Search

This paper describes a batch study on four different mixture ratios of household organic waste and cow manure. The biomethane potential test is used to evaluate the suitability of high solid anaerobic co-digestion of household organic waste and cow manure and its biodegradability. The maximum methane yield was observed for both co-digestions in R3 (247 mL/g VS) and R4 (244 mL/g VS). The percentages of mass recovery were 65-80% (based on VS removal). The biodegradability of each reactor was recorded as 97.7%, 10.7%,71.6% and 76.8% for R1, R2, R3, and R4, respectively. High solid co-digestion of household organic waste and cow manure in different mixture ratios increase the specific methane yields compared to mono-digestion. Hence, this clearly demonstrates a synergistic effect on the stability of anaerobic digestion. Upon correcting the results of the theoretical method with experimental data, an agreement ranged 70-90% was achieved. [ABSTRACT FROM AUTHOR]

The accumulation of organic fraction in municipal solid waste (OFMSW) is now becoming scarce globally due to population and economic boosts, especially in Malaysia. Municipal solid waste (MSW) landfills remain the predominant end-state for waste disposal in most developing countries. Unsustainable MSW management accelerates environmental degradation through landfill gaseous (LFG) emissions of mainly methane (CH4) and carbon dioxide (CO2), which promote global warming that finally is affecting human health. Recently, harnessing CH4 from anaerobic digestion of solid waste has attracted more interest and promised betterment in MSW management. With its current amount of more than 50%, organic material in landfills is estimated to emit 310,225 CH4/year with carbon credit of US$ 85.93, which can potentially generate 2.20x109 kWh of electricity valued at US$ 220 million. This present work is a review manuscript that discusses the state-of-the-art anaerobic digestion of OFMSW as treatment in term of waste diversion from a landfill. The study also estimates the renewable energy potentials from OFMSW waste diversion. Finally, this paper discusses the benefits of harnessing biogas from the perspectives of environmental benefits, energy recovery, and economics. [ABSTRACT FROM AUTHOR]

Life in an estuary and at the beach are unique settlement patterns in the history of Malaysia. Sabah is well known for its water village settlements that are built on wooden pillars and which can be found along Sabah coastal water. However, a lot of problems have occurred at the Sabah water villages. Thus, the aim of this study is to measure the solid waste generation and composition in 150 households at select water villages in Sabah, Malaysia. The study was conducted at three major towns in Sabah, namely Kampung Tanjung Batu Laut, Tawau water village, Kampung Tanjung Aru, Kota Kinabalu water village and Kampung Sim-sim, Sandakan water village. Based on the results, the total waste generation is 1519.30 kg and the average solid waste generation rate per household is 0.29 kg/person/day. The main component of solid waste is food waste, which comprises 37% of the total waste generated, followed by plastic waste at 31%, paper waste 14.7%, glass 7.2%, and metal 6.3%. The remainder (3.8%) includes bulky waste, furniture, wood, etc. Although the solid waste generation rate is comparatively low, it will create a negative impact on the environment and public health if proper management of solid waste is not practiced. [ABSTRACT FROM AUTHOR]

Solid waste management (SWM) is a global issue and has proven to be a key challenge facing many developing countries. SWM constitutes a crucial health and environmental problem. Most cities spend 20-50% of their annual budget on solid waste management, but only 20-80% of the waste is collected. Due to the diversity of different system components that need to be addressed and the inability of a single tool to assess all components, it has necessitated the need for an integrative approach to SWM issues. Recently more integrative techniques and methods are being utilized to address the different issues that arise in solid waste management as a whole. One technique or method is inefficient and cannot encompass all components of a solid waste management system. This paper looks into the different system analysis techniques that have been applied in SWM and shows system engineering tools have a wide and diverse application, require less data, and are quite cost effective when compared to the system assessment tool, which requires a wide and diverse range of data to be applicable and reliable. The system engineering tools when applied do not reflect the actual scenario for assessment and are quite difficult to implement practically. The system engineering tools are very reliable with regard to choosing options and stimulation of a scenario. System assessment tool seem more realistic, practically applicable for the decision makers and analysis/assessment using system assessment tools can easily be understood and simplified. An integration of engineering and system assessment tools seems more appropriate for obtaining a holistic assessment. [ABSTRACT FROM AUTHOR]

