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Plastic waste is one of the world’s most pressing human health and environmental concerns. Plastic constitutes the third highest waste source globally, with the total volume of plastic waste growing in-line with increases in the global population and per capita consumption. Malaysia is tracking global trends in both the overall generation of plastic waste and the consumption of single-use plastics and since 2017 has been the world’s largest importer of plastic waste. These elements create a number of major challenges for the country’s waste management system. This review outlines the current state of plastic waste production and management in Malaysia, including options for landfill, recycling and incineration. It presents information on the scale and both the human and ecological risks of plastic waste in the country (i.e. microplastics, landfill, incineration), outlines key plastic waste management policy initiatives (including plastics alternatives such as biodegradable plastics) and highlights key constraints on the success of these. Significant internal constraints stem from the inconsistent application of policy initiatives by state governments, in addition to the lack of public awareness and interest in household recycling. The paper closes by discussing options for and constraints on the switch to biodegradable alternatives and proposes a model of plastic management based on a circular economy approach and solid waste management hierarchy. Success in reducing the problems posed by plastic in Malaysia will require sustained effort at many levels, but positive experiences in other countries give some cause for optimism.

In this paper, we have discussed the state of the art on numerical techniques for estimating light intensity distribution in photocatalytic reactors. After giving a brief introduction to various photocatalytic reactor designs, a detailed derivation of the radiation transport equation (RTE) has been presented. The RTE is an integrodifferential equation and needs appropriate boundary conditions and optical properties of the medium. To provide a boundary condition for the light emitted from the radiation sources, a number of lamp source models have been described. Different approaches for the numerical simulation of the RTE have been presented with special emphasis on the Monte Carlo and finite volume (or discrete ordinate) approaches. In the Monte Carlo approach, the reaction space was divided into small cubical cells. The path of a photon was traced using a stochastic approach. A conservative variant of the discrete ordinate model available in FLUENT was used to assess the effect of wall reflectivity, catalyst loading, and phase function parameter on the light intensity distribution. For relatively low catalyst loadings, the wall reflectivity strongly influenced the light intensity distribution. However, for an optically thick medium, the wall reflectivity had very little or no effect. The volume‐averaged light intensity distribution decreased rather sharply with the catalyst loading and an opposite trend was obtained for LVREA. Finally, a semiempirical kinetic model was presented to evaluate the rate of reaction and conversion of a photoreactor using the computational fluid dynamics (CFD) approach. Model verification was carried out using experimental data for photodegradation of Bayer liquor. A correlation coefficient of 0.974 between simulated and experimental results indicated that the proposed model was adequate. Copyright © 2008 Curtin University of Technology and John Wiley & Sons, Ltd.

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Anaerobic digestion has been widely employed in waste treatment for its ability to capture methane gas released as a product during the digestion. Certain wastes, however, cannot be easily digested due to their low nutrient level insufficient for anaerobic digestion, thus co-digestion is a viable option. Numerous studies have shown that using co-substrates in anaerobic digestion systems improve methane yields as positive synergisms are established in the digestion medium, and the supply of missing nutrients are introduced by the co-substrates. Nevertheless, large-scale implementation of co-digestion technology is limited by inherent process limitations and operational concerns. This review summarizes the results from numerous laboratory, pilot, and full-scale anaerobic co-digestion (ACD) studies of wastewater sludge with the co-substrates of organic fraction of municipal solid waste, food waste, crude glycerol, agricultural waste, and fat, oil and grease. The critical factors that influence the ACD operation are also discussed. The ultimate aim of this review is to identify the best potential co-substrate for wastewater sludge anaerobic co-digestion and provide a recommendation for future reference. By adding co-substrates, a gain ranging from 13 to 176% in the methane yield was accomplished compared to the mono-digestions.

This study surveys the perceptions and experiences of Australian small-and medium-sized enterprises (SMEs) in the implementation of Internet-based Electronic Commerce (EC) as seen from the perspective of the extent of deployment. With a sample of 115 small businesses in Australia, this article uses regression modelling to explore and establish the factors that are related to the extent of deployment in EC. A multiple regression analysis shows that seven factors: perceived relative advantage, trialability, observability, variety of information sources, communication amount, competitive pressure, and non-trading institutional influences, significantly influence the extent of EC deployment by SMEs in Australia. The managerial implications are discussed.

This study surveys the perceptions and experiences of Australian small- and medium-sized enterprises (SMEs) in the implementation of Internet-based Electronic Commerce (EC) as seen from the perspective of the extent of deployment. With a sample of 115 small businesses in Australia, this article uses regression modelling to explore and establish the factors that are related to the extent of deployment in EC. A multiple regression analysis shows that seven factors: perceived relative advantage, trialability, observability, variety of information sources, communication amount, competitive pressure, and nontrading institutional influences, significantly influence the extent of EC deployment by SMEs in Australia. The managerial implications are discussed.

The rapid emergence of Industry 4.0 implies that our engineering graduates need to acquire new competences to adapt to the digital transformation. This paper evaluates the benefits of integrating 3D printing and Industry 4.0 into engineering undergraduate programs. Surveys were conducted to gather the feedbacks and views from academics and students. 75% and 86% of the participating students and lecturers, respectively, have heard about Industry 4.0. 63% of the students were exposed to modules with such elements. Tangible 3D-printed models enable visualization of fundamental theories and concepts. Enhanced 3D drawing skills and rapid 3D-printed prototypes can greatly help students study common processing equipment, manufacturing, maintenance, logistics, and operations. Some limitations were identified such as budgeting, lack of knowledge, and difficulty in changing from traditional pedagogy. This paper thus proposes a blended learning model for integrating Industry 4.0 into engineering teaching, which consists of traditional, online learning, and flipped classroom approaches. Implementation of the model can be started off with cross-multidisciplinary collaborations or expert-led training for the instructors, followed by traditional face-to-face teaching and online learning. Flipped classroom is one of the essential components of the model which encourages learning-by-making approaches such as ‘bring your own device’ and ‘do it yourself’. Integrating Industry 4.0 into engineering teaching can create a student-based learning environment, where students are gradually trained to become proactive and lifelong learners who are more conscious of the environment and economy.