Municipal solid waste management in Malaysia: practices and challenges

Sustainable leachate treatment by integrating electrolysis with palm-shell activated carbon contactor for environmental protection

The increasingly concerning issue of water pollution caused by untreated leachate necessitates the implementation of effective wastewater treatment methods. This study addresses the crucial issue of landfill leachate treatment through an innovative and environmentally friendly approach that integrates electrolysis with palm-shell activated carbon contactors. The efficacy of an integrated process for pollutants removal was assessed involving electrolysis with aluminum and iron electrodes, activated carbon contactors with varying bed depths, and the influence of salinity. The findings of the study demonstrated significant advancements in the removal of pollutants from landfill leachate. The utilization of aluminum and iron electrodes in electrolysis has exhibited enhanced efficacy in the removal of several parameters, including ammonia nitrogen, total suspended solids (TSS), chemical oxygen demand (COD) and biochemical oxygen demand (BOD). The pollutants removal efficiency was further improved by implementing up-flow activated carbon treatment, with a bed depth of 15 cm yielding most favorable outcomes. Additionally, the investigation explored the impact of salinity on the efficacy of pollutants removal. Except for BOD, which demonstrated good removal efficiency even at 5% salt, results indicated that the removal effectiveness was maximum when no salt was applied to the samples. The results suggest that this integrated method offers a sustainable and effective solution for landfill leachate treatment, potentially leading to better water quality and environmental preservation. Future study should focus on implementing rigorous laboratory protocols, ensuring accurate dilution factors, refraining from reusing activated carbon, maintaining continuous monitoring throughout treatment operations, and investigating alternative treatment approaches. This study makes a valuable contribution to the ongoing endeavors aimed at tackling the environmental issues related to the treatment of landfill leachate.

Identifying high-vulnerable garbage accumulation areas in Coimbatore City, India: an AHP-GIS approach for effective waste management

Urbanization has resulted in a surge in municipal solid waste (MSW) generation, posing critical waste management challenges in urban areas. To tackle this issue, we introduce a novel approach for mapping garbage vulnerability zones (GVZ) in Coimbatore City, India, combining the analytic hierarchy process (AHP) and Geographic Information System (GIS). Seven criteria, including per capita waste generation, open dumping, land use land cover, road/railway networks, and population, were integrated and analyzed in GIS. AHP pairwise comparison method assigned weights to each criterion and principal component analysis (PCA) further validated the interconnectedness of the criteria and their impact on the GVZs. The results indicated that open dumping locations and population density are the most influential factors contributing to the risk of garbage accumulation, making up 23.7% and 21.2% of the total weight, respectively. The GVZ map reveals that 94.6% of Coimbatore City is at risk of MSW accumulation, with 20.2% highly and 74.4% moderately vulnerable. Eleven high GVZ clusters were identified, with Saravanampatti, located in the northeastern part of Coimbatore City, being the most vulnerable area. The H3 hexagon format of the GVZ map enhances its usability for monitoring and mitigation capabilities. In conclusion, our comprehensive AHP-GIS approach facilitates effective waste management practices, sustainable resource utilization, and better environmental and public health outcomes in urban areas. The demonstrated methodology has the potential for application in similar developing urban areas in South Asia and the Global South, serving as a valuable tool to address the challenges posed by increasing MSW generation.

Solid waste management in the context of the waste hierarchy and circular economy frameworks: An international critical review

Growing populations and consumption drive the challenges of solid waste management (SWM); globalization of transport, food production, and trade, including waste trading, distributes risks worldwide. Using waste hierarchy (WH; reduce, reuse, and recycle) and circular economy (CE) concepts, we updated a conceptual waste framework used by international organizations to evaluate SWM practices. We identified the key steps and the important factors, as well as stakeholders, which are essential features for effective SWM. Within this updated conceptual framework, we qualitatively evaluated global SWM strategies and practices, identifying opportunities, barriers, and best practices. We find that, although a few exceptional countries exhibit zero-waste compliance, most fare poorly, as exhibited by the high waste generation, incineration, and disposal (open dumping, landfilling) volumes. In the Global North, SWM strategies and practices rely heavily on technologies, economic tools, regulatory frameworks, education, and social engagement to raise stakeholder awareness and enhance inclusion and participation; in the Global South, however, many governments take sole legal responsibility for SWM, seeking to eliminate waste as a public "nuisance." Separation and recycling in the Global South are implemented mainly by "informal" economies in which subsistence needs drive recyclable material retrieval. Imported, regionally inappropriate tools, economic constraints, weak policies and governance, waste trading, noninclusive stakeholder participation, data limitations, and limited public awareness continue to pose major waste and environmental management challenges across nations. In the context of the framework, we conclude that best practices from around the world can be used to guide decision-making, globally. Despite variations in drivers and needs across regions, nations in both the Global North and South need to improve WH and CE compliance, and enhance stakeholder partnership, awareness, and participation throughout the SWM process. Partnerships between the Global North and South could better manage traded wastes, reduce adverse impacts, and enhance global environmental sustainability and equity, supporting UN Sustainable Development Goals. Integr Environ Assess Manag 2024;20:9-35. © 2023 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Strategies and perceptions towards flood control and waste management in Limbe city, Cameroon

Limbe city in Cameroon is prone to annual flood disasters. The Limbe City Council (LCC) has been making efforts to address the problem of floods and municipal solid waste management (MSWM). This article presents an: (1) assessment of the different strategies by the council towards MSWM and floods; (2) evaluation of public perception on waste disposal practices and (3) examination of the nexus between waste disposal and flooding. The methods employed included qualitative data collection through semi-structured interviews with the aid of questionnaires (open- and closed-ended questions) field observations and interview; and the use of the Benefit Value Tree method (BVT) to analyse sustainability strategies by LCC. The BVT method provided, the following scores for the four strategies used: sustainable basin management against floods and/or landslides = 7; mechanical dredging of river beds = 4; Keep Limbe Clean = 3; manual dredging and cleaning of rivers, gutters, culverts and bridges = 1. An evaluation of the municipal solid waste collection system revealed that (1) over 85% of plastic bins do not meet standard physical conditions; (2) bins at all collection points are insufficient for waste at such points and (3) residents engage in wanton disposal practices because of insufficient service coverage of residential areas. Field observations and interview with authorities established a clear connection between floods and poor waste management. In addition to existing efforts by LCC, it needs to upgrade and expand waste collection services through provision of numerous suitable bins and community awareness raising on the nexus between floods and waste disposal.

Contribution

This is a transdisciplinary research which presents the constraints and challenges in waste generation and collection, its relationship with recurrent floods in Limbe city, and presents a way forward to improve on the situation using the BVT method.

