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  1. A novel real-time monitoring and control system for waste-to-energy gasification process employing differential temperature profiling of a downdraft gasifier
    Chan WP, Veksha A, Lei J, Oh WD, Dou X, Giannis A, et al.
    J Environ Manage, 2019 Mar 15;234:65-74.
    PMID: 30616190 DOI: 10.1016/j.jenvman.2018.12.107
    A novel, cost-effective and real-time process monitoring and control system was developed to maintain stable operation of waste-to-energy gasification process. It comprised a feedback loop control that utilized the differential temperatures of the oxidation and reduction zones in the gasifier to determine the regional heat-flow (endothermic or exothermic), to assess the availability of oxidizing agent (for instance, air or O2) at the char bed and to calculate the fuel feeding rate. Based on the correlations developed, the air-to-fuel ratio or the equivalence air ratio (ER) for air gasification could be instantaneously adjusted to maintain stable operation of the gasifier. This study demonstrated a simplification of complex reaction dynamics in the gasification process to differential temperature profiling of the gasifier. The monitoring and control system was tested for more than 70 h of continuous operation in a downdraft fixed-bed gasifier with refuse-derived fuel (RDF) prepared from municipal solid wastes (MSW). With the system, fuel feeding rate could be adjusted accurately to stabilize the operating temperature and ER in the gasifier and generate syngas with consistent properties. Significant reductions in the fluctuations of temperature profiles at oxidation and reduction zones (from higher than 100 °C to lower than 50 °C), differential temperatures (from ±200 to ±50 °C) in gasifier and the flow rate (from 16 ± 6.5 to 12 ± 1.8 L/min), composition of main gas components, LHV (from 6.2 ± 3.1 to 5.7 ± 1.6 MJ/Nm3) and tar content (from 8.0 ± 9.7 to 7.5 ± 4.2 g/Nm3) of syngas were demonstrated. The developed gasifier monitoring and control system is adaptable to various types (updraft, downdraft, and fluidized-bed) and scales (lab, pilot, large scale) of gasifiers with different types of fuel.
    Matched MeSH terms: Garbage*
  2. Combustion characteristics of refuse derived fuel (RDF) in a fluidized bed combustor
    Johari A, Mat R, Alias H, Hashim H, Hassim M, Zakaria Z, et al.
    Sains Malaysiana, 2014;43:103-109.
    The combustion characteristics of refuse derived fuel (RDF) in a fluidized bed have been studied. The gross heating value (GHv) of the RDF was 14.43 MJIkg with moisture content of 25% by weight. Parameters of interest for sustainable bed combustion were the fluidization number and primary air factor. The study was performed in a rectangular fluidized bed combustor with dimensions of 0.3 m in width, 0.7 m in length and 2 m in height. Sand with mean particle size of 0.34 mm was used as a fluidization medium. The sand bed height was at 0.3 m above the standpipes air distributor. The range of fluidization number under investigation was 5-7 II fin which 5 II newas found to be the optimum. The study was continued for the determination of the optimum primary air factor with the selected range of primary air factors being 0.6, 0.8, 1.0 and 12 in experiments conducted at 5 Unit The final results showed that the optimum primary air factor was at 0.8. An energy balance was also performed to determine the thermal efficiency of the combustion. It was concluded that the thermal efficiency depended on the bed temperature and the primary air factor being used.
    Matched MeSH terms: Garbage
  3. Household Pharmaceutical Waste Disposal in Selangor, Malaysia-Policy, Public Perception, and Current Practices
    Ariffin M, Zakili TST
    Environ Manage, 2019 Oct;64(4):509-519.
