1. SOLID WASTE

2. Outline
Definition
Generation
Collection
Types
Sources
Disposal

3. Solid waste
Solid waste : all the wastes arising from human and animal activities that are normally solid and that are discarded as useless or unwanted

4. Solid waste management system elements

5. Solid waste
Factors affecting solid waste generation: 1- Geographic location 2- Season of the year 3- Collection frequency (affect amounts collected) 4- Public attitude 5- Legislations 6- Use of kitchen waste grinders 7- Characteristics of Populace 8- Lack of recycling and waste minimization

6. Solid waste Generation Rate
Expression unit for generation rates
*Residential kg/c/d kilogram per capita per day
Estimation of unit solid waste generation rates for a Residential Area.
From the following date estimate the unit waste generation rate for a residential area consisting of approximately 1,000 homes. The observation location is a local transfer station, and the observation period is 1 week. each household is comprised of 3.5 people.

7. Solid waste Generation Rate
(1) Number of compactor truck loads = 10 (2) Average size of compactor truck = 15.3 m3 (3) Number of flatbed loads = 10 (4) Average flatbed volume = 1.15m3 (5) Number of loads from individual residents private cars & truck = 20 (6) Estimated volume per domestic vehicle = 0.23m3

8. WASTE GENERATION RATES
Solution
1. Set up the computation table

9. Solid waste Generation Rate
2. Estimate the unit waste generation rate Unit rate = = 1.35 kg/capita/day
33116 kg/wk
(1000x3.5)(7days/wk)

10. Collection Route
Eight(8) condition- to prepare a good Heuristics routing 1) Do not fragment routes, keep in same area. 2) Collection Time + Haul time must be Equal for each route 3) Start collection as close to municipal garage. 4) Do not collect heavily traveled streets during rush hours. 5)Start routes at higher elevations. 6) Make right turn as much as possible. 7)Avoid dead-end roads. 8) Routes must not be overlapping.

11. COLLECTION ROUTING- EXAMPLE
END
START

12. START
ONE WAY
END

13. EX1: For the following neighborhood has a one-way street running east to west. In general, trucks can only pick up from one side of the street at time.
a) Assuming pickups can be made from both sides of the street at the same time on the one way street , devise a heuristic route in which no house on the route is passed twice (no deadheading).
b) If trash can only be picked up from one side of the one- way street at a time (it’s a busy street), modify your heuristic pickup route with a minimum of deadheading and turns

14. Solid waste collection
Total time of one day refuse or waste collection

15. EX2: consider the following data for a municipal waste collection system: Travel time garage to route =20 min. Travel time , route to disposal site= 20 min. Time to unload at disposal site= 15 min. Time from disposal site to garage= 15 min. Time spent on worker breaks= 40 min/day Packer truck volume =19m3 Time loading per stop = 1min. quantity of daily collected wastes = 150 m3/day Container capacity 10 m3/container Collection time= 2 hours per trip a) How many hours per day would the crew have to work if it fills the trucks twice per day?

16. EX3: Suppose it takes 0.4 hour to drive from the garage to the beginning of the route, 0.4 hours to drive between the route and the disposal site, and hours to return from the disposal site to garage. It takes 0.2 hours to offload a truck at the disposal site. The crew is given two 15 minutes breaks per day and another 30 minutes is allowed for unexpected delays ( total 1 hour) . If two trips are made to the disposal site each day, how much time is left in 8 hours shift for actual refuse collection.?

17. 1) HAUL CONTAINER SYSTEM (HCS)
TYPES OF MSW COLLECTION SYSTEMS
2 TYPES OF COMMON MSW COLLECTION SYSTEM:-
1) HAUL CONTAINER SYSTEM (HCS)
Container full of MSW hauled to a single collection and emptied containers returned to its NEXT container location. (truck carry empty container from dispatch station to first container location)
Vehicle used( hoist truck, Tilt Frame, Truck tractor trash trailer)- high MSW generation
2) STATIONARY CONTAINER SYSTEM (SCS)
Container full of MSW hauled to a single collection and emptied containers returned to SAME MSW on site collection location. (Trucks carrying empty container from dispatch station to first container location)
- Vehicle used( front loading, side loading, rear loading, compactor )-

18. TYPES OF MSW COLLECTION SYSTEMS
Hauled container system (HCS)
 Ideally suited for the removal of wastes from sources
where the generation rate is high and relatively large
containers are used.
 Large container reduces the handling time, unsightly
accumulations and unsanitary conditions.
 Main advantages – required only a single member
crew
 However, pick up activity required a round of trip to
disposal site.
 The truck have to travel to and from deposit site.

19. TYPES OF MSW COLLECTION SYSTEMS
Stationary container system (SCS)
 The waste container remain at the point of waste
generation.
 2 types of SCS
-Those in which mechanically loaded collection
vehicle with compaction
-Manually loaded collection vehicles
 Trips to disposal site or transfer station made after the contents of a number of containers collected and compacted.