Life cycle assessment of municipal solid waste generated from hilly cities in India - A case study

Improper disposal of waste poses a grave environmental threat, contributing to pollution of air, water, and soil. It is necessary to address this issue in order to mitigate the adverse effects of solid waste on both the environment and public health. In many developing nations, municipal authorities of bigger cities are enduring significant challenges in proper management of waste. The present study evaluates the impacts of various waste management alternative scenarios for environmental impacts for the selected study locations using Life Cycle Assessment (LCA) methodology. The methodology comprised of five different scenarios of waste management including an existing baseline scenario. In this context, the environmental impact categories analyzed were Global Warming potential (GWP), Acidification potential (AP), Eutrophication potential (EP) and Human Toxicity potential (HTP). The results indicated that amongst all the proposed scenarios, Scenario 1 and 4 exhibited the maximum and minimum environmental impacts respectively. The study revealed that least greenhouse gas emissions, acidification potential, eutrophication potential and human toxicity potential were comparatively lesser for scenario 4 varying from 5.65 to 11.36 kg CO2eq t-1; 1.24-3.345 kg SO2eq t-1, EP 0.19-0.68 kg PO4eq t-1, and 0.35-4.22 kg 1,4-DBeq t-1 respectively. Further, a sensitivity analysis was also performed to evaluate the influence of recycling rate of valuable resources in all the considered scenarios. The sensitivity analysis indicated an inversely proportional relation between change in recycling rate and total environmental burdens.

Microplastics in Malaysia's Aquatic Environment: Current Overview and Future Perspectives

Microplastic pollution has adversely affected the aquatic ecosystem, living creatures, and human health. Several studies in Malaysia have provided baseline information on the existence of microplastics in surface water, ingestion by marine life and sediment. Also, humans are exposed to microplastic due to consumption of contaminated abiotic and biotic products, such as processed seafood. Nonetheless, knowledge is still scarce among Malaysian on the potential remediation and pollution management of microplastics, which poses a significant challenge to preserve a good environmental status. Green technologies also other alternative to mitigate the contamination of microplastics for sustainable future. Hence, this review aims to provide an overview of microplastic's occurrence, fate, and implications in Malaysia's aquatic environment. Detection of microplastics from the water surface, ingestion by aquatics, and sediment samples are highlighted. Available different treatment processes toward microplastic remediation are also discussed. Additionally, the potential challenges, current perspective for plastic management in Malaysia, as well as green strategies for reducing microplastic contamination are also put forward. The goal of this work is to improve the understanding of the seriousness of microplastic contamination in aquatic environments, thus encouraging key concerns that need to be investigated further.

An Assessment of Knowledge, Attitudes and Practices on Pureed Diet Preparation (KAP DYS-PUREE) among Food Handlers in Malaysian Hospitals for Dysphagia Management

This study aims to assess the knowledge, attitude, and practice towards pureed diet preparation among food handlers using a newly developed questionnaire for dysphagia management. A descriptive cross-sectional design study with purposive sampling was conducted in three government hospitals in the Klang Valley, Malaysia. A newly developed questionnaire, comprised of 40 quantitative items, was used and distributed to 161 food handlers from three hospitals who were directly involved in preparing pureed diets. The results demonstrated a low to moderate knowledge score among food handlers (57.54 ± 12.33), with scoring at 1.95% (very low), 28.6% (low), and 68.3% (moderate). Only 1.2% scored well in the knowledge section on pureed diet preparation. The attitude among food handlers showed that they were referred to the right source of reference before preparing the pureed diet (3.97 ± 1.35). The findings also clearly showed that the practice of using the right equipment (4.41 ± 1.19) is essential for pureed diet preparation. In conclusion, this study serves as a prognosis for future improvement in knowledge, attitude, and practice among food handlers toward pureed diet preparation. Knowledge among food handlers needs to be enhanced, and a comprehensive guideline and reference module will aid in refining dysphagia management, specifically in food preparation by food handlers.

Assessment of metal contaminants along the Bay of Bengal - Multivariate pollution indices

The spatial concentration of heavy metals (Mn, Ni, Cu, Co, Zn, Cd, and Pb) was studied in coastal areas (n = 9) including water (n = 27) and sediment (n = 27) in the Palk Bay, India to understand the metal pollution due to prevailing natural and anthropogenic activities. Pollution indices like metal index (MI), geoaccumulation index (Igeo), contamination factor (CF), pollution load index (PLI) and potential ecological risk (PER) were calculated based on the background/reference value. The values of MI index indicated that water was free of metals, whereas Igeo, CF, PLI and PER indicated moderate contamination of sediment in monsoon. Cadmium concentrations were the highest irrespective of the indices (Igeo: 0.04-1.42, Cf: 0.36-0.74, PLI: 0.36-0.74, and PER: 76.89-143.36) indicating moderate pollution. The Principal Component Analysis (PCA) affirmed that Cd was positively correlated with stations indicating anthropogenic sources of Cd contamination.

Insect biorefinery: A circular economy concept for biowaste conversion to value-added products

With rapid growing world population and increasing demand for natural resources, the production of sufficient food, feed for protein and fat sources and sustainable energy presents a food insecurity challenge globally. Insect biorefinery is a concept of using insect as a tool to convert biomass waste into energy and other beneficial products with concomitant remediation of the organic components. The exploitation of insects and its bioproducts have becoming more popular in recent years. This review article presents a summary of the current trend of insect-based industry and the potential organic wastes for insect bioconversion and biorefinery. Numerous biotechnological products obtained from insect biorefinery such as biofertilizer, animal feeds, edible foods, biopolymer, bioenzymes and biodiesel are discussed in the subsequent sections. Insect biorefinery serves as a promising sustainable approach for waste management while producing valuable bioproducts feasible to achieve circular bioeconomy.

Challenges of selective collection of the household waste: A case study in a Brazilian metropolis

This work sought to analyse the main difficulties in implementing and maintaining the selective waste collection in a Brazilian metropolis with more than one million inhabitants. Therefore, a qualitative method was used through in-depth interviews with 18 professionals working in the area of selective collection. The interviews were recorded and the data submitted to content analysis. The results showed the following difficulties: lack of management by the government, low efficiency and limited coverage; poor separation of waste at source; distortions in the selective collection logistics chain and in the distribution of waste by cooperatives; high informality, precarious work and low pay for waste collectors; the presence of middlemen and corruption in the system; and idle capacity of cooperatives and public organs. It was concluded that to overcome the difficulties in the selective collection and for it to be more effective, there is a need to improve the management of the process by the government with greater transparency and integration between the various actors involved, education of the population, better working conditions and remuneration for waste collectors.