Waste is an obvious by-product that comes from human activities. Urbanization, economic development, and improving living standards in cities all have an impact on the increase of the quantity and difficul- ty of generated waste. Fast population growth and industrialization degrades the urban environment and places serious stress on natural resources. Inefficient management and disposal of solid waste is a noticeable cause of degradation of the environment in most cities of the developing world. MSW generation depends on township size and level of economic standards. Thus, it was proven by the MSW generated in the selected area of Kluang (a small town in the southern part of Peninsular Malaysia) amounted to as little as 45 tons and as much as 3,000 tons in Kuala Lumpur (Malaysia's capital). More analysis reported that the largest sources of MSW generation come from household waste, followed by industrial and commercial wastes. In Selangor State, the highest percentage of MSW consisted of putrescible waste of approximately 46%, followed by plastic and paper at 15% and 14%, respectively. This paper focuses on the trend and management of household solid waste composition generated in Balakong City, Malaysia. A survey for household residents in eight housing areas was carried out for one month and data were collected on a daily basis. The composition of solid waste collected was segregated into different components (organic waste, plastic, paper, glass, metal, and other). For overall household solid waste composition generated in the Balakong area, organic waste recorded the highest percentage at 555.5%. Then, followed by plastic waste 82.2%, paper 74.4%, other waste 42.9%, glass 25.8%, the lowest waste generated was metal at 18.9%. There is a relation between the economic position of a country and per capita waste generation rate. While the standard of living rises, waste generation rates also are increasing. The world trend of solid waste generation nowadays (including Malaysia) is mostly dependent on the changing consumption pattern, and also related to climate and seasonal differences. Thus, the management and planning of solid waste generated must be enhanced to improve sustainable solid waste management in Malaysia. Besides, public awareness, funding, expertise, equipment, and facilities that are currently lacking must be provided. [ABSTRACT FROM AUTHOR]

Abstract: Rapid economic development and population growth, inadequate infrastructure and expertise, and land scarcity make the management of municipal solid waste become one of Malaysia’s most critical environmental issues. The study is aimed at evaluating the generation, characteristics, and management of solid waste in Malaysia based on published information. In general, the per capita generation rate is about 0.5–0.8kg/person/day in which domestic waste is the primary source. Currently, solid waste is managed by the Ministry of Housing and Local Government, with the participation of the private sector. A new institutional and legislation framework has been structured with the objectives to establish a holistic, integrated, and cost-effective solid waste management system, with an emphasis on environmental protection and public health. Therefore, the hierarchy of solid waste management has given the highest priority to source reduction through 3R, intermediate treatment and final disposal. [Copyright &y& Elsevier]

The Asian elephant was recognised as being 'endangered' in the IUCN Red List of Threatened Species 2017. Given that Malaysia is one of the 194 parties to the Convention on Biological Diversity (CBD), Malaysia should address the CBD obligations that influence the current wildlife conservation trend across the globe. In Peninsular Malaysia, the Wildlife Conservation Act 2010 (WCA) was implemented to tackle primary issues related to Asian elephants; hence, it is imperative to analyse the CBD obligations related to Asian elephant conservation and the extent that the WCA addresses the CBD obligations. The CBD convention text and decisions between 2004 and 2014 were analysed to gather the obligations and sub-obligations related to Asian elephant conservation. Next, the obligations and sub-obligations were categorised into themes and subthemes inductively and presented as a CBD checklist. Then, the WCA was read and examined against the checklist to determine to what extent the WCA addresses the obligations and sub-obligations. The study indicates that the WCA mainly addresses the protection and conservation of elephant habitats and the genetic resources, including sustainable use through a system of licences, permits, and special permits. However, disputes between the Federal and State governments, abuse of permits, the possible de-gazettement of protected areas, and the penalisation involving immature elephants bred in captivity should be considered and revised. The WCA also addressed the access to elephants' genetic resources and the sharing of the benefits brought about by the utilisation of elephants' genetic resources through a similar system of licences, permits, and special permits. Nevertheless, the WCA has excluded provisions to address issues relating to access to technology and the transfer of technology related to conservation and the sustainable use of elephants' genetic resources. [ABSTRACT FROM AUTHOR]

