swm lnotes ii-061
TRANSCRIPT
SOLID WASTE MANAGEMENT
LECTURE SLIDESM. Sc. Environmental Engineering
Padma Sunder Joshi
CHAPTER II
SOURCES AND TYPES OF SOLID WASTE
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Chapter II SOURCES & TYPES OF SOLID WASTE
Waste Generation:
EconomyCultureUrbanity
Generation of waste depends on:
Generation of waste is influenced by:LegislationSource reductionClimatic condition
Units of waste generation:
Residential – kg/c/dIndustrial kg/unit production
Agriculture – kg/ha or kg/animal/d
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Chapter II SOURCES & TYPES OF SOLID WASTE
P S JOSHI, IOE Pulchowk Campus 410 - 85~5 - 35Particle size = 10 mm1 -201 - 301 - 40Miscellaneous inerts
20 - 5020 – 6540 - 85Vegetable/putrescible
2 - 102 – 101 - 5Textiles
~~1 - 5Wood, bones, straw
~~1 - 5Leather, rubber
2 - 102 - 61 - 5Plastics
3 - 131 - 51 - 5Metals
4 - 101 -101 – 10Glass, ceramics
15 - 4015 - 401 – 10Paper
Ranges of compositions20 - 3040 - 6040 - 80Moisture content (% by wet weight)
100 - 170170 - 330250 - 500Waste densities (wet weight basis- kg/m3)
0.7 - 1.80.5 - 0.90.4 - 0.6Waste generation (kg/c/d)
High income countries
>$3500
Middle income countries per capita
$360><$3500
Low income countries per
capita<360
for lower, middle, and higher income countries (Source: Cointreau 1982)
Patterns of Municipal Refuse Quantities and CharacteristicsChapter II SOURCES & TYPES OF SOLID WASTE
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100100100100100100100100100100100100100TOTAL78829673856579664037703826Compostible total
42240243221910313221154Miscellaneous inerts
368056498243605695505822Food and putrescible
2218427153521346063295774Non-food total
51124-------4Wood, bones, straw
431517-4109-24Textiles
--17---------Leather, rubber
14-234-5664210Plastics
13144541233813Metals
86131232101489Glass, ceramics
321421714223243183735Paper
Calcutta Indi
a
Lucknow
India
Karachi
Pakistan
Lahore
Pakistan
Jakarta
Indonesi
a
Manila
Philippin
es
Lagos
Nigeria
Medelin
Colombia
Hongkon
g
Singapor
e
Rome
Italy
London UK
Brooklyn USA
Type of waste
Low IncomeMiddle IncomeHigh Income
(in percentage by weight) Source: Cointreau, 1982
Urban Refuse Composition DataChapter II SOURCES & TYPES OF SOLID WASTE
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Chapter II SOURCES & TYPES OF SOLID WASTE
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Lecture II SOURCES & TYPES OF SOLID WASTE
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Solid Waste Composition in Kathmandu
Organic materials(69.84%)Plastics (9.17%)
Paper (8.50%)
Construction and otherwaste (4.79%)Textiles (3.02%)
Glass (2.50%)
Metals (0.92%)
Rubber & leather(0.66%)Wood (0.60%)
Lecture II SOURCES & TYPES OF SOLID WASTE
Source: KVMP 2001
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Lecture II SOURCES & TYPES OF SOLID WASTE
Types of Solid Waste
Based on regulatory definition
By source or generatorBy component composition
ResidentialCommercial
Institutional
Construction and demolition
Municipal services
Industrial
Agricultural
Municipal Waste
By source or generator
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Lecture II SOURCES & TYPES OF SOLID WASTE
Residential Waste:
Commercial Waste: Wastes from office buildings, market places, shops, restaurants, hotels, etc.Predominantly – paper, plastics, textiles, food wastes
Various types of wastes generated in residential areas like kitchen waste, waste materials like used newspapers, gift wrappers, broken utensils and equipments, etc.
Residential buildings include houses, flat, apartment blocks
Institutional: Wastes generated from institutions like offices, schools and colleges, etc.These are basically inorganic wastes predominantly papers
……………..Types of solid waste
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Municipal service waste: Street sweeping,Wastes from municipal facilities like sludge from waste water treatment facility, incinerators, etc.
