Environmental Engineering

ALESSANDRA POLETTINI
ALESSANDRA POLETTINI

General outcomes
The module is focused on the fundamentals of processes for recovery, recycling, treatment and disposal of municipal and industrial solid wastes. Integrated waste management is the main approach involved. Specific reference will be made to the role played by integrated waste management in reducing direct and indirect GHG emissions.
The general learning outcomes expected are included among the wider outcomes of the whole master programme in Environmental Engineering. To this regard, the module contributes (as for the waste management sector) to the educational background required for the graduate engineer to manage and design interventions for the preservation of the quality of environmental compartments and mitigation of climate change effects.

Specific outcomes
Knowledge and understanding:
After passing the exam, the students will be able to deal with issues related to the integrated management of municipal and industrial solid wastes, with particular reference to planning of the integrated systems and identification of the appropriate technologies. They will also have acquired the knowledge and understanding of the environmental issues related to the operation of waste treatment and disposal (ref. to section A4.b.2 of the SUA document – “mastering engineering abilities and methods in the field of environmental protection and sustainable use of resources).

Applying knowledge and understanding:
After passing the exam, students will be able to undertake design duties with regard to systems and plants for the integrated management of municipal and industrial solid wastes, mastering the competences and engineering methods for climate mitigation of and adaptation to climate change effects.

Making judgement:
After passing the exam, the students will also be able to make judgement with particular regard to assessing topics requiring further analysis and collecting suitable technical and scientific documentation, as well as to use adequate methods to investigate environmental engineering topics at their level of knowledge and understanding”, with particular regard to technologies and plants for waste treatment and recovery.

Learning skills:
Solving practical numerical and design exercises will also provide the students with a tool to acquire autonomous learning skills, also with specific regard to the ability to make judgement and critical assessment of the faced problems in case of shortage or lack of the relevant information.
The above mentioned skills will contribute to building a backbone that will allow the students to acquire updated information in a continuous, autonomous and in-depth manner, concerning both their professional abilities and the emerging environmental issues related to climate change

After completing the course, the student will:
• Have learned the existing regulatory framework related to waste management
• Have gained familiarity with the concepts related to sustainable waste management
• Have acquired knowledge of the composition, characteristics and properties of relevant municipal and industrial waste flows
• Have acquired knowledge of the principles of waste collection, treatment, recycling, recovery and disposal
• Have become able to plan sustainable waste management systems
• Have learned how to handle the technical tools for the design and operation of waste treatment, recycling, recovery and disposal plants
• Have understood the role of integrated waste management in climate change mitigation

To successfully attend the Solid Waste Treatment Plants module and pass the final exam, basic knowledge of the following subjects is essential:
• maths (with specific regard to differential and integral calculus)
• physics (with specific regard to the basics of thermodynamics)
• chemistry & engineering chemistry (with specific regard to the stoichiometry of chemical reactions, the concepts of chemical equilibrium in aqueous solutions and specific types of chemical reactions [acid-base, redox reactions], chemical reactors engineering)
• sanitary and environmental engineering (with specific regard to the pollution indicators and the principles of effluent treatment)
• fluid mechanics and hydrology (with specific regard to porous media hydraulic, processing of hydrological data and rainfall-runoff transformation)
• geotechnics (with specific regard to soil geotechnical and mechanical properties)
No compulsory prerequisites to access the final exam are required.

TOPIC 1. CLASSIFICATION, PRODUCTION, COMPOSITION AND PROPERTIES OF SOLID WASTE
Classification of solid waste: regulation (lectures 1-4).
Production, composition and properties of solid wastes. Production and composition of solid wastes depending on their source. Statistical analysis of solid waste production. Physical, chemical and biological properties of solid waste. Concepts of integrated waste management: principles, targets and technical issues (lectures 5-8; practical exercises 1-2).

TOPIC 2. SOLID WASTE COLLECTION AND TRANSPORT
Targets of source separation and waste collection. Collection systems. Methods and equipment for waste collection and transport. Collection routes. Algorithms for determination of collection routes (Dijkstra, Floyd, euristic methods, Clarke-Wright). Transfer stations. Economic analysis of waste collection and transport systems. Design of waste collection and transport systems.
Separate waste collection. Recyclable municipal wastes. Hazardous municipal wastes. Commingled selective collection. Design of separate waste collection systems (lectures 9-12; practical exercises 3-4)

TOPIC 3. MECHANICAL TREATMENT, SEPARATION AND MATERIALS RECOVERY
Mechanical waste treatment with production of SOF and RDF. Binary separation theory. Processing units and design criteria. Dry and wet systems for solid waste processing. Production of refuse-derived or solids-derived fuel (RDF/SRF) (lectures 13-18; practical exercises 5 e 6 [part 1 and part 2]).