In this study we identified the main threats to the conservation of Asian elephants and discuss their causes and implications. Primary data from interviews and secondary data from published articles were gathered and analysed using inductive and deductive thematic content analysis assisted by NVivo 10. Our results indicate that the three main threats for the species are human-elephant conflict, habitat loss, and poaching. The conversion of forests into plantations and human-dominated areas, including infrastructure developments, are the primary causes for human-elephant conflict and habitat loss. Meanwhile, the high demand and monetary return from ivoiy trade are the primary causes to illegal poaching. [ABSTRACT FROM AUTHOR]

Malaysia is faced with daunting challenges related to solid waste management. Due to an increase in population, economic growth, inadequate enforcement of waste legislation, infrastructure, and public attitude among others, solid waste management is considered a crucial issue in Malaysia, particularly in urban settings. This paper gives an overview of solid waste management in Malaysian with the aim of presenting the state of waste generation, composition, management practices, and problems with regards to environmental, economic, and other ramifications from previous records. In general, the total waste generated in Malaysia is estimated to be 7 million tons in 2000, with an annual increase of 3%. This is due to many factors such as urban migration, affluence, and rapid development. This circumstance requires greater focus to be in placed on managing solid waste and mitigating the negative public and environmental effects. Presently, management of solid waste is carried out by the Ministry of Housing and local government, with the support of the private sector. This new holistic approach initiated addressing the solid waste issue, taking into account public health and environmental concerns with an emphasis on reduction, reuse, and recycling before reaching final stage -- disposal at landfill, and this to certain extent has a greater potential in addressing SWM problems in Malaysia. [ABSTRACT FROM AUTHOR]

This study developed hybrid briquettes using corncobs and the bark of oil palm trunk (OPTB). The objective was to assess the performance of the briquettes in a cooking application as a potential fuel source for domestic utilization. Corncob was mixed with OPTB in ratios of 100:0, 75:25, 50:50, 25:75 and 0:100 by weight, and wastepaper pulp (10% by weight) was added to each mixture as the binder. The mixtures were densified manually at room temperature using a 20-tonne hydraulic piston press under a ≤7 MPa compaction pressure. The calorific value of the briquettes was determined by a bomb calorimeter, while other fuel properties were determined by proximate and ultimate analysis. The briquettes' performance was evaluated by a water boiling test, and gaseous emission was determined and reported based carbon-dioxide equivalent (CO 2 e). Results showed that the volatile matter, ash content, and calorific value increased with the increase in OPTB in the ratios while fixed carbon decreased. Additionally, briquettes produced from ratios 50:50 and 25:75 were similar in values based on the total time taken to ignite briquettes and boil 1 L of water (17.54 min and 17.13 min), fuel burning rate (0.69 kg/h and 0.70 kg/h) and specific fuel consumption (0.16 kg/l and 0.15 kg/l). However, ratio 50:50 performed better in terms of thermal fuel efficiency (17.25%) and produced less ash during combustion and thus, is considered the optimum combination. Greenhouse gas emission of all briquettes ranged from 241 to 281 gCO 2 e. The results suggest the possibility of producing briquettes with adequate fuel properties for combustion from a blend of corncobs and OPTB. The calorific value and performance of the hybrid briquettes have confirmed and justified the use of OPTB, which have previously not been used for briquette production, thus making a novel contribution to biomass options. The study shows a means of reducing waste, energy shortages, and indoor air pollution in rural communities in Nigeria. Overall, the hybrid briquettes are sustainable, environmentally friendly and cost-efficient compared to fossil fuels. • Oil palm trunk bark blended with corncobs can make quality hybrid briquette. • Calorific value is an important parameter for characterizing briquettes as fuel. • Greenhouse gas emission based on carbon dioxide equivalent was determined. • Hybrid briquettes are environmentally friendly, cost effective and affordable. • Rural communities in Nigeria will benefit from the application of these briquettes. [ABSTRACT FROM AUTHOR]