20. MSW COLLECTION SYSTEMS
1) HAUL CONTAINER SYSTEM (HCS)
MSW COLLECTION SYSTEMS
Hoist Truck
Tilt Frame
Trash Trailer

21. MSW COLLECTION SYSTEMS
HAUL CONTAINER SYSTEM (HCS)-Conventional Mode
MSW COLLECTION SYSTEMS 2 3 n
Truck from dispatch station beginning of daily route, t1
Container Location 1
Pick up loaded container
Haul loaded Container
Haul empty container to original; pick up Location
Transfer station, MRF (content of container are emptied)
Truck to dispatch station end of daily route, t2
Deposit Empty container
Drive to next container location

22. MSW COLLECTION SYSTEMS
1) HAUL CONTAINER SYSTEM (HCS)-Exchange Container Mode
Deposit empty container from previous location and pick up loaded container
Container Location 1 2 3 n
Truck with empty container from dispatch station beginning of daily route, t1
Haul empty container originally at location 1 to location 2
Truck with empty container to dispatch station end of daily route, t2
Haul loaded Container from location 1
Transfer station, MRF or disposal site

23. MSW COLLECTION SYSTEMS
1) HAUL CONTAINER SYSTEM (HCS)
MSW COLLECTION SYSTEMS
For haul container system Phcs= pc +uc +dbc
Phcs = Pick up time per trip for hauled container system, h/trip
pc = time required to pick up loaded container, h/trip
uc = time required to unload empty container, h/trip
dbc = time required to drive between container location, h/trip

24. MSW COLLECTION SYSTEMS
1) HAUL CONTAINER SYSTEM (HCS)
MSW COLLECTION SYSTEMS
Nd =[H(1-W) – (t1- t2)]/ Thcs
Nd = number of trips per day, trips/day
H = length of work day, h/d
W = off-route factor, expressed as a fraction
t1- = time to drive from dispatch station (garage) to first location
to be serviced for the day,
t2- = time to drive from last container to serviced for the day back to dispatch station (garage) ,h.
Tscs = time per trip for haul container system, h/trip

25. MSW COLLECTION SYSTEMS
1) HAUL CONTAINER SYSTEM (HCS)
MSW COLLECTION SYSTEMS
Nd = Vd /c f ………an alternative computation technique.
Nd = number of trips per day, trips/d
Vd = average daily quantity of waste collected, m3/d
c= average container size, m3/trip
f=weighted average container utilization factor

26. MSW COLLECTION SYSTEMS
2) STATIONARY CONTAINER SYSTEM (SCS)
Empty collection vehicle from dispatch station- beginning of daily route, t1
Load contents from container's) at pick up location into collection vehicle 2 3 n
Drive to next container location
Transfer station, MRF (content of container are emptied)
Drive empty collection vehicle to beginning of next collection route or return to dispatch station-end of route, t2
Solid waste pick up location 1
Collection route
Drive loaded collection vehicle to location where contents of vehicle will be emptied

27. MSW COLLECTION SYSTEMS
2) STATIONARY CONTAINER SYSTEM (SCS)
MSW COLLECTION SYSTEMS
For Stationary container system Pscs= Ct (uc) +( np- 1 )(dbc)
Pscs = pickup time per trip for stationary container system, h/trip
Ct = number of container emptied per trip, container/trip
np = number of container pick up location per trip, location/trip
uc = average unloading time per stationary containers for
stationary container system, h/container
dbc = average time spent driving between container location, h/location

28. MSW COLLECTION SYSTEMS
2) STATIONARY CONTAINER SYSTEM (SCS)
MSW COLLECTION SYSTEMS
Ct = v.r /c f
Ct = number of containers emptied per trip, containers/trip
v = volume of collection vehicle, yd3/trip
r = compaction ratio
c = container volume yd3/container
f = Weighted container utilization factor

29. MSW COLLECTION SYSTEMS
2) STATIONARY CONTAINER SYSTEM (SCS)
MSW COLLECTION SYSTEMS
Nd = Vd /v.r (SCS) Nd = Vd /c f (HCS).
Nd = number of collection trips required per day, trips/d
Vd = average daily quantity of waste collected, yd3/d
v = volume of collection vehicle, yd3/trip
r = compaction ratio

30. MSW COLLECTION SYSTEMS
2) STATIONARY CONTAINER SYSTEM (SCS)
MSW COLLECTION SYSTEMS
Time required per day, following equation:-
H = [(t1- t2) + Nd(Tscs)] ……………. (day)
(1-W)
H = Time required per day
t1- = time to drive from dispatch station (garage) to first location to be serviced for the day, hours
t2- = time to drive from last container to serviced for the day back to dispatch station (garage), hours
Nd = number of collection trips required per day, trips/d
Tscs = time per trip for stationary container system, h/trip
W = off-route factor, expressed as a fraction

31. EX4: Consider the following data for a municipal waste
EX4: Consider the following data for a municipal waste collection system:
Travel time garage to route =20 min.
Time to dispatch station= 15 min.
Compaction ratio =4
Time loading per stop = 1min.
Weighted container utilization factor= 0.67
Off-route factor= 0.15
Quantity of daily collected wastes = 150 m3/day
Container capacity 10 m3/container
Times per trip = 3 hrs/trip
Daily working hours = 7 hours / day
a) How much truck volume to collect the above waste?

