# SOLID WASTE Collection and Transportation SOLID WASTE Solid

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SOLID WASTE Collection and Transportation

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

Solid waste management system elements

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

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.

SOLID WASTE GENERATION RATE (1) Number of compactor truck loads = 10 (2) Average size of compactor truck = 15. 3 m 3 (3) Number of flatbed loads = 10 (4) Average flatbed volume = 1. 15 m 3 (5) Number of loads from individual residents private cars & truck = 20 (6) Estimated volume per domestic vehicle = 0. 23 m 3

WASTE GENERATION RATES Solution 7 1. Set up the computation table

SOLID WASTE GENERATION RATE 2. Estimate the unit waste generation rate 33116 kg/wk Unit rate = ----------- = 1. 35 kg/capita/day (1000 x 3. 5)(7 days/wk)

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.

END COLLECTION ROUTING- EXAMPLE 10 START

START 11 ONE WAY END

EX 1: 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

SOLID WASTE COLLECTION Total time of one day refuse or waste collection

EX 2: 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 =19 m 3 Time loading per stop = 1 min. quantity of daily collected wastes = 150 m 3/day Container capacity 10 m 3/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?

EX 3: 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 0. 25 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. ?

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 )-

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

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

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

MSW COLLECTION SYSTEMS 1) HAUL CONTAINER SYSTEM (HCS) 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

MSW COLLECTION SYSTEMS 1) HAUL CONTAINER SYSTEM (HCS) Nd =[H(1 -W) – (t 1 - t 2)]/ Thcs Nd = number of trips per day, trips/day H = length of work day, h/d W = off-route factor, expressed as a fraction t 1 - = time to drive from dispatch station (garage) to first location to be serviced for the day, t 2 - = 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

MSW COLLECTION SYSTEMS 1) HAUL CONTAINER SYSTEM (HCS) Nd = Vd /c f ………an alternative computation technique. Nd = number of trips per day, trips/d Vd = average daily quantity of waste collected, m 3/d c= average container size, m 3/trip f=weighted average container utilization factor

MSW COLLECTION SYSTEMS 2) STATIONARY CONTAINER SYSTEM (SCS) Solid waste pick up location 1 Load contents from container's) at pick up location into collection vehicle 3 2 n Drive to next container location Empty collection vehicle from dispatch stationbeginning of daily route, t 1 Collection route Drive loaded collection vehicle to location where contents of vehicle will be emptied Drive empty collection vehicle to beginning of next collection route or return to dispatch station-end of route, t 2 Transfer station, MRF (content of container are emptied)

MSW COLLECTION SYSTEMS 2) STATIONARY CONTAINER SYSTEM (SCS) 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 uc = number of container pick up location per trip, location/trip = average unloading time per stationary containers for stationary container system, h/container dbc = average time spent driving between container location, h/location

MSW COLLECTION SYSTEMS 2) STATIONARY CONTAINER SYSTEM (SCS) Ct = v. r /c f Ct = number of containers emptied per trip, containers/trip v = volume of collection vehicle, yd 3/trip r = compaction ratio c = container volume yd 3/container f = Weighted container utilization factor

MSW COLLECTION SYSTEMS 2) STATIONARY CONTAINER SYSTEM (SCS) 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, yd 3/d v = volume of collection vehicle, yd 3/trip r = compaction ratio

MSW COLLECTION SYSTEMS 2) STATIONARY CONTAINER SYSTEM (SCS) Time required per day, following equation: - H = [(t 1 - t 2) + Nd(Tscs)] ……………. (day) (1 -W) H = Time required per day t 1 - = time to drive from dispatch station (garage) to first location to be serviced for the day, hours t 2 - = 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

z EX: Consider the following data for a municipal waste collection system: z Travel time garage to route =20 min. z Time to dispatch station= 15 min. z Compaction ratio =4 z Time loading per stop = 1 min. z Weighted container utilization factor= 0. 67 z Off-route factor= 0. 15 z Quantity of daily collected wastes = 150 m 3/day z Container capacity 10 m 3/container z Times per trip = 3 hrs/trip z Daily working hours = 7 hours / day z a) How much truck volume to collect the above waste?

z EX 4: 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 20 min, respectively. Two trucks are being considered: Truck volume (m 3) 15 27 Off-route factor, W 0. 15 Times per trip , hrs/trip 4 4. 5 Solid waste generation 7 8. 5 per day, ton Density of solid waste, kg/m 3 35 35 How many hours per day would each truck and crew have to operate to fill the trucks each day?