    PMID: 31399770 DOI: 10.1007/s00267-019-01199-y
    Although pharmaceuticals treat illnesses and prevent diseases in humans and animals, ironically, they are now among the emerging pollutants in the environment. As individuals continue to consume medicines, households can become a primary source of pharmaceutical pollutants. This paper explains relevant Malaysian law and policy on the issue. Using a questionnaire survey, it also assesses public perception concerning the environmental impact of pharmaceutical waste and the current methods of disposal that are practiced in Selangor. The survey used a convenience sampling and the data collected were analysed using statistical descriptive analysis. Most of the participants were aware that pharmaceutical waste can have an adverse impact on the environment and public health. Half of the participants disposed of their pharmaceutical waste in trash bins. About 2.9% of the respondents poured their household pharmaceutical waste (HPW) directly down the drain, while 8.8% poured them down the sink in the kitchen or toilet. The study also discovered that while 73.8% of the respondents felt that HPW should be separated from other household solid waste, only 25.2% returned their medicinal waste through the medicine return-back programme. The majority of the respondents (82.5%) agreed that information concerning the proper disposal of HPW is insufficient. The study concludes that while the respondents were aware of the adverse impact of HPW, their practices to ensure proper disposal is discouraging. There is a need for effective unwanted medicines return-back programme as a more prudent disposal method of HPW to avoid any risk to the environment or human health.
    Matched MeSH terms: Garbage
  4. Fulltext Knowledge and Practice on Ecopharmacovigilance and Medicine Storage Amongst Medical and Dental Students in Lalitpur, Nepal
    Jha N, Shankar PR, Palaian S
    Risk Manag Healthc Policy, 2021;14:793-802.
    PMID: 33658875 DOI: 10.2147/RMHP.S291025
    Background: Medicines may remain unused and often get expired. Unused medicines can promote self-medication. Unsafe and improper medicine disposal can cause significant environmental harm. Medical and dental students as future prescribers should be aware of the safe disposal of medicines, ecopharmacovigilance and self-medication. The present study examines knowledge and practice about unused and expired medicines and medicine disposal among undergraduate medical and dental students in Nepal.

    Methods: The study was conducted during September 2020 using an online survey form. First to final year undergraduate students provided their consent and signed an integrity pledge electronically. Age, gender, program of study, year of study, whether staying with family or not, method of financing education, and whether they had used any allopathic medicines during the past 6 months were noted. The total knowledge score among different subgroups was compared. The frequency of responses regarding practice items and the free-text comments were also listed. Statistical analysis was performed using Mann-Whitney test and Kruskal-Wallis test.

    Results: Altogether 441 of the 668 students (66%) participated. The majority were below 23 years and female. Over 65% had used allopathic medicines during the last 6 months. The median knowledge score was 8 (maximum 10) and was significantly higher among older respondents, females and students in later years of study. Most kept unused medicines at home/hostel till expiry which were disposed of in the household garbage. Over 40% had educated their family members about safe medicine disposal. Knowledge scores were significantly different among subgroups according to respondents' age, gender and year of study.

    Conclusion: Respondents were aware of expiry of medicines and knew methods to safely dispose expired medicines. However, they practiced self-medication, stored medications at home and did not practice the safe disposal of medications. Understanding why respondents did not dispose medicines properly is important.

    Matched MeSH terms: Garbage
  5. Fulltext Exposure risk assessment of the municipal waste collection activities during COVID-19 pandemic
    Salvaraji L, Jeffree MS, Avoi R, Atil A, Mohd Akhir H, Shamsudin SBB, et al.
    J Public Health Res, 2020 Oct 14;9(4):1994.
    PMID: 33312989 DOI: 10.4081/jphr.2020.1994
    An increasing amount of waste concurrently further extends the risk of exposure to hazardous material among waste collectors. In light of the COVID-19 crisis, municipal waste collectors are one of the most at-risk groups of SARS-Cov-2 exposure. Risk assessment included hazard identification, evaluation of existing control level at the workplace, estimation of likelihood and severity of hazard, risk determination, and control measure recommendations. Five waste collection activities were identified and reviewed. High-risk exposure includes collection of garbage, mechanical manipulation of compactor lorries and unloading of garbage at the disposal site. There is poor practice of personal hygiene and unestablished continuous monitoring of personal protective equipment supplies. The preventive measures in the waste collection industry are influenced by several factors. Until the preventive measures are adopted into practice and adapted according to each company's requirements, biological agents continue to be risk factor to the health workers.
