Introduction to Waste Engineering PDF

**Introduction to Waste Engineering** **What are the steps that follow waste?** - Generation - Collection and transport - Treatment - RUL **What does generation or production refer to?** The source and waste being generated, sorted, and collected "in-house". Where waste is quantified...

**Introduction to Waste Engineering** **What are the steps that follow waste?** - Generation - Collection and transport - Treatment - RUL **What does generation or production refer to?** The source and waste being generated, sorted, and collected "in-house". Where waste is quantified before management. **Can treatment be done in transport stations and which type of treatment?** Yes, mechanical like compacting or shredding **What is desired to reduce when treating waste?** Odour, volume and impurities **What are the types of thermal treatment?** Incineration and gasification/pyrolysis **What are the types of biological treatment?** Composting and biogasification (anaerobic digestion) **How can waste be utilized?** For land, construction and fuel **What is MRF?** Materials Recovery Facility. It is a specialized plant or facility designed to sort, process, and recover recyclable materials from mixed waste streams. 2. **Introduction to Waste Management** **How much waste is there in DK?** 12 million tons **What category is the biggest contributor?** Construction and demolition -- 40% followed by households with 29%. **Which types does residential waste have?** - Household - Garden - Bulky - Hazardous household **Which types does organic waste have?** **What factors affect the viewing/definition of waste?** - Time - Location - Culture - Social conditions **How many municipal waste categories are there?**\ 20 **Which are the main issues with solid waste?** - Space - Collection & Separation - Health problems - Toxicity - Different systems - Costs - Complex materials - Odour **Whats the first and last step in the EU strategy?** 1^st^ is prevention last is disposal (landfill) **2. Waste Characterization: Methods** **What are the challenges of waste characterization?** - Spatial - Temporal - Uncertainty due to mixture **What kind of tests are done when testing samples** - Physical - Chemical - Performance **What instrument is used when characterizing org. waste?** Disc screen  **What's the definition of waste category?** Broad classes of waste coming from sources with common characteristics. Residential waste, commercial and institutional waste, industrial waste, and construction and demolition (C&D) waste are the main categories. **What's the definition of waste type?** Subclasses of waste categories that have common characteristics with respect to source and composition potentially resulting in separate collection and handling. For example, residential waste includes the waste types: Household waste, garden waste, bulky waste and household hazardous waste. Industrial waste holds several types according to industrial branch. **\ *Waste quantities*** are often reported as wet weight, since this is easily measured. Occasionally quantities are given as volume. The **unit generation rate** is a key parameter and is the **quantity of waste per defined time frame and per generating characteristic unit.** For residential waste, the unit generation rate is often kg/year/person (used in this book), or kg/week/household. For commercial waste, the unit generation rate could be kg/year/employee, or kg/year/m2 of store, or kg/1000 Euros of sales. By multiplying together the number of characteristic units and the timeframe the total amount of waste is determined. The unit generation rate is also a convenient parameter for estimating future r waste quantities in areas with a growing population. **\ *Material fractions*** are visually identifiable fractions in the waste with common features: Paper, plastic, glass, organic kitchen waste, etc. Each material fraction may be divided into subfractions such as, for example in the case of paper: Newspaper, advertisements, magazines, paper towels,etc. **\ *Substances*** are individual chemical substances in the waste, which typically require analytical techniques to identify. This could be water, protein, ash content, nitrogen, cadmium, etc. **3. Waste minimization and recycling / prevention** **Which type of weight are unit generation rates referring to?** Wet **5. Mechanical treatment at MRFs** **Whats the purpose?** To sort for recyclables and residual stream, facilitate handling and transport, pre-step of thermal and biological treatment -- improve performance **Which types of technologies?** Separation, size reduction, and compacting **I want to obtain glass and paper fine fibres? What flow should it go through? What types of technology and technologies?** Separation first, consisting of - a debris screen, followed by a new screen (vibrating), a polishing screen, and a negative sort. **Composting** **What are the technological process factors and controls?** 1. Oxygen content, particle size and aeration 2. pH 3. biodegradation 4. temperature 5. moisture content 6. nutrients **what are the steps within a composting plant design?** 1. Source 2. Weighting/storage 3. Pre-processing 4. Composting 5. Refining, screening 6. Market product **What are the steps within composting?** 1. Degradation 2. Stabilization 3. Curing **Whats the nitrogen transformation during composting?** **Anaerobic Digestion** **What is hydrolysis?** Done by extracellular enzymes on carbohydrates, proteins and lipids. What are the processes involved in the formation of biogas? - Hydrolysis - Fermentation - Acetogenesis - Methanogenesis **What does the methane potential depend on?** Oxidation state and degradability **What steps does the anaerobic digestion system have?** - Reception and storage - Pretreatment - Digestion - Gas collection and utilization - Digestate management - Odor control **Whats the typical methane yield and content?** 60-120 v/m3 and content 45-65% **Landfill** **How much energy from incineration contributes to energy and how much to heating in percentage?\ **6% energy, 24% heating **Incineration** **What is LHV? And HHV?** Energy content available from combustion. LHV indicates the energy potential -- the energy used for water evaporation. HHV indicates the highest energy potential when water leaves in its liquid state. **What is pyrolysis?** Thermal degradation of C in the absence of oxidizing agents. **What is gasification?** Partial oxidation of C with oxidizing agents **What is combustion?**\ full oxidation of carbon **What is the purpose of APC (air pollution control) systems?** - Dust/fly ash removal - Acid neutralization - Dioxin removal - Nox removal - Heavy metal removal **CCS** **What are the benefits and drawbacks?** Benefits: - Energy recovery - Material recovery - Heat recovery - Stored CO2 Burdens: - Electricity used - Air emissions - Residues materials - Extra materials **Whats the difference of the kg co2-eq with CCS?** -820. Reduction of 90% ish **What are some solid residues coming from incineration?** - Fly ash - Bottom ash - Wastewater - Sludge - Neutralization products - Grate sifting - Boiler ash - Economizer ash **What is bottom ash and where does it come from?** Mix of metals and solid residues. Formed and transformed through combustion chamber through grate. **What is fly ash and how is it recovered?** Fine ash collected with dust removal, filters and electrostatic precipitators. **Which are some ash treatment methods?**\ - extraction and separation - Thermal treatment - Chemical stabilization - Solidification **Whats the potential of bottom ash utilization per ton of waste generated?** 0.25