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Rice is a special crop that requires a thin layer of water to produce, and is produced differently from other crops. The rice sectors in Malaysia continue to be developed in a proactive and progressive manner. Due to its growth process, rice has a different water footprint (WF) compared to other crops. This study improved the calculation of the blue and green WF of rice production and examined the variations of these footprints under the primary granary area of Malaysia. The effects of climate change will, however, make it more difficult to achieve food security and increase rice yields in the future. Therefore, this paper aims to discuss climate change impacts on rice production and food security in Malaysia. Many countries worldwide are becoming increasingly vulnerable to natural disasters due to climate change. Many climate models predict a decline in agricultural productivity due to excessive heat in tropical and subtropical regions, especially in Southeast Asia. Malaysia is no exception. Therefore, the present study examined the impact of climate change on rice yields in Muda Granary, Malaysia. Utilizing literature reviews, we assessed the value of evapotranspiration (ET) in order to calculate the green WF for the area. Climate variables (such as ET), yield, and variance of impact during the main season and off-season were the primary objectives of the study. Precipitation did not show a statistically significant difference between the main and off-seasons from 2011-2015. During the main crop season, the maximum ET was negatively associated with yield, but the minimum ET showed a positive association. In the off-season, green WF levels were higher than those in the main season. These findings indicate that climate change poses a serious threat to rice production, which will in turn affect food security as they are highly interconnected. Thus, it is high time for Malaysia to revamp its paddy and rice intervention strategies by giving due attention to enhancing the adaptive capacity of rice farmers to cope with climate change.

Oil palm cultivation in Malaysia is known to be labour-intensive. Human rights issues primarily related to workers have always been contentious. This study performed social life cycle impact assessment using one of the type 1 impact assessment methods called Subcategory Assessment Method (SAM). It aimed to evaluate the social performance of some palm oil companies and identify the social hotspots of workers in crude palm oil production starting from nursery, plantation to palm oil mill, and test the applicability of SAM. The basic requirements of SAM were guided to classify the performance reference points, which were used as the threshold where the social inventory indicators were developed to collect the data. A qualitative research approach was used to acquire a better understanding of the issue highlights. Five companies located in Peninsular Malaysia were chosen in this study. The required data were collected via face-to-face interview with the workers and company representatives. The data analysis via SAM was found able to assess the social performance, and identify the social hotspots. The results obtained indicated that all companies involved were similar as the same laws and regulations were adhered to. The subcategory of working hours was found as the social hotspot requiring further improvement. The findings of this study become useful to serve as a guideline in mapping the social hotspots for workers in the palm oil supply chain, and in formulating effective strategies to overcome the resulted social impacts. However, further studies are required to fill the gaps that have not been solved in this study. These include more participation from other companies and inclusion of other stakeholders to explore and assess the industry's social performance more holistically.

The use of composting technologies to treat food waste (FW) now represents an environmentally friendly form of waste treatment, in which organic matter can decompose biologically. However, the damaging emissions of composting technologies for FW treatment vary, thus a life cycle assessment (LCA) approach is often used to certify the quality of the decision-making process. This study quantifies and compares the environmental impact of two scenarios in Malaysia: windrow and hybrid composting (windrow integrated with a landfill) technologies. The scenario modeling was performed via GaBi v6.0 software using 1 ton of pre-treated FW as a functional unit, with the analysis based on the ReCiPe (H) v1.07 characterization method. The midpoint results revealed that windrow composting technology has a lower environmental impact and is an environmentally friendly option compared to hybrid technology. Treating FW in a windrow scenario has relatively low power requirements for operation with the added advantageous properties of compost production, and a substantial reduction in the distances transferred by the road. The hybrid scenario had the largest negative environmental impact in all categories, such as climate change (1.45E+03 kg CO2 eq), and ozone depletion (4.39E-09kg CFC-11 eq) because of the energy-intensive waste collection and treatment activities it needs, and with no landfill gas filtration. Finally, based on the single score synthesis, windrow is considered as an appropriate treatment with the avoidance of Resource Depletion (6.61E+02 Pt).

This paper appraised divergent chemical depolymerization routes for reprocessing chemically synthesis polyethylene terephthalate (PET) plastics bottle waste and offer resolutions to control the environmental complications emanating attributable to its utilize and disposal to the habitat. The consciousness to prune environs contaminants and make it “green” demand for the reclaim and reprocessing it back to PET bottles, precursor products like glycolyzate, and other inventions such as unsaturated polyester resins, epoxy resins, composites etc. Controlling this necessitates assorted reprocessing methods of which chemical recycling that transform PET into monomer/oligomer is the most prosperous one. This review explored in detail current events in the PET chemical recycling using glycolysis method. The study was based on their current evolution concerning their depolymerization agents, reaction conditions, kinetics of reactions, catalysts used, products of reprocessing, and their prospective use. Benefits of PET recycling and glycolysis as well as criteria and necessitation factors that used to adjudge them as the best method and sub-method respectively were highlighted. The prospect for the conversion of glycolyzate into other PET recycling methods products were shown. PET recycling was concluded to be a partial resolution to wastes management, and also grants the conservation of natural petrochemical resources and energy.