Construction and demolition waste:
Waste generated from new constructionDemolition of old structuresSand, dirt, brick bats, aggregates, cement bags, metal scraps, wood and timber, glasses, etc.Dominantly inert, recyclable and can be used for reclaiming land or as a cover to the landfill
Components of construction like paints, treated woods, etc. may demand attention as these contain hazardous materials
Lecture II SOURCES & TYPES OF SOLID WASTE
……………..Types of solid waste
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Industrial Waste: Non hazardous waste – produced during fabrication, refinery and transformation into consumablesHazardous waste
Agricultural Waste: Wastes generated from harvesting, processing and storing of agricultural productsMost of the wastes are organic and recyclable wastes
Lecture II SOURCES & TYPES OF SOLID WASTE
……………..Types of solid waste
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……………..Types of solid waste
By component composition
Food wastes
Paper
Cardboards
Plastics
Textiles, leather, rubber
Glasses
Tins/cans, ferrous and non ferrous materials
Special wastes
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Lecture II SOURCES & TYPES OF SOLID WASTE
……………..Types of solid waste
Plastics
High density polyethelene (HDPE/2)
Polyvinyl Chloride (PVC/3)
Low density polyethlene (LDPE/4)
Polyethelene terephthalate (PETE/1)
Soft drink bottles, salad dressing and vegetable oil bottles, photographic film
Milk jugs, water containers, detergent and cooking oil bottles
Home landscaping irrigation piping, some food packaging, and bottles
Thin-film packaging and wraps, dry cleaning film bags, other film materials
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Lecture II SOURCES & TYPES OF SOLID WASTE
……………..Types of solid waste
Polypropylene (PP/5)
Polystyrene (PS/6)
Other multilayered plastic materials
Closures and labels for bottles and containers, battery casings, bread and cheese wraps, cereal box liners
Packaging for electronic and electrical components, foam cups, fast food containers, tableware and microwave plates
Multilayered packaging, ketchup and mustard bottles, various combinations of above products
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Lecture II SOURCES & TYPES OF SOLID WASTE
Special wastes:Bulky items:
furniture
large items
Consumer electronics:
radio, television, stereo, camera, computer etc.
White goods:
cooking stove, washing machine, refrigerators, etc.
……………..Types of solid waste
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Lecture II SOURCES & TYPES OF SOLID WASTE
……………..Types of solid waste
Hazardous wasteAny waste or combination of wastes which pose a substantial presence
or potential hazard to human health or living organism because they are lethal, non-degradable, can be biologically magnified or otherwise cause or tend to cause detrimental cumulative effects.
Sources of hazardous waste:Explosivity: mining, oil refinery, etc. Corrosivity: acids from tanning industries, heavy metal industries Inflammability: oil sludge, solvents, etc. Toxicity: chemical industries, pesticides, plastic, fertilizers, etc.
Hazardous waste defined Medical waste defined
Solid waste as defined by the regulation
By component composition
Carcinogenicity: waste which can cause cancer with elongated exposure
Infectious: hospital waste, especially clinical waste
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……………..Types of solid waste
Medical Waste: Clinical and non-clinical wastes
Clinical waste:Pathological waste: limbs, organs, blood, tissuesInfectious waste: solid surgical dressing (all materials in contact with infectious diseases)Sharps: needles, syringes, nails, blades, glassesPharmaceutical wastes: all pharmaceutical products, drugs, chemicals etc.Chemical waste: discarded solid and liquid chemicals from laboratoriesHazardous waste: corrosive (alkaline, acidic)
radioactive waste (X rays)Non-clinical waste: kitchen waste, packaging, etc.
HOUSEHOLD HAZARDOUS WASTEHousehold waste because of its point of generation would be a hazardous waste. It includes used oil, paints, solvents, drain cleaners, pesticides and herbicides.
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Lecture II SOURCES & TYPES OF SOLID WASTE
Properties of Municipal Solid Waste:
Individual components in solid waste
Physical properties:
Particle size
Moisture contentDensity
Field capacity
• Physical properties
• Chemical properties
• Biological properties
Permeability
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……………Properties of MSW
Particle SizeImportant for material recovery processFor the design of shredder, screens, etc.Largest dimension and ability to pass the sieve
Size of the component (mm) Sc = (l+w)/2
or = (l*w)1/2
or = (l+w+h)/3
or = (l*w*h)1/3
Individual componentsPaperCardboardPlastics
RubberLeatherWood
Garden trimming/yard waste
Glass Tins/cans
Non ferrous metalsFerrous metalsDirt, ash, bricks
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……………Properties of MSWDensity
It is used to determine compacted volumeDetermine volume and weight to be transportedDetermine landfill sizeEvery time waste is handled its density changes
It is location specific: loose, as found in container, compacted, etc.
