Displaying publications 161 - 180 of 216 in total

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  1. A new technique to pyrolyse biomass in a microwave system: effect of stirrer speed
    Abubakar Z, Salema AA, Ani FN
    Bioresour Technol, 2013 Jan;128:578-85.
    PMID: 23211483 DOI: 10.1016/j.biortech.2012.10.084
    A new technique to pyrolyse biomass in microwave (MW) system is presented in this paper to solve the problem of bio-oil deposition. Pyrolysis of oil palm shell (OPS) biomass was conducted in 800 W and 2.45 GHz frequency MW system using an activated carbon as a MW absorber. The temperature profile, product yield and the properties of the products were found to depend on the stirrer speed and MW absorber percentage. The highest bio-oil yield of 28 wt.% was obtained at 25% MW absorber and 50 rpm stirrer speed. Bio-char showed highest calorific value of the 29.5 MJ/kg at 50% MW absorber and 100 rpm stirrer speed. Bio-oil from this study was rich in phenol with highest detected as 85 area% from the GC-MS results. Thus, OPS bio-oil can become potential alternative to petroleum-based chemicals in various phenolic based applications.
    Matched MeSH terms: Refuse Disposal/instrumentation*
  2. Synthesis of methyl esters from waste cooking oil using construction waste material as solid base catalyst
    Balakrishnan K, Olutoye MA, Hameed BH
    Bioresour Technol, 2013 Jan;128:788-91.
    PMID: 23186664 DOI: 10.1016/j.biortech.2012.10.023
    The current research investigates synthesis of methyl esters by transesterification of waste cooking oil in a heterogeneous system, using barium meliorated construction site waste marble as solid base catalyst. The pretreated catalyst was calcined at 830 °C for 4h prior to its activity test to obtained solid oxide characterized by scanning electron microscopy/energy dispersive spectroscopy, BET surface area and pore size measurement. It was found that the as prepared catalyst has large pores which contributed to its high activity in transesterification reaction. The methyl ester yield of 88% was obtained when the methanol/oil molar ratio was 9:1, reaction temperature at 65 °C, reaction time 3h and catalyst/oil mass ratio of 3.0 wt.%. The catalyst can be reused over three cycles, offer low operating conditions, reduce energy consumption and waste generation in the production of biodiesel.
    Matched MeSH terms: Refuse Disposal/methods*
  3. Towards sustainable use of potassium in pineapple waste
    Ahmed OH, Husni MH, Anuar AR, Hanafi MM
    ScientificWorldJournal, 2004 Nov 20;4:1007-13.
    PMID: 15578124
    Due to the 1997/98 haze problem in South-East Asia and the increasing need for sustainable food production and development, the usual management of crop residues (including pineapple wastes) through burning is prohibited. As a result, the need for alternative uses of pineapple wastes in pineapple production has been emphasized. This study investigated an environmentally friendly means of recycling pineapple leaves for agricultural use. Pineapple leaves were shredded and composted in a composting drum for 30 days. Part of the shredded leaves was ashed in a muffle furnace for 4 h. Humic acid (HA), K-fulvate, and K in HA and compost were analyzed using standard procedures. An ash to water ratio of 1:7 was used to extract 0.1 molar (M) KOH from the shredded leaves. The 0.1 M KOH contained 50% K and was able to extract 20% HA from the composted pineapple leaves. Percent K in the fulvate using 0.1 M KOH was 43. Besides serving as a foliar spray (supplement soil application K fertilizers), source of K for freshwater fish (e.g., tilapia), the HA produced can be used as a soil conditioner. Studies show that between 0.05-0.01 g of HA per kg soil retards runoff by 36% in sandy and sandy loam soils. The K-fulvate can be used as a fluid fertilizer. In addition, the pH of 2 of the K-fulvate suggests it could be used to dissolve phosphate rocks, particularly those in the arid regions where high soil pH does not facilitate the dissolution of these important rocks that serve as one of the sources of phosphorus fertilizer in agriculture.