River systems in developing and emerging countries are often fragmented relative to land and waste management in their catchment. The impact of inconsistent waste management and releases is a major challenge in water quality management. To examine how anthropogenic activities and estuarine effects impact water quality, we characterised water conditions, in-situ microbiomes, profiles of faecal pollution indicator, pathogenic and antibiotic resistant bacteria in the River Melayu, Southern Malaysia. Overall, upstream sampling locations were distinguished from those closer to the coastline by physicochemical parameters and bacterial communities. The abundances of bacterial DNA, total E. coli marker genes, culturable bacteria as well as antibiotic resistance ESBL-producing bacteria were elevated at upstream sampling locations especially near discharge of a wastewater oxidation pond. Furthermore, 85.7% of E. faecalis was multidrug-resistant (MDR), whereas 100% of E. cloacae, E. coli, K. pneumoniae were MDR. Overall, this work demonstrates how pollution in river estuaries does not monotonically change from inland towards the coast but varies according to local waste releases and tidal mixing. We also show that surrogate markers, such dissolved oxygen, Bacteroides and Prevotella abundances, and the rodA qPCR assay for total E. coli, can identify locations on a river that deserve immediate attention to mitigate AMR spread through improved waste management.

Haze pollution is one of the major environmental issues caused by aerosols, having brought about a history of heavy smog pollution events like the London smog in 1952 and the Los Angeles smog in the 1960s. However, in Malaysia, haze events are attributed to forest and peat fires in Kalimantan and Southern Sumatra, Indonesia. The burned biomass basically contains concentrated particulate matters that are hazardous to health among susceptible population groups. Based on the extensive literature review conducted, the small number of available local studies on the health effects of air pollution in Malaysia conducted so far focused on air pollution sciences. In this paper, a comprehensive overview of studies done on the impacts of haze on health conditions among populations in Malaysia is presented. The result shows that the number of upper respiratory tract infection cases was directly proportional to the particulate matter concentration and Air Pollution Index value in Johor in the years 2014 and 2015. Particulate matteris the major contributor in the formation of heavy hazes and is more likely to initiate detrimental health effects compared to other inhalable particles due to their size, large area, and strong activity, making them more likely to carry harmful substances causing a higher number of infected patients with upper respiratory tract infections.

Life cycle assessment (LCA) is an analytical tool used to quantify the overall environmental impacts associated with products, processes or human activities from cradle to grave. The LCA is important to determine the impact of wastewater treatment and the technologies used on human health and the environment. It performs well to find the best solutions to improve the sustainability. Therefore, it is important to review how previous studies on wastewater treatment have applied LCA. This paper presents a wide-ranging review of papers published from 1990 to 2016 that have used a range of LCA to cover the objectives, boundaries, functional units (FUs) and life cycle impact assessment(LCIA) of wastewater treatment. The analysis of the reviewed papers revealed that there are some differences in term of the FUs, system boundaries, and LCIA methods. These differences normally contribute to obtaining a few non-prosaic results. Moreover, the FUs adopted in some reviewed studies were not able to achieve the purpose of providing a reference to ensure compatibility of the results. Therefore, it is highly recommended that more attention is paid to choosing the FU in future studies. Thus, to ensure the quality and comparability of LCAs, it is very important to develop the LCA guidelines and standards and the LCIA impact categories.

The world is experiencing high rates of urbanisation and it has slowly become an alarming social process, especially in developing countries. This has demanded an urgent investigation on human thermal comfort, especially in tropical climates. In this study, a surrogate human sensor (SHS) was developed to establish a linkage between human skin surface and SHS with the surrounding environments. Black plastic corrugated cardboard was used in the SHS fabrication as its thermal conductivity was close to the thermal conductivity and emissivity of the human epidermal skin layer. The SHS was designed to correlate with human skin surface temperature and a regression model was developed. The regression equation was obtained for the human skin temperature prediction (Th) by using SHS. Statistical analysis of the ANOVA (F = 13,700; ρ