Density also varies with the length of time it is stored, therefore, collection frequency also effects
Density depends on
Compaction of waste,
Season of the year: humidity, rainfall, wind, etc.
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Lecture II SOURCES & TYPES OF SOLID WASTE
Compaction ratio r = (compacted density ρc/ discarded density ρd)
……………Properties of MSW
Density of waste (as discarded basis)
Kathmandu: 600 kg/m3 (Lohani, 1978)
630 ~ 430 kg/m3 (SWMRMC)
250 kg/m3 (KVMP 2001)
India (Poone) 300 kg/m3
USA 128 kg/m3
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Lecture II SOURCES & TYPES OF SOLID WASTE
Moisture ContentImportant for
leachate calculation
Feasibility of incineration
composting
……………Properties of MSW
MC may be expressed inWet weight basis
Dry weight basis
MC in wet weight basisMC% = [(w-d)/w] * 100
Where w = initial weight of the sample as delivered, kg
d = weight of the sample after drying at standard temperature (1050c)
MC in MSW of Kathmandu: 39~58% (SWMRMC)
52% (KVMP, 2001)
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Lecture II SOURCES & TYPES OF SOLID WASTE
ΣDMMunicipal solid waste86-12480320-960
Dirt, ashes, brickbats etc.
32-49045-160Tins/cans21-4195160-480Glass
2015-40240120-320Wood
6030-8010560-225Garden trimmings108-1216090-260Leather21-413090-200Rubber106-156530-100Textiles21-46530-130Plastics64-108530-130Paper7050-80290120-480Food wastes
TypicalRangeTypicalRangeDry mass,
kg
Moisture, %Density, kg/m3Mass,
kgComponents*
The moisture content of the total mix isMC = {(ΣM – ΣDM) / ΣM}* 100
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Lecture II SOURCES & TYPES OF SOLID WASTE
Field capacityThis is the capacity of solid waste retaining moisture content against gravity
Important to determine leachate production in landfill
FC varies with the degree of applied pressure and state of decomposition of the waste
FC of commingled MSW is found to be 50~60%
FC in a landfill may be determined by following empirical formula
FC = 0.6 – 0.55 [W/(10000+W)]Here FC = field capacity
W = overburden weight calculated at the mid height of the waste in the lift in question. Unit of W is in lb.
……………Properties of MSW
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Lecture II SOURCES & TYPES OF SOLID WASTE
PermeabilityHydraulic conductivity governs the movement of liquid and gases in landfills
Permeability depends on pore size distribution
Surface area
Porosity
Properties of the waste materials
K = C d2 (γ/µ) = k (γ/µ)
K = Coefficient of permeability C = dimensionless constant or shape factor
d = average size of pores γ = specific weight of water
µ = dynamic viscosity of water k = intrinsic permeability
……………Properties of MSW
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Lecture II SOURCES & TYPES OF SOLID WASTE
Chemical properties:
……………Properties of MSW
This is useful to determine waste processing techniques like waste incineration, composting and heat recovery, etc.
1. Proximate analysis
2. Fusing point of ash
3. Energy content
4. Ultimate analysis
To determine surrogate parameters, especially after/during incinerationThe parameters considered are:
1. Proximate analysis
Moisture: loss of moisture when heated to 1050C for 1 hourVolatile combustible matter: additional loss of weight on ignition at 9500C in covered crucibleFixed carbon: the carbon not burnt after volatile matter is removedAsh: weight of residue after combustion in an open crucible
2015-30Non combustibles75-12Fixed carbon5340-60Volatile matter2015-40Moisture
TypicalRangeProximate analysis
Value %Typical data of
proximate analysis
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……………Properties of MSW
When MSW is heated at very high temperature the ash formed will convert into solid form as clinker by fusion and agglomeration.
This characteristic is important while designing incinerator and its by-products.
Normally, ash has fusing point at 1100~12000C
2. Fusing point of ash
Determination of heat of combustion when SW is burntThere are three methods of determining energy content:
Full scale boiler as calorimeterBomb calorimeterCalculations using standard table. Normally energy content is
determined in dry mass basis.