Homework to be submit on 10 -Oct. -2012 1) Solid waste from a new industrial park is to be collected in large containers (drop boxes), some of which will be used in conjunction with stationary compactors. 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 10 and 15 min, respectively. If the average time required to drive between containers is 6 min and the one way distance to disposal site is 15. 5 mi(speed limit: 55 mi/h), Determine the number of trips that can be made per day and the time per trip based on an 8 -h workday. Assume the off-route factor, is equal to 0. 15. The container size is 6 m 3, container utilization factor equal to 0. 67 and quantity of solid waste generated as 150 m 3/week.

2) Solid waste from a new industrial park is to be collected in large containers (drop boxes), some of which will be used in conjunction with stationary compactors. 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 10 and 15 min, respectively. If the average time required to drive between containers is 6 min and the one way distance to disposal site is 15. 5 mi(speed limit: 55 mi/h), Determine the number of trips that can be made per day if the time per trip is 5 minutes. Based on an 10 -hours workday compute the off route factor. Asssume The container size is 8 m 3, container utilization factor equal to 0. 67 and quantity of solid waste generated as 180 m 3/week.

TRANSFER STATION 32

TRANSFER AND TRANSPORT Three Questions for Transfer Station 1) Is it needed? 2) What type should be built? 3) Where should it be located? The Need for Transfer Operation The 6 MAJOR factors that tend to make the use of transfer operations attractive include: 33

TRANSFER AND TRANSPORT 1. Long distances to disposal 2. Small collection vehicles (especially with three man crews) 3. The existence of low-density residential areas (lots of 1 acre or larger with long driveways) 4. The widespread use of medium-sized containers for the collection of waste from commercial courses. 5. The use of hydraulic or pneumatic collection systems. 6. The presence of illegal dumps and large amount of litter. 34

TRANSFER AND TRANSPORT Transfer and transport operations become a necessity when haul distances to available disposal sites or processing centres increase to the point that direct hauling is no longer economically feasible. They also become a necessity when disposal sites or processing centres are in remote locations and cannot be reached directly by highway. The decision to use a transfer operation is based on economics The time and economic advantage of the stationary container system over the hauled container system. 35

MRF (MATERIAL RECOVERY FACILITY) Factors to be considered for MRF design : A) Type of loading 1) Direct loading- truck load directly 2) Storage Loading- waste kept prior 3) Discharge Loading- Combination of 1 & 2 B) Design Criteria 1) Design Operation Period (yrs) 2) MSW quantity & types of waste for storage & processing 3)Types of machinery and equipments required 4) Other facilities ( Aesthetic & Sanitation) 36

MRF (MATERIAL RECOVERY FACILITY) C) Layout consideration for MRF 1) Waste deliveries 2) Material delivery rate 3) Loading rates including storage for peak times 4) Material flow & Handling Patterns 5) Performance criteria for equipment selection: - • Equipment • Environment (NIMBY) • Aesthetics 37

MSW MANAGEMENT (MRF) Commingled waste Receiving Area Residue to Landfill Screen Magnetic Separator Ferrous Metals Bulky items/ Manual Removal Of Material Shred (Shredder) Screening (Trommel) Magnetic Separator White. Good Cardboards Conveyer Oversize Materials Shredding Ferrous Metals Air Classification Residue to Landfill Cyclone Dust Collector Mainly Organic Fraction 38

MSW (MATERIAL RECOVERY FACILITY) PROCESS UNITS Cyclone Air & Solid Separator 39

MSW (MATERIAL RECOVERY FACILITY) FINAL PRODUCTS Separated Plastic Waste Separated Paper waste Aluminum Cans 40

MSW (MATERIAL RECOVERY FACILITY) QUESTION The director wants to know how many sorters, jobs, will be needed on the sorting conveyer line, You know the town population is 120, 000. Assume waste generation rate as 3. 82 lb. /capita. day Working hours per week = 40 hrs Waste sorted ton person. hr = 2. 5 41

MSW MANAGEMENT 42

MSW MANAGEMENT STRATEGY Optimal MSW Management Strategy are as follows: PART 1 -Waste Reduction PART 2 -Waste Recovery PART 3 -Waste Treatment PART 4 - Waste Disposal 43

MSW MANAGEMENT STRATEGY ( Optimal MSW Management Strategy : PART 1 -Waste Reduction 1. Waste audit 2. Product reformulating 3. Substitution 4. More efficient equipment 5. Process redesign 6. Process control 7. Waste concentration 44

MSW MANAGEMENT STRATEGY Optimal MSW Management Strategy : PART 2 -Waste Recovery (RECYCLING & REUSE) 1) Recycling 2) Waste recovery 3) Waste segregation 4) Inter-industry exchange 5) Combine specific 6) Waste streams 45

MSW MANAGEMENT STRATEGY Optimal MSW Management Strategy : PART 3 -Waste Treatment 1) Pyrolysis 2) Hydrolysis 3) Composting PART 4 - Waste Disposal 1) Controlled tipping 2) landfill 3) Incineration 46