Self-Reported Household Waste Recycling and Segregation Practices among Families in Eastern Region of Saudi Arabia: A Cross-Sectional Study

BACKGROUND

The reuse and recycling of household waste are correlated with a household's daily activities and commonly depend on sociodemographic factors. In this study, we aimed to assess and probe the level of awareness of waste reuse and recycling, self-reported household waste recycling and segregation practices, and the variables affecting the practices of households in Al-Ahsa, Saudi Arabia.

METHODS

We employed a cross-sectional study utilizing the multi-stage random sampling of 279 households and a researcher-structured, online questionnaire in English and Arabic. Data were analyzed using SPSS Version 20. Descriptive statistics was used to describe the level of awareness/practices, and inferential statistics was used to describe the correlational aspects.

RESULTS

It was determined that female participants, younger participants, participants of both genders with university and postgraduate education levels, and urban residents were significantly associated with self-reported household waste segregation and recycling practices at the source. Plastics, paper, glass, food waste, textiles, and electronic waste were determined to be the most common types of household waste. A lack of expertise, awareness, demand for recycled products, and laws that support recycling was reported to affect female participants' failure to recycle. Social media, television, and educational institutions were shown to be sources of information regarding waste segregation and recycling. Therefore, awareness-raising polices must be developed to improve the prevalence, expertise, and efficiency regarding recycling and segregation. In addition, inventive methods, such as a card-based reward system, should be used to increase the demand level for recycled products.

Understanding barriers and motivations in solid waste management from Malaysian industries: a comparative analysis

The objective of this study is to explore the similarities and differences in the barriers and motivations between the plastic and resins and food and beverages industries as these two industries are the major contributors of solid waste in Malaysia. Prior studies are lacking with regard to explaining the barriers and motivations in solid waste management from the Malaysian context. This study is focused on 10 firms from the plastics and resins industry and 9 from the food and beverages industry in Malaysia. Through Rasch measurement theory, the results indicate that the barriers of lack of skills and qualifications and lack of closed-loop control and the motivations of cost savings and a business model are performed differently. The findings further confirm that the lack of skills and qualifications is a more difficult barrier to overcome than the lack of closed-loop control, while the motivation factor of a business model is more difficult to achieve than cost savings. In terms of practical contribution, this study provides results that can help policy makers in Malaysia to close the gaps present regarding the adoption of solid waste management practices and to devise appropriate incentives. The study also supports managers of companies in regard to working on the most pressing hindering and promoting factors in the field of solid waste management.

Evaluating the waste management situation and attitudes of residents in Bandung, Indonesia

The increasing amount of waste is becoming a crucial topic in developing countries, causing health-related and environmental issues. In past decades, the Indonesian government implemented regulations dedicated to municipal solid waste management (MSWM); unfortunately, these have not been well communicated to the public. The set tax level is inadequate for the MSWM financial needs in Bandung, Indonesia. Previous studies determined the public interest in MSWM as the critical factor of sustainable MSWM. However, this aspect is not well considered. This study investigated public perception and involvement in MSWM in Bandung. These investigations were conducted through two leading indicators: public interest in MSWM in environmental issues and willingness of inhabitants to pay for sufficient MSWM services. Using a binary probit model, it was found that age, educational level, locality, and satisfaction with MSWM practices play a significant role in the respondents' interest in MSWM, which is crucial to the public perception of MSWM. The results also demonstrate that more than 97% of respondents are not satisfied with MSWM practices, and more than 83% of respondents consider MSWM services insufficient. Awareness of essential operations such as waste handling and recycling is at a low level. On the other hand, more than 67% of respondents are interested in MSWM in connection with environmental issues and are familiar with the 3R concept (reducing waste, reusing, and recycling resources and products). Our MSWM research provides new perspectives on the public perception and involvement in Bandung that could be considered in the planning and implementation of sustainable MSWM. The results indicate that the public's perception and approach to MSWM in Bandung city should be enhanced by better education, providing sufficient awareness, and offering workshops.  Integr Environ Assess Manag 2023;19:114-125. © 2022 SETAC.

Environmental Sustainability Impacts of Solid Waste Management Practices in the Global South

Solid waste management (SWM) is one of the key responsibilities of city administrators and one of the effective proxies for good governance. Effective SWM mitigates adverse health and environmental impacts, conserves resources, and improves the livability of cities. However, unsustainable SWM practices, exacerbated by rapid urbanization and financial and institutional limitations, negatively impact public health and environmental sustainability. This review article assesses the human and environmental health impacts of SWM practices in the Global South cities that are the future of global urbanization. The study employs desktop research methodology based on in-depth analysis of secondary data and literature, including official documents and published articles. It finds that the commonplace SWM practices include mixing household and commercial garbage with hazardous waste during storage and handling. While waste storage is largely in old or poorly managed facilities such as storage containers, the transportation system is often deficient and informal. The disposal methods are predominantly via uncontrolled dumping, open-air incinerators, and landfills. The negative impacts of such practices include air and water pollution, land degradation, emissions of methane and hazardous leachate, and climate change. These impacts impose significant environmental and public health costs on residents with marginalized social groups mostly affected. The paper concludes with recommendations for mitigating the public and environmental health risks associated with the existing SWM practices in the Global South.

Evaluation of the effect of landfill leachate on surface and groundwater quality: a case study in tropical Sri Lanka using the evidence of stable isotopes

The disposal of solid wastes is a significant problem in urban areas in many developed and developing countries. Waterways are often subjected to pollution by effluents discharged from solid waste dumpsites. The stable isotopes and water quality data provide useful information on tracing pollutant sources and their contaminant pathways. The effect of a major solid waste dumpsite on surface and groundwater quality of the surrounding area was investigated by measuring water quality parameters and stable isotopes of deuterium (²H), oxygen (¹⁸O), ¹⁵ N-ΝΟ₃ and ¹⁸O-NO₃ in tropical Sri Lanka. The surface water and groundwater wells close to the dumpsite indicated clear evidence of leachate contamination with enriched total dissolved solids (TDS), total suspended solids (TSS), ammonia, biochemical oxygen demand (BOD₅) and Cl^- levels. The correlation of groundwater quality parameters, i.e. EC (-r² = 0.8), TDS (-r² = 0.8), TSS (-r² = 0.5), ammonia (-r² = 0.4), phosphates (-0.6), sulphates (-0.5), Cl^- (-0.6) and isotope δ²H‰ (-0.9) with distance from the dumpsite, further confirmed the effects of dumpsite on groundwater quality. The composition of δ¹⁵N-ΝΟ₃ and δ¹⁸O-NO₃ isotopes in the groundwater indicated that the dominant source of NO₃^- to groundwater is manure septic originating from the dumpsite. The findings of the study provided clear evidence of the effect of open dumping on the water resources of the surrounding area and the need for remedial measures.

