Issue 4, November 2011
ACTIVATED CARBON PRODUCED FROM AGRO-FORESTRY WASTES USING SINGLE-STEP STEAM PYROLYSIS
Ignatious Ncube*1, Vincent Murotho2, Victor Chipofya2 and Gordon McConnachie3 1Department of Biochemistry, Microbiology and Biotechnology School of Molecular and Life Sciences, University of Limpopo P.Bag X1106, Sovenga 0727, SOUTH AFRICA 2University of Malawi, The Polytechnic Private Bag 303, Chichiri, Blantyre 3, MALAWI 3School of Engineering and Electronics, Institute for Infrastructure and Environment University of Edinburgh, The King’s Buildings, Edinburgh, UNITED KINGDOM
Adsorption by activated carbon is a suitable and efficient method for the removal of impurities from waters. In most developing countries, activated carbon is imported at high cost and as a result activated carbon use is limited. Southern Africa has, in abundance, agro-forestry waste materials that may be suitable precursors for activated carbon. We assessed the viability of carbon production from agro-forestry waste materials using a simple, single-step steam pyrolysis process. A number of precursor materials from farming and forest regions in Malawi and Zim-babwe were used to produce activated carbon at laboratory scale. To produce the activated carbons, each material was heated in a steam atmosphere at temperatures of 650, 750 and 800oC for 30 minutes. The resulting carbons were tested for their ability to remove contaminants from water using phenol adsorption and determination of their iodine numbers. The majority of waste materials produced carbons with properties similar to, and in some cases better than, those of the commercial carbons. Based on their adsorption properties, Marula (Sclerocarya birrea) fruit stones and corn (Zea mays) cob stems have been identified as the most promising adsorption carbon precursors for possible scaled up production in southern Africa.
Keywords: Activated carbon, adsorption, phenol, water
EFFECT OF FILTER MUD APPLICATIONS ON SUGARCANE GROWTH AND SOIL CHEMICAL AND PHYSICAL PROPERTIES
T.M. Elsayeda*, H.M. Babikerb, E.M. Abdelmalikb, N.O. Mukhtarc, D. Montanged
aIndustrial Research Section, Research & Development Centre Kenana Sugar Company, P.O. 2632, SUDAN bDepartment of Soil and Water Science, Faculty of Agricultural Sciences University of Gezira, SUDAN cGezira Research Station ARC, SUDAN dCIRAD PERSYST Department, TA B78/01, 34398 Montpellier Cedex 5, FRANCE
Effect of filter mud applications on sugarcane growth and soil chemical and physical properties was investigated. A pot experiment was set up in 2006 at the Kenana Sugarcane Estate, Su-dan. For this study, 0%, 25%, 50%, 75% and 100% FM/soil “w/w” mixtures were used in a ran-domized complete block design with three replications. Sugarcane variety CO6806 was used. Observations included germination %, number of tillers, plant height and dry matter content af-ter four months of growth. Chemical analyses of soil and bulk density were determined. Results revealed that the application of filter mud favoured germination of sugarcane setts and in-creased the number of tillers. Plant height increased with moderate amounts of filter mud. Planting of sugarcane in filter mud alone adversely affected the dry matter content. Organic carbon, total N, total and available P increased with the increase in the amounts of FM in the mixture. Bulk density decreased with the increase of filter mud concentration in the mixture.
Keywords: Filter mud, Sugarcane, organic carbon, Nitrogen, Phosphorus
CHARACTERIZATION OF TANNERY SOLID WASTES BASED FERTILIZERS AND FISH-FOOD
B. Chattopadhyay1, A. Roy Goswami1*, A. Aich1, S. Datta2, S.K. Mukhopadhyay3 1Government College of Engineering and Leather Technology, Block –LB Sector- III Salt Lake City, Kolkata-700 098, INDIA 2Department of Chemical Engineering, Jadavpur University Jadavpur, Kolkata 700 032, INDIA 3Hooghly Mohsin College, Chinsurah, Hooghly
Email: email@example.com; Tel: +91-9831931952; Fax: +91-33-23356977
Solid wastes generated for processing of raw hides contain nearly 30% fleshing and around 6% shaving dust. Fleshing is used extensively as fish food as it is rich in protein. Shavings are processed to produce some kind of fertilisers. The elemental composition of fleshing and shav-ing dust revealed high C content (57.67% w/w) in fleshing, compared to raw hides and skins and shavings which have a carbon content of 50.2% and 42.78% w/w respectively. High energy content in fleshing 6.40 kcal g-1 compared to raw hides and skins 5.61 kcal g-1 is due to the higher percentage lipid in subcutaneous tissues, shaving dust on the other hand contains the least energy 5.41 kcal g-1. Physico chemical analyses of aqueous extract of shaving dust and fertiliser reveals significant increase in pH, total acidity and total alkalinity in fertiliser than shav-ing dusts. High total chromium (340.69 mg kg -1), lead (8.83 mg kg -1) content and low pH could lead to metal contamination and soil acidification. Necessary modifications are needed for the eco-friendly use of fleshing and shaving dust to avoid chances of heavy metal contamination of the environment and the agricultural produces.