The increased use of freshwater for domestic, industrial and agricultural activities has rapidly led to the scarcity of global water supplies with agricultural industry being the main consumer of fresh water, accounting to approximately 85% of the global freshwater consumption. Palm oil is the biggest and fastest growing vegetable oil on the world market and oil palm plantations are covering large land areas especially in Indonesia and Malaysia. Several environmental problems related to oil palm plantation have been reported, such as biodiversity loss, land use change, huge water consumption and river pollution. Water footprint analysis has been used to indicate the water consumption of a country, product, services or even an individual. However, methods to assess water usage in crude palm oil plantations is not available to date. Thus, this paper aims to provide a method in calculating water footprint for crude palm oil productions in Malaysia. The most appropriate method was identified based on an extensive literature survey. ISO 14046 was chosen as a guideline because it is an international standard in reporting and assessing water footprint (WF) with LCA approach. This study preferred the use of the comprehensive water footprint assessment compared to the stand-alone assessment because this approach can assess all the potential environmental impact related to water which are associated with a product, process or organization. It is expected that the water degradation level in this plantation can be identified to provide guidelines to the government, plantation companies as well as developers for the development of sustainable palm oil plantation in Malaysia.

The activities related to agri-food production and the disposal of its waste account for a large number of greenhouse gas emissions. In many cases, food waste (FW) management is established by making a single assessment for its sustainability based on economical or environmental impacts. However, social impact assessments on stakeholders are often incomplete or missing, and its efficiency is seldom measured. Decision-making in waste management strategies, such as the acquisition of appropriate waste treatment sites or methods used, frequently involves multiple stakeholders such as government, municipalities, industries, experts, or public sectors. Due to the complication of differing criteria and alternatives in FW management technology, a multi-criteria decision-making (MCDM) methodology is recommended to certify the quality of the decision-making process. This paper reviews the use of MCDM as decision supporting techniques in modelling and analysing decision making in situations with multiple stakeholders for FW management. The synthesis results obtained through the MCDM tool will be more reliable when requesting confirmation from stakeholders based on a recommended minimum range of criteria for each sustainability dimension in the FW issues. Finally, potential studies in this area have been proposed.

Life cycle assessment (LCA) is broadly used around the world. The comprehensiveness of the method helps to avoid problem-shifter in reducing environmental impact from anthropogenic activities. In Southeast Asia, some countries have adopted gradually the application of life cycle approach in government action plans and marketing strategies. However, its progress remains unclear due to the lack of investigative studies. The aim of this paper is to provide a review of the current application of LCA framework in Malaysia. The paper also highlights the acceptance of the concept within government sectors and industrial players. The life cycle assessmentLCA progress in Malaysia can be seen from three perspectives: 1) government planning and policy; 2) industry involvement and 3) LCA priorities. This study reviewed the current progress of LCA implementation in Malaysia based on the current literature. In government planning and policy, LCA has been embedded in project development and monitoring through the Carbon Reduction Initiative and National Database Development. However, the progress in industry involvement so far has shown less participation due to low demand towards green products. In moving towards a high-income nation and open economy, the Malaysian government has emphasized on the need for greater inclusiveness where green initiatives were put forward in Malaysia’s development.

Water demands are the most referred indicators for water distribution system operators to regulate production and storage of potable water. Many regional in Southeast Asia are greatly dependent on freshwater resources, which most of the time comes from large rivers basin, with starting point in high mountains and the flowing water which distribute into many parts in particular region for daily activities. Hence, understanding the projection of water demand by the reservoir that are formed by constructing dams across rivers need to be done which can contribute to water demand framework for river basin. Evaluation on consideration and estimation between water withdrawal and water availability can provide the quantity of water loss. This paper presents a review of water demand projection for different reservoir in river basin across Southeast Asia.

River pollution from the agriculture industry has become an important cause of unscheduled water disruptions in Malaysia. Thus, rigorous control and treatment of high strength wastewater prior to discharge into the river are needed. This study aims at evaluating the performance of a pilot membrane bioreactor (MBR) for the treatment of palm oil mill effluent (POME). POME was subjected to MBR operating in an aerobic environment for 40 days, followed by 10 days without aeration and water pumping to simulate failure event, and finally resumed to operational condition. Higher proportions of protein (-PN) compared to polysaccharides (-PS) were present in both the mixed liquor and biofilm, indicating that protein was the main constituent of extracellular polymeric substances (EPS). Biological samples from the mixed liquor and biofilm on the membrane surfaces were collected on day 25, 50 and 75 to investigate taxonomic distribution of microbial community. High throughput sequencing of the 16S rRNA gene was used to investigate the composition of microbial communities in the MBR. Microbial groups such as the phyla Proteobacteria (19–23%), OD1 (11–15%), Chloroflexi (11–13%) were the dominant members in biofilm under operational condition while OD1 (20%), Proteobacteria (18%) and Planctomycetes (16%) were found to be dominant in biofilm under static and non-operational conditions. The taxonomic profile of the microbial community on day 75 is more similar to that of day 25, compared to day 50, suggesting the capability of the microbial communities to revert to the operational state despite a period of downtime.