    Matched MeSH terms: Refuse Disposal*
  4. Biodegradation potential and ligninolytic enzyme activity of two locally isolated Panus tigrinus strains on selected agro-industrial wastes
    Ruqayyah TI, Jamal P, Alam MZ, Mirghani ME
    J Environ Manage, 2013 Mar 30;118:115-21.
    PMID: 23422153 DOI: 10.1016/j.jenvman.2013.01.003
    The degradation potential and ligninolytic enzyme production of two isolated Panus tigrinus strains (M609RQY and M109RQY) were evaluated in this study. These strains were grown on three selected abundant agro-industrial wastes (rice straw; rice husk and cassava peel) under solid-state fermentation conditions. Degradation potential was determined by analyzing the chemical composition of the selected substrates before and after fermentation along with ligninolytic enzyme production. The strain M609RQY led to the highest lignin degradation of 40.81% on cassava peel, 11.25% on rice husk and 67.96% on rice straw. Both strains significantly increased the protein content of cassava peel. Rice husk stimulated maximum laccase (2556 U/L) and lignin peroxidase (24 U/L) production by the strains M109RQY and M609RQY, respectively. Furthermore, cassava peel stimulated maximum manganese-dependent peroxidase (141 U/L) production by the strain M109RQY. The de-lignified rice straw and the nutritionally-improved cassava peel could serve as potential animal feed supplements.
    Matched MeSH terms: Refuse Disposal/methods*
  5. Biodegradability of degradable plastic waste
    Agamuthu P, Faizura PN
    Waste Manag Res, 2005 Apr;23(2):95-100.
    PMID: 15864950
    Plastic waste constitutes the third largest waste volume in Malaysian municipal solid waste (MSW), next to putrescible waste and paper. The plastic component in MSW from Kuala Lumpur averages 24% (by weight), whereas the national mean is about 15%. The 144 waste dumps in the country receive about 95% of the MSW, including plastic waste. The useful life of the landfills is fast diminishing as the plastic waste stays un-degraded for more than 50 years. In this study the compostability of polyethylene and pro-oxidant additive-based environmentally degradable plastics (EDP) was investigated. Linear low-density polyethylene (LLDPE) samples exposed hydrolytically or oxidatively at 60 degrees C showed that the abiotic degradation path was oxidative rather than hydrolytic. There was a weight loss of 8% and the plastic has been oxidized as shown by the additional carbonyl group exhibited in the Fourier transform infra red (FTIR) Spectrum. Oxidation rate seemed to be influenced by the amount of pro-oxidant additive, the chemical structure and morphology of the plastic samples, and the surface area. Composting studies during a 45-day experiment showed that the percentage elongation (reduction) was 20% for McD samples [high-density polyethylene, (HDPE) with 3% additive] and LL samples (LLDPE with 7% additive) and 18% reduction for totally degradable plastic (TDP) samples (HDPE with 3% additive). Lastly, microbial experiments using Pseudomonas aeroginosa on carbon-free media with degradable plastic samples as the sole carbon source, showed confirmatory results. A positive bacterial growth and a weight loss of 2.2% for degraded polyethylene samples were evident to show that the degradable plastic is biodegradable.
    Matched MeSH terms: Refuse Disposal/methods*
  6. Mini review: hydrogen and ethanol co-production from waste materials via microbial fermentation
    Soo CS, Yap WS, Hon WM, Phang LY
    World J Microbiol Biotechnol, 2015 Oct;31(10):1475-88.
    PMID: 26185061 DOI: 10.1007/s11274-015-1902-6
    The simultaneous production of hydrogen and ethanol by microorganisms from waste materials in a bioreactor system would establish cost-effective and time-saving biofuel production. This review aims to present the current status of fermentation processes producing hydrogen accompanied by ethanol as a co-product. We outlined the microbes used and their fundamental pathways for hydrogen and ethanol fermentation. Moreover, we discussed the exploitation of renewable and sustainable waste materials as promising feedstock and the limitations encountered. The low substrate bioconversion rate in hydrogen and ethanol co-production is regarded as the primary constraint towards the development of large scale applications. Thus, microbes with an enhanced capability have been generated via genetic manipulation to diminish the inefficiency of substrate consumption. In this review, other potential approaches to improve the performance of co-production through fermentation were also elaborated. This review will be a useful guide for the future development of hydrogen and ethanol co-production using waste materials.