Keywords: Tannery solid wastes, CHNO analysis, energy content, fertilizer, fish food, piscicul-ture
SEQUESTERING LEAD BY UTILIZING LEAD-BASED PAINT (LBP)-CONTAMINATED MASONRY MATERIALS AS RECYCLED AGGREGATE IN PORTLAND CEMENT CONCRETE
Jiong Hu1, Kejin Wang2, James A. Gaunt3
1Assistant Professor, Department of Engineering Technology Texas State University–San Marcos, San Marcos, TX 78666, USA Phone: (512) 245-6328, Fax: (512) 245-3052, Email: firstname.lastname@example.org
2Associate Professor, Department of Civil, Construction and Environmental Engineering Iowa State University, Ames, IA 50011, USA Phone: (515) 294-2152, Fax: (515) 294-8216, Email: email@example.com
3Manager, Environmental Engineering Research Laboratory Department of Civil, Construction and Environmental Engineering Iowa State University, Ames, IA 50011, USA Phone: (515) 294-8768, Fax: (515) 294-8216, Email: firstname.lastname@example.org
A systematic study has been conducted to evaluate the ability of portland cement to sequester lead in concrete. Four different masonry materials (two types of concrete blocks and two types of clay bricks) that contained lead-based paint (LBP) were crushed and used as aggregate in concrete. Properties such as gradation, absorption and lead toxicity of the masonry materials are characterized. Workability, unit weight and compressive strength of the concrete are meas-ured. Leachability of lead was characterized by the toxicity characteristic leaching procedure (TCLP). The results indicate that lead in LBP-contaminated, recycled aggregate can be seques-tered in well-designed concrete due to the high alkalinity of portland cement. Concrete made with LBP-contaminated, recycled aggregates possesses proper workability and strength and can therefore be used satisfactorily for a variety of constructions.
Keywords: Aggregate, concrete, lead, masonry, recycled
SIGNIFICANCE OF THE SOURCE OF WASTE USED TO PRODUCE AUTOTHERMAL AEROBIC DIGESTED BIOSOLIDS ON THE APPARENT PHYTOAVAILABILITY OF COPPER AND ZINC
A. Unca*, G. Hoekstrab
aNew Mexico State University, 945 College Avenue MSC 3Q, Las Cruces, New Mexico 88003-8003, USA Email: email@example.com bUniversity of Guelph, Kemptville Campus Box 2003, 830 Prescott Street, Kemptville, Ontario K0G 1J0, CANADA
While treatment of organic wastes does not change the amount of metal that leaves a waste treatment facility it may affect their chemical form and thus their behavior in the environment. Autothermal aerobic digestion (ATAD), relatively new in use in North America, can produce bio-solids from a wide range of wastes. Currently there are no reports on how the parameters of the ATAD treatment cycle or the waste feedstock affect metal phytoavailability and thus potential bioremediation efforts. We assessed phytoavailability of copper and zinc from ATAD biosolids of three waste types, obtained at five distinct locations in USA and Canada, and at full-scale or pilot plants. Three plant species with different growth parameters were used. While all tested ATAD biosolids had large organic carbon contents, results indicate that metal phytoavailability was clearly dependent on the type of organic waste fed to the ATAD systems, independent of their apparent quality as determined by chemical testing. Total metal concentration was not a good indicator of plant uptake.
Keywords: Autothermal aerobic digestion (ATAD), biosolids, copper, zinc, phytoavailability, metal uptake
SURVEY OF HOUSEHOLD WASTE GENERATION AND COMPOSITION TO DRIVE STRATEGY DEVELOPMENT—A CASE OF THREE RESIDENTIAL AREAS IN DOUALA, CAMEROON
Lawrence Oben Mbeng The University of Douala, Institute of Fisheries and Aquatic Sciences of Yabassi P.O. Box 7236, Bassa Douala, Cameroon, UK Email: firstname.lastname@example.org
Terry Tudor, Roy Fairweather School of Science and Technology, Newton Building, Avenue Campus University of Northampton, Northampton UK, NN2 6JD Email: email@example.com; Roy.Fairweather@Veolia.co.uk
Household waste is a major environmental problem in Cameroon. In order to know the compo-sition, distribution and quantities generated in the high, medium and low income residential areas (HIRA, MIRA and LIRA) of Douala, a waste composition study based on seasonality (February and April of 2008) was undertaken. In the waste composition study, we found that waste generation per capita was high, LIRA (1.38kg), MIRA (1.10kg) and HIRA (0.86kg) on av-erage compared to municipalities in other developing countries in Africa. However, we did not find a statistically significant relationship between waste generation and household size in the LIRA. In the MIRA and HIRA the positive correlation between waste generation and household size could be linked to the increase in consumption orientated lifestyles and qualitative change in consumer goods in Cameroon. It was found that the waste stream was predominantly pu-trescible with 62% by weight in the LIRA, MIRA (54.3%) and HIRA (19.2%) and contained few recyclable materials (4.6% by weight in the LIRA, MIRA (5.6%) and HIRA (12.9%). The results demonstrate the importance of a waste composition study for assessing whether composting and the recovery of recyclables is a feasible option and an important income source for local communities.
Keywords: Household waste; waste composition study; composting; recycling
ENZYMATIC DEINKING WITH CELLULASES: A REVIEW
Nitin Verma*, Mukesh C. Bansal, Vivek Kumar
Department of Paper Technology, Indian Institute of Technology Roorkee, Saharanpur Campus, Saharanpur, U.P. 247001, INDIA
The use of recycled fibers has increased greatly over the last few decades, particularly due to many successful deinking operations. Besides being a low cost fiber source for paper manufac-turing, it preserves forest resources, reduces environmental pollution and conserves water and energy. As waste paper is the largest component of solid waste stream, enzymatic recycling could be a better way to manage this. But the removal of ink remains a major technical hin-drance for a greater use of recycled paper. Enzymatic deinking provides a novel means to con-vert recycled fibers into quality product. Results from enzymatic deinking with cellulases appear promising, which indicate that enzymes facilitate easy ink removal with significantly improved pulp and paper properties such as brightness, tear index, tensile strength, ERIC value, residual ink area, freeness in comparison to conventional deinking. Enzymatic deinking also reduces load on waste water treatment by minimizing the COD value of the water effluent. This paper describes the role of cellulase in enzymatic deinking and its effect on pulp and paper properties of various grades of waste papers.