The global transportation sector is one of the significant fuel consumers and contributes directly to greenhouse gas emissions due to fossil fuel consumption. Diesel blending used to reduce the reliant of fossil diesel in the transportation sector. Thus to reduce the environmental burden of fuel usage, new diesel blending formulations consist of biofuels were developed. The objective of the study is to assess the environmental performance of the five new diesel blending formulations with the existing diesel blending formulation by using Life Cycle Assessment method. In midpoint categories, the conventional B5 diesel blending has shown the lowest environmental impact compared to other fuels in most categories except for marine eutrophication, natural land transformation, ozone depletion, and terrestrial ecotoxicity. In the weighting stage, B5 diesel blending scored the lowest value and followed by blending 5, thus indicating its potential as an alternative to the existing diesel blending formulation. The presence of butanol in the new diesel blending majorly affects the environmental impact for many impact categories.

Building consumes 40% of global energy consumption which contributes for such a majority amount of carbon dioxide emission. Enhancing the energy efficiency strategies in buildings by retrofitting through different approaches is essential for reducing end user on the amount of energy consumption and carbon footprint emission. Previous research shows that only a few studies have been conducted on retrofitting the energy performance on Rest and Service Area yet the result shows that lack of technical feasibility practice was reviewed. Hence, this paper explores the energy efficiency strategy by improving the lighting performance based on 24 hours service building at Rest and Service Area Ayer Keroh Northbound Malaysia. The simulation that was performed in lighting energy consumption was EnergyPLUS software, Autodesk Revit and RELUX Plug in tool in Revit. Preliminary study was conducted to identity the problem on energy performance at Rest and Service Area Ayer Keroh by determine the total energy consumption by sources and Building Energy Intensity [BEI]. The result shows lighting contributes to the most total load consumption due to lack of energy conservation management and energy efficiency strategy practices. The lighting simulation scenarios was created to enhance the energy consumption performance and reduced the irrelevant carbon footprint emission. The simulation in Revit and EnergyPLUS showed 17% and 49% reduction respectively on the end load of lighting energy consumption by reducing the overall time operation and daylight control dimming system.

This study assessed the health risk analysis of haze pollution in Pasir Gudang and Larkin. The relationship between health risk and economic effect due to air pollution exposure in Johor is still poorly understood. Therefore, the objective of this study was to analyse the relationship between air pollution and health. Then, the economic impact due to smoke haze on associated outpatients was calculated. Daily morbidity data from 2014 to 2016 for three haze-related illnesses were collected from two health clinics. Data on air quality were obtained at two Continuous Air Quality Monitoring (CAQM) stations in Johor. Health risks for all age categories in the haze periods were higher than those in non-haze periods. The outpatient morbidity cases in health clinics increased with the rising occurrence of smoke haze in Johor Bahru. The average annual economic losses due to the outpatient health impact of haze were valued at RM83,233 and RM107,486 for Pasir Gudang and Larkin, respectively.

Based on the current generation rate of 1 kg−1 person−1, the production of organic waste in Malaysia is estimated to reach 9 metric tons per year by the year 2020. Components of these wastes, however, can be used to generate biogas, not only to decrease waste-related issues, but also to produce renewable energy. There is a growing interest in resource recovery and waste/energy integration through biogas generation from organic waste through anaerobic digestion method. However, due to the anaerobic digestion process varies in different facilities, thus proactive assessment on the status of biogas production and its effect on the environment through life cycle assessment is vital. The objective of this review is to assess factors that affect environmental performance results such as the system boundaries setting, the databases used and the life cycle impact assessment methods applied. This review underscores the fact that goal definition and scope, functional units, system boundaries setting, characterization and life cycle impact assessment methodology, as well as types of software and databases used influence and affects the life cycle assessment results. It suggests that for future cross study comparisons, all assessment guidelines should be addressed to avoid biased comparisons on climate performance between different alternatives.