    Matched MeSH terms: Refuse Disposal/methods*
  7. Enhanced fermentable sugar production from kitchen waste using various pretreatments
    Hafid HS, Rahman NA, Md Shah UK, Baharudin AS
    J Environ Manage, 2015 Jun 1;156:290-8.
    PMID: 25900092 DOI: 10.1016/j.jenvman.2015.03.045
    The kitchen waste fraction in municipal solid waste contains high organic matter particularly carbohydrate that can contribute to fermentable sugar production for subsequent conversion to bioethanol. This study was carried out to evaluate the influence of single and combination pretreatments of kitchen waste by liquid hot water, mild acid pretreatment of hydrochloric acid (HCl) and sulphuric acid (H2SO4) and enzymatic hydrolysis (glucoamylase). The maximum total fermentable sugar produced after combination pretreatment by 1.5% HCl and glucoamylase consisted of 93.25 g/L glucose, 0.542 g/L sucrose, 0.348 g/L maltose, and 0.321 g/L fructose. The glucose released by the combination pretreatment method was 0.79 g glucose/g KW equivalent to 79% of glucose conversion. The effects of the pre-treatment on kitchen waste indicated that the highest solubilization was 40% by the combination method of 1.5% HCl and glucoamylase. The best combination pre-treatment gave concentrations of lactic acid, acetic acid, and propionic acid of 11.74 g/L, 6.77 g/L, and 1.02 g/L, respectively. The decrease of aliphatic absorbance bands of polysaccharides at 2851 and 2923 cm(-1) and the increase on structures of carbonyl absorbance bands at 1600 cm(-1) reflects the progress of the kitchen waste hydrolysis to fermentable sugars. Overall, 1.5% HCl and glucoamylase treatment was the most profitable process as the minimum selling price of glucose was USD 0.101/g kitchen waste. Therefore, the combination pretreatment method was proposed to enhance the production of fermentable sugar, particularly glucose from kitchen waste as the feedstock for bioethanol production.
    Matched MeSH terms: Refuse Disposal/methods*
  8. Land application technique for the treatment and disposal of sewage sludge
    Zain SM, Basri H, Suja F, Jaafar O
    Water Sci Technol, 2002;46(9):303-8.
    PMID: 12448482
    Some of the major concerns when applying sewage sludge to land include the potential effect on pH and cation exchange capacity; the mobility and the accumulation of heavy metals in sludge treated soil; the potential of applying too much nutrients and the problems associated with odors and insects. The main objective of this study is to identify the effects of sewage sludge application on the physical and chemical properties of sludge treated soil. Sewage sludge was applied to soil at various rates ranging from 0 L/m2 to 341 L/m2. In order to simulate the natural environment, the study was carried out at a pilot treatment site (5.2 m x 6.7 m) in an open area, covered with transparent roofing material to allow natural sunlight to pass through. Simulated rain was applied by means of a sprinkler system. Data obtained from sludge treated soil showed that the pH values decreased when the application rates were increased and the application period prolonged. The effect of sewage sludge on cation exchange capacity was not so clear; the values obtained for every application rate of sewage sludge did not indicate any consistent behaviour. The mobility of heavy metals in soils treated with sludge were described by observing the changes in the concentration of the heavy metals. The study showed that Cd has the highest mobility in sludge treated soil followed by Cu, Cr, Zn, Ni and Pb.
    Matched MeSH terms: Refuse Disposal/methods*
  9. Increasing the fertilizer value of palm oil mill sludge: bioaugmentation in nitrification
    Onyia CO, Uyu AM, Akunna JC, Norulaini NA, Omar AK
    Water Sci Technol, 2001;44(10):157-62.
