By growing urban population, Iran faces numerous environmental issues and solid waste management is on the top of these problems. Studies showed that a daily average of 700-1000 g of wastes are produced per person in Iran, in which organic waste accounts for a significant amount. On the other hand, hospital waste represents a part of the wastes, which need careful consideration from the environmental point of view. In the present study, the amount, composition, and management of urban and hospital wastes were evaluated in 7 Iranian metropolises, which account for about 30% of the population and produce about 35% of the country wastes. Based on prior surveys, landfill method is the current main method for waste management in these cities, which is generally not completely sanitary and therefore causes many environmental problems. The other common methods for waste management in these cities are composting of organic wastes, and the use of waste conversion methods to energy. However, the latter is ongoing only in Tehran which also includes some limitations. Therefore, the study also evaluated the future perspectives and feasibility of waste-to-energy conversion as a promising economic route for waste disposal.
Due to a huge increase in polymer production, a tremendous increase in municipal solid waste is observed. Every year the existing landfills for disposal of waste polymers decrease and the effective recycling techniques for waste polymers are getting more and more important. In this work pyrolysis of waste polystyrene was performed in the presence of a laboratory synthesized copper oxide. The samples were pyrolyzed at different heating rates that is, 5°Cmin-1, 10°Cmin-1, 15°Cmin-1 and 20°Cmin-1 in a thermogravimetric analyzer in inert atmosphere using nitrogen. Thermogravimetric data were interpreted using various model fitting (Coats-Redfern) and model free methods (Ozawa-Flynn-Wall, Kissinger-Akahira-Sunose and Friedman). Thermodynamic parameters for the reaction were also determined. The activation energy calculated applying Coats-Redfern, Ozawa-Flynn-Wall, Kissinger-Akahira-Sunose and Friedman models were found in the ranges 105-148.48 kJmol-1, 99.41-140.52 kJmol-1, 103.67-149.15 kJmol-1 and 99.93-141.25 kJmol-1, respectively. The lowest activation energy for polystyrene degradation in the presence of copper oxide indicates the suitability of catalyst for the decomposition reaction to take place at lower temperature. Moreover, the obtained kinetics and thermodynamic parameters would be very helpful in determining the reaction mechanism of the solid waste in a real system.
The high-strength leachate produced from sanitary landfill is a serious issue around the world as it poses adverse effects on aquatic life and human health. Physio-chemical technology is one of the promising options as the leachate normally presents in stabilized form and not fully amendable by biological treatment. In this research, the effectiveness of natural zeolite (clinoptilolite) augmented electrocoagulation process (hybrid system) for removing high-strength ammonia (3,442 mg/L) and color (8,427 Pt-Co) from naturally saline (15 ppt) local landfill leachate was investigated. A batch mode laboratory-scale reactor with parallel-monopolar aluminum electrodes attached to a direct current (DC) electric power was used as an electrocoagulation reactor for performance enhancement purpose. Optimum operational conditions of 146 g/L zeolite dosage, 600 A/m2 current density, 60 min treatment time, 200 rpm stirring speed, 35 min settling duration, and pH 9 were recorded with up to 70% and 88% removals of ammonia and color, respectively. The estimated overall operational cost was 26.22 $/m3 . The biodegradability of the leachate had improved from 0.05 to 0.27 in all post-treatment processes. The findings revealed the ability of the hybrid process as a viable option in eliminating concentrated ammonia and color in natural saline landfill leachate. PRACTITIONER POINTS: Clinoptilolite was augmented on the electrocoagulation process in saline and stabilized landfill leachate (15 ppt). The high strength NH3 -N (3,442 mg/L) and color (8,427 Pt-Co) were 70% and 88% removed, respectively. The optimum conditions occurred at 140 g/L zeolite, 60 mA/cm2 current density, 60 min, and final pH of 8.20. The biodegradability of the leachate improved from 0.05 to 0.27 after the treatment. This hybrid treatment was simple, faster, and did not require auxiliary electrolyte.
Anaerobic digestion is a process by which microorganisms break down biodegradable material in the absence of oxygen. The process involves hydrolysis, acidogenesis and methanogenesis stages. Anaerobic digestion of food waste has been widely investigated for biogas recovery but limited study was performed on phosphorus recovery, which is reported depleting. Food waste is produced every day and dumped on landfill for final disposal which may lead to environmental issues such as odour problems and greenhouse gases release, due to decomposing of food waste, hence impacts global climate change. In anaerobic digestion pH is a very crucial parameter in an attempt to recover phosphorus as it highly influences the production of organic acids during acidogenesis.
