Solid Waste Management Waste Management. Liquid and solid Waste ( )

Transcription

1 Liquid and solid Waste ( ) Very Important Note: Most of the figures and tables are downloaded from google and various text books Solid Waste Evolution and Concepts: Since the beginning of humanity, both humans and animals have been using earth resources to support their life. As a result of these activities, waste is being produced. At small community No waste problem, but when people starts live in bigger communities (city) more waste produced... thus the demand for waste management (WM) appear. Heterogeneous nature of commingled solid waste makes studying it not an easy job What is waste: The term solid waste refers to thrown items that have no value for its owner even though it may consider as a material or heat resources for other users. Why we need to manage the solid waste (SW)? The relationship between public health and the improper waste storage, handling and disposing is significant. Improper WM leads to suffer from rats and flies breeding and epidemic diseases. Reduce the pollution form waste and its emissions like Methane (CH 4 ), hydrogen sulphide (H 2 S), CO (العصارة) Protect ground water from leachate

2 Waste Classifications: 1 Classification in dependent on waste physical status a Solid b liquid c gas 2 classification based on waste nature: a hazardous waste: that has one of the hazardous characteristics that pose human and environmental risks b nonhazardous waste c Medical waste d Special waste like tires, car batteries (acid lead), used oil HW# what are the hazardous characteristics??

3 3 Classification in dependent to wastegeneration source to the following: a) Residential or Domestic waste:includes nonhazardous waste generated in households, It includes commercial,business establishments and institutions that has same composition. b) Commercial: all municipal solid waste generated from business establishments such as stores, markets, office buildings, restaurants and shopping centers. c) Institutional: waste originating in universities, schools, hospitals, prisons, research centers and other public buildings. Note: since the commercial and institutional wastes are generated from people activities thus its composition almost same as the domestic d) Industrial: Heterogeneous mixture of different materials generated during an industrial process. It may be gaseous, liquid, sludge, or solid. It's composition depends upon the natural resources, raw materials, markets, and manufacturing process.

4 eagricultural: The solid waste resulted from plant cultivation activities such trees trimming waste, grass, plastic house, and irrigation hoses. f Construction and Demolition: All solid waste generated from construction activities, dredging materials, rubble (انقاض) resulting from construction, demolition of homes, and other structures or pavements. The nature of this type of SW depends upon the used resources in a given region or country for the purposes of construction. g Municipal Services: Street sweeping (cleaning), landscaping, parks and beaches

5 htreatment plant sites: such as sludge I Special waste: such as car tiers, consumer electronic and white goods (refrigerator, washing machines), used oil. Composition of Solid Waste It s the term used to describe the individual components that is included within a solid waste stream and their relative distribution usually based on percentage by weight. Metals, 3.1 Miscellaneous, Glass, Rubber & Leather, 2.6 Textile, 5.8 Plastics, 15.2 Organics (food waste), 48.9 Paper & Cardboard, Waste composition in zarqa city (almost same as Jordanian waste composition)

6 Waste composition is vary through the time due to changes in consumption trend and life style. Waste composition is vary from one place to another Main Components of SWComposition for Different Studies and time periods. Study MoEnv. and RSS JUST CMCE Fichtner RSS Composition Weight %by (2009) )2007( )2002( )1996( )1994( Organics Paper and Cardboard Metals Plastics Glass Textile Rubber and Leather Hazardous waste Miscellaneous Ministry of Environment, (2009)

7 Comparison of Jordanian Solid Waste Contents with other Countries. Waste Composition Jordan Asian Countries Organic Paper Metal glass Plastic AlAnsari A. et al. (2005) UK USA Example: a family brings approximately 50 kg of consumer good a week (food,magazine, appliances ) of this amount 60% is consumed as food. half of the food is used for biological maintenance and ultimately released as CO2 and the reminder is discharged to sewer. The green recycle is about 25% of the solid waste that is generated. Approximately 1kg is accumulated at home. Estimate the solid waste amount that placed at curb each week?? Main equation: Accumulation = input output consumer good food (input) Accumulation Solid waste

8 Consumed food = 0.6 * 50 = 30 kg Input = output (food) + output (solid waste) + accumulation 50 = 30 + solid waste + 1 total amount of generated solid waste = 19 kg 25% of the solid waste is recycled = 0.25 * 19 = 4.75 kg is recycled Thus the solid waste send to curb side collection weekly = = kg. Characteristics of Solid Waste It is the identification of chemical,physical and biological properties of waste. Characterization is limited to residential, commercial and some industrial waste. It is difficult process due to the limited number of samples, that can be collected and analyzed, the large number of sources and the heterogeneous nature of solid. 1 Physical Properties of Solid Waste The main physical prosperities of solid waste are: specific weight, moisture content, particle size, size distribution and field capacity. I. Specific weight: The weight of materials per unit volume lb/yd 3 or kg/m 3. Each waste component has its own specific weight. Compaction process can affect the specific weight, so the specific weight is reported for uncompacted waste or as found in the container. Typical value of specific weight for delivered solid waste in compactor is kg/m 3 (500 lb/yd 3 ) (Tchobanoglous, et al., 1993). II. Moisture content: Represents the amount of water in the waste. This is considered the major parameter in measuring the heat value of the solid waste, as the moisture content is higher; the lower is the heat or calorific value of the solid waste.

9 Moisture content is measured as the difference in weight for an item wet and after dried in an oven at 105 o C. The typical data for the moisture content is between 1550%.

10 III. Particle size and size distribution: It is an essential term in material recovery especially with mechanical sorting machines like screens or magnetic separator. The average size for individual solid waste components is between cm (7 8 inches). IV. Field capacity: It is the total amount of moisture that can be retained in a waste sample subject to the downward pull of gravity. It is important to determine the leachate formation in the landfill (Vesilind et al., 2002). 2 Chemical Properties of Solid Waste It is essential to design processing and recovery options, especially heat recovery. The main chemical prosperities are ultimate and proximate analysis, fusing point of ash and energy content. a) Proximate analysis: The determination of the combustible components in solid waste. It includes moisture content, volatile combustible matter, fixed carbon and ash (Vesilind et al., 2002).

11 b) Fusing point of ash: The temperature at which ash resulting from the burning of waste at o C (Tchobanoglous, et al., 1993). c) Ultimate analysis of solid waste: The determination of the percentage of Carbon, Nitrogen, Oxygen, Hydrogen, Sulfur, and Ash. Ultimate analysis is used to characterize the chemical composition of the organic matter in municipal solid waste. Determining chemical composition is necessary to achieve the optimum C/N in the composting treatment of solid waste, or to calculate the heat content (Vesilind et al., 2002).

12 d) Energy content of solid waste: It is determined by full scale boiler as colorimeter and laboratory bomb colorimeter or by calculations if the elemental composition is known. The moisture content directly affects the energy content?? why because portion of the heat within the solid waste will be consumed to evaporate the moisture. be determined. KJ/kg or K calori/kg Average Jordan energy content: 2747 kcal/kg

13 3 Biological Properties of Solid Waste Include the content of the organic fractions in the solid waste except the plastic, rubber and leather components. The main organic fractions are the oil, fat, water soluble substances as sugar and starch, cellulose, lignin and protein. Usually the organic fraction is degradable even though some fractions may take long time to degrade as lignin (Vesilind et al., 2002). Biodegradability of the organic fraction of the solid waste is determined by the volatile solid content (VS) that is determined at a temperature of 550 o C. Degradation of the organic fraction is responsible for most of the odor produced from the solid waste degradations (Tchobanoglous, et al., 1993).