    PMID: 11794647
    Malaysia is essentially an agricultural country and her major polluting effluents have been from agro-based industries of which palm oil and rubber industries together contribute about 80% of the industrial pollution. Palm oil sludge, commonly referred to, as palm oil mill effluent (POME) is brown slurry composed of 4-5% solids, mainly organic, 0.5-1% residual oil, and about 95% water. The effluent also contains high concentrations of organic nitrogen. The technique for the treatment of POME is basically biological, consisting of pond systems, where the organic nitrogen is converted to ammonia, which is subsequently transformed to nitrate, in a process called nitrification. A 15-month monitoring program of a pond system (combined anaerobic, facultative, and aerobic ponds in series) confirmed studies by other authors and POME operators that nitrification in a pond system demands relatively long hydraulic retention time (HRT), which is not easily achieved, due to high production capacity of most factories. Bioaugmentation of POME with mixed culture of nitrifiers (ammonia and nitrite oxidizers) has been identified as an effective tool not only for enhancing nitrification of POME but also for improving quality of POME as source of liquid nitrogen fertilizer for use in the agricultural sector, especially in oil palm plantations. Nitrate is readily absorbable by most plants, although some plants are able to absorb nitrogen in the form of ammoniun. In this study, up to 60% reduction in HRT (or up to 20% reduction in potential land requirement) was achieved when bioaugmentation of POME was carried out with the aim of achieving full nitrification.
    Matched MeSH terms: Refuse Disposal/methods*
  10. Effects of high temperature melting on fractionation of heavy metals in sewage sludge
    Idris A, Saed K
    J Environ Sci Health A Tox Hazard Subst Environ Eng, 2002;37(6):1123-31.
    PMID: 12090284
    Sewage sludge from aerobic treatment plant was found to contain high amounts of heavy metals. Research was carried out to investigate the speciation and leaching behavior of heavy metals when using high temperature melting technology for treatment. This was achieved by conducting a sequential chemical extraction procedure and EP-TOX leaching test. The thermal treatment led to increased shift of metals from organic fraction to residual fraction, indicating that the thermal treatment caused metals in sewage sludge to become stable. Furthermore, results from leaching test revealed that metals were not leached from the final product after thermal treatment and this was verified using US EPA standard limits. Results from this study indicated that melting technology could convert the sludge to product that can be either reused or landfilled without an adverse environmental impact.
    Matched MeSH terms: Refuse Disposal*
  11. Physico-chemical removal of iron from semi-aerobic landfill leachate by limestone filter
    Aziz HA, Yusoff MS, Adlan MN, Adnan NH, Alias S
    Waste Manag, 2004;24(4):353-8.
    PMID: 15081062
    Limestone has been proven effective in removing metals from water and wastewater. A literature review indicated that limestone is capable of removing heavy metals such as Cu, Zn, Cd, Pb, Ni, Cr, Fe and Mn are through a batch process or by filtration technique. The removal capability is reported at up to 90%. However, to date most of the studies have been focused on synthetic wastewater. The present study attempts to investigate the suitability of limestone to attenuate total iron (Fe) from semi aerobic leachate at Pulau Burung Landfill Site in Penang, Malaysia. Iron was found in significant quantities at the landfill site. The study also aims to establish the Fe isotherm and breakthrough time of the proposed limestone filter for post-treatment to the migrating landfill leachate before its release to the environment. The Fe isotherms were established using a batch equilibrium test, while the breakthrough characteristics were determined using continuous flow permeating through a limestone column. The latter was used in order to simulate the continuous flow of leachate that would occur in the proposed limestone filter. The limestone media used in the experiment contain more than 90% CaCO3 with particle sizes ranging from 2 to 4 mm. Four filter columns (each 150 mm in diameter and 1000 mm depth) were installed at the landfill site. Metal loadings were kept below 0.5 kg /m3 day and the experiment was run continuously for 30 days. Initial results indicated that 90% of Fe can be removed from the leachate based on retention time of 57.8 min and surface loading of 12.2 m3/m2 day. For the batch study on the Fe isotherm, the results indicated that limestone is potentially useful as an alternative leachate treatment system at a relatively low cost.
