Performance assessment of gasification reactors for sustainable management of municipal solid waste.

The issue of waste management has received considerable critical attention due to the increase of waste generation worldwide. One of the solutions for waste disposal that has been widely implemented is through the use of the landfill due to its economic benefits. Landfill, however, results in many adverse impacts on the environment and human health. Recycling can extract some useful materials from waste, however not every waste can be recycled and a significant volume of waste, particularly the municipal solid waste (MSW) goes to landfill even though it has extractable energy potentials. Extraction of energy from MSW has been a key focus of research due to the scope of energy recovery, environmental and economic benefits. The principal concept of waste to energy is to convert waste into energy through thermal and/or biological processes. In addition, thermochemical processes such as gasification have been found as a promising technology offering several benefits. This paper presents a critical assessment of waste to energy gasification technology for MSW on processing, energy recovery, environmental performance and economic perspectives. These aspects have been analyzed for the landfill as well. The review also explored and identified suitable simulation tools for optimizing gasification. Subsequently, an assessment and comparison of different gasification reactors were carried out which indicate that the plasma gasification can be a feasible technology for MSW management due to higher energy efficiency (816 kWh/tonne) with minimum emission and lowest residue. Although plasma gasification is an energy intensive application which has relatively higher investment cost, it can be built as a large system (up to several 1000 MW system), which can make it economically competitive too. Other technologies such as; fluidized bed gasifier, fixed bed gasifier also have good energy efficiency (547-571 kWh/tonne) however, they contribute to higher CO2 emission. Considering overall waste management, it was found that gasification technology is beneficial to economy, environment and energy extraction compared to the landfill option. A number of tools and their relevant properties have been identified to develop appropriate gasifier model. It is expected that this study will advance further research and innovation that will be helpful to manage waste efficiently as well as to improve the environment.

COVID-19: Impact analysis and recommendations for power sector operation.

The demand of electricity has been reduced significantly due to the recent COVID-19 pandemic. Governments around the world were compelled to reduce the business activity in response to minimize the threat of coronavirus. This on-going situation due to COVID-19 has changed the lifestyle globally as people are mostly staying home and working from home if possible. Hence, there is a significant increase in residential load demand while there is a substantial decrease in commercial and industrial loads. This devastating situation creates new challenges in the technical and financial activities of the power sector and hence most of the utilities around the world initiated a disaster management plan to tackle this ongoing challenges/threats. Therefore, this study aims to investigate the global scenarios of power systems during COVID-19 along with the socio-economic and technical issues faced by the utilities. Then, this study further scrutinized the Indian power system as a case study and explored scenarios, issues and challenges currently being faced to manage the consumer load demand, including the actions taken by the utilities/power sector for the smooth operation of the power system. Finally, a set of recommendations are presented to support the government/policymakers/utilities around the world not only to overcome the current crisis but also to overcome future unforeseeable pandemic alike scenario.

Serovar diversity of Leptospira sp. infecting wild rodents in Sarawak, Malaysia.

Leptopsirosis is a zoonotic disease with global distribution and rodents, in particular rats, have been identified as the main reservoir host. A study was conducted to determine the prevalence of antibodies against Leptospira sp. in wild rodents caught in selected areas of Sibu, Sarikei and Kapit in Sarawak during the period of July 2011 to May 2014. In total, 241 sera samples were collected from rodents caught from these three administrative divisions in Sarawak. Ninety-eight rodents (40.7%) were positive with antibody titre >1:50 by microscopic agglutination test (MAT) against 13 out of 20 common local leptospiral serovars tested. Sera of rodents caught in Sibu, Kapit and Sarikei divisions were positive at 43.9%, 37.5% and 36.4%, respectively. The top five serovars detected were: Autumnalis (25.5%), Tarassovi (23.5%), Bataviae (15.3%), Hebdomadis (8.2%) and Celledoni (7.2%). The main species of rodent positive for antibodies against Leptopsira sp. were Sundamys muelleri (50.0%), Rattus rattus (37.5%), Callociurus notatus (35.6%) and Rattus exulans (32.6%). This study indicates that leptospiral antibodies are prevalent amongst wild rodents in central Sarawak, which could be translated as high leptospiral carriage. The close interaction that exists between the local community and the environment could potentially propagate the transmission of Leptospira sp. to human in these areas. This study also provided essential information about local circulating Leptospira serovars, which could be useful for eventual prevention measures in disease transmission.

