Issue 1, February 2020
THERMAL ENERGY AND IGNITION PROPAGATION
ESTIMATES OF WATERMELON PEEL BRIQUETTES
A.R. Ige*1, C.M. Elinge1, L.G. Hassan2, D.R. Akinkuotu3, O.J. Ajakaye1
1Department of Pure and Applied Chemistry,
Kebbi State University of Science and Technology, Aliero, Nigeria
2Department of Pure and Applied Chemistry, Usmanu Danfodiyo University, Sokoto, Nigeria
3Starville School, First Avenue, Gwarinpa, Abuja.Nigeria
The idea of utilizing biomass as renewable energy source is appealing due to its accessibility, cheapness and ecological friendliness. Briquette is an alternative source of fuel to firewood and charcoal which can avoid some environmental problems that can be generated from their use. Briquettes were produced from watermelon peels with cassava starch and gum Arabic as binders, the two binders were chosen because they are naturally abundant in rural communities. The briquettes produced have favourable thermal and ignition propagation properties which are contributed by the initial raw material (watermelon peels) properties such as density, calorific value, resistance to humidity, moisture content, ash content etc. It can be concluded that the higher the ignition propagation the higher the thermal energy of the briquettes.
Keywords: Briquette, watermelon, biomass fuel, binder, starch, gum Arabic
EXPERIMENTAL RESEARCH ON CONSTRUCTION-WASTE-CLASSIFICATION ALGORITHMS FOR A HYPERSPECTRAL-CAMERA SYSTEM
Yuedong Ku1, Jianhong Yang1*, Huaiying Fang1, Jiangteng Zhuang1, Wen Xiao1
1Key Laboratory of Process Monitoring and System Optimization for Mechanical and Electrical Equipment (Huaqiao University), Fujian Province University, Huaqiao University, College of mechanical engineering and automation, Xiamen, Fujian Province, China
No. 668, Jimei Street, Xiamen City, Fujian Province 361021, China
Tel: 86-18959291108, firstname.lastname@example.org
A large proportion of construction waste has a high recovery value, and some of the existing recycling-classification methods rely mainly on physical properties for vibration screening. In order to effectively recover construction waste, an industrial near-infrared hyperspectral camera is proposed in this paper to distinguish the spectral characteristics of the objects. The testing results were verified using an extreme learning machine, an adaptive-learning multilayer perceptron, and a one-dimensional convolutional neural network classification model. By establishing several different models to classify and identify the same kinds of experimental materials, the experimental results not only output the correct recognition rate, but also use the recognition efficiency and stability as indices for comprehensive evaluation. The results show that different classification models have different efficiencies and levels of correctness. Under different analytical conditions, such as when using data from different bands, it is very important to select the appropriate classification model to classify construction waste.
Keywords: Classification, construction waste, extreme learning machine, hyperspectral data
OF PORTLAND CEMENT PASTES REHYDRATED
Tiago Assunção Santos*, Guilherme Augusto de Oliveira e Silva, Daniel Véras Ribeiro
Federal University of Bahia, Dept. of Material Science and Technology, Technical School,
Rua Aristides Novis, 02. Federação, 40210-630, Salvador/BA, Brasil
Hydrated products, such as (hydrated) cement pastes, decomposition through physical-chemical alterations when submitted to high temperatures. One of the main factors that lead to microstructural changes during calcination up to 800ºC, is the dehydration phases of hydrated Portland cement. The present study sought to characterize crystalline phases occurring before and after calcination to the produced pastes using X-ray diffraction (XRD) analysis. Cement pastes were produced using Portland cement CP V-ARI RS, similar to type II (ASTM C150-07), with water/cement ratio 0.5. After a 28-day curing period, the pastes were calcinated at 800°C for 60 minutes with a 10°C / min heating rate. Afterwards, the newly produced hydraulic binder was cooled abruptly and reactivated through a rehydration process, and underwent analyses on the 7 and 28 day. During this study it was observed that the originally hydrated products can be rehydrated.
Keywords: Cement dehydration; cement rehydration; incineration
AN ECONOMIC, TECHNICAL AND ENVIRONMENTAL FEASIBILITY STUDY FOR SLURRY INJECTION FOR BIOSOLIDS MANAGEMENT IN THE DALLAS FORT WORTH METROPLEX
Panchal, Y., Mohamed, I.M., Dale Pierce, Mounir, N., Abou-Sayed, O.,
Loloi, M., Abou-Sayed, A.S.