    Matched MeSH terms: Garbage
  6. Gasification of refuse-derived fuel from municipal solid waste for energy production: a review
    Yang Y, Liew RK, Tamothran AM, Foong SY, Yek PNY, Chia PW, et al.
    Environ Chem Lett, 2021 Jan 13.
    PMID: 33462541 DOI: 10.1007/s10311-020-01177-5
    Dwindling fossil fuels and improper waste management are major challenges in the context of increasing population and industrialization, calling for new waste-to-energy sources. For instance, refuse-derived fuels can be produced from transformation of municipal solid waste, which is forecasted to reach 2.6 billion metric tonnes in 2030. Gasification is a thermal-induced chemical reaction that produces gaseous fuel such as hydrogen and syngas. Here, we review refuse-derived fuel gasification with focus on practices in various countries, recent progress in gasification, gasification modelling and economic analysis. We found that some countries that replace coal by refuse-derived fuel reduce CO2 emission by 40%, and decrease the amount municipal solid waste being sent to landfill by more than 50%. The production cost of energy via refuse-derived fuel gasification is estimated at 0.05 USD/kWh. Co-gasification by using two feedstocks appears more beneficial over conventional gasification in terms of minimum tar formation and improved process efficiency.
    Matched MeSH terms: Garbage
  7. Fulltext ACCOUNTING FOR TRASH MANAGEMENT AT UNIVERSITIMALAYSIA TERENGGANU
    NUR AQILAH AWANG NASRAN, SHAYUTI MOHAMED ADNAN, FATIMAH SHAHMAN, SITI HAJAR ZAWAWI
    UMT Journal of Undergraduate Research, 2019;1(3):36-45.
    MyJurnal
    This paper provides preliminary evidence ofthe need foraccounting for trash management in public organizations, in particular, UniversitiMalaysia Terengganu (UMT). It has two objectives: tosolicit opinions from students regarding their behaviorsand perceptions towards recycling habits,and to provide data on the extent of accounting for trash management at UMT. A survey among155 UMT students indicatedthat theyrecycled the trashandwereaware of environmental issues caused by the waste. However, they were not informed about the benefits of environmental management accounting practice particularly regardingtrash management. Interviewswith UMT management also revealed that while UMT supported recycling activities byfunding the projects and providing facilities, the data on the opportunity cost involved in the current practice was never integrated into UMT accounting system. As a result, the management hadno idea of how much was lost (or gained) during the process. Based on the findings,this study callsfor the implementation of accounting for trash management in a public university.
    Matched MeSH terms: Garbage
  8. Total vulnerability of the littoral zone to climate change-driven natural hazards in north Brittany, France
    Mathew MJ, Sautter B, Ariffin EH, Menier D, Ramkumar M, Siddiqui NA, et al.
    Sci Total Environ, 2020 Mar 01;706:135963.
    PMID: 31862602 DOI: 10.1016/j.scitotenv.2019.135963
    Current worldwide projections of sea-level rise show a staggering increase in water level of up to 2 m by 2100 owing to global warming exacerbated by anthropogenically induced climate change. While amplified rates of sea-level rise is an immense hazard to coastal communities, storm surges are expected to increase in intensity and frequency making it an equally significant threat to coastal populations. In France, these hazards are not uncommon with records of extreme tempests every thousand years in the Holocene. Despite these recurring devastating events, in the Bay of Saint-Brieuc, Brittany, legislated laws for coastal management do not entirely focus on protecting littoral zones from such calamities. 130,739 people are concentrated in 21 municipalities with major cities located at close proximity to the shoreline with numerous socio-economic activities, which increases the vulnerability of the coastal population and infrastructures; thus, affirming the indispensable need of a thorough vulnerability assessment. Here, we conduct a mechanistic appraisal of the vulnerability of the bay considering thirteen parameters within three governing sub-systems that demonstrate the multidimensional dynamics in these municipalities. In the occasion of an extreme climatic event, our results of total vulnerability show risks in the sub-systems highlighting erosional processes due to augmented hydrodynamics, socio-economic and administrative vulnerabilities associated with anthropogenic development. Eight municipalities of the bay portray moderate to very high vulnerability and the remaining exhibits a lower risk; however, not devoid of high vulnerabilities for certain sub-systems. We posit that a more accurate fit for predicting the total vulnerability of the region can be achieved by exclusively integrating physical-natural and administrative sub-system vulnerabilities. We propose generic but requisite recommendations for Integrated Coastal Zone Management such as surveillance of urban development along the coast, implementation of coastal defense systems and appropriate industrial corridors to attenuate and dispose hazardous refuse.