Introduction: Food poisoning usually occurs with the consumption of contaminated food. Some related factors are unsafe water supply, poor sanitation, unhygienic waste disposal and unhygienic practices or poor personal hygiene by food handlers. The purpose of this study is to describe the spatial epidemiology of food poisoning cases in the four districts of Sabah. Methods: This review consists of all food poisoning cases reported from 2011 to 2014 from Kota Kinabalu, Penampang, Putatan and Papar, Sabah. The coordinates used for locations of cases are based on home addresses. Tools such as SPSS v20, ArcGIS v10 and CrimeStat IV were used for data analysis and mapping. Results: A total of 1,787 cases of food poisoning were reported during this review period. In 2011, only Kota Kinabalu and Pa-par illustrated significant food poisoning clusters. Meanwhile, in the year 2012 to 2014, Kota Kinabalu, Penampang and Putatan had clustering of cases. Analysis of nearest neighbour hierarchical clustering analysis showed 32 food poisoning clusters. There were 4 food poisoning points at 500 meters radius around a market place, 2 food poisoning points near a sewage plant and 1 food poisoning point near a water treatment plant. No cases were near a municipal landfill. For rivers and coastline, there were 37 points of food poisoning cases in the proximity of 500 meters. Con-clusion: Food poisoning usually occurs in clusters with possible associated environmental factors.
Industrial, and municipal wastes are part of the main sources of environmental hazards as well as groundwater and surface water pollutions. If not well composed, treated, and safely disposed, it could permeate through the subsurface lithologies by reaching down to the underground water aquifers, particularly in zones of unprotected aquifer units. Pollutants, most especially the landfills leachates that encompassed organic contaminants, ammonia, nitrates, total nitrogen, suspended solids, heavy metals and soluble inorganic salts, i.e., soluble nitrogen, sulphur compound, sulphate and chlorides, could posed undesirable environmental impacts due to inappropriate disposals that may give rise to gaseous fumes and leachate formations. An electrical resistivity geophysical technique utilizing the RES2D no-invasive, cost-effective and rapid method of data collection was integrated with the 3D Oasis Montaj software to approximate the volume of the generated rectangular prism model of the contaminants delineated from mixtures of the industrial, and municipal wastes plumes to be 312,000 m 3.
As the population increases, energy demands continue to rise rapidly. In order to satisfy this increasing energy demand, biogas offers a potential alternative. Biogas is economically viable to be produced through anaerobic digestion (AD) from various biomass feedstocks that are readily available in Malaysia, such as food waste (FW), palm oil mill effluent (POME), garden waste (GW), landfill, sewage sludge (SS) and animal manure. This paper aims to determine the potential feedstocks for biogas production via AD based on their characteristics, methane yield, kinetic studies and economic analysis. POME and FW show the highest methane yield with biogas yields up to 0.50 L/g VS while the lowest is 0.12 L/g VS by landfill leachate. Kinetic study shows that modified Gompertz model fits most of the feedstock with R 2 up to 1 indicating that this model can be used for estimating treatment efficiencies of full-scale reactors and performing scale-up analysis. The economic analysis shows that POME has the shortest payback period (PBP), highest internal rate of return (IRR) and net present value (NPV). However, it has already been well explored, with 93% of biogas plants in Malaysia using POME as feedstock. The FW generation rate in Malaysia is approximately 15,000 tonnes per day, at the same time FW as the second place shows potential to have a PBP of 5.4 years and 13.3% IRR, which is close to the results achieved with POME. This makes FW suitable to be used as the feedstock for biogas production.
A four-month cross-sectional study found five species of parasitoids parasitizing puparia of filth flies breeding at the Taman Beringin landfill in Kepong and a poultry farm in Sungai Pelek, Sepang, Selangor. Effect of monthly rainfalls towards density of flies and percentage of parasitoids emerging from collected puparia were also analyzed. Spalangia sp. was the most common, consisting of Spalangia endius Walker, S. cameroni Perkins and S. gemina Boucek. Other parasitoids collected were Pachycrepoideus vindemmiae Rondani and Exoristobia phillipinensis Ashmead. The parasitized fly hosts were Musca domestica Linn. and Chrysomya megacephala Fabricius. S. endius was the most common parasitoid attacking M. domestica at both locations. M. domestica was the most common fly found at the Sg. Pelek poultry farm whereas C. megacephala was the most numerous at the Taman Beringin landfill. During heavy rainfall month of November 2003, density of flies were high whereas the emerging parasitoids were low at both landfill and poultry farm. The present study revealed the endemic presence of parasitoids especially S. endius in both poultry farm and garbage landfill and the potential of the parasitoid species in fly control in Malaysia.