Advantek Waste Management Services
11000 Richmond Ave, Ste 195 Houston, TX 77042
In Dallas Fort Worth (DFW), sewage is treated with a combination of anaerobic digestion, effluent filtration and lime stabilization to create biosolids which are then composted, landfilled, or land applied. The current treatment procedure has certain concerns including emissions or accumulation of odors, pathogens, nutrients, metals, and pharmaceutical products.
An alternative method, the Slurry Injection technique, enables the digestion of biosolids in the deep earth and can replace the current practice of wastewater treatment or disposal in a much more environmentally friendly and cost-efficient manner. By completely sequestering methane and CO2 into deep geologic formations which are produced as biosolids breakdown, reduces the greenhouse gas emissions and enables the operator to create greenhouse gas emission offset credits which can be marketed to offset the operating costs.
The economic, environmental, and technical aspects of building a new biosolids slurry injection facility in DFW, includes both the surface construction requirements as well as the subsurface strata evaluation for containment assurance. For the subsurface aspects, a geomechanical and stress analysis is performed on the Atoka formation (near the city of Fort Worth) and it confirms a confining layer above and below the injection zone to keep the waste contained for permanent storage.
Keywords: Biosolids/Slurry Injection, Environment Friendly, CO2 and Methane Sequestration, Economic Process, Advanced Waste Disposal Technique, Deep Geological Digestion
RECYCLED PVC AS MATERIAL FOR NATURAL FIBER COMPOSITE MANUFACTURING—STUDY OF MECHANICAL PERFORMANCE AND DURABILITY
Turku Irina*, Kärki Timo
Fiber Composite Laboratory, School of Energy Systems,
Lappeenranta University of Technology, Lappeenranta, Finland
Manufacturing wood plastic composites from polyvinyl chloride (PVC) construction waste is one of the options for its continuously increasing scrap utilization. The aim of this study is to estimate the mechanical properties and durability of composites manufactured from recycled and commercially available PVC grades. The mechanical properties of PVC were reduced significantly after wood flour loading, showing weak compatibility between the matrix and the wood fibers. The composites from both PVC sources had weak durability, declining by up to 64% in tensile strength. The composite samples from recycled PVC displayed, however, better resistance to weathering compared to the composites from neat PVC. Chemical analysis of the composite surfaces by infrared spectroscopy and morphology study with a scan electron microscope before and after weathering confirmed the mechanical test results.
Keywords: Polyvinyl chloride, mechanical recycling, wood plastic composites, mechanical properties, durability
SELECTING SUSTAINABLE TECHNOLOGIES
FOR MUNICIPAL SOLID WASTE TREATMENT AND DISPOSAL: AN EXPERT BASED MCDM APPROACH
*Manoj Govind Kharat1, Shankar Murthy1, Sheetal Jaisingh Kamble2, Mukesh Govind Kharat1
1National Institute of Industrial Engineering (NITIE)
Vihar Lake Road, Powai, Mumbai – 400087, State: Maharashtra, India
2Assistant Professor, School of Sciences, PP Savani University, Surat – 394125, State: Gujrat, India
Selection of appropriate municipal solid waste (MSW) treatment and disposal technology is a complex multi-criteria process. This paper demonstrates the reliability of the use of multi-criteria decision-making (MCDM) framework for the purpose of selecting the best MSW treatment and disposal alternatives. In this paper, a modified fuzzy Delphi-AHP-TOPSIS methodology is developed for the selection of the most appropriate MSW treatment and disposal technology. The study provides a systematic three-stage methodology towards technology selection. In the first stage, experts’ opinions were sought to select the relevant criteria and the fuzzy Delphi Method (FDM) was used to obtain the critical factors for the evaluation of alternatives. In the second stage, the criteria weights and their importance degree were calculated by using AHP. Finally, the TOPSIS technique was used for ranking the alternatives to determine the most appropriate option. The study identifies a minimal relevant set of evaluation criteria and appropriate technologies for the handling, treatment and disposal of MSW in a more economical and environmentally sustainable way. Thus, the developed MCDM framework enables decision-makers to make informed decisions and achieve optimal results. It helps the decision makers select the best possible technology in a scientific manner. To demonstrate the approach taken, a real case of Mumbai city is taken.