The demand for rice in year 2030 is projected to be around 533 million ton of milled rice and known to be a high water consuming crop. In Asia alone, irrigated rice consumes as much as 150 billion m3 of water. With water being the most important component for rice production, yielding more rice with less water is therefore a formidable challenge. The aim of this study is to assess the water footprint of paddy plantation at Muda Rice Granary, Kedah for five consecutive years; 2012 to 2016. By using the life cycle assessment (LCA) approach, the potential environmental impacts due to water consumption in planting and processing rice will be assessed. By integrating water footprint with LCA may assist in analysing environmental impacts associated with direct and indirect water consumption throughout the whole process; starting from raw material extraction, processing or production, distribution, use, and disposal. The methodological framework follows the LCA framework; setting up goal and specifying the scope of study, followed by inventory analysis, water footprint sustainability assessment and finally interpretation or response formulation. The research boundary for this study include the growing phase of paddy; seedling and cultivating of the paddy until the rice milling process. By implementing this water footprint research in paddy field, it will be essential not only in research area but also in agricultural development in Malaysia. Consequently, it will become the baseline for other agricultural in Malaysia in this research area.

The purpose of this paper is to propose an alternative methodology for aggregation in a life cycle assessment (LCA). The comprehensive aggregation method is based on a damage approach and done through an analytical hierarchy process. Consistency analysis is also presented to justify the reliability of the judgements and the magnitude of change in the values developed. A case study of electricity generation is applied to demonstrate its applicability in LCA study within a Malaysian context. Results from this case study show that the weighting value is higher compared to global and European values; however, they are consistent as in the case of product ranking towards greener products. Regional impacts such as particulate matter formation and photochemical oxidant formation have higher score compared to global impacts such as climate change. The results show that the method is simple and replicable.

The increasing concerns of water resource are becoming an important issue as severe shortage of water has been seen throughout the world. Though membrane bioreactor (MBR) has made an enormous progress and has become a promising approach in wastewater treatment, there are still several limitations on conventional MBR and thus there emerged integrated MBR for wastewater treatment technology. This paper aims to provide a consolidated review on the current state of research for the integrated MBR system with other technologies for wastewater treatment and help to sustain the treatment process itself. The areas for potential applications of various types of MBR are discussed in this review article. It is expected to provide future prospects to implement integrated MBR as a promising wastewater treatment technology. The valorization of wastewater in integrated MBR would reduce pollution and more importantly open a new source of energy and nutrients. Moreover the integrated MBR makes energy and nutrient recovery to be environmentally and economically feasible.

Rapid urbanization has greatly impacted housing demand and housing development in Iskandar Malaysia, Johor. Iskandar Malaysia vision towards development of a low carbon society and in line with Malaysian government policy promoting industrialized building system (IBS) to meet the increasing housing demand. Hence, a comparative analysis of life cycle analysis (LCA) at assembly phase has been conducted to identify life cycle impact assessment and hotspot for material and construction stage between IBS and conventional cast in situ for residential apartment buildings in Iskandar Malaysia. The purpose is to apply IBS in residential building construction towards greener building and sustainable development. The functional unit of the comparison analyses was one square metre of produced building area for the respective construction period. A comparable inventory analysis will be carried out between two case studies. An input-output flowchart is created for each process to determine the components included in the analysis. Flows of assembly phase will be modelled in Gabi 6.0 software to further interpret the life cycle impact assessment (LCIA) between the two construction methods, and to determine the hotspot between the processes. Finally, a sensitivity analysis will be conducted to determine the influence of variations in assumptions, methods and data on the results.

Aerobic granulation is increasingly used in wastewater treatment due to its unique physical properties and microbial functionalities. Granule size defines the physical properties of granules based on biomass accumulation. This study aims to determine the profile of size development under two physicochemical conditions. Two identical bioreactors namely Rnp and Rp were operated under non-phototrophic and phototrophic conditions, respectively. An illustrative scheme was developed to comprehend the mechanism of size development that delineates the granular size throughout the granulation. Observations on granules' size variation have shown that activated sludge revolutionised into the form of aerobic granules through the increase of biomass concentration in bioreactors which also determined the changes of granule size. Both reactors demonstrated that size transformed in a similar trend when tested with and without illumination. Thus, different types of aerobic granules may increase in size in the same way as recommended in the aerobic granule size development scheme.

© 2019 This study conducted a life cycle assessment of palm oil mill effluent (POME) based energy generation using the CML 2001 method and Gabi 8 software, focusing on two POME treatment technologies: the covered lagoon bio-digester (CLB) and the continuous stirred tank reactor (CSTR). The analysis determined the respective environmental impacts of the technologies, both of which are currently in use in Malaysia. The global warming potential (GWP) and acidification potential (AP) for CSTR were −4.48 kg CO2 eq/kWh and −2.21 kg SO2 eq/kWh respectively, while for CLB the values were −4.09 kg CO2 eq/kWh and −0.15 kg SO2 eq/kWh. Both technologies produced a negative result, which equates to a net environmental benefit. However, both systems had a negative impact in terms of eutrophication potential (EP). The CSTR nevertheless achieved a better EP result of 0.048 kg PO43− eq/kWh than the CLB with 0.054 kg PO43− eq/kWh. A sensitivity analysis was carried out in order to find a way to overcome the impacts of EP. The findings provide useful data to guide decision-makers in the sustainable management of POME, in Malaysia and globally where similar technologies are in use.