3. Energy content
105008000-12000Total in MSW kJ/kg1400012000-16000Organic fraction kJ/kgTypicalRangeHeating value kJ/kg
Value
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Lecture II SOURCES & TYPES OF SOLID WASTE
ΣEC Municipal solid waste
70002300-11650Dirt, ashes, brickbats etc.700250-1200Tins/cans150100-250Glass
1860017450-19800Wood65002300-18600Garden trimmings1745015100-19800Leather2325020900-27900Rubber1745015100-18600Textiles3260027900-37200Plastics1675011600-18600Paper46503500-7000Food wastes
TypicalRangeEnergy kJ/kg
Components
Typical energy contents of various components of MSW
……………Properties of MSW
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i) Unit energy content (as discarded) = ΣEC / ΣM
ii) Determining energy content at dry basisMoisture content of the MSW = MC
Energy content (as dry basis) ΣEC * 100 / (100 – MC) kJ/kg
iv) Determining the energy content on an ash-free dry basis= ΣEC * 100 / (100 – MC - % ash) kJ/kg
Modified Dulongs FormulakJ/kg = 337 C + 1428 (H – O/8) + 95S
WhereC = carbon %H = Hydrogen %O = Oxygen %S = Sulphur %
……………Properties of MSW
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What is the heat value of PVC?
PVC = C2 H Cl%C = (2*12)
{(2*12)+(1*1)+(1*35.45)}
%H = (1*1){(2*12)+(1*1)+(1*35.45)}
Applying Modified Dulong’s Equation
kJ/kg = 337 * 39.7 + 1428 * 1.65 = 15735.1 kJ/kg
What is the heat value of Ethanol ?
Ethanol = CH3 CH2 OH
= 39.70%
= 1.65%
……………Properties of MSW
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To determine basic elements that compose the solid wasteHelps to determine harmful affects to atmosphere when released as fumes –chlorinated and sulphur compounds, etc.Determines C, H, O, N, S and ash Helps to characterize the chemical composition of the organic matter in MSWHelps to determine C/N ratio for biological activities
4. Ultimate analysis (elemental analysis)
……………Properties of MSW
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Biological properties:1. Most of the organic fraction of MSW lies within following seven
groups (excluding plastics, rubber and leather)
Water soluble constituents- sugar, starch, amino acids, and various organic acids
Hemi-cellulose – a condensation product of 5-carbon sugar and 6- carbon sugars
Cellulose - a condensation product of the 6-carbon sugar glucose,
Fats, oils, and waxes- are esters of alcohols and long-chain fatty acids.
Protein- chain of amino acids
Lignin- a complex polymer occurring in certain plant cell walls making it rigid, wood
Ligno-cellulose- combination of lignin and cellulose
……………Properties of MSW
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Lecture II SOURCES & TYPES OF SOLID WASTE
2. Biodegradability of organic waste componentsFood waste
Paper
Cardboard
Yard waste
Wood, leather, rubber (?)
Conceptual Waste Composition for Biodegradability Characterization
Biological Volatile Solids
(BVS)
Residual Volatile Solids
(RVS)
Inorganics
Water
Biological Volatile Solids (BVS) is the fraction of degradable components “destroyed” during treatment Residual Volatile Solids (RVS) is the organic fraction of Biodegradable components that remains after treatment + plastic
Inorganic: glass, metal, dirt + inorganic part of biodegradable materials
……………Properties of MSW
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.
How to determine BVS? Run a test in the lab and measure: normally ignition at 5500C is often used. This is misleading as some organic constituents (like news paper and some plant cells) are highly volatile but low in biodegradability.Analyze surrogate parameters and estimate: Lignin content of the waste can be used to estimate biodegradable fraction
Biodegradable Fraction BF = (BVS/VS) = 0.83 – 0.028 (LC)Where BVS = Biological Volatile Solids;
VS = Volatile Solids 0.83 and 0.028 are empirical constantsLC = Lignin content of the VS in % of dry weight
Biodegradability varies with the components, for simplicity MSW are classified as rapidly decomposable and slowly decomposable 0.724.150~90Yard wastes
0.4712.994Cardboard
0.820.496.4Office paper
0.2221.994Newspaper
Paper
0.820.47~15Food wastes
Biodegradable Fraction BF
Lignin Content (LC) % of VS
Volatile solids (VS) % of total solids (TS)Component
BF of selected organic waste components based on lignin content LC
……………Properties of MSW
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3. Production of odourOdour is developed in solid waste due to anaerobic decomposition of readily decomposable organic compounds
In the process of reducing the putrescible waste in anaerobic condition Sulphate is reduced to sulphide (S2-) which subsequently combining with hydrogen forms H2S giving rise to bad odor Food waste
2CH3CHOHCOOH + SO42- → 2CH3COOH + S2- + H2O + CO2
Lactate Sulphate Acetate Sulphide ion
4H2 + SO42- → S2- + 4H2O
S2- + 2H+ → H2S (hydrogen sulphide)
……………Properties of MSW
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The sulphide ion can also combine with metal salts to form metal sulphides
S2- + Fe2+ → Fe S (Iron sulphide)The black color of leachate in the solid wastes is due to these metal sulphides.