Keywords: Cellulase, Endoglucanase, Brightness, ERIC value, BOD, COD
FIELD INVESTIGATION OF CONCRETE INCORPORATING MILLED WASTE GLASS
Roz-Ud-Din Nassar1 and Parviz Soroushian2
1Research Associate, Civil and Environmental Engineering Department Michigan State University, USA Email: firstname.lastname@example.org; Telephone: +1 517 993 7017
2FACI, FASCE, Professor of Civil and Environmental Engineering Michigan State University, USA
About 12.5 million tons of waste glass is generated annually in the U.S., 77% of which is dis-posed of in landfills. Waste glass can be cost-effectively collected in mixed colors, but has li-mited markets. Mixed-color waste glass offers desired chemical composition and reactivity for use as a supplementary cementitious material for enhancing the chemical stability, moisture re-sistance and durability of concrete. To realize this potential, waste glass needs to be milled to micro-scale particle size for accelerating its beneficial chemical reactions in concrete. In this in-vestigation, recycled glass concrete was produced by partial replacement of cement with milled waste glass. Recycled glass concretes with 15, 20 and 23 wt.% of cement replaced with milled glass were investigated in field (pavement) construction projects. The compatibility of recycled glass concrete with conventional construction techniques was evaluated, and the field perfor-mance of recycled glass concrete under weathering effects (in mid-Michigan) was monitored over a two-year period. Compressive strength, water sorption, chloride permeability, and abra-sion resistance tests of recycled glass concretes were performed on cores drilled from the ex-perimental pavements, and the results were compared with those obtained with normal con-crete. Flexural strength tests were carried out on concrete specimens at various ages. Test re-sults indicated that recycled glass concrete incorporating milled waste glass as partial replace-ment for cement offers excellent strength and durability attributes when compared with normal concrete. The pozzolanic reactions of milled waste glass with cement hydrates improve the mi-crostructure and chemical composition of concrete. Use of milled waste glass in concrete as partial replacement of cement represents an important step towards development of sustaina-ble (environmentally friendly, energy-efficient and economical) concrete-based infrastructure systems.
Keywords: Waste glass, recycling, supplementary, cementitious material, concrete, energy saving, environmentally friendly, economics
Issue 3, August 2011
RECYCLING OF WASTE GLASS IN MORTAR MIXTURES
Nabil M. Al-Akhras*, Ayman N. Ababneh**, Imad A. Al-Qasem***
*College of Engineering, University of Dammam, Dammam, KSA
(on sabbatical leave from Jordan University of Science and Technology)
**Civil Engineering Department, Jordan University of Science and Technology, Jordan
***Civil Engineering Department, An-Najah National University, Nablus
There is a growing environmental concern in many countries around the world from the accumulation of solid waste glass since not all glass can be recycled into new glass. This study explores the recycling of solid waste glass in concrete mixtures to reduce the environmental pollution and to improve the properties of concrete material. Three waste glass powder (WGP) levels were considered in this study: 5%, 10% and 15%. The properties investigated include: setting time, workability, compressive and flexural strength and micro-structure of mortar. The mortar mixtures proportions were 1:3:0.7 by weight for cement, sand and water, respectively.
The results showed that the solid waste glass can be recycled in cement concrete mixtures and improve the properties of concrete. The setting time of cement paste increased and the workability decreased with the increase of the WGP content. The compressive strength of mortar increased with the increase of WGP as partial replacement of limestone sand under moist curing. The flexural strength of mortar increased with the increase of WGP as partial replacement of cement or sand under moist curing. The autoclaved WGP mortar showed higher compressive strength and lower flexural strength compared to the moist cured mortar. The scanning electron microscopy images showed that WGP material is good filler because it reduced the porosity of mortar.
Keywords: Autoclaving; Mortar; Mechanical properties; Setting time; Waste Glass powder; Workability
REMOVAL AND RECOVERY OF PENTACHLOROPHENOL ONTO LOW COST NANO POROUS CARBON—KINETICS AND ISOTHERMS
R. Subha, C. Namasivayam*
Environmental Chemistry Division, Department of Environmental Sciences
Bharathiar University, Coimbatore – 641046
Removal and recovery of pentachlorophenol (PCP) from aqueous solution was investigated using ZnCl2 activated carbon developed from coir pith (ZnCPC), an agricultural solid waste. Variables studied include adsorbate concentration, adsorbent dose, pH and temperature. Langmuir, Freundlich, Dubinin Radushkevich (D-R) and Temkin isotherms were used to model the adsorption equilibrium data and the system followed Langmuir and Freundlich isotherms. Langmuir adsorption capacity of the adsorbent was found to be 189 mg/g. Kinetic studies showed that the adsorption obeyed second order kinetics. Effect of temperature on adsorption was not significant. pH effect and desorption studies showed that ion exchange mechanism might be predominant at pH 10.0 in the adsorption process. Removal of PCP from synthetic wastewater was also tested.
Keywords: Coir pith, ZnCl2 activated carbon, Adsorption, Kinetics, Isotherms, pH effect
CHARACTERIZATION OF AIR-QUENCHING STEEL SLAG AND ITS UTILIZATION AS ADMIXTURE IN PORTLAND CEMENT
Guanghong Sheng1, Yaqin Mou1, Xinrong Wu 2, Liaosha Li2
1School of Architecture and Civil Engineering, Anhui University of Technology
Maanshan 243002, CHINA
2Anhui Provincial Key Laboratory for Metallurgical Engineering & Resources Recycling
Anhui University of Technology, Maanshan 243002, CHINA
Steel slag coming from air quenching process is different from slags from other pretreatment processes, such as air cooling process, hot-splashing process, etc. This research investigated the characterization of steel slag producing from the air-quenching process and its utilization in Portland cement. The results showed that the air-quenching steel slag was about <10mm spherical particle and the D50 particle sizes of the investigated samples were only 0.98 mm and 1.22 mm, respectively. Its main mineralogical compositions were calcium silicate (including dicalcium silicate and tricalcium silicate), dicalcium ferrite, merwinite, RO phase and magnetite, while its minor mineralogical composition was periclase. A little free CaO existed in the steel slag but couldn’t be detected by the XRD for its lower content. The study of effects of grinded air-quenching steel slag on the physical performance and hydration process of Portland cement showed that the pozzolanic activity of air-quenching steel slag was lower at early time but increased continually in the future. The air-quenching steel slag wasn’t damaged to the volume stability performance of the Portland cement for its lower free CaO and free MgO content in this research. The hydration products of the steel slag- Portland cement were hydrated calcium silicate, portlandite and ettringite.