TOPIC 4. BIOLOGICAL WASTE TREATMENT
Biological processes. Treatment of the organic fraction of solid waste. Aerobic digestion. Treatment techniques and processes. Design criteria. Anaerobic digestion. High- and low-load processes. Biogas production and recovery. Health and safety issues. Use of compost and quality requirements. Uses and destinations of the stabilized organic fraction and digestate (lectures 19-22; practical exercise 7).

TOPIC 5. FINAL WASTE DISPOSAL
Sanitary landfilling. Concepts of sustainable landfill. Classification of sanitary landfills and waste acceptance criteria. Waste pre-treatment. Technical site characterization. Mechanical behaviour and stability of landfills. Bottom liner system. Surface water drainage and collection. Top covers: objectives and technical characteristics. Leachate drainage, collection, monitoring and treatment. Biogas collection and transport. Control of biogas dispersion. Health and safety issues (lectures 23-29; practical exercises 8 and 9).

TOPIC 6. THERMAL WASTE TREATMENT
Combustion, pyrolysis and gasification. Waste combustion: thermodynamic issues. Analysis of combustibles. Higher and lower heating value. Measurement of heating value. Combustion stoichiometry and kinetics. Combustion stages. Air excess. Combustion products. Composition and quality of effluent gases. Influence of chlorine on gas composition. Adiabatic flame temperature. Units of a waste combustion plant: storage unit, combustion chamber, post-combustion section, gas cooling section, air pollution control section. Energy recovery. Characterization of outlet streams from waste combustion. Organic and inorganic pollutants in solid residues. Techniques for optimization of solid residues composition. Reuse, treatment and disposal of solid residues from waste combustion (lectures 30-31).
Treatment of gaseous effluents. Control of particulate matter (gravity separation, centrifugal separation, electrostatic precipitation, filtration, scrubbing). Control of sulphur oxides. Control of nitric oxides. Acid gas removal (lecture 32).

• T.H. Christensen, Solid Waste Technology & Management, Blackwell Publishing Ltd.
• W.A. Worrell, P.A. Vesilind, Solid Waste Engineering, Cengage Learning Ed.
• De Feo G., De Gisi S., Galasso M., Rifiuti solidi. Progettazione e gestione di impianti per il trattamento e lo smaltimento, Flaccovio Ed.
• Tchobanoglous G., Noto La Diega C., Sirini P., Ingegneria dei rifiuti solidi, McGraw-Hill Ed.
• Tchobanoglous G., Theisen H., Vigil A., Integrated Waste Management, McGraw-Hill Ed.
• Niessen W.R., Combustion and Incineration Processes, Marcel Dekker, Inc., New York
• Dispense a cura del docente
Note: the learning material is available at the following link (password-protected access; password provided upon registration at the course's Classroom group [detailed information on the teacher's online notice board]):
https://alessandrapolettini.site.uniroma1.it/didattica

• R.C. Bailie, J.W. Everett, B.G. Lipták, D.H.F. Liu, F. Mack Rugg, M.S. Switzenbaum, Solid Waste, CRC Press Ed.
• La Grega M.D., Buckingham P.L., Evans J.C., Hazardous Waste Management, McGraw-Hill Ed.
• Borman G.L., Ragland K.W., Combustion Engineering, McGraw-Hill Ed.
• De Nevers N., Air Pollution Control Engineering, McGraw-Hill Ed.

The module consists of a combination of lectures and classroom exercises (either of numeric or design type). The knowledge and understanding abilities defined in the module objectives will be mainly acquired through conventional lectures; applying knowledge and understanding will be acquired through both conventional lectures and classroom exercises; soft skills (making judgements and learning skills) will be acquired through the preparation of the final technical report as well as private study.

Attendance to lectures is not compulsory.

The knowledge acquired by the students on the course topics will be evaluated through a final exam. The latter will involve an oral discussion of the main subjects of the course (as a rule, 3 subjects selected by the teacher during the exam), out of which one will be specifically focused on the practical/design projects implemented during the classroom sessions.
The final evaluation will take into account mainly (70-80%) the acquired knowledge and understanding and the ability of their application, and for the remaining 20-30% the demonstrated making judgements abilities and autonomous learning skills. Each of these aspects will be judged on the 3 topics selected by the teacher during the exam.

• Basic principles for one of the processes for waste treatment, recycling, recovery: underlying hypotheses, analytical description, operating parameters, yield
• Design and operation criteria for one of the processes for waste treatment, recycling, recovery and disposal
• Prediction calculations related to the application of one of the processes for waste treatment, recycling, recovery and disposal: mass/energy balances, effluent generation, production of secondary materials, potential emissions