Background: Environmental policies should be developed in a contextual decision-making process regarding local environmental concerns emphasizing the economic, technical, social and institutional considerations. Establishing emission limit levels, especially in the industrial sector, is one of the most problematic environmental issues in developing countries, for which it is essential to include several criteria that reflect their country-specific constraints and capacities. Since Best Available Technology (BAT) is acknowledged to be the reference element for sustainable development and a basis for Emissions Limit Values (ELVs), the objective of this study is to present a reliable methodology for establishing ELVs thresholds with an emphasis on the BAT concept for national regulation at the sector level. Methods: A hybrid fuzzy multiple-criteria decision-making (FMCDM) process, consisting of the Analytic Hierarchy Process (AHP) and fuzzy Technique for Order of Preference by Similarity to Ideal Solution (fuzzy TOPSIS) method, is structured to aggregate the different criteria and rank different ELV alternatives in this complicated evaluation. In order to use the most profound knowledge and judgment of a professional expert team, this qualitative assessment highlights the importance of supportive information. Results: The results obtained indicate that experts have considered the country-specific information as a reliable reference in their decisions. Among different key evaluation criteria in effluent standard setting, the highest experts' priority is "Environmental protection". For both the conventional and toxic pollutants, the influence of all other criteria namely "Economic feasibility", "Technology viability" and "Institutional capacity", as constraining criteria in developing countries, have not reduced the responsibility towards the environmental objectives. In ELVs ranking, experts have made their decisions with respect to the specific characteristics of each pollutant and the existing capacities and constraints of the country, without emphasizing on any specific reference. Conclusions: This systematic and transparent approach has resulted in defensible country-specific ELVs for the Iron and Steel industry, which can be developed for other sectors. As the main conclusion, this paper demonstrates that FMCDM is a robust tool for this comprehensive assessment especially regarding the data availability limitations in developing countries. [ABSTRACT FROM AUTHOR]

Selecting the optimal wastewater treatment technology (WTT) is one of the biggest challenges in the sustainable management of industrial wastewaters. In Iran’s economy, the strategic role of the steel sector highlights its importance in sustainability assessments. Using Iran’s steel industry as a case study, this paper develops an integrated methodology for determining the most appropriate WTT. Since, the most common approach for technology evaluation, in both developed and developing countries, is expert judgment, this issue is studied by means of a multi-dimensional approach that considers the sector characteristics; the interaction of the technical, environmental and economic aspects; and the specific preferences in developing countries. The proposed modelling framework presents a rational decision-making process based on two multi-criteria decision-making (MCDM) techniques including the Analytic Hierarchy Process (AHP) and the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) in combination with fuzzy logic to make use of the combined benefits of several methods The methodology is carried out as a stepwise procedure and the fuzzy concept is introduced in both the weighting and ranking procedures. The most commonly used industrial WTTs in the steel industry are identified and ranked with respect to the six evaluation criteria and their thirty associated indicators. Finally, the results from different models, with crisp and fuzzy values, are compared to propose a straightforward and pragmatic operational decision tool. The study indicates that a hybrid model of AHP, TOPSIS and fuzzy logic offers better results and provides a higher degree of confidence for sophisticated judgments. According to the findings, the experts largely prefer the more advanced treatment systems, such as “Electrolytic splitting with Reverse osmosis and Evaporation in addition to the conventional technologies” because of their high system efficiency and compatibility with environmental impact criteria. This approach can be applied for other sectors at any industry level of decision-making—from the level of individual plants to national. [ABSTRACT FROM AUTHOR]