Keywords: Air-quenching steel slag, Portland cement, pozzolanic activity, mineralogical composition
CHARACTERIZATION OF INDIAN RED MUD FOR CATALYTIC APPLICATIONS
Snigdha Sushil and Vidya S Batra*
Centre for Energy and Environment, TERI University
Darbari Seth Block, Habitat Place, Lodhi Road
New Delhi 110 003
Red mud (Bauxite waste) collected from different aluminium industries in India was characterized for its potential catalytic properties. X-ray diffraction (XRD), inductively coupled plasma analysis (ICP), BET surface area, scanning electron microscopy (SEM) and temperature-programmed reduction (TPR) were employed for the characterization. In addition, the effect of acid activation and calcination was investigated on the surface area of the solids. Ferric oxide (Fe2O3) was the main component in all samples. The main crystalline phases present were hematite, goethite, gibbsite, boehmite along with other minor forms. Surface area was found to increase after treatments (acid activation and calcination). The highest surface area obtained in activated sample was 172.54 m2/g while in non-activated sample it was 90.06 m2/g corresponding to a calcination temperature of 400 °C. The increase in surface area due to calcination was observed till a temperature of 400 °C after which it started declining. Based on the properties, it is proposed that without any major treatment, red mud may be a substitute for the metal oxide catalysts in several reactions.
Keywords: Red mud, aluminium industry, catalyst, characterization, activation
SINGLE STREAM RECYCLING – A STRATEGY AND OPTIMIZATION MODEL FOR CONVERTING FROM MULTIPLE STREAMS TO A SINGLE STREAM IN OHIO, USA
Matthew Franchetti1 and Alexander Spivak
The Mechanical, Industrial, and Manufacturing Engineering Department
The University of Toledo
2801 W. Bancroft Street
Toledo, OH 43606, USA
Phone: (419) 530-8051; Fax: (419) 530-8206
This paper concentrates on the modeling and optimization of the truck routing collection system for recyclable materials for the Lucas County Solid Waste Management District (the District), located in Northwest Ohio, USA. The purpose of the paper is to describe the process to convert from a multiple-stream recycling process to a single-stream recycling process to reduce operating costs to ensure the sustainability and viability of the system. The newly developed and optimized recycling collection systems contributed to over $100,000 (25%) in annual savings for the District. The District is currently operating a program for collection of recyclable solid wastes from a number of drop-off collection sites throughout Lucas County. The current collection program involves collection of three different streams of recyclables (paper, old corrugated containers and commingled containers). This research considered a proposed optimized single-stream collection system, where all recyclables are initially collected together and separated later at a Material Recovery Facility (MRF). After studying the District’s current collection system three supporting activities were devised: the first activity involved modeling and optimizing the current three-stream collection system. The second activity was to devise, model and optimize a single-stream (commingled) recycling system. The third activity was to demonstrate that the optimized systems resulted in cost savings compared to the current non optimized collection system. The optimized systems were developed in such a way, that both systems are economical and convenient to implement. Then, the optimized systems were compared to determine whether single-stream (commingled) collection is superior to three-stream collection. The following results were obtained when systems were compared: By optimization of the single-stream and three-stream collection, the savings, compared to the current system, would be at least $107,000 per year. By commingling the recyclables into a single collection stream, total annual collection savings, compared to the current system, would be at least $118,000.
Keywords: Recycling, single-stream, multi-stream, optimization, modeling
VOLUMETRIC SHRINKAGE OF COMPACTED LATERITIC SOIL TREATED WITH BAGASSE ASH
Kolawole J. Osinubi
Dept. of Civil Engineering, Ahmadu Bello University
Zaria 810001, NIGERIA
Adrian O. Eberemu
Dept. of Civil Engineering, Ahmadu Bello University
Zaria 810001, NIGERIA
A reddish brown lateritic soil treated with up to 12% bagasse ash content was compacted using reduced Proctor, standard Proctor, West African Standard or ‘intermediate’ and modified Proctor efforts at moulding water contents -2, 0, 2 and 4% of optimum moisture content. Samples were extruded from the compaction moulds and allowed to air dry in the laboratory in order to assess the effect of desiccation-induced shrinkage on the material for use as a hydraulic barrier in waste containment application. Results recorded show that volumetric shrinkage strain (VSS) values were large within the first 5 days of drying; VSS values increased with higher moulding water content, water content relative to the optimum and bagasse ash content. VSS generally increased with higher initial degree of saturation for all compactive efforts, irrespective of the level of bagasse ash treatment. A compaction plane of acceptable zones for VSS based on the regulatory value ≤ 4% gave an optimal 8% bagasse ash treatment for lateritic soil to be used in waste containment application.
Keywords: Acceptable Zones, Compaction, Covers, Lateritic Soil, Liner, Volumetric Shrinkage, Waste Containment, Water Content
WASTE MANAGEMENT AWARENESS, KNOWLEDGE, AND PRACTICES OF SECONDARY SCHOOL TEACHERS IN OGUN STATE, NIGERIA—IMPLICATIONS FOR TEACHER EDUCATION
Department of Curriculum Studies & Instructional Technology
Faculty of Education
Olabisi Onabanjo University
Ogun State, NIGERIA
This paper presents the findings of the waste management awareness, knowledge and practices held by a group of secondary school teachers in Ogun State, South-West, Nigeria. Using the theory of planned behaviour as framework, a 34-item researcher designed survey instrument-waste management awareness, knowledge and practice questionnaire (WMKABQ) was administered on 240 teachers selected across the four geo-political zones in the State. The data were analysed using percentage, mean, chi-square, t-test, analysis of variance (ANOVA) and multiple regression analysis. The results show that teachers are aware and knowledgeable about waste management in their schools. However, they possess negative waste management practices. Significant differences were found in teachers’ sex, age, educational qualification, teaching experience, subject of specialisation and their knowledge and practice of waste management. While no significant differences were found in the awareness of waste management of teachers according to sex, class taught, and school location. Sex, age, subject specialisation, class taught, school location and educational qualification were found to be related to teachers waste management practices. Moreover, sex, age, teaching experience, class taught, school location and subject of specialisation were found to be predictors of teachers’ knowledge and practice of waste management. The findings from this study are of relevance to decision makers bringing environmental education into the policy of teacher education institutions, and for programme developers, on effective directions for integrating environmental education given the structures and frameworks of current programmes.