Effectiveness of pictorial health warning on cigarette packages: A cross-sectional study in Sarawak, Malaysia.

INTRODUCTION: Specific health warning placed on the tobacco product packages is considered as an effective and low-cost method for increasing the knowledge and awareness among the community. Thus, a study was conducted to assess the perception of pictorial health warnings (PHWs) against smoking among the adult rural population of Sarawak. METHODS: Cross-sectional data were collected from 10 villages in Kota Samarahan and Kuching Division by face to face interview using modified Global Adult Tobacco Survey questionnaire. Nonprobability sampling method was adopted to select the villages. All the households of the selected villages were visited and an adult member was selected randomly from each house irrespective of the sex. After missing value imputation, 1000 data were analysed using statistical software IBM SPSS 20.0 version. RESULTS: Analysis showed that 28.8% of the respondents were current smokers, 7.8% were past smokers and the rest were non-smokers. Six items of pictorial health warnings were evaluated with five point Likert's scales for attractiveness, fearfulness and adequacy of the information. Analysis revealed that the majority of the respondents had perceived awareness on PHWs, but the smokers believed that this was not adequate to make them quit smoking. Only one-fifth (19.7%) of them reported that current pictorial health warnings were sufficient to motivate people to quit smoking. CONCLUSION: Though the PHWs on cigarette packages are appealing, it is not sufficient as a reason to stop smoking. Thus, an approach using an integrated anti-tobacco public health programme should be focused into the specific targeted community.

Nipah virus infection among abattoir workers in Malaysia, 1998-1999.

BACKGROUND: An outbreak of encephalitis primarily affecting pig farmers occurred during 1998-1999 in Malaysia and was linked to a new paramyxovirus, Nipah virus, which infected pigs, humans, dogs, and cats. Because five abattoir workers were also affected, a survey was conducted to assess the risk of Nipah infection among abattoir workers. METHODS: Workers from all 143 registered abattoirs in 11 of 13 states in Malaysia were invited to participate in this cross-sectional study. Participants were interviewed to ascertain information on illness and activities performed at the abattoir. A serum sample was obtained to test for Nipah virus antibody. RESULTS: Seven (1.6 %) of 435 abattoir workers who slaughtered pigs versus zero (0%) of 233 workers who slaughtered ruminants showed antibody to Nipah virus (P = 0.05). All antibody-positive workers were from abattoirs in the three states that reported outbreak cases among pig farmers. Workers in these three states were more likely than those in other states to have Nipah antibody (7/144 [4.86%] versus 0/291 [0%], P < 0.001) and report symptoms suggestive of Nipah disease in pigs admitted to the abattoirs (P = 0.001). CONCLUSIONS: Nipah infection was not widespread among abattoir workers in Malaysia and was linked to exposure to pigs. Since it may be difficult to identify Nipah-infected pigs capable of transmitting virus by clinical symptoms, using personal protective equipment, conducting surveillance for Nipah infection on pig farms which supply abattoirs, and avoiding handling and processing of potentially infected pigs are presently the best strategies to prevent transmission of Nipah virus in abattoirs.

Case-control study of risk factors for human infection with a new zoonotic paramyxovirus, Nipah virus, during a 1998-1999 outbreak of severe encephalitis in Malaysia.

An outbreak of encephalitis affecting 265 patients (105 fatally) occurred during 1998-1999 in Malaysia and was linked to a new paramyxovirus, Nipah, that infected pigs, humans, dogs, and cats. Most patients were pig farmers. Clinically undetected Nipah infection was noted in 10 (6%) of 166 community-farm controls (persons from farms without reported encephalitis patients) and 20 (11%) of 178 case-farm controls (persons from farms with encephalitis patients). Case patients (persons with Nipah infection) were more likely than community-farm controls to report increased numbers of sick/dying pigs on the farm (59% vs. 24%, P=.001) and were more likely than case-farm controls to perform activities requiring direct contact with pigs (86% vs. 50%, P=.005). Only 8% of case patients reported no contact with pigs. The outbreak stopped after pigs in the affected areas were slaughtered and buried. Direct, close contact with pigs was the primary source of human Nipah infection, but other sources, such as infected dogs and cats, cannot be excluded.