Ineffective construction waste management has become a serious problem that impacted significantly to environmental pollutions especially in a developing country like Malaysia. Despite the enactment of law by the government, Malaysia is still far behind as compared to other countries like Denmark and Hong Kong in terms of implementation of recycling and reuse of construction waste. Recycling and reuse of waste materials seems to be a profitable method that will boost the
lifetime of landfills and cut down the usage of virgin natural resources. This paper discusses the practices of recycling and reuse of construction waste materials in the Klang Valley. A questionnaire survey was administered to 117 respondents from construction companies. The most common types of construction waste materials that can be recycled and reused are concrete, metal, asphalt, brick, plastic, cardboard, timber and glass. A descriptive analysis using Relative Important Index (RII) was used to rank the items asked in the survey. It was found that the most frequent types of recycling and reuse of construction waste materials based on ranking is timber,
while the key benefit of recycle and reuse of construction waste is reduction of landfill space. On the other hand, the key challenge that affects recycling and reuse of construction waste is the risk of contamination. This study is beneficial for all parties involved in construction activities to achieve a more sustainable construction in Malaysia and throughout the world.
The production of cement contributes to 10% of global carbon dioxide (CO2) pollution and 74 to 81% towards the total CO2 pollution by concrete. In addition to that, its low strength-to-weight ratio, high density and thermal conductivity are among the few limitations of heavy weight concrete. Therefore, this study was carried out to provide a solution to these limitations by developing innovative eco-friendly lightweight foamed concrete (LFC) of 1800 kg/m3 density incorporating 20-25% palm oil fuel ash (POFA) and 5-15% eggshell powder (ESP) by weight of total binder as supplementary cementitious material (SCM). The influence of combined utilization of POFA and ESP on the fresh state properties of eco-friendly LFC was determined using the J-ring test. To determine the mechanical properties, a total of 48 cubes and 24 cylinders were prepared for compressive strength, splitting tensile strength and modulus of elasticity each. A total of 24 panels were prepared to determine the thermal properties in terms of surface temperature and thermal conductivity. Furthermore, to assess the environmental impact and eco-friendliness of the developed LFC, the embodied carbon and eco-strength efficiency was calculated. It was determined that the utilization of POFA and ESP reduced the workability slightly but enhanced the mechanical properties of LFC (17.05 to 22.60 MPa compressive strength and 1.43 to 2.61 MPa tensile strength), thus satisfies the ACI213R requirements for structural lightweight concrete and that it can be used for structural applications. Additionally, the thermal conductivity reduced ranging from 0.55 to 0.63 W/mK compared to 0.82 W/mK achieved by control sample. Furthermore, the developed LFC showed a 16.96 to 33.55% reduction in embodied carbon and exhibited higher eco-strength efficiency between 47.82 and 76.97%. Overall, the combined utilization of POFA and ESP as SCMs not only enhanced the thermo-mechanical performance, makes the sustainable LFC as structural lightweight concrete, but also has reduced the environmental impacts caused by the disposal of POFA and ESP in landfills as well as reducing the total CO2 emissions during the production of eco-friendly LFC.