Keywords: Environmental awareness, attitude, knowledge, environmental practice, waste management, teacher education
Issue 2, May 2011
METAL ELEMENT UPTAKE IN VEGETABLES AND WHEAT AFTER BIOSOLIDS APPLICATION
W.E. Cotching*, J.R. Coad
Tasmanian Institute of Agricultural Research & CSIRO Sustainable Ecosystems
University of Tasmania
P.O. Box 3523 Burnie, Tas. 7320
Fax +61 3 64304959
Metal element concentrations were measured in the edible portions of silverbeet, potato and wheat grown in a glasshouse experiment after application of lime amended biosolids (LAB) and digester sludge. Biosolids were mixed into soil for the replicated pot experiment at rates of 1, 2 and 5 times the N requirement of each crop grown. No significant effect was found of different biosolids application rates on uptake of As, Hg or Se. The concentration of As was less than the maximum permitted limit (ML) of 1mg/kg in all crops grown. The ML for lead (0.1 mg/kg in vegetables) was only exceeded at the greatest LAB treatment rate in silverbeet. No significant differences in the concentration of Cd were found at different application rates of LAB or digester sludge in potato, wheat fodder or wheat grain. Silverbeet was found to contain much higher concentrations than potato or wheat fodder of Al, Fe and Zn and higher concentrations of Cu, Ni, Cd, and Co and the concentration of Cd in silverbeet exceeded the ML (0.1 mg/kg) in most treatments including the control, which may be due to species specific bioaccumulation. Correlation of soil pH and EC to rate and type of biosolids applied are likely explanations for different metal element concentrations due to contrasting bio-availability resulting from pH or EC effects. An increased plant uptake of metal elements associated with the greatest biosolids application rates applied in this glasshouse experiment are unlikely under realistic field conditions in Tasmania.
Keywords: Heavy metals, potato, silverbeet, wheat
REGIONAL RECYCLING EFFICIENCY IN TAIWAN WITH TIME-VARYING EFFECTS OF DETERMINANTS
Jin-Li Hu* and Tzu-Pu Chang
Institute of Business and Management
National Chiao Tung University
118, Chung-Hsiao W. Rd., Sec. 1, Taipei City 100, Taiwan
The stochastic frontier approach with heteroscedasticity and non-monotonic effects proposed by Wang (2002) is applied to evaluate regional recycling efficiency and to simultaneously estimate coefficients of the factors of inefficiency. There are three input variables, one output variable, and six exogenous determinants of twenty-three municipalities in Taiwan from 1998 to 2004. The average recycling performance has improved progressively. Taichung City is the best performer and Chiayi City is the worst. Municipalities with a higher proportion of highly-educated population, higher household income, and more promoting activities have better recycling performances. Proportions of high-educated people, household income, and promoting activities have decreasing marginal effects while population density has increasing marginal effects on recycling efficiency. In later periods, only an increase in household income and a decrease in population density significantly help reduce regional recycling inefficiency.
Keywords: Stochastic frontier, heteroscedasticity, non-monotonic effects, recycling, Taiwan
A STUDY OF THE MOTIVATION AND DE-MOTIVATION FACTORS INFLUENCING THE PARTICIPATION OF PEOPLE OF PULAU PINANG IN RECYCLING OF SOLID WASTES
O. Abdelnaser1*, A. Mahmood 2, A.D. Read 3
*1School of Housing, Building and Planning, 11800, Minden, Universiti Sains Malaysia
2 Department of Architecture and Building Science, College of Architecture and Planning,
Kind Saud University, Riyadh 11574, Kingdom of Saudi Arabia
3 Knowledge Leader, Waste Management and Resource Efficiency
AEA, The Gemini Building, Harwell IBC, Didcot Oxon, OX11 OQR
The motivating and de-motivating factors that affect the effective participation of people of Pulau Pinang in the recycling of their domestic solid wastes were studied. 300 questionnaires were distributed to different areas of Pulau Pinang using a sampling frame that allowed various ethnic groups, different age groups, diverse vocations and a range of residential arrangements and the sexes to be captured – ensuring the sample was representative of the general population of the area. The research adopted a stratified sampling technique, where the Island was divided into several strata and each stratum was administered with questionnaires using a snowball approach. 275 of the questionnaires (91.7%) were completed and returned. Data collected were analyzed by converting Likert scale scores to Relative Importance Index (RII). Results of the survey showed that the majority (61%) of residents of Pulau Pinang did participate in recycling. Most recyclers are Malays, Chinese and other Malaysians, who were either students or workers in the private sector. Recyclers also tended to be those living in condominiums/apartments or terrace houses and the materials recycled were mostly paper or paper products. These groups obtain recycling related information mostly from the television. The recycling activity is generally motivated by personal concerns for the environment and the promotion of good health whereas participation in recycling services/activities is ‘de-motivated’ by a lack of suitable/local facilities for recycling and the time and effort spent/required in using them.