An overview of progress towards implementation of solid waste management policies in Dhaka, Bangladesh

OBJECTIVES

Considering the increased solid waste generation and its management, this paper aims at reviewing and identifying the gaps and challenges in implementing the existing solid waste management relevant policies, strategies and action plans in Bangladesh for providing further strategic recommendations to establish a sustainable waste management system.

METHODS

This study adopted a multi-method approach by reviewing 24 policy/strategy documents; implementation gap analysis with extensive desk review and data obtained from the qualitative approach and co-production workshop. It allowed this study to capture the multidimensional and comprehensive scenario of waste management in Dhaka city.

RESULTS

Bangladesh has undergone reforms in solid waste management since 1983 with the adoption of the Dhaka City Corporation Ordinance and the enactment of the National 3R Strategy in 2010. With few exceptions, the overall waste management system cannot be defined as an effective comprehensive waste reduction, recycling and disposal mechanism based on global standards. Study found that several action plans have been introduced yet not all of those have proper implementation like adhering the waste segregation and recycling practices from households to landfill level. Lack of monitoring and coordination among the existing policy implementing agencies have emerged as significant concerns in Bangladesh.

CONCLUSION

Challenges in the implementation of pragmatic and improved policies and strategies should be addressed.

Government intervention in municipal waste collection with a sustainable approach: a robust bi-level problem

Conservation of the environment has taken a prime position among areas of concern for managers and practitioners worldwide. This study aims to provide a bi-level mathematical model for municipal waste collection considering the sustainability approach. The mathematical model with conflicting objects was proposed at the upper level of the model of maximizing government revenue from waste recycling and at the lower level of minimizing waste collection and recycling costs, which had stochastic parameters and was scenario based. A case study was conducted in the Saveh processing site (Iran). Due to the complexity of the bi-level model, the KKT approach was adopted to unify the model. Finally, the relevant calculations were performed based on actual information. The results of the problem in the case study showed the efficiency of the proposed method. Several computational analyses randomly generated different waste recycling rates and obtained significant management results.

Selection of optimal aggregation function for the revised leachate pollution index (r-LPI)

A tool to quantify the pollution potential of leachate, termed the revised leachate pollution index (r-LPI), has been developed. It was developed using the fuzzy Delphi analytic hierarchy process (FDAHP). The formulation entails four major steps: parameter selection, weight calculation, normalization of parameters, and aggregation of the parameters. Eleven leachate parameters categorized into three criteria were selected using the fuzzy Delphi method (FDM). The relative weights of the parameters and the criteria were computed using the fuzzy analytic hierarchy process (FAHP), and rating curves were used for normalization of the parameters. The selection of an aggregation function is one of the most critical steps in the development of a composite indicator. In this study, the concept of r-LPI was briefly discussed and 14 different aggregation functions were examined to estimate the pollution potential of landfill leachate. Based on accountability and non-accountability of weights of the parameters, ambiguity, eclipsing, and constant functional behavior, 8 aggregation functions were eliminated. The remaining six aggregation functions were subjected to sensitivity analysis. Furthermore, information lost due to aggregation of parameters was quantified. Based on the findings, it was concluded that the weighted additive function effectively quantifies the pollution potential of landfill leachate and thus recommended for the r-LPI.

Potential for future reductions of global GHG and air pollutants from circular waste management systems

The rapidly rising generation of municipal solid waste jeopardizes the environment and contributes to climate heating. Based on the Shared Socioeconomic Pathways, we here develop a global systematic approach for evaluating the potentials to reduce emissions of greenhouse gases and air pollutants from the implementation of circular municipal waste management systems. We contrast two sets of global scenarios until 2050, namely baseline and mitigation scenarios, and show that mitigation strategies in the sustainability-oriented scenario yields earlier, and major, co-benefits compared to scenarios in which inequalities are reduced but that are focused solely on technical solutions. The sustainability-oriented scenario leaves 386 Tg CO2eq/yr of GHG (CH4 and CO2) to be released while air pollutants from open burning can be eliminated, indicating that this source of ambient air pollution can be entirely eradicated before 2050.

Household solid waste management practices and perceptions among residents in the East Coast of Malaysia

BACKGROUND

Poor waste disposal practices hamper the progress towards an integrated solid waste management in households. Knowledge of current practices and perception of household solid waste management is necessary for accurate decision making in the move towards a more sustainable approach. This study investigates the household waste practices and perceptions about waste management in Panji, one of the sub-districts in Kota Bharu, Kelantan, Malaysia.

METHODS

A stratified random sampling technique using a cross-sectional survey questionnaire was used to collect data. A total of 338 households were interviewed in the survey and data were analyzed using SPSS. Chi-square goodness of fit test was used to determine the relationships between categorical variables, whereas Chi-square bivariate correlation test was performed to observe the correlation between the perceptions of waste segregation with socio-demographic background of the respondents. The correlation between perception of respondents with the locality, house type and waste type were also conducted. Principal component analysis was used to identify grouping of variables and to establish which factors were interrelated in any given construct.

RESULTS

The results of the study revealed that 74.3 % of households disposed of food debris as waste and 18.3% disposed of plastic materials as waste. The study also showed that 50.3% of the households segregate their waste while 49.7% did not. About 95.9% of the respondents were aware that improper waste management leads to disease; such as diarrhea and malaria. There were associations between locality, age and house type with waste segregation practices among respondents (Chi-square test, p<0.05). Associations were also found between locality with the perception of improper waste management which lead to disease (Chi-square test, p<0.05). Principal Component Analysis showed that 17.94% of the variance has high positive loading (positive relationship) with age, marital status and, type of house.

CONCLUSION

This study highlights the importance to design waste separation programs that suit the needs of targeted population as a boost towards sustainable solid waste management practices.

Marine litter pollution on coral reefs of Darvel Bay (East Sabah, Malaysia)

Marine litter is recognized as an increasing component of marine ecosystem pollution. In this baseline study, we document the magnitude, types, sources, and potential impacts of litter on six coral reefs in East Sabah. We applied a simplified classification of litter to extract abundance data from video transects. The average density was 10.7 items per 100 m². Plastics represent 91% and the remaining 9% were metal, glass, and wood. Most (~70%) plastics are single-use items derived from dumping. Discarded fishing gear accounts for ~25%. Litter pollution increases closer to urban developments, with Sakar reef having higher densities (51 items per 100 m²), and higher Clean Coast Index (CCI = 10.2, dirty) and higher Plastic Abundance Index (PAI = 4.68) scores. This method could and should be readily integrated into ongoing monitoring programs to support assessments of the extent and magnitude of marine litter pollution on reefs worldwide.

