The functionalization of pyrolyzed palm empty fruit bunches-based membranes adsorbent by fourier-transform infrared spectroscopy

Membranes adsorbent are successfully prepared derived from palm empty fruit bunches (PEFB) which pyrolyzed by furnace as physical activation. The PEFB membrane adsorbent was activated to develop porous structures and surface area which able to be applied for gas separation. The aims of this study are to fabricated the pyrolyzed PEFB-based membrane adsorbent with different loading of PEFB mass to identify the surface organic functional groups of the PEFB membrane adsorbent. Fabrication of this membrane adsorbent was conducted into three steps, i.e. (1) pre-treated PEFB materials; (2) pyrolyzed the PEFB adsorbent at 500°C; and (3) PEFB membrane adsorbent fabrication by mixed both of PVA and PEG polymers into PEFB adsorbent with varied mass (15-17.5 grams). The functionalization of this membrane adsorbents was analysed by Fourier Transform Infra-Red (FTIR) spectra. The result shows the three variations of the PEFB membrane adsorbents present the surface oxygen, functional group. The effect of PEFB mass loading to the carbon pores formation of PEFB membrane adsorbent was exhibited by the escalating of C-H and C-O groups. The membrane adsorbent by adding 17.5 grams of PEFB mass indicating the highest peak of hydroxyl C-O at wavenumber 1070 cm−1. It demonstrates that membrane adsorbent with high PEFB mass loading and physic activation by pyrolyzing is great to tailoring the membrane adsorbent structure properties which capable to be applied for gas separation, especially for biogas upgrading.

Membranes adsorber from oil palm empty fruit branches (OPEFB): preparation and fabrication

Oil Palm empty fruit branches (OPEFB) are solid waste that are numerous produced from palm oil mills. OPEFB is economically and potentially used as membrane adsorber material due to has good thermal stability, chemical resistance and biodegradability. The objectives of this work is to preparate and fabricate the OPEFB membrane adsorber which is activated by physical activation. The OPEFB has been cleaned and dried, subsequently heated at 500 °C for 30 min via pyrolysis. The activated OPEFB was sieved using 200-400 mesh and followed by the addition of 2-propanol, NH4Cl, polyvinyl alcohol (PVA) and polyethylene glycol (PEG) to become a mixture. The activated OPEFB ratio were varied in the mixtures to obtain the best composition in order to produce a good membrane adsorber texture for casting. FTIR shows on wavenumber at 1082 cm−1 indicates that there is O-H stretching functional groups and bands at 943 cm−1 correspons to C=O functional group. It is concluded that the membrane mixtures can be employed as membrane adsorber due to carbon content which creates strong matrix applied for gas separation.

Using quail waste as an adsorbent on biogas quality

The aim of this research is to determine the effect of coconut and mineral waste of quail as adsorbents on the biogas purity. This research was designed to use the Completely Randomized Design (CRD) method with 6 treatments and 4 replications and the significant influence will be tested using Duncan Test. The result form this research showed that the use of coconut waste and mineral waste of quail as adsorbents gives highly significant influence (P<0,01) to increase the CH4 gas concentration, highly significant influence (P<0,01) to decrease CO2 gas concentration, highly significant influence (P<0,01) to decrease gas pressure and highly significant influence (P<0,01) to increase gas flow rate on biogas purity. The conclusion of this research is the use of 100% of activated coal from coconut waste, the use of 50% of activated coal from coconut waste and 50% of mineral waste from quail waste as an adsorbent are able to increase the quality of biogas. However, it is lack of effectiveness due to inappropriate application of biogas purification. It is suggested to do physical activation for both adsorbents in order to avoid saturation of the adsorbent so those absorbents be able to adsorb optimally the impurities gases on biogas.

Adsorption of Methylene Blue and Reactive Black 5 by Activated Carbon Derived from Tamarind Seeds

One of the most environmentally friendly methods to treat wastewater, especially synthetic dyes, is the production of activated carbon from agricultural waste. Tamarind seeds were transformed from negative-value waste into activated carbon in order to study the removal of synthetic dyes. The particular agro waste was soaked in ZnCl2 for chemical activation to increase its surface area and enhance its porosity. Physical activation of tamarind seeds was done by the carbonization process by burning at a temperature of 300 °C for 1 hour and cooling for 24 hours before washing with HCL to activate a pore surface for the tamarind seeds' carbon. The effects of parameters related to the adsorption of the dyes by tamarind seed activated carbon, such as contact time, initial concentration, absorbance dosage, and pH, were studied. The experimental data found that adsorption on both synthetic dyes exhibited a Langmuir isotherm in which the correlation value, R2, was 0.9227 (methylene blue) and 0.6117 (Reactive black 5). Meanwhile, the rate of adsorption for methylene blue (MB) and Reactive black 5 (RB5) by tamarind seed activated carbon was found to be well fitted in a pseudo-second-order model. More research is needed to meet the standard effluent of dyeing wastewater from the industrial sector.