    Matched MeSH terms: Refuse Disposal/methods*
  12. Fulltext Disposal practices of unused and expired pharmaceuticals among general public in Kabul
    Bashaar M, Thawani V, Hassali MA, Saleem F
    BMC Public Health, 2017 01 07;17(1):45.
    PMID: 28061902 DOI: 10.1186/s12889-016-3975-z
    BACKGROUND: Most of the medicine users remain unaware about the disposal of unused or expired medicines. The aim of this study was to know the disposal practices of unused and expired medicines among the general public in Kabul.

    METHODS: This was a descriptive, cross-sectional survey, conducted through face-to-face interviews using prevalidated structured questionnaire. Returned questionnaires were double-checked for accuracy. Statistical Package for Social Science (SPSS) version 23 was used for statistical analysis.

    RESULTS: Total of 301 valid questionnaires were returned with a response rate of 100% in which 73.4% men and 26.6% women participated. More than half of the respondents were university graduates. Interestingly, 83.4% of the interviewees purchased medicines on the prescription of which 47.2% were university graduates, while 14.6% purchased medicine over the counter. Among the respondents, 46.5/100 purchased antibiotics and the remaining purchased NSAIDs, anti-hypertensive and anti-diabetic medicines. Significantly, 97/100 checked the expiry date of medicine before buying. Majority (95.3%) of the respondents' stored medicines at home. 77.7% of the respondents discarded the expired medicines in household trash. Majority of respondents held government responsible for creation of awareness for proper medicine disposal. Almost entire sample (98%) felt that improper disposal of unused and expired medicines can affect the environment and health.

    CONCLUSION: Gaps exist in practices, therefore robust, safe and cost-effective pharmaceutical waste management program supported with media campaign is needed. Healthcare practitioners and community pharmacists should offer training to educate customers on standard medicine disposal practices.

    Matched MeSH terms: Refuse Disposal/methods*
  13. Toward sustainable solid waste minimization by manufacturing firms in Malaysia: strengths and weaknesses
    Mallak SK, Ishak MB, Mohamed AF, Iranmanesh M
    Environ Monit Assess, 2018 Sep 06;190(10):575.
    PMID: 30191321 DOI: 10.1007/s10661-018-6935-5
    Malaysia is facing an increasing trend in industrial solid waste generation due to industrial development. Thus, there is a paramount need in taking practical actions and measurements to move toward sustainable industrial waste management. The main aim of this study is to assess practicing solid waste minimization by manufacturing firms. Analysis showed that majority of firms (92%) dispose of their wastes rather than utilize other sustainable waste management options. Also, waste minimization methods such as segregation of wastes, on-site recycle and reuse, improved housekeeping, and equipment modification were found to have significant contribution to waste reduction (p 
    Matched MeSH terms: Refuse Disposal/methods*
  14. Development and Validation of the Return and Disposal of Unused Medications Questionnaire (ReDiUM) in Malaysia
    Sim SM, Lai PSM, Tan KM, Lee HG, Sulaiman CZ
    Asia Pac J Public Health, 2018 11;30(8):737-749.
    PMID: 30486652 DOI: 10.1177/1010539518811161
    The aim of our study was to develop and validate the return and disposal of unused medications (ReDiUM), as there are currently no validated tools available (worldwide) to assess this. The ReDiUM was developed by an expert panel. It was then administered to community-dwelling adults, who could understand English, at baseline and 2 weeks later. A total of 338/354 participants agreed to participate (response rate = 95.4%). Flesch reading ease was 60. The overall Cronbach's α was 0.703 (range = 0.609-0.762). At test-retest, κ values ranged from 0.244 to 0.523. Median total knowledge score was 60% (interquartile range = 40% to 70%). The majority of participants (94.4%) knew that improper drug disposal has harmful effects on the environment. However, their knowledge was low (11.2%) regarding the disposal of pressurized metered-dose inhalers in the garbage. The ReDiUM was found to be a valid and reliable instrument to assess the knowledge, attitude, and practice on the ReDiUM in Malaysia.