An analysis on the effect of coronavirus (COVID-19) pandemic movement control order (MCOS) on the solid waste generation in Peninsular Malaysia

This study intends to deal with the environmental consequences of the COVID-19 pandemic in Malaysia, by providing a summary of the effects of COVID-19 on municipal solid waste (MSW). In this analysis, the data on domestic waste collection were collected from the Solid Waste Management and Public Cleaning Corporation (SWCorp) from 1 January 2020 to 31 December 2020 to evaluate the relative changes in MSW percentage via a waste weighing method. The data consisted of the cumulative tonnage of MSW for every local authority in Peninsular Malaysia and was classified according to MCO phases; before the MCO, during the MCO, during the conditional MCO (CMCO) and during the recovery MCO (RMCO) phases. The results indicated that the enforcement of the early MCO showed a positive effect by decreasing the volume of MSW. This decrease was noted across 41 local authorities, which accounts for 87.23% of Peninsular Malaysia. However, the amount of MSW began to increase again when the MCO reached the conditional and recovery stages. From this, it can be concluded that the implementation of the MCO, in its various incarnations, has shown us that our lifestyles can have a harmful impact on our environment. While the pandemic was still spreading and limitations were still in place in Malaysia, local governments and waste management companies had to quickly alter their waste management systems and procedures. The current circumstance allows us to rethink our social and economic structures while improving environmental and social inclusion.

Escalating SARS-CoV-2 circulation in environment and tracking waste management in South Asia

The novel coronavirus disease of 2019 (COVID-19) pandemic has caused an exceptional drift of production, utilization, and disposal of personal protective equipment (PPE) and different microplastic objects for safety against the virus. Hence, we reviewed related literature on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA detected from household, biomedical waste, and sewage to identify possible health risks and status of existing laws, regulations, and policies regarding waste disposal in South Asian (SA) countries. The SARS-CoV-2 RNA was detected in sewage and wastewater samples of Nepal, India, Pakistan, and Bangladesh. Besides, this review reiterates the enormous amounts of PPE and other single-use plastic wastes generated from healthcare facilities and households in the SA region with inappropriate disposal, landfilling, and/or incineration techniques wind-up polluting the environment. Consequently, the Delta variant (B.1.617.2) of SARS-CoV-2 has been detected in sewer treatment plant in India. Moreover, the overuse of non-biodegradable plastics during the pandemic is deteriorating plastic pollution condition and causes a substantial health risk to the terrestrial and aquatic ecosystems. We recommend making necessary adjustments, adopting measures and strategies, and enforcement of the existing biomedical waste management and sanitation-related policy in SA countries. We propose to adopt the knowledge gaps to improve COVID-19-associated waste management and legislation to prevent further environmental pollution. Besides, the citizens should follow proper disposal procedures of COVID-19 waste to control the environmental pollution.

Proposed Methodology for End-of-Life Option using Multi Criteria Decision Analysis: A Study for General Paper Product

Over the years, the world population has been growing exponentially. This population growth affects the number of waste products due to the increased production, which leads to greater environmental impact and other problems. There are different numbers of product end-of-life (EOL) options to handle waste based on product characteristics. This research is designed to develop a methodology to determine the best EOL option for a paper product using the analytical hierarchy process (AHP). AHP is one of the multi-criteria decision analysis (MCDA) methods employed to select the best option by considering the user’s preferences and output of competing EOL options related to different product criteria. A graphical user interface (GUI) called AHP-based software was developed using Microsoft Excel through the programming function of Visual Basic for Applications as a user facilitating tool when conducting the analysis. The case study technique is applied to five different types of paper products to assess the capability of the proposed AHP-based software. Results from the AHP-based software reveal that recycling is the most suitable EOL technique for most paper products compared to other techniques. However, polluted products with ink or food waste and coating may not be suitable for this method. The research assists the users to identify the most sustainable ways to handle paper product waste based on the product condition.

Marine debris in Malaysia: A review on the pollution intensity and mitigating measures

The launch of Roadmap towards Zero Single-use Plastics in 2018 demands baseline data on the management of marine debris in Malaysia. In 2021, Malaysia is placed 28th top plastic polluter in the world with plastic consumption at 56 kg/capita/year, therefore data on mismanaged plastic is imperative. This paper reviews the abundance and distribution of marine debris in selected Malaysian beaches over the last decade (2010-2020) and discusses issue on its management. Plastic debris on beaches in Malaysia, was reported to range from 64 items/m², to as high as 1930 items/m², contributing 30-45% of total waste collected. Plastics film was the most dominant, mainly originated from packaging materials. Therefore, appropriate action including improved marine waste management system is crucial to tackle the problem, together with effective governance mechanisms. Various suggestions were proposed based on the statistical-environmental data to reduce the occurrence of marine debris in the country.

The nexus of macroplastic and microplastic research and plastic regulation policies in the Philippines marine coastal environments

The Philippines was reported as one of the top plastic polluters (macroplastics and microplastics (MPs)) to the marine coastal environment, which necessitated the development and enforcement of plastic regulation policies. However, the nexus between the growing research on macroplastic/MP and the plastic regulation policies in the country is unexplored. Current review suggests that macroplastic/MP research in the Philippines is still in its infancy owing to methodological and technological constraints to apportion the sources and fluxes, characterize macroplastics/MPs, and identify influencing socio-environmental factors. While government efforts are underway, it is also unclear if local researches on macroplastics/MPs were the basis in institutionalizing the existing plastic regulation policies. Therefore the nexus between the researches carried out on this problem and the policies enforced cannot be concluded. Overall, this review presents gaps on the macroplastic/MP research needing more work on the problem to establish a sound science plastic regulation policy.

Municipal waste management and electrical energy generation from solid waste: a mathematical programming approach

Purpose

Waste production and related environmental problems have caused urban services management many problems in collecting, transporting and disposal of waste. The purpose of this study is to design a new model for municipal waste collection vehicle routing problems with time windows and energy generating from waste. To this purpose, a bi-objective model is presented with the objectives of increasing the income of waste recycles and energy generation from waste and reducing emissions from environmental pollutants.

Design/methodology/approach

A bi-objective model is presented with the objectives of increasing income of recycles trade and energy generation and reducing emissions from environmental pollutants. Concerning the complexity of the model and its inability to solve large-scale problems, non-dominated sorting genetic algorithms and multi-objective particle swarm optimization algorithms are applied.