Keywords: Municipal solid waste, Technology selection, Environmental management, Fuzzy Delphi, AHP, TOPSIS
EFFICIENCY OF MUNICIPAL SOLID WASTE
COLLECTION SYSTEMS IN GHANA
Alhassan Sulemana1*, Emmanuel A. Donkor2, Sampson Oduro-Kwarteng2
1Department of Environmental Science, Kwame Nkrumah University of Science and Technology,
Private Mail Bag, University Post Office, Kumasi, Ghana
2Department of Civil Engineering, Kwame Nkrumah University of Science and Technology,
Private Mail Bag, University Post Office, Kumasi, Ghana
For purposes of establishing a benchmark against which performance of municipal solid waste (MSW) collection systems can be evaluated by sector regulators, investors and managers, this study assessed the cost efficiency of MSW collection systems in Ghana, using stochastic frontier analysis (SFA). Data from seventy municipal solid waste collection systems were used to estimate the parameters of a Cobb-Douglas cost function. The study developed a cost function, estimated the parameters using maximum likelihood, and applied SFA to determine the efficiencies. Four variables (quantity of waste collected, distance travelled, fuel consumed and number of trips) which affect operating cost were used to estimate the efficiency. Results from the analysis showed that the cost efficiencies ranged from 59.82% to 93.23%, with a mean value of 84.16% and, that fuel consumed was the significant cost driver at the 5% significant level. Efficiencies for Municipal Assemblies ranged from 71.80% to 90.77%, with a mean value of 84.26% while District Assemblies recorded 59.82% to 93.23%, with a mean value of 83.79%. There was no significant difference in the mean relative efficiency estimates of the District and Municipal Assemblies. The findings establish a benchmark and methodology, essential for industrial players in performance evaluation. The study also serves as a resource material for further study in performance evaluation of solid waste collection systems, particularly in developing economies.
Keyword Stochastic Frontier Analysis, Cost Function, Solid Waste Collection, Operating Cost
EFFECT OF INCORPORATING TIRE RUBBER WASTE
ON THE MECHANICAL BEHAVIOUR OF RAILWAY BALLAST LAYER: EXPERIMENTAL AND MODELLING STUDIES
Hafsa Ben Jemaa*, Saloua El Euch Khay, Ph.D.,
Amara Loulizi, Ph.D., P.E. , Jamel Neji, Ph.D.
Tunis El Manar University, Laboratory of Materials, Optimization and Energy for Sustainability (LRMOED), National Engineering School of Tunis, B.P. 37 Le Belvédère, 1002, Tunis, Tunisia; Email:
Phone: 21622581697; Fax: 21671872729
In order to delay the degradation of railway tracks, several techniques have been developed in recent years; the best known of which are: under sleeper pads, geogrid and the use of polymers as elastic elements between ballast particles. The objective of the research described in this paper is to evaluate the effectiveness of incorporating tire rubber waste into the ballast layer in reducing its settlement. For that purpose, a small-scale testing laboratory setup has been developed, which consists of a bi-block concrete sleeper surrounded by a layer of ballast. The developed apparatus is subjected, through the actuator of a servo-hydraulic machine, to a vertical cyclic force reproducing the passage of a train bogie. This study has been performed in two stages: the first is to identify a suitable existing model that well-describes the ballast settlement with cycle applications and the second is to study the influence of the variation of the percentages of addition of rubber on the behaviour of the ballast layer. Finally, a finite element model was developed to simulate the experimental setup. The results show that using 10% of tire waste rubber could decrease the track settlement and reduce the breakage of ballast particles.
