Environment Engineering I An- Najah National University Civil Engineering Department Environment Engineering I Chapter Twelve- section 2 Solid Waste Management Dr. Amal Hudhud Dr. Abdel Fattah Hasan

Method of Disposal

Combustion (1) To reduce waste volume, local governments or private operators can implement a controlled burning process called combustion or incineration Burning waste at extremely high temperatures also destroys chemical compounds and disease-causing bacteria.

Sanitary landfill (2) Before 1979 MSW disposal to open dump which result in bad impact to Environment and human health After 1978 open dumping of waste was banned and replaced by sanitary landfill

sanitary landfill Land disposal site employing an engineered method of disposing of SW on a land in a manner that minimizing environmental hazards by spreading solid waste to the smallest practical volume, applying and compacting cover material at the end of each day

sanitary landfill Site selection Restricted location such as wetland flood plain, seismic impact areas Public opposition Proximity to roadways and bridge Location of GW table Soil condition and topography Availability of cover material

Sanitary landfill Operation Area method the most common method in operation SLF it uses three step: spreading the waste, compacting and covering with soil The waste is spread in 0.4 -0.6 m layer and compacted

Sanitary landfill

Sanitary landfill Depths of Cover

Sanitary landfill Environmental consideration Good compaction of waste, and daily covering with good covers are a must to control flies, rodents and fires

Sanitary landfill Leachate Liquid that passes through the landfill, extract dissolved and suspended matter from waste material Liquid contains: decomposition of waste, rainfall, surface drainage and Groundwater

Sanitary landfill

Sanitary landfill Quantity of leachate

Sanitary landfill When the landfill reach its field capacity (the quantity of water held against gravity) leachate begin to flow Amount of leachate is determined by Darcy law

Sanitary landfill Control of leachate: landfill must be lined in a specific manner to meet maximum contaminate level for G.W Specific liner include synthetics membrane 0.76 mm thick (HDPE, PVC….)

Sanitary landfill

Sanitary landfill Leachate treatment New landfill high concentration of Ammonia, organic chemical Old landfill high concentration of salts Treatment options: 1) directly to WWTP 2) pretreatment on site (flocculation- sedimentation –filtration) 3) treatment on site Activated sludge and Reverse Osmosis (RO)

Sanitary landfill Methane and other gases production: Emitted from a landfill as a result of microbial decomposition (CO2 and CH4)

Sanitary landfill Leachate monitoring Groundwater monitoring Surface water monitoring To provide data that leachate is not infiltrating into groundwater to identify risk associated with improved operation of the landfill

Sanitary landfill Landfill Design Site Preparation, building, monitoring wells, size, liners, leachate collection system, final cover, gas collection. Where = volume of landfill (in m3) P = population E = ratio of cover (soil) to compacted fill = = volume of solid waste ( in m3) = volume of cover ( in m3) C = average mass of solid waste collected per capita ( in Kg. person -1) Dc= density of compacted fill (in Kg. m-3)

Sanitary landfill Landfill closure Final cover to be applied in order to prevent moisture from entering the closed landfill

Sanitary landfill issues that need to be considered in developing a landfill closure plan Landfill will be threaten for ever (heavy metals and salts) Liners integrity issues Leachate collection system Landfill cover GW monitoring Gas emission