The positive side of formation of metal sulphides in the landfills is otherwise formation of H2S giving odor problem.
Biochemical reduction of methionine to methyl mercaptane and amino-butyric acid and subsequent hydrolysis to methyle alcohol and hydrogen sulphide
+2H
CH3 SCH2CH2CH(NH2)COOH → CH3SH + CH3CH2CH2(NH2) COOHMethionine Methyl mercaptane Amino-butyric acid
CH3 SH + H2O → CH4OH + H2SMethyle alcohol
……………Properties of MSW
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……………Properties of MSW
Waste Generation StudyEstimation of waste generation:
Planning waste generation study:
Few considerations need to be borne in mind while planning the study
What is the use of the study information?
Is that the right season, month, day for the survey?
What are the components of the waste we need to consider, density, volume, etc. ?How extensive are we making the study?Area coverage, sectoral coverage, representative data?
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Total waste generated includes:At household level:
Waste collected from HH/source (Wh)+ salvage by house owner/servant
+ salvage by scavengers from house+ waste disposed on unauthorized places
At transfer station (Wt):Wh - salvage by collector (door to door collection)
- salvage at transfer stationAt disposal site (Wd):
Wt – salvage by scavengers at disposal site- salvage by disposal staff
Comprehensiveness in the sources of waste
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……………Properties of MSW
Methods of estimation of waste quantities:
Load count analysisWeight –volume analysisMass balance analysis
Load count analysisNormally 8-day continuous survey neededOut of the eight days, first day collection is discardedAt least 100~200 kg samples are analyzed.For seasonal variations several studies are needed in different seasons
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Steps:No. of individual loads and the type of waste noted over a specified period of timeQuarter the waste – select the quarter of quarter until sample size is reduced to 100~200 kgs.
Separate all individual components of the waste according to their typesPlace the separated components in containers of known volume andtare mass. Try to compact the waste as found in the collection container.Determine mass of each type of waste by weighingDetermine % distribution of each component by mass as discarded density
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Weight - Volume Analysis:This is easier method where weighing bridge is available in the transfer station/disposal site.
The volume and density of each truck load is noted to collect data on waste generation each day.
The limitation may be of composition of the waste.
Therefore, this can be conducted along with Load Count Analysis.
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Mass balance method:Suitable for determining industrial waste generation.
Accumulation = inflow –outflow + generationdM / dt = Σ Min + Σ Mout + rw
Where dM / dt = rate of change of the material in the system, kg/dΣ Min = sum of all materials flowing into the system, kg/dΣ Mout = sum of all materials flowing out of the system, kg/d
rw = rate of waste generation, kg/dt = time, d
Stored materials(raw materials, products,
solid wastes)
Inflow materials
Outflow(combustion gases) and
ashes
Outflow(solid waste,
solids in waste water)
Outflow(materials)
Outflow(products)
System boundary
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……………Properties of MSW
Working with concentrations1. Conversion from chemical concentration based on dry weight and
wet (or total) weight.Example:
Sludge from a waste water treatment plant has arsenic concentration of 0.6 mg/kg based on total weight.
What is the dry weight concentration of As if moisture content of the sludge is 80%?
0.6 mg As 1 kg wet sludge
X 1 kg wet sludge 0.2 kg dry sludge = 3.0 mg As
kg dry sludge
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……………Properties of MSW
2. Finding average concentration of mixed waste.Example:
Considering two waste components:Sludge has 100 mg/kg (wet) Pb; solid content = 10%Wood chips has 300 mg/kg (wet) Pb; moisture content = 20%
What is the Pb concentration in the dry sludge if you cix the components in 50/50 mix by total weight?
0.6 mg As 1 kg wet sludge
X