Keywords: Railway track, Ballast, Tire rubber, Small-scale setup, Settlement-model, Finite element
HOUSEHOLD SOLID WASTE MANAGEMENT IN MONROVIA, LIBERIA: INFLUENCING FACTORS, CHARACTERISTICS, AND MANAGEMENT SOLUTIONS
Victor Emery David Jr.a*, Jiang Wenchaoa, Daniel Mmerekib
aFaculty of Urban Construction and Environmental Engineering,
Chongqing University, Chongqing, 400045, PR China
bOccupational Health Division, School of Public Health, University of the
Witwatersrand, Parktown, 2193, Johannesburg, South Africa
The ineffective management of household solid waste (HSW) in most developing cities in Africa including Monrovia has become a major issue threatening the environment and public health. In response to these waste challenges, developed countries have embarked upon major environmental reforms, and have made advances in best practices and sustainable management of their Municipal Solid Waste (MSW). However, in most developing countries like Liberia, such environmental reforms have not been initiated and therefore the situation has become compounded; this is due to several factors impeding the development of a sustainable municipal solid waste system. This study, therefore, aims to critically analyze the influencing factors of solid waste management; the characteristics of household waste and suggest management solutions for effective and sustainable management.
Results from the analysis of data, using The Ordinary Least Square Regression (OLS) method estimates the average household waste per capita generation as 0.76kg/capita/day. Regarding the composition of the waste stream, the results show that 67% of the waste sampled from Monrovia is biodegradable and mostly comprised of high wet weight and high moisture content kitchen waste. On the other hand, the remaining percentage is mostly non-degradable but recyclable materials such as glass ceramics and metals. This suggests that due to the high moisture content in the waste, samples are suitable for composting and other mechanical and biological management options. Using the stratified sampling method, 300 households were chosen. Multiple regressions were conducted to determine the relationship between waste generation and socio-economic factors and these showed that the effect of income, household size and the environmental concern on HSW generation is statistically significant at a 1% significance. However, further findings revealed a negative relationship between income and HSW generation at a 1% level of significance. These findings provide new insight regarding the role of socio-economic characteristics affecting the generation of household waste in Monrovia.
Keywords: Household Solid waste (HSW), Influencing factors, Waste Generation, Management, Monrovia, Liberia
SOLID WASTE MANAGEMENT POLICIES IN KENYA:
THE SILENCE ON THE PLIGHT OF WOMEN AND CHILDREN
Dickson A. Amugsi1*, Jane N. Mwangi1, 2, Tilahun Nigatu Haregu1, Isabella Aboderin1,
Kanyiva Muindi1, Blessing U. Mberu1
,1African Population and Health Research Centre (APHRC), Box 10787-00100, Nairobi, Kenya
2Diaspora Interlink, P.O Box 19208-00100, Nairobi, Kenya, Tel: +254737140000
APHRC Campus, P.O Box 10787-00100, Nairobi, Kenya
Tel: +254204001125, Fax: +254204001101
Building on available evidence that there are differences of exposure to solid waste among men, women and children, it follows that effective solid waste management (SWM) policies need to recognise such variations, as a prelude to rolling out programmes to address associated socio-economic and health risks. However, this logical scenario does not seem to be the case in many middle- and low-income countries. In this paper, we use analytical review methodology to examine integrated environmental management and sector specific policies in Nairobi and Mombasa, Kenya’s two biggest cities, to highlight the extent to which existing policies cover the differential challenges of exposure to solid waste and associated health challenges for women and children. We found that apart from one municipal policy and the Kenya Vision 2030 documents respectively, which underscore the importance of including women and young people in waste management, 16 other policy documents reviewed are generally silent on women and children issues. Beyond the limited focus on women- and children- specific challenges, the general lag in policy implementation and enforcement of regulations will still hinder the emergence of an effective SWM system out of the best policy frameworks. The preceding discussion underscores both policy and implementation gaps, which need to be filled, if policies will potentially engender SWM practices that will be relevant and effective in protecting the health of the most vulnerable in urban Africa.