Metals accumulating in mud crab from Indonesia's East Java estuaries have been assessed for potential health effects. Mud crabs from the Solo River estuary (JS) had the highest levels of all metals tested when compared to mud crabs from the Brantas River estuary (MS) and the Banyuwangi coastal area (BS). Metal accumulation in mud crabs occurred in the following order: Zn > Cu > Cr > Pb > Cd > Hg. The estimated weekly intake values for all metals from all stations were less than the provisional tolerable weekly intake requirement. Similarly, all metal target hazard quotient values from all stations were less than one, suggesting that all metals were within the allowable intake limit. The target cancer risk values for Cd and Cr, on the other hand, were somewhat higher than 10-4, indicating that they were dangerous for human ingestion and possibly linked to a risk associated with carcinogenic agent exposure over a lifetime. • In mud crabs, metal accumulation happened in the following order: Zn > Cu > Cr > Pb > Cd > Hg. • The highest levels of all metals were found in mud crabs from the Solo River estuary (JS). • Cd and Cr had the cancer risk values based on daily ingestion. [ABSTRACT FROM AUTHOR]

Summary: In recent years soft computing methods are being increasingly used to model complex hydrologic processes. These methods can simulate the real life processes without prior knowledge of the exact relationship between their components. The principal aim of this paper is perform hydrological regionalization based on soft computing concepts in the southern strip of the Caspian Sea basin, north of Iran. The basin with an area of 42,400sq. km has been affected by severe floods in recent years that caused damages to human life and properties. Although some 61 hydrometric stations and 31 weather stations with 44years of observed data (1961–2005) are operated in the study area, previous flood studies in this region have been hampered by insufficient and/or reliable observed rainfall-runoff records. In order to investigate the homogeneity (h) of catchments and overcome incompatibility that may occur on boundaries of cluster groups, a fuzzy expert system (FES) approach is used which incorporates physical and climatic characteristics, as well as flood seasonality and geographic location. Genetic algorithm (GA) was employed to adjust parameters of FES and optimize the system. In order to achieve the objective, a MATLAB programming code was developed which considers the heterogeneity criteria of less than 1 (H<1) as the satisfying criteria. The adopted approach was found superior to the conventional hydrologic regionalization methods in the region because it employs greater number of homogeneity parameters and produces lower values of heterogeneity criteria. [Copyright &y& Elsevier]

Since at least half of the world's population resides and works within coastal land, the coastal zone processes and resource management is of great economic and social importance. One of the fundamental issues for coastal city planners, researchers, managers, and engineers is the coastal city land-use suitability. Land-use suitability is the ability of a given type of land to support a defined use. Rapid urbanization and consequent haphazard growth of cities result in deterioration of infrastructure facilities, loss of agricultural land, water bodies, open spaces, and many micro-climatic changes. Hence, accurate data on coastal city hazards are essential and valuable tools for coastal planning and management, sustainable coastal development, coastal environment conservation, selection of a site for coastal city structures, and coastal resources. In this investigation, the Delphi and Analytical Hierarchy Process (D-AHP) Hybrid model and Geographic Information System (GIS) technique for Coastal Land-Use Assessment (CLUA) are mapped to detect the most suitable and unsuitable areas in the Kuala Terengganu coastal zone. Furthermore, this research offered information not only on the present urban land-use trend and established amenity status in Kuala Terengganu, but also on the suitability of land for the potential establishment of urban facilities for improved urban planning and appropriate decision-making. Using the D-AHP Hybrid model and GIS tool for coastal city management is broadly practical for government, policymakers, and planners to appropriately strategize and plan for the future of coastal cities in Malaysia and other analog coastal cities around the world. [ABSTRACT FROM AUTHOR]