    Matched MeSH terms: Garbage
  9. Development of probiotic carriers using microbial transglutaminase-crosslinked soy protein isolate incorporated with agrowastes
    Lew LC, Bhat R, Easa AM, Liong MT
    J Sci Food Agric, 2011 Jun;91(8):1406-15.
    PMID: 21384373 DOI: 10.1002/jsfa.4325
    Probiotics are live micro-organisms that exert beneficial effects on their host. A high survival rate during gastrointestinal transit and storage is often desirable. The main aim of this study was to develop protective carriers for probiotics via the use of enzymatically crosslinked soy protein isolate incorporated with agrowastes such as banana peel, banana pulp, cempedak rind and cocoa rind.
    Matched MeSH terms: Garbage*
  10. Cellulose acetate from oil palm empty fruit bunch via a one step heterogeneous acetylation
    Wan Daud WR, Djuned FM
    Carbohydr Polym, 2015 Nov 5;132:252-60.
    PMID: 26256348 DOI: 10.1016/j.carbpol.2015.06.011
    Acetone soluble oil palm empty fruit bunch cellulose acetate (OPEFB-CA) of DS 2.52 has been successfully synthesized in a one-step heterogeneous acetylation of OPEFB cellulose without necessitating the hydrolysis stage. This has only been made possible by the mathematical modeling of the acetylation process by manipulating the variables of reaction time and acetic anhydride/cellulose ratio (RR). The obtained model was verified by experimental data with an error of less than 2.5%. NMR analysis showed that the distribution of the acetyl moiety among the three OH groups of cellulose indicates a preference at the C6 position, followed by C3 and C2. XRD revealed that OPEFB-CA is highly amorphous with a degree of crystallinity estimated to be ca. 6.41% as determined from DSC. The OPEFB-CA films exhibited good mechanical properties being their tensile strength and Young's modulus higher than those of the commercial CA.
    Matched MeSH terms: Garbage*
  11. Conceptual framework for the study of food waste generation and prevention in the hospitality sector
    Papargyropoulou E, Wright N, Lozano R, Steinberger J, Padfield R, Ujang Z
    Waste Manag, 2016 Mar;49:326-336.
    PMID: 26803473 DOI: 10.1016/j.wasman.2016.01.017
    Food waste has significant detrimental economic, environmental and social impacts. The magnitude and complexity of the global food waste problem has brought it to the forefront of the environmental agenda; however, there has been little research on the patterns and drivers of food waste generation, especially outside the household. This is partially due to weaknesses in the methodological approaches used to understand such a complex problem. This paper proposes a novel conceptual framework to identify and explain the patterns and drivers of food waste generation in the hospitality sector, with the aim of identifying food waste prevention measures. This conceptual framework integrates data collection and analysis methods from ethnography and grounded theory, complemented with concepts and tools from industrial ecology for the analysis of quantitative data. A case study of food waste generation at a hotel restaurant in Malaysia is used as an example to illustrate how this conceptual framework can be applied. The conceptual framework links the biophysical and economic flows of food provisioning and waste generation, with the social and cultural practices associated with food preparation and consumption. The case study demonstrates that food waste is intrinsically linked to the way we provision and consume food, the material and socio-cultural context of food consumption and food waste generation. Food provisioning, food consumption and food waste generation should be studied together in order to fully understand how, where and most importantly why food waste is generated. This understanding will then enable to draw detailed, case specific food waste prevention plans addressing the material and socio-economic aspects of food waste generation.