Introduction: Due to rapid urbanization, Malaysia is currently undergoing extensive amount of construction activities and significant rise in the construction waste. Improper construction wastes management practices have led to rise in the waste open dumping sites which may significantly affect the environment and public health. This study was undertaken to assess air pollution in such a site and the impact to the respiratory health of children studying in a nearby school. Methods: A comparative cross-sectional study was conducted in Sungai Buloh (exposed) and Kuala Selangor (comparative). Concentration of PM10 was monitored at the open dumping site (n=15), a nearby primary school (n=45) and a comparative primary school (n=12). Parents who gave consent (n=229) answered a questionnaire related to child’s respiratory health whereas their children participated in lung function assessment. Results: Concentration of PM10 at the dumping site, exposed school and comparative school was 0.245±0.048mg/ m3 , 0.270±0.020mg/m3 and 0.051±0.016mg/m3 respectively, with the first two significantly exceeded the 24-hour Malaysian Air Quality Standard (MAQS) for PM10 (0.150mg/m3 ). Besides, PM10 concentration in the exposed school was similar to the dumping site (p>0.05) and many folds higher than the comparative school (p
Food waste is a universal problem in many countries. In line with Sustainable Development Goals 7 and 12, it is crucial to identify a cost-effective food waste valorization management framework with the least human health and environmental impacts. However, studies on the synergistic effect of life cycle assessment and mathematical optimization interconnected with human health, environment, and economic are relatively few and far between; hence they cannot provide holistic recommendations to policymakers in developing environmental and economic feasibility of food waste management frameworks. Taking Malaysia as a case study, this study proposes a simple and deterministic model that integrates life cycle assessment and multi-objective mathematical optimization to unpack the health-environment-economic wellbeing nexus in food waste management sector. The model evaluates the life cycle human health, environmental, and economic impacts of five food waste disposal and valorization technologies: open landfill, sanitary landfill, aerated windrow composting, high-temperature drying sterilization, and anaerobic digestion, and identifies the optimal food waste valorization configuration solution in Malaysia. Based on the results modeled by SimaPro 9.0 and General Algebraic Modeling System with augmented ε-constraint, valorization of food waste into electricity via anaerobic digestion is the most favorable option, with 146% and 161% reduction of human health and ecosystems, respectively, as compared with open landfill. If cost is combined as an objective function with human health and ecosystems, high-temperature drying sterilization is the most attractive scenario due to the high livestock feed revenue. Among the 10 Pareto-optimal solutions, 9% sanitary landfill, 3% aerated windrow composting, 30% high-temperature drying sterilization, 30% anaerobic digestion to electricity, and 28% anaerobic digestion to cooking gas, is recommended as future food waste management configuration. The sensitivity results demonstrate that prices of electricity, cooking gas, and livestock feed affect the optimal configuration food waste management system.
Leachate is one of the main surface water pollution sources in Selangor State (SS), Malaysia. The prediction of leachate amounts is elementary in sustainable waste management and leachate treatment processes, before discharging to surrounding environment. In developing countries, the accurate evaluation of leachate generation rates has often considered a challenge due to the lack of reliable data and high measurement costs. Leachate generation is related to several factors, including meteorological data, waste generation rates, and landfill design conditions. The high variations in these factors lead to complicating leachate modeling processes. This study aims at identifying the key elements contributing to leachate production and developing various AI-based models to predict leachate generation rates. These models included Artificial Neural Network (ANN)-Multi-linear perceptron (MLP) with single and double hidden layers, and support vector machine (SVM) regression time series algorithms. Various performance measures were applied to evaluate the developed model's accuracy. In this study, input optimization process showed that three inputs were acceptable for modeling the leachate generation rates, namely dumped waste quantity, rainfall level, and emanated gases. The initial performance analysis showed that ANN-MLP2 model-which applies two hidden layers-achieved the best performance, then followed by ANN-MLP1 model-which applies one hidden layer and three inputs-while SVM model gave the lowest performance. Ranges and frequency of relative error (RE%) also demonstrate that ANN-MLP models outperformed SVM models. Furthermore, low and peak flow criterion (LFC and PFC) assessment of leachate inflow values in ANN-MLP model with two hidden layers made more accurate values than other models. Since minimizing data collection and processing efforts as well as minimizing modeling complexity are critical in the hydrological modeling process, the applied input optimization process and the developed models in this study were able to provide a good performance in the modeling of leachate generation efficiently.
Plastics have been one of the highly valued materials and it plays an significant role in human's life such as in food packaging and biomedical applications. Bioplastic materials can gradually work as a substitute for various materials based on fossil oil. The issue like sustainability and environmental challenges which occur due to manufacturing and disposal of synthetic plastics can be conquering by bio-based plastics. Feathers are among the most inexpensive abundant, and renewable protein sources. Feathers disposal to the landfills leads to environmental pollutions and it results into wastage of 90% of protein raw material. Keratin is non-burning hydrophilic, and biodegradable due to which it can be applicable in various ways via chemical processing. Main objective of this research is to synthesis bioplastic using keratin from chicken feathers. Extracted keratin solution mixed with different concentration of glycerol (2 to 10%) to produce plastic films. The mixture was stirred under constant magnetic stirring at 60 °C for 5 h. The mixtures are then poured into aluminum weighing boat and dried in an oven at 60 °C for 24 h. The mechanical properties of the samples were tested and the physic-chemical properties of the bioplastic were studied. According to the results, Scanning Electron Microscopy test showed good compatible morphologies without holes, cavity and edge. The difference in chemical composition was analyzed using Fourier transform infrared spectroscopy (FTIR). The samples were also characterized by thermo gravimetric analysis (TGA), differential scanning calorimetry (DSC), X-Ray diffraction (XRD) to check the thermal and crystallinity properties. Other than that, bioplastic made up from keratin with 2% of glycerol has the best mechanical and thermal properties. According to biodegradability test, all bioplastic produced are proven biodegradable. Therefore, the results showed possible application of the film as an alternative to fossil oil based materials which are harmful to the environment.