    Matched MeSH terms: Refuse Disposal*
  15. Study of contaminant transport at an open-tipping waste disposal site
    Ashraf MA, Yusoff I, Yusof M, Alias Y
    Environ Sci Pollut Res Int, 2013 Jul;20(7):4689-710.
    PMID: 23292199 DOI: 10.1007/s11356-012-1423-x
    Field and laboratory studies were conducted to estimate concentration of potential contaminants from landfill in the underlying groundwater, leachate, and surface water. Samples collected in the vicinity of the landfill were analyzed for physiochemical parameters, organic contaminants, and toxic heavy metals. Water quality results obtained were compared from published data and reports. The results indicate serious groundwater and surface water contamination in and around the waste disposal site. Analysis of the organic samples revealed that the site contains polychlorinated biphenyls and other organo-chlorine chemicals, principally chloro-benzenes. Although the amount of PCB concentration discovered was not extreme, their presence indicates a potentially serious environmental threat. Elevated concentrations of lead, copper, nickel, manganese, cadmium, and cobalt at the downgradient indicate that the contamination plume migrated further from the site, and the distribution of metals and metals containing wastes in the site is nonhomogeneous. These results clearly indicate that materials are poorly contained and are at risk of entering the environment. Therefore, full characterization of the dump contents and the integrity of the site are necessary to evaluate the scope of the problem and to identify suitable remediation options.
    Matched MeSH terms: Refuse Disposal/methods*
  16. Investigation of biogas production and its residue with fertilization effect from municipal waste
    Bee ST, Nithiyaa M, Sin LT, Tee TT, Rahmat AR
    Pak J Biol Sci, 2013 Oct 15;16(20):1104-12.
    PMID: 24506009
    This study was aimed to investigate the production of methane gas from three different types of food waste (vegetables waste, fruit waste and grain waste) using batch type anaerobic digestion method. The digestion process was conducted by using temperature range of 27 to 36 degrees C and pH 6.5 to 7.5 to yield an optimum condition for the digestion process. The digestion was continued for a period of two weeks with the aid of cow dung as the inoculums. It was found that the grain waste yielded the highest methane 2546 mL due to the high content of carbohydrate. At the mean time, the fruit waste produced the second highest methane gas with 2000 mL as well as the vegetable waste generated the lowest methane gas with volume of 1468 mL. The vegetable waste produced the lowest methane gas because the vegetables waste contains high fibres and cellulose walls but low in glucose amount. For the fertilization test, fruit waste demonstrated the best observation for the growth of plant due to high content of potassium and followed by vegetable waste. The least effective fertilizer was grain waste due to less content of nutrients essential for plants growth.
    Matched MeSH terms: Refuse Disposal/methods*
  17. Determination of quarantine period in African catfish (Clarias gariepinus) fed with pig (Sus sp.) offal to assure compliance with halal standards
    Wan Norhana MN, Dykes GA, Padilah B, Ahmad Hazizi AA, Masazurah AR
    Food Chem, 2012 Dec 1;135(3):1268-72.
    PMID: 22953853 DOI: 10.1016/j.foodchem.2012.05.083
    Pig (Sus sp.) and pig by-products are considered as najasa (impurities) in Islam and forbidden in Muslim consumer products. Animals fed on najasa are categorised as al-jallālah (contaminated animals) which are allowed to be consumed as long as they have been quarantined for a certain period of time. During this quarantine period the animals will have undergone a natural purification process or istihālah. African catfish (Clarias gariepinus) are commonly consumed in Malaysia and may be fed on najasa. This study was carried out to estimate the istihālah period for catfish after feeding with pig offal, based on the absence of pig DNA in catfish gut and to suggest the quarantine period in catfish fed with pig offal. The results indicated that the maximum istihālah period could reach 36h in the stomach, 6h in the midgut and less than 2h in the hindgut although in many cases shorter periods were observed. Based on these results it is estimated that the minimum quarantine period for catfish fed with pig offal is 1.5days.
    Matched MeSH terms: Refuse Disposal
  18. An overview of landfill leachate treatment via activated carbon adsorption process
    Foo KY, Hameed BH
    J Hazard Mater, 2009 Nov 15;171(1-3):54-60.