Keywords: Motivation and de-motivation factors, households’ participation, recycling solid waste, Pulau Pinang, Malaysia
CAPACITY FOR BIOLOGICAL METHANE OXIDATION IN DIFFERENT TYPES OF SOIL AND COMPOST
Muna Albanna*, Leta Fernandes
Department of Water and Environmental Engineering, German Jordanian University
P.O. Box 35247 Amman 11180
Telephone: (6) 530 0666 ext. (864)
Fax: (6) 530-0661
In this study, patterns of methane (CH4) oxidation under various environmental conditions were studied and compared in two types of landfill cover soils and compost. In all the experimental runs, CH4 oxidation rates increased with time indicating the growth of well established microbial populations capable of utilizing CH4 as substrate. It was found that CH4 oxidation can be enhanced using compost as a landfill cover medium at higher temperature levels only. The highest CH4 oxidation rates were observed when compost was tested under different moisture content levels at 35oC in the range of 27.3 to 35.5 μg CH4 h-1 g-1wet wt. The lowest oxidation rate ranged between 2.5 – 3.9 μgCH4 h-1 g-1wet wt. obtained for all the experiments conducted at 5oC using the three media: clay, clayey silt soils and compost.
The experimental results were analyzed statistically and used to develop an empirical model that showed the individual and combined effects of the tested environmental variables (cover medium, temperature, and moisture content) on the CH4 oxidation process. The statistical model was validated using CH4 oxidation rates in different types of landfill cover systems reported in the literature.
ECONOMIC AND LEGAL CHALLENGES OF REGULATION-INDUCED CHANGES IN WASTE TECHNOLOGY AND MANAGEMENT IN THE U.S.A.
Molly K. Macauley
Senior Fellow, Resources for the Future
1616 P St NW, Washington, DC 20036
Beginning in the early 1990s, stricter government regulation to protect public health and the environment led to radical changes in waste technology and management in the United States. More stringent regulation induced wholly new technologies including the lining of landfills, the control of their gas emissions, and changes in the economic scale and geographic location of operation. Economic integration of waste management transformed “the local dump” into a nationwide and modernized industry. These changes led in turn to intervention by local government to control price, quantity, and location-specific attributes of the U.S. waste market. Regulatory-induced changes in markets have long been a topic of academic and policy interest, but unique in this case was the emergence of legal challenges concerning public governance and the private sector. Of concern in a host of court cases was whether state intervention in the nationwide waste market violated constitutional protection of unfettered movement of goods and services across state boundaries (as protected by the US Constitution). This article first reviews the regulatory and technology changes and subsequent industry reorganization, and then summarizes major legal findings, including two decisions by the U.S. Supreme Court. These developments illustrate the challenges faced by other countries as well, insofar as they attempt to balance localized management of waste streams with the larger scale and broader, regional geography of new waste technology.
Keywords: Municipal solid waste, technology, landfills, economics, regulation
REMOVAL EFFICIENCY OF POTATO PEELS AS A NEW BIOSORBENT MATERIAL FOR UPTAKE OF PB(II) CD(II) AND ZN(II) FROM THEIR AQUEOUS SOLUTIONS
G.M. Taha1*, A.E. Arifien1 and S. El-Nahas2
1Chemistry Dept., Aswan Faculty of Science
South Valley University, Aswan, EGYPT
*Telfax: 0020973480450; Email: email@example.com
2Chemistry Dept., Qena- Faculty of Science
South Valley University, Qena, EGYPT
The biosorption ability of potato peels (as a new waste material obtained from commercial processing of potato chips factories) was investigated for removal of Pb(II), Cd(II) and Zn (II) from aqueous solutions. The adsorption of metal ions under investigation is strongly pH, contact time, initial metal ion concentration and temperature dependent, while adsorbent particle size independent. The percentage removals are 92, 75 and 42 % for Pb(II), Cd(II) and Zn(II), respectively at initial metal ion concentration of 100 mg/L and at room temperature. The removal follows the order of Pb(II) > Cd(II) > Zn(II). The adsorption equilibrium is achieved within 60min. The experimental data fitted both Freundlich and Langmuir isotherm models.
The rate constant (the changes in the sorption of metal ions with time) of each metal ion was determined using pseudo first order and pseudo second order rate models. The obtained results follow the pseudo-second order model. The thermodynamic behavior of metal-potato peels systems were studied at different temperatures, 298, 313, 323 and 333 K. The obtained results show that the adsorption process is exothermic for the studied metal ions. Transform Infrared (FTIR) and Scanning Electron Microscopy (SEM) of potato peels were done to illustrate the physicochemical nature for potato peels.
Keywords: Adsorption, Potato peels, Lead, Cadmium, Zinc, FTIR, SEM
SOIL STABILIZATION USING STONE-SLURRY-WASTE RECOVERED FROM CUTTING STONE PROCESS IN ROCK QUARRIES
Mousa F. Attom*, Associate Professor
Magdi El-Emam, Assistant Professor
Civil Engineering Department
American University of Sharjah
P.O. Box 26666
This paper investigated the effect of using cutting stones slurry waste (SSW) as a stabilizing material with clay soil. For this study, three types of clayey soils with different plasticity indices and different clay fractions were selected to be used. Physical properties of the clayey soils such as Atterberg’s limits, maximum dry density, optimum water content, specific gravity, and clay fraction were evaluated in accordance with American Standard for Testing and Materials (ASTM) standard specification. The testing program includes measurement of cohesion, angle of internal friction and unconfined compressive strength of soil samples, remolded and compacted at different water content and different SSW content. For unconfined compression tests, two sets of soil samples were prepared to be identical in all physical properties except the type of fluid that is occupying the voids. The first set (i.e. unstabilized soil) was prepared by mixing a specific weight of pure water with pre-determined weight of clay solids and compact it to reach specific water content and dry density. However, in the second set (i.e. stabilized soil) a weight of clay solids similar to that used in the first set is mixed with an amount of SSW that has weight similar to the pure water used in the first set. Four different initial dry densities at each soil type with the same water content (unstabilized soil) or with the same SSW content (stabilized soil) have been used. For direct shear test, six specimens of each soil type (i.e. three for unstabilized soil and three for stabilized soil) are prepared at maximum dry density and optimum water content, or optimum SSW content. Results indicated that mixing the clay soil with cutting stone slurry waste increased maximum dry density and decreased optimum water content. Also, both unconfined and direct shear strength and stiffness were improved significantly due to the addition of stone slurry waste to the clay soil. Finally, it was found that the cutting stone slurry waste has more effect on soil with high plasticity.