Findings

In this research, an integrated approach to urban waste collection modeling that coordinates the various activities of waste management in the city of Kermanshah and energy generation from waste are provided. Besides, this study calculates the criteria that show the environmental effects of municipal waste. The proposed model helps to collect municipal wastes in the shortest possible time in addition to reducing the total cost, revenues from the sale of recycled materials and energy production.

Originality/value

The proposed model boosts the current understanding of the waste management and energy generation of waste. The paper adds additional value by unveiling some key future research directions. This guidance may demonstrate possible existing and unexplored gaps so that researchers can direct future research to develop new processes.

A novel cooperative model in the collection of infectious waste in COVID-19 pandemic

Purpose

Production of waste has been increased exponentially due to world industrialization and urban and machine life expansion. On the other hand, the outbreak of the COVID-19 coronavirus quickly became a global crisis. This crisis has added a large amount of waste to urban waste. The purpose of this study is to create cooperation between municipal waste collector contractors.

Design/methodology/approach

Thus, a mathematical model is proposed under uncertain conditions, which includes the volume of municipal waste and infectious waste including personal protective equipment and used equipment for patients. To reduce total costs, the results are evaluated with four cooperative game theory methods such as Shapley value, t value, core center and least core. Ultimately, the saved cost by cooperation in each coalition is allocated fairly among the contractors. Finally, a comparison was made between the solution methods based on the value of the objective function and the solution time.

Findings

The results indicate that the proposed cooperative method increases cost savings and reduces the fine of residual waste. Therefore, it can be mentioned that this kind of cooperation would finally result in more incentives for contractors to form larger coalitions. Genetic algorithms were used to solve the large-scale model.

Originality/value

The proposed model boosts the current understanding of waste management in the COVID-19 pandemic. The paper adds additional value by unveiling some key future research directions. This guidance may demonstrate possible existing and unexplored gaps so that researchers can direct future research to develop new processes.

What Key Drivers Are Needed to Implement Material Efficiency Strategies? An Analysis of the Electrical and Electronic Industry in Malaysia and Its Implications to Practitioners

A circular economy can be achieved by the efficient use of materials across different industries and sectors. In the manufacturing sectors, practicing material efficiency is one of the effective strategies to reduce material usage and solid waste generation. However, due to many unknown factors, such as key drivers to enhance material efficiency, most of the time, manufacturers are practicing at the minimum level of material saving. This study aims to examine the key drivers of material efficiency among electrical and electronic (E&E) companies to fulfill the aims of sustainable manufacturing. The data collection and synthesis were conducted using semi-structured interviews and an analytical hierarchy process survey. In this study, thirteen key drivers were found. Five internal drivers and eight external drivers with different priorities were found to influence E&E companies in the practice of material efficiency strategies. In addition, the drivers’ implications to different practitioner groups are suggested. To conclude, achieving material efficiency can be done effectively if the incentivized key drivers are clearly notified. This research is important to show the key drivers that influence the implementation of material efficiency strategies in the E&E industries.

Exposure risk assessment of the municipal waste collection activities during COVID-19 pandemic

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.

Impact of Movement Control Order (MCO) due to Coronavirus Disease (COVID-19) on Food Waste Generation: A Case Study in Klang Valley, Malaysia

The outbreak of a neurological disorder was first discovered as a new coronavirus (2019-nCoV) in Wuhan, China. The infection spread rapidly in China and throughout the world, including Malaysia. Malaysia recorded its initial case on 25 January 2020 with intensifying numbers since March 2020. Due to this uncertain circumstance, Malaysia has introduced the Movement Control Order (MCO) with the main aim of isolating the source of the COVID-19 outbreak, which was effective from 18 March 2020. The restriction has observed fewer vehicles on the road with industrial and commercial activities being suspended. The objective of the study is to quantify the effects of MCO to food waste generation in town and district areas of Klang Valley, Malaysia. Food waste generation data was derived from the Project Delivery Department, KDEB Waste Management on a daily basis before (19 February–17 March 2020) and during the MCO (18 March–14 April 2020) at 12 local authorities in Selangor, Malaysia. The data was obtained with the limitation of assumption that there is no waste compositional analysis to be conducted in 2020. Despite the stay-at-home order, food waste data showed a descriptive reduction of up to 15.1% during the MCO. Statistical analysis of food waste generation from one-way variance has shown that municipal and district local authorities recorded a significant reduction (p < 0.50) during the MCO. The food waste reduction during the MCO will deliver as the evidence-based results to push the need for policies in Malaysia as per the goals outlined in Sustainable Development Goals of global food loss and waste.

How COVID 19 effect Malaysian paddy industry? Adoption of green fertilizer a potential resolution

The COVID-19 pandemic resulted in more than 4.3 million confirmed cases and more than 2,90,000 deaths worldwide. It has also given rise to fears of an imminent economic crisis and recession. Social distance, self-isolation, and travel restrictions have led to a reduction in the workforce across all economical sectors and have led to a loss of many jobs. Schools have closed down, and the need for commodities and manufactured goods has decreased. On the other hand, the need for medical supplies has increased significantly. The food sector is also facing increased demand as a result of panic buying and storing food products. In response to this global outbreak, we summarize the socioeconomic effects of COVID-19 on the various aspects of the world economy. In Malaysia, the COVID-19 epidemic has checked the resilience of the agriculture sector. Especially the Malaysian paddy industry as country imports 30% of its overall consumption from different parts of the world. The real price of rice triplicating for the consumers, which was alarming for nations in this pandemic situation. The Government of Malaysia introduced the National Agrofood Policy 2011-2020 (NAP4) in 2010 as a guidance document for the implementation of agricultural sector development programs and projects in Malaysia. The NAP4 's 10-year term is to be finished by the end of 2020. Several sectors demonstrate substantial success after approximately 8 years of introduction, while the other classes often lag behind the goal and progress quite slowly. Agricultural sector performance is affected by many problems and challenges. In acknowledgment of the poor success of this field, the Ministry of Agriculture and Agri-Based Industry has launched new approaches, policies, and programs that can change the agricultural sector more rapidly. The new direction is aimed at ensuring national food security and boosting farm and revenues. The authorized government agency needs to revise the policy formulation where Malaysia needs to set stages to revolutionize and modernize the rice farming to address the problem faced by the paddy sector in this pandemic situation to adopt GF. In this study, the researcher focuses on the improvisation of the policy to increase the paddy production sustainably.

