The values are expressed in mg/L

Biological treatment

To remove the organic matter and nitrogen

involve one or more of the following techniques:

activated sludge treatment contact aeration rotary disc

deep shaft oxidation ditch

trickling filter

aerated lagoon treatment

anaerobic biodegredation

an aerobic fixed film treatment

A leachate evaporation pond

Landfill Leachate Treatment Plant

physicochemical treatment

to removes/reduce COD, metal, suspended solid and colour

the process used are:

sedimentation with coagulation

sand filtration

ozone oxidation

Activated carbon adsorption

Chelating resin adsorption

Landfill gas

the microbial degradation generate gaseous products.

methane production begins several month to one/two years after deposition

the rate of production depends on: size and composition of solid

waste age of solid waste and landfill

moisture contain

temperature conditions in landfill

quantity and quality of nutrients

organic contain of refuse

pH and alkalinity of liquids

presence of toxic or hazardous material

gas production ranges from 1.3 to 1.7 L/kg/yr

the main component of the gas is CH4

(55%), CO2 (45%),

Biodegradation of solid waste could be describe under four phases:

the aerobic phase

hydrolysis and fermentation anaerobic phase

decelerated methane production

Biological treatment

Consists two main options

Composting (aerobic)

Biogasification (anaerobic)

Definition

Composting define as the biological degradation of the organic components of waste under

controlled condition to produce a stable end product call compost

Objectives biotreatment:

Volume reduction

Stabilization

Sanitisation

Valorisation

composting of organic material generates CO2 and H2O.

Biogasification generates CH4 , CO2, and H2O.

The final products of biotreatment are stable & could be use as fertilizer.

Composting is an exothermic process & max. temperature 60 -700C

The aerobic phase

in the presence of O2,

oxygen & nitrogen are depleted while CO2 increases

The phase lasts only a few days

Hydrolysis and fermentation

biological polymers

Anaerobic phase

beginning of methane generation

bacteria (methanogens) responsible for degradation substances.

decelerated methane production

concentrations of carboxylic acid decreases to below 100 mg/l.

Gas monitoring

involve the monitoring of methane and other volatile organic compound.

Monitoring wells are installed within and around the landfill.

Two type of gas monitoring device can be use.

barhole probe

permanent probe

Barhole probe performe near structure or along the

parameter of a landfill.

only obtain one time measurement of gas concentration at shallow depts.

permanent probe located along the parameter of the

landfill at location identify during the hydrogeology investigation

Periodically gas samples collected from these wells are analysed for methane contain & and other gas.

TANK YOU