Keywords: Shear strength, soil stabilization, clay, stiffness, slurry waste
Issue 1, February 2011
RECYCLING PRACTICES OF SOLID WASTE IN KHULNA CITY, BANGLADESH
S.M. Moniruzzaman1, Q.H. Bari2 and T. Fukuhara3
1Assistant Professor, Department of Civil Engineering
Khulna University of Engineering & Technology, Khulna-9203
2Professor, Department of Civil Engineering
Khulna University of Engineering & Technology, Khulna-9203
3Professor, Department of Architecture and Civil Engineering
University of Fukui, 3-9-1 Bunkyo, Fukui 910-8507
A solid waste recycling approach is a part of the sustainable and effective waste management system for most of the cities in the world. Although the recycling part of waste management has been ignored by the local authorities, many individual waste collectors and dealers have been performing recycling activity as a source of income for a long time in Bangladesh. In this paper, a traditional recycling practice of solid waste was investigated and analyzed in the Khulna city of Bangladesh. A complete hierarchy from waste collectors to recycling industries in the private sector was identified. The study revealed that 7.2 % (37.23 tons/day) of the total generated waste or 53.2 % of the recyclable solid waste (RSW) was recycled daily in Khulna. The private sector was found to deal only with RSW. RSW collected by the private sector included paper, glass, plastic, aluminum, iron, tin, bones and tyres. Except for bones, paper, iron, plastic and tyres all other retrieved materials were transported to industries located in Dhaka, the capital city of Bangladesh as raw materials for new products. Three models are proposed to evaluate the possibility of organizing the unorganized waste recycling practice. The third model seems to be feasible both economically and socially.
Keywords: Recyclable solid waste; Recycling; Waste collectors; Recycling dealers; Recycling industries; Private sector
FAILURE MODE AND MODULUS ELASTICITY OF CONCRETE CONTAINING RECYCLED TIRE RUBBER
Bashar S. Mohammed* and Najwa Juaini Azmi
Civil Engineering Department
University Tenaga Nasional
Jalan Kajang- Puchong, 43009, Kajang, Selangor
The test program was carried out to develop information about failure mode and modulus elasticity of crumb rubber concrete. Crumb rubber was used as partial replacement to fine aggregate in the production of crumb rubber concrete mixture. Four designated crumb rubber contents varying from 10% to 30% as replacement to fine aggregate by volume were tested. Total of 15 concrete mixes with three different water cement ratios (0.41, 0.57 and 0.68) were cast and tested for compressive modulus elasticity.
The results revealed that inclusion of crumb rubber in concrete reduced the static modulus elasticity. Although there was a reduction in modulus elasticity the deformability of crumb rubber concrete increased compared to normal concrete when crumb rubber content increased from 0% to 30%. Visual inspection showed that crumb rubber did not exhibit brittle failure when loaded in compression as the crumb rubber concrete absorbs more energy compared with conventional concrete. An equation to predict the modulus elasticity of crumb rubber concrete has been developed.
Keywords: Crumb rubber, recycled tire, concrete material, modulus elasticity
LOCATING REGIONAL MATERIALS RECOVERY FACILITIES—A CASE STUDY
Shoou-Yuh Chang, Rebecca Cramer, Kumar Bindiganavile,
and Elobeid Elobeid
Department of Civil and Environmental Engineering
North Carolina A&T State University
The Sandhills region of North Carolina, which consists of six counties, is currently landfilling most of its municipal solid wastes in the various local sanitary landfills or shipping as needed to surrounding counties for disposal. The lack of existing landfill space for steadily increasing amounts of municipal solid wastes and an immediate need to develop better environmentally friendly disposal alternatives have resulted in the implementation of waste diversion programs such as recycling, incineration and composting.
This study addresses the feasibility of a regional materials recovery facility in the Sandhills Region. A multi-step process including the set up of a linear programming modeling to determine the optimum locations of material recovery facilities was employed. The financial ability for each county to participate, based on no additional costs to them, was also determined. A linear programming software LINDO was used to obtain the solution of the model. Since the market price of recyclables fluctuates significantly and the transportation cost cannot be accurately defined, additional sensitivity analysis was carried out with the transportation cost varied from $0.13 to $0.50/ton/mile and the potential average sales price varied from $50-$90/ton.
Keywords: Solid waste recycling, MRF, regional planning, linear programming model
ANAEROBIC DIGESTION OF THE ORGANIC FRACTION OF MUNICIPAL SOLID WASTE (OFMSW)—FULL SCALE VS LABORATORY RESULTS
J.M. Challen Urbanic*, B. VanOpstal**, W. Parker***
*Environment Canada, 867 Lakeshore Road, Burlington, Ontario, L7R 4A6, CANADA
**City of Toronto, Solid Waste Management, 100 Queen Street West, Toronto, Ontario, M5H 2N2, CANADA
***University of Waterloo, Department of Civil Engineering, 200 University Avenue West Waterloo, Ontario, N2L 3G1, CANADA
There is limited information available to describe anaerobic digestion of OFMSW that are generated in North America. In this study, the impact of SRT, solids recycle and feeding frequency on VS destruction and biogas generation was investigated at bench, pilot and full scale. VS destruction and biogas production were improved by approximately 20% when the SRT was increased from 10 to 30 days. Recycling of solids to maintain an SRT of 30 days while operating at an HRT of 15 days was able to achieve similar VS destruction to the once-through reactor with an SRT of 30 days. The pilot scale digester that was fed 4 times per day and 7 days per week had superior performance over the bench scale digester that was operated at the same SRT and was fed once per day and 5 times per week, indicating that more consistent feeding could enhance digester performance. The VS destruction at the full scale facility was considerably less than that observed in the smaller scale digester. Implementation of more consistent feeding may significantly improve process performance. Other factors that impact the process performance, such as inadequate mixing might also be responsible for the reduced performance of the full scale facility.
