated carbon derived from rambutan peel via microwave irradiation technique

Bisphenol S (BPS) was introduced to replace Bisphenol A (BPA) in plastic production. Unfortunately, recent studies have shown that BPS is toxic. This study explores the conversion of rambutan peel into rambutan peel-based activated carbon (RPAC) via the economic route of single-stage microwave irradiation technique at radiation power and radiation time of 440 W and 6 min, respectively, under CO2 gasification. The resulted RPAC posed BET surface area of 402.68 m2/g, mesopores surface area of 332.98 m2/g, total pore volume of 0.23 cm3/g, and average pore diameter of 2.26 nm, which lies in the mesopores region. The surface of RPAC was filled with various functional groups such as methylene, aliphatic fluoro, phenol, nitro, and alkyl compounds. Adsorption of BPS onto RPAC achieved equilibrium faster at lower BPS initial concentration as compared to the higher ones. Isotherm study found that the Langmuir model suits this adsorption process the best with a maximum monolayer adsorption capacity of 27.89 mg/g whereas the kinetic study showed that pseudo-second order (PSO) represented the kinetic data the best. Intraparticle diffusion plots suggested that the adsorption process consisted of three regions and each region was controlled by a different type of diffusion mechanism. Boyd plot confirmed that film diffusion was responsible for the slowest step in the adsorption process whilst thermodynamic parameters disclosed that adsorption of BPS onto RPAC was spontaneous, exothermic, governed by physisorption, and the randomness of the adsorption process was found to reduce at the solid-liquid interface

Polycyclic aromatic hydrocarbons (PAHs) levels and toxicity in herbal teas marketed in Malaysia using QuEChERS and GC-FID

In line with the growing health trend in Malaysia, more consumers drink herbal tea for medicinal benefits. However, herbal tea products could be contaminated with polycyclic aromatic hydrocarbons (PAHs) from various production sources. There is a little study focused on the detection of PAHs in herbal tea species distributed in Malaysia. This study was performed to investigate PAHs content and toxicity in selected commercial herbal teas in Malaysia. A total of seven different Malaysian herbal tea samples were extracted using QuEChERS extraction method and the contamination level of PAHs were evaluated using gas chromatography (GC) with a flame ionization detector (FID). The total content of 10 PAHs (Σ10PAHs) in the herbal tea samples ranged from 2.53 to 9.39 μg/kg. Acenaphthene, fluorene, phenanthrene and anthracene were the most abundant compounds with 53% contribution of all PAHs content. All tested herbal teas species showed low toxic equivalency (TEQ) values ranging from 0.0027 to 0.1148. The least contaminated samples were Strobilanthes crispus, Senna alata, Orthosiphon aristatus, Clinacanthus nutans, and Stevia rebaudiana

Trapping synthetic dye molecules using modified lemon grass adsorbent

Please read abstract in the article.Universiti Sains Malaysia, LAUTECH 2016 TET Fund Institution Based Research Intervention and the TWAS-NRF.https://www.tandfonline.com/loi/ldis20hj2023Chemistr

Analysis of labour market needs for engineers with enhanced knowledge in sustainable renewable energy solutions in the built environment in some Asian countries

Despite the rapid growth in the uptake of renewable energy technologies, the educational profile and the skills gained at University level do not always comply with the practical needs of the organisations working in the field. Furthermore, even though the residential sector has very high potential in curbing its CO2 emissions worldwide thus meeting the challenging goals set out by the international agreements, such reduction has been limited so far. Within this context, the 'Skybelt' project, co-funded by the EU under the framework of the Erasmus + programme aims at enhancing in several Universities of Asia and Europe the engineering skills of students of all level for application of sustainable renewable energy solutions in the built environment. With the target of increasing the employability of graduates and the impact of the project, a survey on the labour market needs for specialists with enhanced knowledge and skills in the topic of the project has been conducted in the related Asian countries. Hence, relevant industries, labour market organisations and other stakeholders have been interviewed and the main results of this analysis is reported in the present paper. As first outcome of this activity, the obtained results have been considered in the selection of the modules to be improved according to a student centred study approach

Optimization of durian peel based activated carbon preparation conditions for ammoniacal nitrogen removal from semi-aerobic landfill leachate

554-560This study presents optimal conditions for preparation of durian peel based activated carbon (DPAC) for removal of ammoniacal nitrogen (NH3-N) from semi-aerobic landfill leachate. DPAC was prepared using chemical activation method which consisted of phosphoric acid (H3PO4) treatment and nitrogen gasification. Optimum conditions for DPAC preparation (activation temperature, 400 °C; activation time, 2.27 h; and IR, 3) resulted in DPAC yield (21.02%) of and NH3-N removal (46.49%)

Ahmad

554-560This study presents optimal conditions for preparation of durian peel based activated carbon (DPAC) for removal of ammoniacal nitrogen (NH3-N) from semi-aerobic landfill leachate. DPAC was prepared using chemical activation method which consisted of phosphoric acid (H3PO4) treatment and nitrogen gasification. Optimum conditions for DPAC preparation (activation temperature, 400 °C; activation time, 2.27 h; and IR, 3) resulted in DPAC yield (21.02%) of and NH3-N removal (46.49%)

Catalytic co-pyrolysis of empty fruit bunch and high-density polyethylene

The main objective of the present work is to investigate the thermal degradation behaviour of the non-catalytic and catalytic co-pyrolysis of empty fruit bunch (EFB) and high-density polyethylene (HDPE) over commercial hydrogen exchanged zeolite socony mobil five (HZSM-5) and rice husk ash (RHA) catalysts via thermogravimetric analyser (TGA). RHA catalysts were produced using the solvent-free method by converting RHA into HZSM-5. XRD characterization was conducted for the synthesized catalysts and RHA catalyst showed less amount of peaks compared to commercial HZSM-5. Non-catalytic and catalytic co-pyrolysis of EFB and HDPE over commercial HZSM-5 and RHA catalysts were conducted using TGA. A fixed EFB-to- HDPE mass ratio of 1:1 and a fixed catalyst-to-feedstock mass ratio of 1:1 were used for the TGA experiments. The sample was heated up under pyrolysis conditions at a heating rate of 20 °C/min until 700 °C. The thermal degradation behaviour of EFB and HDPE did not change significantly when RHA catalysts were used, based on the TG curves. Volatilization of matter was maximum between temperatures 240 °C and 500 °C (Phase II) for all cases of the pyrolysis process, where the highest volatilized matter of 93.2 wt% was produced from the catalytic process over commercial HZSM-5, followed by the catalytic process over RHA catalysts with 92.3 wt% of volatilized matter and non-catalytic process with 83.0 wt% of volatilized matter. When using catalysts, 0.44 wt% of solid residual was left when commercial HZSM-5 was used while 0.38 wt% of solid residual was left when RHA catalyst was used