Insights into the generation of hydroxyl radicals from H2O2 decomposition by the combination of Fe2+ and chloranilic acid

In this work, the degradation of chloranilic acid (CAA) by chemical oxidation with H2O2 alone and in the presence of ferrous iron Fe2+ catalyst was investigated in order to improve our understanding on the novel metal-independent approach. The interesting and efficient metal-independent hydroxyl radicals (OH) production by using halogenated quinones and H2O2 has been currently demonstrated. The results clearly confirmed the formation of OH radicals from the reaction of CAA with H2O2. CAA was slowly decayed by chemical oxidation with H2O2 and followed a pseudo-first kinetics. H2O2 doses ≥ 1000 mM were required to achieve complete CAA decay from 1 mM CAA. However, low total organic carbon (TOC) removal was measured with the accumulation of carboxylic acids. The addition of Fe2+ enhanced the kinetics of CAA degradation and reduced the required dose of H2O2. High TOC removal was obtained, almost complete release of chloride ions, without accumulation of carboxylic acids. The decolorization of methylene blue (MB) aqueous solutions was performed using H2O2, H2O2/CAA, H2O2/Fe2+, and H2O2/CAA/Fe2+. H2O2/CAA/Fe2+ was the most effective method in decolorizing MB solutions due to the accelerated Fe2+ regeneration. Coupling Fenton reagent with CAA seems to be promising alternative to physical activation in water and soil treatment.

Pembuatan Karbon Aktif dari Limbah Plastik PET (Polyethylene terephthalate) Menggunakan Aktivator KOH

Pengunaan plastik setiap hari mengakibatkan terjadinya penumpukan sampah plastik yang dapat mencemari lingkungan dan menjadi salah satu masalah serius yang harus ditangani karena plastik tidak dapat terdegradasi. Plastik merupakan senyawa yang unsur penyusun utamanya adalah karbon dan hidrogen. Sehingga limbah plastik berpotensi sebagai pembuatan karbon aktif dan akan membuat limbah plastik menjadi lebih bermanfaat. Penelitian ini bertujuan untuk mengetahui pengaruh konsentrasi aktivator dan waktu aktivasi terhadap proses aktivasi fisika kimia sehingga menghasilkan produk karbon aktif yang sesuai dengan SNI 06-3730-1995. Plastik PET terlebih dahulu dikarbonasi pada temperatur 480oC selama 2 jam menggunakan furnace hingga membentuk arang. Lalu, direndam dalam aseton selama 24 jam. Setelah itu disaring dan dikeringkan menggunakan oven pada temperatur 110oC selama 3 jam dan dilanjutkan dengan proses aktivasi fisika pada temperatur 750oC selama 2 jam. Karbon yang telah teraktivasi fisika selanjutnya diaktivasi secara kimia dengan menggunakan KOH konsentrasi 1 M, 2 M, 3 M, dan 4M dengan variasi waktu 2 jam dan 4 jam. Diperoleh hasil terbaik yaitu pada karbon aktif dengan konsentrasi KOH 4 M dan waktu aktivasi 2 jam dengan nilai daya serap iod sebesar 980,17 mg/g, kadar abu 0,28%, kadar air 7,55%, dan kadar volatile matter 3,47%. Karbon aktif yang diperoleh telah memenuhi SNI 06-3730-1995.The use of plastic every day results in the accumulation of plastic waste that can pollute the environment and was a serious problem that must be addressed because plastic cannot be degraded. Plastic was a compound whose main constituent elements were carbon and hydrogen. So that plastic waste has the potential to produce activated carbon and will make plastic waste more useful. This study aims to determine the effect of activator concentration and activation time on the physical-chemical activation process so as to produce activated carbon products in accordance with SNI 06-3730-1995. PET plastik was first carbonated at a temperature of 480oC for 2 hours using a furnace to form charcoal. Then, soaked in acetone for 24 hours. After that it was filtered and dried using an oven at a temperature of 110oC for 3 hours and continued with the physical activation process at a temperature of 750oC for 2 hours. The physically activated carbon was then chemically activated using KOH concentrations of 1 M, 2 M, 3 M, and 4 M with time variations of 2 hours and 4 hours. The best results were obtained on activated carbon with a concentration of KOH 4 M and an activation time of 2 hours with an iodine absorption value of 980.17 mg/g, 0.28% ash content, 7.55% water content, and volatile matter levels 3,47%. Activated carbon obtained has complied with SNI 06-3730-1995.