Source identification and pollution degree of deposited dust on green space in Tehran

The information about concentration, sources, and pollution degree of heavy metals belong to deposited dust (DS) can be used for decision-making in air quality control, removal role of green space, and urban forest management. The objectives of the study were to identify and evaluate DS pollution degree with the introduction of a new index. DS samples were collected from five tree species. The concentration of heavy metals and pollution degree of DS were evaluated by enrichment factors (EF), geoaccumulation index (I_geo), modified degrees of contamination (mC_d), and a new comprehensive index as weighted degree of contamination factor (wC_d). The values of EF showed that all samples were significant to extremely high enrichment and DS samples were emitted from anthropogenic activities. I_geo values indicated that DS samples were polluted by Cd (80-97%) and Pb (100%). In addition, mC_d results showed more than 67% of samples were unpolluted. There was a clear fact that I_geo results showed high pollution levels for Pb, Cd, and low for Ni, and the mCd results were incompatible with them. When all heavy metals were used without their importance to mC_d, calculation can cause bias from reality. For this reason, the new index was suggested as wC_d for all heavy metals that its results showed high to very high degree of pollution and that it was compatible with other indices results.

Assessment of changes in the municipal waste accumulation in Poland

The aim of the work was to assess the effectiveness of municipal waste management in Poland over the period 2012-2017, considering the accumulation of waste collected selectively and non-selectively per capita and the changes resulting from the implementation of Directives 1999/31/EC and 2008/98/EC in Polish legislation. Within 6 years, noticeable changes in the country initiated by the EU and national legislation indicated an increase in the amount of waste to be recovered. However, the achieved efficiency of limiting the deposited waste at the level of 20% was moderate, despite the existence of infrastructure allowing for increased recovery. The analysis of the efficiency of waste management showed a certain convergence of the increase in the amount of generated waste and gross domestic product (GDP). On the other hand, the increase in accumulated organic waste per capita in all three dimensions of time was the most significant and exceeded 20%.

Assessment of factors affecting source recycling among metropolitan Johannesburg residents

Waste recycling, in particular source separation contribute significantly to the extension of landfill life and the evolution of green communities. Factors that affect participation in source waste separation amongst Metropolitans Johannesburg residents was investigated by social survey using field questionnaire data to assess socio-demographic factors and was analysed by statistical tools and behavioural constructs i.e. attitudes, subjective norms, perceived behavioural control, intentions, and situational factors. The results revealed that for graduates, source separation was driven by social responsibilities and family size while council awareness campaign, financial incentives and provision of recycling facilities are the driving force for source separation amongst respondents with matric and lower formal education. Family size and level of education are correlated to attitude with low correlations. The weak correlation was due to the perception of quality of services provided by the council. Incentives are moderators of intention of source separation but distances to buyback centre have to be carefully selected in order not to be a deterrent. Waste management agencies should accommodate the level of formal education and different family size in the formulation of source separation program.

Robust information for effective municipal solid waste policies: Identifying behaviour of waste generation across spatial levels of organization

Existing studies have studied influencing factors of MSW generation behaviour at different spatial levels of organization, but always one at a time and not simultaneously. Income is a strong influencing factor, affecting MSW generation from the individual to the country level, capable of hiding the effects of the others. This study shows that when MSW generation behaviour is holistically analysed across multiple levels of organization (individuals, households, and communities) hierarchically organized as functional units of MSW generation within a specific study area, it is possible to identify influencing factors in addition to income (education, demographic, health, ethnic, economic activity and financial types) as explanatory variables. Increasing the number of influencing factors of MSW generation makes it possible to create a robust knowledge base for MSW management policies in fast-growing urban areas of developing countries, improving the information used to select proper policies and plans within their MSW management systems and avoiding overlapping policies causing legal gaps. Betania, an urban area of the Panama City district, has been chosen as a case study area. The results show that the household income explains 86% of its memberś MSW generation and the community indigenous population explains 21% of householdś MSW generation. It is concluded that MSW generation is not linear across levels, it has as many degrees of freedom as influencing factors shaping the levels of organization where functional units generating waste exist. Influencing factors appearing at each spatial level affects MSW generation in an interdependent manner in variable degrees of magnitude.

Future improvements on performance of an EU landfill directive driven municipal solid waste management for a city in England

Sustainable municipal solid waste (MSW) management is regarded as one of the key elements for achieving urban sustainability via mitigating global climate change, recycling resources and recovering energy. Landfill is considered as the least preferable disposal method and the EU Landfill Directive (ELD) announced in 1999 requires member countries to reduce the volume of landfilled biodegradable materials. The enforcement of ELD initiated the evolution of MSW management system UK. This study depicted and assessed the transition and performance of MSW management after the millennium in Nottingham via materials flow analysis (MFA), as well as appropriately selected indicators based on the concept of waste management hierarchy and targets set in waste management regulations. We observed improvements in waste reduction, material recycling, energy recovery, and landfill prevention. During the period 2001/02 to 2016/17, annual waste generation reduced from 463 kg/Ca to 361 kg/Ca, the recycling and composting share increased from 4.6% to 44.4%, and the landfill share reduced from 54.7% to 7.3%. These signs of progress are believed to be driven by the ELD and the associated policies and waste management targets established at the national and local levels. An alternative scenario with food waste and textile separation at source and utilizing anaerobic digestion to treat separately collected organic waste is proposed at the end of this paper to fulfil the high targets set by local government and we further suggest that the recycling share may be improved by educating and supporting the public on waste separation at the sources.

Integrated leachate management approach incorporating nutrient recovery and removal

This manuscript presents an integrated management scheme for leachate which employed struvite precipitation to recover ammonia nitrogen and phosphorus, aerobic granular sludge process for carbon oxidation (in the form of BOD and sCOD) and single stage anaerobic ammonia oxidation (ANAMMOX) for nitrogen management. The influent fed to the integrated treatment scheme was a mixture of anaerobic digester centrate and real leachate in 4:1 ratio. Almost 77% recovery of phosphorus and 25% removal of NH₄⁺-N were accomplished through struvite precipitation at an optimum pH of 9. High pH contributed to free ammonia loss during struvite precipitation experiments. In the aerobic granular sludge reactor overall, BOD₅, COD and NH₄⁺-N removal percentages were 74%, 45% and 35% and in the PN/A reactor, overall 35% removal of total inorganic nitrogen (TIN) was observed. More than 80% BOD removal was recorded in the granular reactor with soluble COD (sCOD) removal fluctuating between 28 and 57% depending on the operational phase. High-throughput amplicon sequencing of 16S rRNA gene targeting V4 region revealed a dominance of phylum Planctomycetes, in the PN/A reactor system. Presence of Rhodobacteraceae, Xanthomonadaceae, Flavobacteriaceae in the granular biomass confirmed the defined redox zones inside mature granules indicating simultaneous removal of nitrogen (N) and organics in aerobic granular sludge technology. Exposing the synthetically cultured aerobic granules directly to the mixture of leachate and centrate unveiled an alteration in physical characteristics of granules; however, reactor operational data and microbial community analysis ascertain the effectiveness of the treatment scheme treating two urban waste-streams.