Keywords: Anaerobic digestion, municipal solid waste, specific methane production, volatile solids destruction
EXTRACTION OF CHROMIUM AS SODIUM CHROMATE FROM STAINLESS STEEL DUST
Metal Extraction & Forming Division
National Metallurgical Laboratory
The objective of this investigation was to recover chromium as sodium chromate of 99.5% purity from stainless steel dust. The dust contains 7.72% chromium obtained from stainless steel processing plants. The stainless steel dust mostly contained iron in oxide form along with chromium, nickel (1.71%) and manganese (3.55%). The steel dust was roasted with soda ash followed by water leaching to recover the major constituent chromium. It was found that roasting at 1073 K for 90 minutes resulted in maximum (95%) chromium recovery. Kinetics of sodium chromate formation followed a topochemical model involving chemical reactions at the surface with activation energy of 39 kJmol-1. TG/DTA, XRD phase identification and SEM microphotographs confirmed the experimental observation and the mode of reaction.
Keywords: stainless steel dust, roasting, sodium chromate, solid waste, leaching, soda ash
DEGRADATION OF VARIOUS LOW DENSITY POLYETHYLENE PRODUCTS ON ALUMINA SURFACE WITH SULPHURIC ACID—DTS TECHNIQUE
Dr. Deepak Pant*
Assistant Professor in Chemistry, Waste Management Laboratory
Dolphin (P.G.) Institute of Biomedical and Natural Science
Manduwala, Chakarata Road
Dehradun 248 007
Various low density polyethylene products commonly present in municipal solid waste were degraded on alumina surface with sulphuric acid. Sulphuric acid plays two important roles in the degradation (i) supplies protons to polymer via alumina for the initiation of degradation using triphase catalytic activity of alumina; (ii) acts as a scavenger for degraded fragments. During degradation sulphuric acid was circulating in two step cyclic pattern, dropping towards the hot reaction surface containing polymer and alumina in its first half, and then in its second half sulphuric acid condensed on the upper end of the assembly. This cyclic rotation of sulphuric acid was continuously changing the reaction surface temperature and produced scavenging on the degraded products. Resultant scavenging of the degraded fragments from the different temperature conditions was named as different temperature scavenging (DTS) technique. The application of this technique towards polymeric degradation was justified by using a relative weight loss study. The oily fraction obtained as a result of degradation was thoroughly analyzed by GC- MS measurements. The product selectivity towards liquid function (�60-70%) was found to be almost unaffected by the type of polymer but it, principally, influenced the formation of branched hydrocarbons.
Keywords: Scavenging, polyethylene degradation, triphase catalyst, alumina, Difference Temperature Scavenging (DTS), municipal solid waste
EVALUATION OF FATIGUE AND RUTTING PERFORMANCE OF SEWAGE SLUDGE ASH (SSA) IN ASPHALT CONCRETE
1Prashant Shirodkar, 1Khyati Sonpal, 2Alan Norton, 2Ryan Weaver, 2Chris Tomlinson,
3Aaron Nolan, 4Dr. Yusuf Mehta, P.E., 5Dr. Kauser Jahan, P.E.
1Graduate Students, 2Undergraduate Students, 3Research Associate, 4Associate Professor,
5Professor, Department of Civil and Environmental Engineering
Glassboro, NJ 08028
Phone: (856) 256-5327; Fax: (856) 256-5242
A study was conducted evaluating the effects of sewage sludge ash (SSA) in hot mix asphalt (HMA) as mineral filler and/or as a fine aggregate substitute. For the purposes of this study, 0% and 2% SSA by weight of aggregates were used in HMA samples. Fatigue and rutting performance of HMA was evaluated using disk-shaped compact tension testing (DCT) and creep compliance testing respectively. DCT and creep compliance were used to determine the fracture energy and slope of secondary region to evaluate fatigue and rutting performance. Through these tests, it was found that the fracture energy and slope of the secondary region for HMA containing 0% and 2% SSA were statistically similar. From these tests, it was concluded that the HMA with 2% SSA shows similar performance in fatigue and rutting as that of 0% SSA. Since the performance of the HMA does not drop with the addition of 2% SSA, future studies could be conducted analyzing the effects of higher percentages of SSA, which could significantly reduce the amount of raw materials required in construction.
Keywords: Sewage sludge ash, hot mix asphalt, disk-shaped compact tension test, creep compliance, mineral filler, fracture energy
ELABORATION OF A DATABASE OF THE SOLID INDUSTRIAL WASTES AND INDUSTRIAL ACTIVITIES IN MOROCCO
B. Oular1*; K El Kacemi1**; A. Touzani2
1Department of Chemistry, Laboratory of Electrochemistry and Analytical Chemistry
Faculty of Sciences, Avenue Ibn Batouta, BP: 1014, Rabat
2Department of Processes Engineering, Laboratory of Rheology and Energetic of Industrial Operations Mohammadia School of Engineers, Avenue Ibn Sina BP: 765, Agdal, Rabat
A study of characterisation of the industrial activities and solid waste was carried out on 21 industrial companies in the areas of Casablanca, Mohammedia and F�s. This paper relates their raw materials, environmental protection, processes used, quality control and solid waste. Questionnaires were used to collect data in the areas of study. The majority of these companies in Morocco are small or medium-size, and belong to the surface treatment sector, manufacturing of metallic packaging, tyres manufacturing, and plastic packaging manufacturing industries. From this study, a database was constructed. It includes the solid waste structure and generating activities of wastes. The solid waste structure includes 6 solid waste categories and 38 subcategories. The generating activities of wastes includes 8 industries types, 29 categories and 107 industries subcategories.
Keywords: Solid Waste, Industries Database, Industries Activities, Morocco