Volatile organic compounds in water and wastewater can be removed using air stripping. The effects of temperature and air-water ratios on the air stripping of benzene, toluene and xylene (BTX) from wastewater have been examined at a temperature range of 30–50°C and air-water ratios of 20–100. Removal efficiencies of >99%, >93% and 93% for BTX, respectively, were obtained at 50°C and air-water ratios of 100. The removal efficiencies increase non-linearly with temperature and air-water flow ratio. The effects of increasing temperature on the removal efficiency were found to be more significant at temperatures between 30 and 35°C than at 45 and 50°C. The effects of increasing water-air ratios on the removal efficiency were more significant at air-water ratios of 20–60 than at 80–100. The results indicate that a high removal of BTX can be achieved by operating the air stripper at high temperature conditions even at relatively low air-water ratios and vice versa.

Exposure to the haze pollutants may cause a diverse range of health impacts including symptoms that lead to treatment-seeking behavior, outpatient and emergency department visits, and hospitalization for moderate and severe cases and mortality for the worst-case scenarios. This study is carried out as an effort to understand how the haze occurrence that has been plaguing South East Asia affect the health of the citizen in Malaysia, particularly in Johor due to its close proximity to Sumatra which has been identified as one of the hotspots for frequent forest fires. The study is done in Larkin and Pasir Gudang where health cases caused by poor air quality such as conjunctivitis, URTI and asthma have been identified while HYSPLIT model indicates the trajectory of the wind at different heights to help us understand how wind movement during the selected time of the year causes haze formation. The findings of this study showed that low wind heights below 2000m AGL in September cause particular matter accumulation over Malaysia as the wind over Malaysia. In turn, this causes high API reading which leads to higher conjunctivitis, URTI and asthma cases. The investigation of the exposure and health risks of the air pollutants through a risk-based approach will definitely be beneficial in providing new information about the correlation between health risks and air pollution in Johor, which may also have implications on the environmental and social policies.

Highway infrastructure emits large quantities of carbon dioxide over their entire life cycle including emission from production of raw materials and also emission from construction, operation, maintenance, and rehabilitation of the roads. The past emission trends of carbon dioxide from these sectors are investigated through their sources while mitigation and abatement strategies are suggested. This paper brings together, for the first time, a systematic review of the carbon footprint calculator of 21 case study highway from 8 different countries were investigated. This review focuses on method for calculate carbon footprint of highway development, through the synthesis of the overall outcomes of these studies, to identify whether using excel tool or Life Cycle Assessment (LCA) software achieve better performance and easier to calculate the emission from highway development. It is observed that using excel tool is better to calculate and analysis the carbon footprint from many sources and stage compare than calculate using LCA software. Therefore, understanding the relationships between methods for calculate carbon footprint life cycle energy consumption and GHG emissions are critically important for highway agencies to evaluate their annual greenhouse gas emission reports. Chang C.d

Carbon dioxide that emitted throughout the construction lifespan is crucial from development of design, construction, up to demolition stage. Focusing in the rehabilitation of highway pavement, the activities that normally involved are from milling, roller up to dumping the wastes asphalts. The aim of this paper is to estimate the carbon footprint emission in unit of tonnes for carbon dioxide equivalents (t CO2-eq/km-lane). The case study involved based on five selected projects for north-south bound expressway of Malaysia. The results show that highest carbon footprint were from the Mill and Pave 250 mm (MP 250) with 117.94 t CO2-eq/km-lane. This is due to its depth of pavement with 140 mm dense bituminous macadam, 60 mm asphalt concrete base course and 50 mm asphalt concrete wearing course as compared as other Mill and Pave. The result followed by MP 200, MP 110 and MP 50 at 95.19, 54.10, and 27.37 t CO2-eq/km-lane respectively. The critical activities involved during the construction shows the asphalt concrete production as the highest generation of emission with 53.78 t CO2-eq/km-lane, followed by lorry transportation of asphalt waste, lorry transportation of asphalt concrete, fuel consumption from machineries, neomed coat, and water consumption with the value of 28.58, 24.50, 10.83, 0.23, and 0.01 t CO2-eq/km-lane respectively. The results from this study considered as references guidelines for carbon footprint calculator to calculate emission as compared to other expressway in Malaysia.