Physicochemical Properties of Membrane Adsorber from Palm Empty Fruit Bunch (PEFB) by Acid Activation

A membrane adsorbent was successfully made from palm empty fruit bunches (PEFB), which was pyrolysed as physical activation. The effect of adding the impact of one-step catalyst (hydrochloric acid) and differences in the concentration on the characteristics and structure and deconvolution are investigated in this study. The results of the research have been successfully created and characterised using Fourier-Transform Infrared (FTIR), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) isotherm, and membrane morphology using SEM test. Membrane performance testing was carried out using a biogas flame test. The adsorber membrane was made by adding NH4Cl as a cationic surfactant, polyvinyl acetate (PVA), and polyethylene glycol (PEG) with a ratio of 1:3. The FTIR test has a functional group: O-H; C-H stretch; C=C-C; Arly O-Strech; C-O. Adsorbent membrane with the addition of 0.5 M HCl catalyst had the highest ratio of O-H/C=C-C relative area of 4.33. The diffractogram shows an amorphous structure with (002) and (100) graph planes. Adsorber membrane with a concentration of 1.5 M HCl has formed amorphous structured fibre. The adsorber membrane with a concentration of 0.5 HCl activator gave a surface area of 0.5345 m2 g−1 and a pore volume of 0.000983 cm3 g−1.

Physically Switchable Antimicrobial Surfaces and Coatings: General Concept and Recent Achievements

Bacterial environmental colonization and subsequent biofilm formation on surfaces represents a significant and alarming problem in various fields, ranging from contamination of medical devices up to safe food packaging. Therefore, the development of surfaces resistant to bacterial colonization is a challenging and actively solved task. In this field, the current promising direction is the design and creation of nanostructured smart surfaces with on-demand activated amicrobial protection. Various surface activation methods have been described recently. In this review article, we focused on the “physical” activation of nanostructured surfaces. In the first part of the review, we briefly describe the basic principles and common approaches of external stimulus application and surface activation, including the temperature-, light-, electric- or magnetic-field-based surface triggering, as well as mechanically induced surface antimicrobial protection. In the latter part, the recent achievements in the field of smart antimicrobial surfaces with physical activation are discussed, with special attention on multiresponsive or multifunctional physically activated coatings. In particular, we mainly discussed the multistimuli surface triggering, which ensures a better degree of surface properties control, as well as simultaneous utilization of several strategies for surface protection, based on a principally different mechanism of antimicrobial action. We also mentioned several recent trends, including the development of the to-detect and to-kill hybrid approach, which ensures the surface activation in a right place at a right time.

Enhanced Breaking of Lignin and Mesopore Formation in Zinc Chloride Assisted Hydrothermal Carbonization of Waste Biomasses

Hydrochars from hydrothermal carbonization of different biowaste materials (dried dandelion, sawdust, coconut shell powder) formed in the presence of aqueous salt solutions were compared to those obtained by the common method in pure water. Hydrochars with increased carbon contents, pore volume and surface areas were specifically obtained from coconut shell powder in the presence of zinc chloride. Compositional and structural changes within the hydrochar products caused by the process conditions and/or the additive were characterized by solid state 13C NMR spectroscopy, proving that cellulose and, in particular, lignin units in the biomass are more easily attacked in the presence of the salt. Under saline conditions, a distinct particle break-up led to the creation of mesoporosity, as observable from hysteresis loops in nitrogen adsorption isotherms, which were indicative of the presence of pores with diameters of about 3 to 10 nm. The obtained hydrochars were still rich in functional groups which, together with the mesoporosity, indicates the compounds have a high potential for pollutant removal. This was documented by adsorption capacities for the methylene blue and methyl orange dyes, which exceeded the values obtained for other hydrochar-based adsorbers. A subsequent physical activation of the mesoporous hydrochars in steam at different temperatures and times resulted in a further drastic increase in the surface areas, of up to about 750 m2/g; however, this increase is mainly due to micropore formation coupled with a loss of surface functionality. Consequently, the adsorption capacity for the quite large dyes does not provide any further benefit, but the uptake of smaller gas molecules is favored.

Advances in the Safe Disposal and Comprehensive Utilization of Spent Carbon Anode From Aluminum Electrolysis: Prospects for Extraction and Application of Carbon Resources From Hazardous Waste

Spent carbon anode (SCA) is a dangerous solid waste that is continuously discharged from the aluminum electrolysis industry and has a large number of valuable resources and a high risk of environmental pollution. Its safe disposal and resource utilization have become a resource and environmental problem that must be solved urgently. Current methods for SCA disposal include flotation, vacuum metallurgy, physical activation, roasting, bubbling fluidized bed combustion, alkali fusion, alkali leaching, and chemical leaching combined with high temperature graphitization. In this paper, the material composition, resource properties, and environmental risks of SCA are discussed. Working principle, treatment process, advantages and disadvantages of the above methods are also briefly described and compared. Results showed that flotation is the safest disposal and comprehensive utilization technology that is suitable for characteristics of SCA raw materials and has the most large-scale application potential. In addition, characteristics of SCA recovery products are correlated to the recycling of aluminum reduction cells. This technology can alleviate the shortage of high-quality petroleum coke resources in China’s carbon material industry and the high cost of raw materials in aluminum electrolysis industry.