Techno-Economic Evaluation of Food Waste Fermentation for Value-Added Products

Food waste (FW) is one of the most critical problems in the world. Most FW will be sent to landfills, generally accompanying some significant disadvantages to the surrounding environment. Fermentation is considered as another disposal method to deal with FW. In this study, using a techno-economic analysis (TEA) method, an evaluation of the economic impact of three different scenarios of FW fermentation is carried out. A SuperPro Designer V9.0 simulation was used to model a commercial scale processing plant for each scenario, namely, a FW fermentation process producing hydrolysis enzymes and featuring a 2-step distillation system, a FW fermentation process without enzymes, using a 2-step distillation system, and a FW fermentation process without enzymes, using a 1-step distillation system. Discounted cash flow analysis is used to estimate the minimum ethanol selling price (MESP), where the lowest MESP result of $2.41/gal ($0.64/L) of ethanol is found for the second aforementioned scenario, showing that, even without enzymes in FW fermentation, the product cost can be competitive when compared to the other scenarios considered in this study. This project thus reflects a significant positive economic impact while minimizing the environmental footprint of a commercial production facility.

Leptospirosis: Increasing importance in developing countries

Leptospirosis is a zoonotic disease caused by the pathogenic helical spirochetes, Leptospira. Symptoms include sudden-onset fever, severe headaches, muscle pain, nausea and chills. Leptospirosis is endemic in developing countries such as Malaysia, India, Sri Lanka, and Brazil where thousands of cases are reported annually. The disease risk factors include the high population of reservoirs, environmental factors, recreational factors, and occupational factors. To end the endemicity of leptospirosis, these factors need to be tackled. The management of leptospirosis needs to be refined. Early diagnosis remains a challenge due to a lack of clinical suspicion among physicians, its non-specific symptoms and a limited availability of rapid point-of-care diagnostic tests. The purpose of this review is to provide insight into the status of leptospirosis in developing countries focusing on the risk factors and to propose methods for the improved management of the disease.

Respiratory Symptoms Among Domestic Waste Collectors

Objective

Increasing amount of waste concurrently increases the risk of exposure to hazardous materials among waste collectors. Vigorous exertion in the field intensifies the abundance of contaminated inspirable droplets. If left undetected and untreated, it may provoke significant pernicious health effects and redundant burdens to employees and employers. The purpose of this study is to determine the prevalence of respiratory symptoms and their associated factors among domestic waste collectors.

Method

A cross-sectional study was conducted in Kota Kinabalu, Sabah between January and April 2020. Data were collected using a validated questionnaire which encompasses details about sociodemographic, health status, environment, and employment characteristics.

Results

A total of 290 waste collectors with a mean age of 40 (±9) years old were participated in the study. Most of them were from Kadazan-Dusun-Murut ethnic origin with educational background till secondary school. The average monthly income of the workers was USD 298.45 (±171.9) per month, and they had been in service for 11 (±9.04) years. Respiratory symptoms were seen in 21% of the workers. The identified significant risk factors were determined as underlying chronic diseases (OR=2.34; 95% CI=1.054, 5.219) and contact with pets (OR=1.87; 95% CI=1.004, 3.288).

Conclusion

Respiratory symptoms are prevalent amidst domestic waste collectors and related to their health and field activities.

Sustainable Waste-to-Energy Development in Malaysia: Appraisal of Environmental, Financial, and Public Issues Related with Energy Recovery from Municipal Solid Waste

As Malaysia is a fast-developing country, its prospects of sustainable energy generation are at the center of debate. Malaysian municipal solid waste (MSW) is projected to have a 3.3% increase in annual generation rate at the same time an increase of 3.3% for electricity demand. In Malaysia, most of the landfills are open dumpsite and 89% of the collected MSW end up in landfills. Furthermore, huge attention is being focused on converting MSW into energy due to the enormous amount of daily MSW being generated. Sanitary landfill to capture methane from waste landfill gas (LFG) and incineration in a combined heat and power plant (CHP) are common MSW-to-energy technologies in Malaysia. MSW in Malaysia contains 45% organic fraction thus landfill contributes as a potential LFG source. Waste-to-energy (WTE) technologies in treating MSW potentially provide an attractive economic investment since its feedstock (MSW) is collected almost for free. At present, there are considerable issues in WTE technologies although the technology employing MSW as feedstock are well established, for instance the fluctuation of MSW composition and the complexity in treatment facilities with its pollutant emissions. Thus, this study discusses various WTE technologies in Malaysia by considering the energy potentials from all existing incineration plants and landfill sites as an effective MSW management in Malaysia. Furthermore, to promote local innovation and technology development and to ensure successful long-term sustainable economic viability, social inclusiveness, and environmental sustainability in Malaysia, the four faculties of sustainable development namely technical, economic, environmental, and social issues affiliated with MSW-to-Energy technologies were compared and evaluated.

Factorial Design and Optimization of Landfill Leachate Treatment Using Tannin-Based Natural Coagulant

In this study, tannin-based natural coagulant was used to treat stabilized landfill leachate. Tannin modified with amino group was utilized for the treatment process. Central composite design (CCD) was used to investigate and optimize the effect of tannin dosage and pH on four responses. The treatment efficiency was evaluated based on the removal of four selected (responses) parameters; namely, chemical oxygen demand (COD), color, NH3-N and total suspended solids (TSS). The optimum removal efficiency for COD, TSS, NH3-N and color was obtained using a tannin dosage of 0.73 g at a pH of 6. Moreover, the removal efficiency for selected heavy metals from leachate; namely, iron (Fe2+), zinc (Zn2+), copper (Cu2+), chromium (Cr2+), cadmium (Cd2+), lead (Pb2+), arsenic (As3+), and cobalt (Co2+) was also investigated. The results for removal efficiency for COD, TSS, NH3-N, and color were 53.50%, 60.26%, and 91.39%, respectively. The removal of selected heavy metals from leachate for Fe2+, Zn2+, Cu2+, Cr2+, Cd2+, Pb2+, As3+ and cobalt Co2+ were 89.76%, 94.61%, 94.15%, 89.94%, 17.26%, 93.78%, 86.43% and 84.19%, respectively. The results demonstrate that tannin-based natural coagulant could effectively remove organic compounds and heavy metals from stabilized landfill leachate.