32. EX5: Based on traffic studies at similar parks, it is estimated that the average time to drive from the garage to the first container location and from the last container location to the garage each day will be 15 and 20min, respectively. Two trucks are being considered:
Truck volume (m3)
Off-route factor, W
Times per trip , hrs/trip
Solid waste generation
per day, ton
Density of solid waste, kg/m
How many hours per day would each truck and crew have to operate to fill the trucks each day?

33. WASTE DISPOSAL
No matter what processing is done, there will be some residue that needs to be disposed of safely
Options for disposal
Modern, engineered landfill
Incineration.

34. WASTE DISPOSAL
Sanitary Landfill
Is defined as a land disposal site employing an engineered method of disposing of solid wastes in a manner that minimizes environmental hazards by spreading the solid wastes to the smallest practical volume, and applying and compacting cover material at the end of operation of each day.
Systems- Sanitary Landfill
i. Gas collection system
ii. Leachate collection system
iii. Monitoring well

35. Solid Waste - Sanitary Landfill

36. A landfill in México showing geomembrane in one of the slopes.

37. Cross-Section of Sanitary Landfill
WASTE DISPOSAL
Cross-Section of Sanitary Landfill

38. Sanitary Landfill-Site selection consideration
WASTE DISPOSAL
Sanitary Landfill-Site selection consideration
1. Public Opinion/opposition
2. Proximity of major roadways
3. Speed Limits
4. Load limits on roadways
5. Bridge capacities
6. Traffic patterns and congestion
7. Haul distance (time)
8. Detours
9. Hydrology

39. Sanitary Landfill-Site selection consideration
WASTE DISPOSAL
Sanitary Landfill-Site selection consideration
10. Availability of cover material
11. Climate (e.g. floods, mud slides, snow)
12. Buffer areas around the site (e.g. high trees on site perimeter)
13. to operate for at least 5 years
14. ultimate use of completed landfill

40. Sanitary Landfill-Methods of Operation
WASTE DISPOSAL
Sanitary Landfill-Methods of Operation
Area Method
Solid waste is deposited on the surface, compacted, then covered with a layer of compacted soil at the end of a working day.
The cover material may come from on or off site.

41. WASTE DISPOSAL
Area Method

42. Area method for constructing a sanitary landfill

43. Sanitary Landfill Cross Section - Area Method
WASTE DISPOSAL
Sanitary Landfill Cross Section - Area Method

44. Cell - volume of material place in the landfill
Cell - volume of material place in the landfill during one day operating period.
Daily cover
- 6 to12 in of native soil/ alternative material applied into surface of the landfill at end of each one day
- to control the blowing of wastes material.
Lift - complete layer of cells over the native area of the landfill

45. Bench
- height of the landfill exceed 15 to 20 m.
- to maintain the slope stability of the landfill
Final lift - final cover layer
Final cover layer
- applied to entire landfill surface after all landfilling operations are
complete.
- usually multiple layers of soil/geomembrane material

46. Sanitary Landfill-Methods of Operation
WASTE DISPOSAL
Sanitary Landfill-Methods of Operation
Trench Method:
A trench is excavated and the solid waste is placed in it and compacted; and the soil that was taken from the trench is then laid on the waste and compacted.
This method is used on level or gently sloping land where the water table is low.
The advantage of this method is that the soil taken from the trench can readily be used as daily cover and final cover.

47. WASTE DISPOSAL
Trench Method

48. Trench method for constructing a sanitary landfill

49. Environmental Considerations of Sanitary Landfill
WASTE DISPOSAL
Environmental Considerations of Sanitary Landfill
1.A well designed and operated landfill will minimize vectors (carrier of disease), water and air pollution.
2.Burning is not permitted in a landfill. Keeping the waste covered will prevent the production of flies, control of rodents and fires.

50. WASTE DISPOSAL Landfill Leachate:
Liquid that passes through the landfill and that has extracted dissolved and suspended matter from it is called leachate.
Liquid enters the landfill from external sources such as rainfall, surface drainage, groundwater, and the liquid in and produced from the decomposition of the waste.

51. Leachate Collection System
WASTE DISPOSAL
Leachate Collection System
Impermeable liner
Granular material
Collection piping
Leachate storage tank
Leachate is trucked to a wastewater treatment facility

52. WASTE DISPOSAL Estimating Landfill Requirements
Sizing of landfill requires estimates of:
- The rate at which wastes are discarded.
The density of wastes when they are compacted in the fill.
The density of wastes will be depends on how well it is spread and compacted .
For MSW, the density in a landfill will usually between 480 to 600 kg/m3.

53. WASTE DISPOSAL
vMSW=
Vcell =
Alift =