Assessment of city's sustainability performance via Fuzzy Lingustic Scale: East Malaysia case study

The rapid growth of urbanization is not without any impact to the economic, environmental and even socially. There has been a constant call to develop measurement tool to provide a fair weightage for the urban sustainability indicators. The aim of this research is develop a measurement tool integrating Fuzzy Linguistic Scale to assess sustainability performance and test it on two selected cities; Kuching and Kota Kinabalu were selected due to their geographical location and their demographic similarities. 16 indicators were utilized in this research where the actual data were obtained from secondary sources on the two cities and were associated with the FLS to obtain the city's final value where Kuching scored 0.595 which falls under 'Fair' sustainability performance, and Kota Kinabalu scored 0.642, which falls under 'Good' sustainability performance. The results then lead to 4 hotspots in Kuching and 5 hotspots in Kota Kinabalu which are considered critical areas that needs to be considered for immediate action

Overview of urban heat island (UHI) phenomenon towards human thermal comfort

Urban Heat Island (UHI) is expected to be a disastrous challenge to human in the following decade as a result of continuous urbanization without appropriate planning and design. The impacts of UHI are even getting worse due to large population density with improper building design especially in dense metropolitan cities. A lot of research has been carried out for UHI phenomenon both in tropical and seasonal climates. There are many factors contributing to the formation of UHI phenomenon that includes increasing rate of urbanization and population density, uncontrollable factors and controllable factors. In a fundamental study, a prolonged exposure to heat impact will significantly contribute to human discomfort and health problems resulting in heat-related illness. The cases of heat related deaths, such as heat strokes, are due to the result of climate changes and further the problem of heat waves will increase year by year. Since the consequences of UHI are considered to be more significant, the severity of the problem should be critically examined and carefully reported. Many research efforts have been implemented for making conceptual design and also a wide range of literature is available for continuing the mitigation strategies. Therefore, this study is emphasized on the critical investigation of the features, factors and impacts of UHI towards evaluating human safety and thermal comfort. Future research direction should also be encompassed on the design and planning parameters as well as assessment of climate change risks and vulnerability for reducing the effects of urban heat island onto human health and safety

Application of the triangular model in quantifying landfill gas emission from municipal solid wastes

Municipal solid waste landfills are significant parts of anthropogenic greenhouse gas emissions. The emission of significant amount of landfill gas has generated considerable interest in quantifying such emissions. The chemical composition of the organic constituents and potential amount of landfill gas that can be derived from the waste were determined. The chemical formulae for the rapidly biodegradable waste (RBW) and slowly biodegradable waste (SBW) were determined as C39H62O27N and C36H56O20N, respectively. The triangular method was used to calculate landfill gas obtainable from rapidly biodegradable waste over a 5-year period and for slowly biodegradable waste over a 15-year period. A plot was obtained for a landfill life span of 20 years. The volume of methane and carbon dioxide from RBW were 12.60 m3 and 11.76 m3 respectively while those from SBW were 6.60 m3 and 5.48 m3 respectively at STP. For the initial deposit of 2002 the highest landfill gas emission rate occurred in 2007 at 0.2829 Gg/yr with an average cumulative emission of 0.3142 Gg while for a landfill closed after five years the highest landfill gas emission rate was in 2010 at 1.2804 Gg/yr with an average cumulative emission of 1.5679 Gg while this cumulative emission will start declining by the year 2029

Optimization of nickel removal from electroless plating industry wastewater using response surface methodology

Optimum pH and coagulant dosage for chemical precipitation in wastewater treatment plants is conventionally obtained through repeated jar test. In this research, optimization of the performance of polyacrylamide in the treatment of industrial wastewater was carried out using response surface methodology. The individual linear and quadratic effect of coagulant dosage and pH on the degree of removals of nickel, total suspended solids, Chemical Oxygen Demand and turbidity were investigated. The optimum pH and polyacrylamide dosage were found to be 10.5 and 1.6 ml/L respectively and the optimum percentage nickel removal was 96.9%. The model used in predicting the precipitation process gave a good fit with the experimental variables and hence the suitability of response surface methodology for the optimization of polyacrylamide performanc

A Review of Scenario Planning for Emissions in Environmental Assessments

Various scenario classifications apply in attempts to make the field of future studies easier to outline. This paper discusses the appropriateness of various creating, coordinating, and consistency procedures for creating specific emission scenarios in environmental assessments. The Intuitive Logics, Story and Simulation (SAS), Social, Technological, Economic, Environmental and Political (STEEP), and La Prospective Models approaches are the five emission scenarios discussed in the paper analytically with their stages, storylines, steps, and building analysis. Every scenario method was examined and sorted into its separate benefits and limitations. Subsequently, the study selected the appropriate technique of emission scenario in environmental assessment with fulfilled scenario planning to deliver constructive scenarios. The study helps the upcoming designers by providing the fundamental direction on the extensive change towards a sustainable environment