Keywords: Solid waste, policy, women, children, Kenya
A STUDY ON ENVIRONMENTAL IMPACT
OF MSW LANDFILL SITE OF TWO DIFFERENT REGIMES
Rubina Chaudharya*, Shukti Singhb and Nighat Ganic
a*Professor, bResearch Scholar, cM.Phil Student
School of Energy and Environmental Studies, Devi Ahilya University,
Takshshila Campus, Khandwa Road, Indore-452017, INDIA
Tel: 91-731-2460309 (O)
This paper assessed an Environmental Impact Assessment (EIA) for Municipal Solid waste landfill sites of two different regimes. The study deals with two sites of entirely different geographical areas and waste generation pattern. India enforced Municipal Solid Waste Management and Handling rules,2000 and its subsequent amendments for all the cities and towns having entirely physical and climatically different conditions for solid waste management. Still, MSW dumped in open places without any treatment results in severe environmental impacts in and around the surrounding areas, making it essential to assess its impact. Quantitative assessment of ground water, soil and air quality was determined. Whereas in this study, we used Rapid Impact Assessment Matrix (RIAM), because all the components and parameters can easily be integrated into one platform, applying the criteria that were considered to be the most significant in the evaluated cases to compare the environmental and social impact of the two MSW dump site. The RIAM results revealed that the method could be used for comparison and ranking of separate and distinct areas, based on their negative or positive impact. No significant difference was observed in the scoring of the two sites, i.e. the Indore city landfill obtained slightly more negative scoring (100%) than Srinagar landfill (96.6%). The decomposition of waste seems to be more in Indore than in Srinagar due to cold climatic zone. The paper reveals the adverse impact of dump sites on the nearby areas in both the regions.
Keywords: Environmental impact Assessment, MSW Dumpsites, RIAM analysis, Devguradia landfill, Acchan landfill
NUTRIENT AND EXO-ENZYME DYNAMICS
IN ORGANICALLY AMENDED IRON MINE SPOIL
Samrudhi Nayak1, S.P Mishra2, C.S.K Mishra1*
1Department of Zoology, Orissa University of Agriculture and Technology
College of Basic Science and Humanities, Bhubaneswar-751003, India
2School of Life Sciences, Sambalpur University, Jyoti Vihar, Burla-768019,India
The aim of this study is to restore the nutrient status of iron ore mine spoil through suitable organic interventions. This paper reports the effects of different organic manure and bio-fertilizer amendments with inoculation of the earthworm Eisenia fetida in iron mine spoil on certain chemical parameters, microbial load and soil exoenzyme activities. The mine spoil samples were collected at random from five years old spoil dump and amended with farmyard manure (FYM), poultry manure (PM) and vermimanure (VM) along with biofertilizer in different combinations. The pH, conductivity, % organic carbon, N,P,K, bacterial and fungal population with activities of soil exoenzymes amylase, cellulase and invertase were studied in organically amended mine spoil. Significant variations (p<0.05) in the chemical and biological parameters were observed between treatments and days of incubation. Higher values were obtained with PM followed by FYM and VM. Earthworm inoculation enhanced the values of all the chemical parameters except % organic carbon. Bacterial population and exoenzyme activities increased significantly (p<0.05) with earthworm. PM with biofertilizer was found to be the most suitable combination followed by FYM. Inoculation of Eisenia fetida could facilitate mineralization of organics resulting in higher nutrient availability, higher microbial load and exoenzyme activities required to facilitate spoil reclamation.
Keywords: Earthworm, Eisenia fetida, exoenzyme, iron mine spoil, organic amendment, biofertilizer
SIMULATING CONTINUOUS COUNTER-CURRENT LEACHING PROCESS FOR INDIRECT MINERAL CARBONATION UNDER MICROWAVE IRRADIATION
Zhibo Tong 1,2, Guojun Ma2,*, Dan Zhou1
1The Key Laboratory of Extraordinary Bond Engineering and Advanced Materials Technology,
Yangtze Normal University, Chongqing 408100, China
2The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan 430081, China
Tel.: +86 27 68862810, Fax: +86 27 68862529
Mineral carbonation is a promising avenue to realize a deep reduction in carbon dioxide emissions. Though many methods were studied to improve the leaching ratio of mineral leached by ammonium salt, little attention has been received to the problem that the calcium leaching ratio increases while its concentration drops rapidly with the liquid-solid ratio increasing. The continuous counter-current leaching for mineral carbonation process under microwave irradiation is proposed in this study, and the results show that the simulating continuous counter-current leaching process in this article not only is beneficial to improve the leaching ratio and concentration of calcium ions in solution at the same time, but also increases the relative purity of calcium in leached solution. And the produced calcium carbonate products meet the requirements of industrial precipitation of calcium carbonate.
Keywords: Continuous Counter-current leaching; Indirect Mineral carbonation; Calcium carbonate; Ammonium chloride; Microwave irradiation