    PMID: 19577363 DOI: 10.1016/j.jhazmat.2009.06.038
    Water scarcity and pollution rank equal to climate change as the most urgent environmental issue for the 21st century. To date, the percolation landfill leachate into the groundwater tables and aquifer systems which poses a potential risk and potential hazards towards the public health and ecosystems, remains an aesthetic concern and consideration abroad the nations. Arising from the steep enrichment of globalization and metropolitan growth, numerous mitigating approaches and imperative technologies have currently drastically been addressed and confronted. Confirming the assertion, this paper presents a state of art review of leachate treatment technologies, its fundamental background studies, and environmental implications. Moreover, the key advance of activated carbons adsorption, its major challenges together with the future expectation are summarized and discussed. Conclusively, the expanding of activated carbons adsorption represents a potentially viable and powerful tool, leading to the superior improvement of environmental conservation.
    Matched MeSH terms: Refuse Disposal
  19. Activated carbons derived from oil palm empty-fruit bunches: application to environmental problems
    Alam MZ, Muyibi SA, Mansor MF, Wahid R
    J Environ Sci (China), 2007;19(1):103-8.
    PMID: 17913162
    Activated carbons derived from oil palm empty fruit bunches (EFB) were investigated to find the suitability of its application for removal of phenol in aqueous solution through adsorption process. Two types of activation namely; thermal activation at 300, 500 and 800 degrees C and physical activation at 150 degrees C (boiling treatment) were used for the production of the activated carbons. A control (untreated EFB) was used to compare the adsorption capacity of the activated carbons produced from these processes. The results indicated that the activated carbon derived at the temperature of 800 degrees C showed maximum absorption capacity in the aqueous solution of phenol. Batch adsorption studies showed an equilibrium time of 6 h for the activated carbon at 800 degrees C. It was observed that the adsorption capacity was higher at lower values of pH (2-3) and higher value of initial concentration of phenol (200-300 mg/L). The equilibrium data fitted better with the Freundlich adsorption isotherm compared to the Langmuir. Kinetic studies of phenol adsorption onto activated carbons were also studied to evaluate the adsorption rate. The estimated cost for production of activated carbon from EFB was shown in lower price (USD 0.50/kg of activated carbon) compared the activated carbon from other sources and processes.
    Matched MeSH terms: Refuse Disposal
  20. Fulltext Biodegradable Gloves for Waste Management Post-COVID-19 Outbreak: A Shelf-Life Prediction
    Ab Rahman MF, Rusli A, Misman MA, Rashid AA
    ACS Omega, 2020 Nov 24;5(46):30329-30335.
    PMID: 33251468 DOI: 10.1021/acsomega.0c04964
    With increased awareness on the importance of gloves arising from the COVID-19 pandemic, people are expected to continue using them even after the pandemic recedes. This scenario in a way increased the rubber solid waste disposal problem; therefore, the production of biodegradable gloves may be an option to overcome this problem. However, the need to study the shelf life of biodegradable gloves is crucial before commercialization. There are well-established models to address the failure properties of gloves as stated in the American Society for Testing and Material (ASTM) D7160. In this study, polysaccharide-based material-filled natural rubber latex (PFNRL) gloves, which are biodegradable gloves, were subjected to an accelerated aging process at different temperatures of 50-80 °C for 1-120 days. Prediction models based on Arrhenius and shift factors were used to estimate the shelf life of the PFNRL gloves. Based on the results obtained, the estimated time for the PFNRL gloves to retain 75% of their tensile strength at shelf temperature (30 °C) based on Arrhenius and shift factor models was 2.8 years. Verification on the activation energy based on the shift factor model indicated that the shelf life of PFNRL gloves is 2.9 years, which is only a 3.6% difference. The value obtained is aligned with the requirement in accordance with ASTM D7160, which states that only up to a maximum of 3 years' shelf life is allowed for the gloves under accelerated aging conditions.
    Matched MeSH terms: Refuse Disposal
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