Life cycle assessment analyzing with gabi software for food waste management using windrow and hybrid composting technologies

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 study provides valuable insights for policy-making groups to help predict the environmentally preferred choice of FW management technologies in a particular area, resulting in improved environmental management sustainability

Process simulation of bis (2- Hydroxyethyl) terephthalate and its recovery using two-stage evaporation systems

To preserve the petroleum feedstock and eliminate the environmental problems peculiar to polyethene terephthalate (PET) bottles littering the environment. Chemical recycling method was adopted to convert PET into useful products of prosperous sizeable industrial application. This work employed ASPEN PLUS V8.8 to simulate chemical glycolysis depolymerisation process of PET plastic wastes, using plug flow reactor for commercial production of pure bis (2- hydroxyethyl) terephthalate (BHET). The data for modelling were gotten from the experimental PET glycolysis depolymerisation work. Excess ethylene glycol (EG) was used to degrade PET waste with zinc acetate (Zn(Ac)2) as the active catalyst. The optimum operating conditions of the reaction were mean particle size PET of 127.5 μm, EG:PET (w/w) ratio of 5:1,469 K temperature, 101325 N/m 2 pressure and 3 h residence time. Reaction results were 100 % depolymerisation of PET, 85.24 % yield of BHET and 14.76 % Oligomer. Purification of the BHET was done with two stages evaporation processes using flash columns and crystallizer. Higher temperature and lower pressure were observed to increase the efficiency of the evaporators, but the heat duties increased and momentarily reduced the BHET recovery. BHET recovery was observed to decrease with increase in temperature in the case of crystallisation operation. This work achieved a higher yield and purity of BHET, a higher EG removal for re-use and less heat duties demanded in comparison to previous works. The processes with its operating conditions can be used for future scaling up of commercial processes

Identification of pharmaceutical residues in treated sewage effluent in Johor, Malaysia

The introduction of pharmaceutical residues into aquatic environment has threatened the livelihood of aquatic organisms worldwide. The entrance of these residues into the environment originates from sewage effluents discharged from domestic wastewater treatment plants. Up to date, their presence in the sewage effluent is not monitored in Malaysia. Therefore, this study aims to identify the presence of pharmaceutical residues in the effluent domestic sewage treatment plants employed in Johor Bahru, Malaysia. Briefly, ten pharmaceutical compounds, including acetaminophen, sulfathiazole, sulfamethazine, sulfamethoxazole, clarithromycin, trimethoprim, lincomycin, carbamazepine, naproxen and ibuprofen, were selected based on their worldwide consumption. Sewage samples from five different types of sewage treatment system were collected. The samples were filtered prior to solid-phase extraction. Finally, the extracted samples were analysed with LC-MS/MS. The analyses showed that only sulfathiazole was not present in all effluent samples. Acetaminophen recorded the highest concentration of 9299 ng/L in an Imhoff Tank. Meanwhile, the lowest concentration of pharmaceutical residue detected was sulfamethazine, i.e. 0.843 ng/L, in a sequencing batch reactor. Overall, six out from ten pharmaceutical residues were found in all sewage samples denoting the inefficiency of current biological treatment systems in removing trace pharmaceutical compounds from sewage

Assessment of Membrane Bioreactor in Treating Spent Sulfidic Caustic Wastewater: Effects of Organic Biomass Concentration and Solid Retention Time

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

Removal of boron from industrial wastewater by chitosan via chemical precipitation

Chitosan is natural organic polyelectrolytes of high molecular weight and charge density; obtained from deacetylation of chitin. This study explored the potential and effectiveness of applying chitosan as a primary coagulant and flocculent for boron removal. A series of batch coagulation and flocculation processes with chitosan under different conditions, i.e. dosage, pH and temperature were conducted, in order to determine the optimum operating conditions for boron removal. The performance was accessed through total suspended solids (TSS), turbidity and boron concentration reductions. From the study, the optimum dosage for chitosan was recorded at 0.8 g/L with 94.2%, 91% and 79.7% for TSS, turbidity and boron, respectively. The optimum pH of 5 with the removal of TSS, turbidity and boron concentration were 97.8%, 93.4% and 87.5%, respectively. At the temperature of 60C, the reduction of all the parameters (i.e. TSS, turbidity and boron concentration) was the highest compared to other temperature (i.e. 99%, 95.3% and 91% of TSS, turbidity and boron concentration reductions were achieved respectively