    Matched MeSH terms: Garbage
  12. Fulltext A bionomic study of Hymenopteran parasitoids at the Taman Beringin landfill in Kepong and a poultry farm in Sungai Pelek, Selangor, Malaysia
    Baharudin Omar, Raja M. Zuha Raja Kamal, Goh, Daniel Chuan Lee, Wan Omar Abdullah, Jeffery, John
    Jurnal Sains Kesihatan Malaysia, 2008;6(2):15-21.
    MyJurnal
    A four-month cross-sectional study found five species of parasitoids parasitizing puparia of filth flies breeding at the Taman Beringin landfill in Kepong and a poultry farm in Sungai Pelek, Sepang, Selangor. Effect of monthly rainfalls towards density of flies and percentage of parasitoids emerging from collected puparia were also analyzed. Spalangia sp. was the most common, consisting of Spalangia endius Walker, S. cameroni Perkins and S. gemina Boucek. Other parasitoids collected were Pachycrepoideus vindemmiae Rondani and Exoristobia phillipinensis Ashmead. The parasitized fly hosts were Musca domestica Linn. and Chrysomya megacephala Fabricius. S. endius was the most common parasitoid attacking M. domestica at both locations. M. domestica was the most common fly found at the Sg. Pelek poultry farm whereas C. megacephala was the most numerous at the Taman Beringin landfill. During heavy rainfall month of November 2003, density of flies were high whereas the emerging parasitoids were low at both landfill and poultry farm. The present study revealed the endemic presence of parasitoids especially S. endius in both poultry farm and garbage landfill and the potential of the parasitoid species in fly control in Malaysia.
    Matched MeSH terms: Garbage
  13. Occurrence of sweet refuse at disposal sites: rainwater retention capacity and potential breeding opportunities for Aedes aegypti
    Dieng H, Satho T, Meli NKKB, Abang F, Nolasco-Hipolito C, Hakim H, et al.
    Environ Sci Pollut Res Int, 2018 May;25(14):13833-13843.
    PMID: 29512008 DOI: 10.1007/s11356-017-1078-8
    Nectar is the staple diet of adult mosquitoes in the wild, but its availability is inconsistent and can be affected by rainfall. In urban centers, Aedes vectors commonly use man-made containers as their major habitat; however, they can colonize any items replenished by rainfall. Garbage output has increased significantly in recent years, at a time when collection frequency is reducing. Such garbage usually includes organic components, some of which are sweet and can be fed upon by other animals or become can containers for rainwater. Despite evidence that Aedes larvae can thrive in containers comprised of organic waste material, which can be produced by rodents gnawing on fruits or vegetables, and that adults can survive on sweet waste fluids, the capacity of organic waste materials to accumulate rainwater and act as egg deposition sites has not been examined. It is also unknown for how long sweet extracts can sustain the life of adult vectors. Here, we investigated the abundance of sweet leftovers at garbage sites and the rainwater retention capacity of some organic materials through a field survey and laboratory bioassays. We also examined whether sweet waste fluids impact egg hatching success and longevity of Aedes aegypti. The results of this study indicated that sweet products with leftovers are highly prevalent in garbage. When exposed to rain, food items (BAFrc, banana fruit resembling container; and BSPrc, boiled sweet potato resembling container) and the packaging of sweet foods (SMIc, sweetened condensed milk can) retained water. When provided an opportunity to oviposit in cups containing BAF extract (BAFex), BSP extract (BSPex), and SMI extract (SMIex), eggs were deposited in all media. Egg maturation in the BAFex environment resulted in similar larval eclosion success to that resulting from embryo development in a water milieu. Adults maintained on sweet waste extracts had long lifespans, although shorter than that of their sugar solution (SUS)-fed counterparts. Taken together, these results indicated that sweet waste materials are useful to dengue mosquitoes, acting both as oviposition sites and energy sources.
    Matched MeSH terms: Garbage
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