This paper reviewed the application of membrane bioreactor in treating high strength industrial wastewater by analysing operational parameters, limitations and mitigations of MBR for industrial wastewater. High strength industrial wastewater is difficult to classify but by its characteristics can be predicted using biodegradability criteria (BOD5/COD). Several factors need to be taken into consideration to find suitable operating parameters such as hydraulic retention time (HRT), solid retention time (SRT), mix liquor suspended solid (MLSS), food to microorganism (F/M), transmembrane pressure (TMP) and Flux (J) to obtain good quality effluent and reduce the fouling effect. Fouling factors by membrane, biomass and MBR operation need to be taken seriously because they are the major problems affecting the performance of the MBR and quality of the effluent. There are specific methods to reduce and clean the clogging membrane depending on the level of severity of the fouling. The mitigation covers physical cleaning such as membrane relaxing, backwashing, a combination of both and chemical cleaning which is used for irreversible fouling. In some cases, modification of MBR is needed to improve the performance and to achieve high quality of effluent.

Tannery wastewater treatment using two isolated micro-organisms (Bacillus subtilis and Pseudomonas fragii) has been investigated in the present study. The growth patterns, pH normalisation and the abilities of these micro-organisms to reduce the concentrations of chemical oxygen demand (COD), total suspended solids (TSS) and chloride were studied using the shake flask apparatus. The specific growth rate and biomass concentration of B. subtilis and P. fragii were observed 0.138 h−1 and 3.01 mg/l and 0.051 h−1 and 2.34 mg/l, respectively, after 84 h. Both micro-organisms normalised pH of the wastewater. COD removal efficiency for B. subtilis was 87.6% while that of P. fragii was 85.2%. For TSS, B. subtilis caused a reduction of 91.7% (from 876 mg/l to 73 mg/l), while P. fragii reduced the solid concentration from 876 mg/l to 98 mg/l (88.8%). B. subtilis could only achieve 48.5% reduction in chloride concentration (from 127.08 mg/l to 65.39 mg/l compared to a reduction of 54.6% (from 127.08 mg/l to ...

The problems posed by municipal solid waste in Asia are more complex because here, most nations urbanize rapidly with about 30–50% population increase. In developing countries, the growth rate of most cities exceeds 4% per annum. The issue at stake is that the 20–40% of municipal revenues spent in most countries to manage the waste is not enough to handle the rising trend of the waste generated. The problems are multi-dimensional. In Asia for example, issues ranging from disputes, norms, health concerns have continued to create obstacles and sometimes alarming situations. This had interfered with proper decisions in managing the waste that menaces the environment at a pace faster than the modern technology itself. In the paper some of the municipal solid waste management options are reviewed in some of these Asian countries with emphasis on a life cycle assessment (LCA) to adopt an integrated approach in solving the problem. Some solid waste management options were evaluated where some viable and suitable options could be derived based on Asian approach. Therefore, sustainable scenarios are suggested for stakeholders to manage municipal solid waste properly. The results are specifically intended to be used as a basis for decisions on strategies and policies for waste management and investments for new waste treatment facilities by decision makers in local, regional and national authorities or industries in the region.

Problem statement: The rearing of animals for domestic consumption and export invariably lead to the production of methane as a product of digestion. This study investigated the emission of methane from Malaysian livestock between 1980 and 2008. Approach: Seven categories of animals identified were camel, buffalo, sheep, goats, horse, pigs and poultry. The estimation of methane was based on the IPCC Tier 1 and Tier 2 methods. Methane emission from cattle rose by 44% within the period from 45.61-65.57 Gg. Results: Buffalo recorded a drop in methane emission by 54% from 17.12-7.86 Gg while the methane emission from sheep initially rose by 350% in 1992 only to drop by another 56% by 2008. Goats emission only declined by 17% from 1.79 Gg in 1980-1.49 Gg by 2008. Methane emission from horse has been consistent at around 0.14 Gg. The decreasing stock of pigs has led to a drop in methane emission from these set of animals with most of the emission coming from manure management. Conclusion: The healthy export market for poultry has seen a rise in methane emission by 274% from 2.18 Gg in 1980-8.17 Gg by 2008. The overall increase in methane emission from all the livestock is 20% from 81.83 Gg in 1980-98.76 Gg in 2008. With the aggressive drive of government to boost cattle and goat production, there is the likelihood of an increase in methane emission in the future and mitigation options will have to be applied.