Background: Prolonged exposure of heavy metals in the respirable particulate matter (PM10) from municipal solid waste (MSW) landfills may affect children health. Objective: To investigate the association of reported respiratory symptom with heavy metals in PM10, with heavy metals in fingernails among children residing close to MSW landfills. Methods: Two groups of children age 7 to 12 years old were involved in this cross-sectional study. Those residing within 3 km radius from a landfill were the exposed group and those residing more than 3 km radius as the unexposed group. Questionnaires adapted from American Thoracic Society were applied in the survey. Fingernails were used as biomarker. Ten heavy metals elements in PM and fingernail samples were analysed using inductively coupled plasma mass spectrometry (ICP-MS). Results: The cadmium, chromium, copper, manganese, nickel and lead concentrations in PM around the MSW landfills and residential areas exceeded the Canada and USEPA standard permissible limit. Heavy metals in fingernails (p
This study determined the optimum conditions for preparation and adsorptive treatment of landfill leachate from banana pseudo-stem based activated carbon. Response surface methodology (RSM) based on Box-Behnken was applied to optimize the combination effect of three important reaction variables, i.e. activation temperature (°C), activation time and impregnation ratio (IR). The reaction was performed via a single step activation with ZnCl2 in a closed activation system. A series of 17 individual experiments were conducted and the results showed that the RSM based on BBD is very applicable for adsorptive removal of pollutants from landfill leachate treatment. The optimum conditions obtained by Design of Experiments (DOE) was at 761°C activation temperature, 87min activation time and 4.5g/g impregnation ratio with product yield (27%), iodine number (1101mg/g), color removal (91.2%) and COD removal (83.0%).
There is an interest in the sustainable utilization of waste cotton cloths because of their enormous volume of generation and high cellulose content. Waste cotton cloths generated are disposed of in a landfill, which causes environmental pollution and leads to the waste of useful resources. In the present study, cellulose nanocrystals (CNCs) were isolated from waste cotton cloths collected from a landfill. The waste cotton cloths collected from the landfill were sterilized and cleaned using supercritical CO2 (scCO2) technology. The cellulose was extracted from scCO2-treated waste cotton cloths using alkaline pulping and bleaching processes. Subsequently, the CNCs were isolated using the H2SO4 hydrolysis of cellulose. The isolated CNCs were analyzed to determine the morphological, chemical, thermal, and physical properties with various analytical methods, including attenuated total reflection-Fourier transform-infrared spectroscopy (ATR-FTIR), field-emission scanning electron microscopy (FE-SEM), energy-filtered transmission electron microscopy (EF-TEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The results showed that the isolated CNCs had a needle-like structure with a length and diameter of 10-30 and 2-6 nm, respectively, and an aspect ratio of 5-15, respectively. Additionally, the isolated CNCs had a high crystallinity index with a good thermal stability. The findings of the present study revealed the potential of recycling waste cotton cloths to produce a value-added product.
The remarkable journey of progression of mankind has created various impacts in the form of polluted environment, amassed heavy metals and depleting resources. This alarming situation demands sustainable energy resources and approaches to deal with these environmental hazards and power deficit. Pyrolysis and co-pyrolysis address both energy and environmental issues caused by civilization and industrialization. The processes use hazardous waste materials including waste tires, plastic and medical waste, and biomass waste such as livestock waste and agricultural waste as feedstock to produce gas, char and pyrolysis oil for energy production. Usage of hazardous materials as pyrolysis and co-pyrolysis feedstock reduces disposal of harmful substances into environment, reducing occurrence of soil and water pollution, and substituting the non-renewable feedstock, fossil fuels. As compared to combustion, pyrolysis and co-pyrolysis have less emission of air pollutants and act as alternative options to landfill disposal and incineration for hazardous materials and biomass waste. Hence, stabilizing heavy metals and solving the energy and waste management problems. This review discusses the pyrolysis and co-pyrolysis of biomass and harmful wastes to strive towards circular economy and eco-friendly, cleaner energy with minimum waste disposal, reducing negative impact on the planet and creating future possibilities.