Water Footprint Assessment (WFA) has emerged as a new interdisciplinary field of study, that specialize in the study of water use, scarcity, and pollution, in respect to production, consumption, and trade of water-intensive products and services. It consists of the analysis of various techniques and practices, policy plans, and governance mechanisms that contributed to the rise of sustainability, efficiency, and equitability of water footprints. This study focuses on WFA specifically for electronic and food manufacturing products. It determined contributions of different players namely the governments, companies, investors and civil society. This study typically reviews water use in relation to demand for electronic products, food and energy used. It appraisals the sustainable water use translated into coherent food, energy, incentives and trade policies. Water-Food-Energy (WFE) nexus from the perspective of electronic and food manufacturing products are also reviewed. In this study, the challenges in estimating water footprints and WFE nexus for electronics and food manufacturing products include the understanding of various levels of demand, geographical, temporal variations, assessment of uncertainties involved, and the assessment of water-footprint related problems and solutions. The outcomes showed that combining several methods of WFA can obtain adequate results for the water footprint accounting. The WFE nexus is preferred to use life-cycle assessment (LCA) method to identify the environmental impacts. The significances of this study are to raise the awareness on water usage in the supply chain process of the electronic and food products then recommend good practices in water usage.

Change in climate, increasing world population and industrialization have placed considerable stress on water availability at certain places. Water Footprint accounting is a reliable technique that can be used for a better water management. This study focuses on establishing a doable methodology on water footprint accounting and assessment for direct water consumption from domestic and institutional sectors located in an urbanized environment such as Klang Valley, Kuala Lumpur. It includes investigation of Water Footprint at domestic household, schools, colleges, terminals and offices in Klang Valley. The value of water consumption, water production and water pollution will be determined using Hoekstra’s approach for green water, blue water and grey water. In addition, findings from this study will be linked to two other elements namely energy and food. This link is named as Water-Energy-Food Nexus. This study will establish the quantity and criteria of Water-Energy-Food Nexus specifically tailored to domestic and institutional sectors in Klang Valley.

This paper presents a study on the performance of an Aerobic Submerged u-shaped membrane bioreactor (ASMBR) in treating sulfidic spent caustic (SSC) in terms of mixed liquor suspended solid (MLSS) concentration and solid retention time (SRT). SSC wastewater is categorized as high strength wastewater and consists of high inorganic and organic matter. U-shape membrane bioreactors have a higher tendency to foul compared to other types of MBR. MLSS concentration and SRT are the major parameters when operating membrane bioreactor. In this study, COD removal recorded reduction of more than 95% for average MLSS concentration runs and 90% for SRTs runs. Meanwhile, sulfide was removed 99%, and formed up to 79% of sulfate. The biofouling for MLSS concentration and SRTs were observed through TMP rate change and TMP average performance, TMP trend and SMP and EPS trends. Biocake layer and biolayer deposited on membrane surface was found influenced by biomass, the inert particulate biomass products accumulating in the reactor.Chemical Engineering Research Bulletin 19(2017) 102-110

There is new trend in the value of oil and gas in the world, with the value of Liquefied Petroleum Gas (LPG) soaring higher. It is due to its uses as a potential fuel in the several parts of the world, its demand in the petrochemical industries for plastics and automotive composites productions, and other uses. These results in steadily increases in price. There is also increase in volume of feed gas, which demands efficient LPG processing and recovery technology. This paper mainly focuses on comparative economic investigation options for Liquefied Petroleum Gas plant, which processes feed from natural gas wells and dehydrating units to produce Liquefied Petroleum Gas along with natural gasoline having a higher value as separate product. Recovery of LPG is possible but raises both the initial cost of plant and operational cost considerably. The value of LPG recovered should be high enough to widen the operating margins between the processing costs and the market price for which the recovered liquids can be sold. Therefore, the most economic means of extracting this product must be used. This was done using two alternatives; the Conventional Fractionation process and Single column overhead recycle process (SCORE). Both alternatives were simulated with Hysys and are analyzed based on product recovery level, energy required and fixed capital cost. There are two feeds to the plant, one from the natural gas wells and the other from dehydrating units of natural gas processing plants with a total flow rate of 6.99 MMSCFD. Analysis of result from modeling shows that Single column overhead recycle process has a total product recovery of 97.2 % while Conventional fractionation process has a total recovery of 88.5 %, the require energy margin between the alternatives is about 38.9 % in favor of conventional process and the fixed capital cost is in the favor of Single column process. Sensitive to choosing the most economic option of LPG recovery between the conventional process and SCORE process is the recovery level of LPG from each of the options, total energy required and the cost of the equipment. From the analysis, it shows that, it is more economical to use the Single column overhead recycle process, as compared to conventional fractionation process.