Waste treatment

Occupational Safety and Environmental Safety for the Food Industry

• This module covers health and safety in manufacturing, including hazards, their control, biosafety, risk assessment, waste management, and legal requirements.
• ECTS: 5
• Module Breakdown:
  • 70% Final Exam - 2 hours - TBC January 2025 (In-person)
  • 30% Continuous Assessment - MCQ - Saturday 9th November (Online)
  • Lectures: 5 evenings, 1 Saturday
• Contact details: [email protected]

Module Learning Outcomes

• LO 1: Discusses the roles and responsibilities of employees, employers, and regulatory agencies under national and international legal frameworks.
• LO 2: Explains the types of information in a safety statement and discusses its preparation.
• LO 3: Lists different hazards, exposure routes, personal protection equipment (PPE), explains safety data sheets (SDS), and details the information they contain.
• LO 4: Discusses biohazards and contaminants, cleaning, and sterilisation methods.
• LO 5: Explains the waste management hierarchy and the role/function of regulatory agencies.
• LO 6: Describes waste material classification and waste treatment/disposal methods (gaseous, liquid, solid).

Lecture 5

• Waste Characterisation
• Waste Analysis Techniques
• Waste Treatment
  • Gas
  • Solid
  • Liquid

Introduction to Waste

• Waste is any substance needing disposal due to contamination, damage or spoilage.
• Industrial plants produce various types of waste:
  • Solids
  • Liquids
  • Gases
  • Hazardous waste
  • Non-hazardous waste

Examples of Recyclable Waste

• Waste packaging
• Paper
• Canteen waste
• Office waste

Waste Classification

• Waste is hazardous if its concentration, quantity, physical, chemical or infectious nature poses a threat to human health or the environment.
• Classified if listed in the European Waste Catalogue or Hazardous Waste List.
• Must exhibit certain hazardous properties.

Examples of Hazardous Waste

• Chemicals
• Pesticides and medicines
• Paints
• Biological samples
• Containers contaminted with raw materials or products
• Contaminated PPE
• Gaseous Waste
• Liquid or solid residues from a process (process waste)
• Sludge from waste water treatment plant
• Electrical and Electronic Waste

Waste Analysis

• Microbiological Analysis
• Instrumentation Techniques
• Chemical Analysis

Chemical Analysis

• pH Determination
  • Measures acidity/alkalinity of waste.
  • Indicates suitable treatment.
• Biological Oxygen Demand (BOD)
  • Measures oxygen required to break down organic matter.
  • Represents biodegradable portion of waste.
• Chemical Oxygen Demand (COD)
  • Measures oxygen required to breakdown all compounds (organic/inorganic)
  • Easier than BOD measurement.
• Dissolved Oxygen
  • Measures oxygen dissolved in wastewater, crucial for biological treatment.
• Nutrient Analysis (e.g., Phosphate, Ammonia)
  • Measures nutrient concentrations
  • High concentrations can negatively affect biological treatment.
• Suspended Solids
• Concentration expressed in mg/l, and usually about 2 hour analysis.

Instrumentation Techniques

• HPLC & Gas Chromatography (GC)
  • Separates, identifies and quantifies chemical components of waste
• Mass Spectrometry (MS)
  • Identifies chemicals based on mass and charge, esp. powerful with chromatography.
• Total Organic Carbon (TOC)
  • Screening test that measures the amount of organic carbon.
  • Indicates waste concentration.
• Atomic Absorption Spectroscopy
  • Measures metal content of waste streams (e.g., calcium, mercury, cadmium).

Microbial Analysis

• Determines microbial counts in water samples.
• Bacteria collected on a membrane and transferred to an agar plate for incubation.
• Counts to determine colony-forming units (CFUs).

Waste Treatment

• Techniques that alter the physical, chemical, or biological character of waste.
  • Reduce volume and/or toxicity
  • Change physical form for safer disposal
• Method selection based on waste quantity and form.

Gaseous Waste

• IPC licence condition: monitoring and control of occupational air quality.
• Gaseous emissions can be:
  • Particulate: dusts, powders
  • Gaseous

Particulate Emissions

• Created from dispensing/processing powders/granules.
• Ingredients fed manually to mixing vessels.
• Can cause respiratory problems (bronchitis, asthma, heart attacks).
• Controlled by air extraction systems.

Gaseous Emissions

• Volatile Organic Compounds (VOCs)
• Nitrous Oxides
• Sulphur Oxides
• Inorganic Emissions
• Contains various chemicals, including acidic gases, that can be harmful to health.

Inorganic Emissions

• Usually associated with stack emissions from boilers, generators, and incinerators.
• Combustion type determines emission type.
• Emissions monitored as IPC condition.

Organic Emissions

• Large family of carbon-containing compounds.
• Emitted/evaporated into atmosphere
• VOCs (Volatile Organic Compounds)
• Can lead to respiratory, heart, kidney, and liver problems; also carcinogenic.

Gaseous Emission Classifications

• Point Source: controlled emission points (stacks, valves etc). Monitored by IPC license
• Diffused Source: ineffective ventilation, accidents, secondary sources (wastewater)

Treatment Methods

• Filtration: suitable for removing particulates and heavy metals, often HEPA filters.
• Flue Gas Scrubbing: cleans/scrubs flue gasses, typically with acid solutions to neutralise acidic gasses.
• Incineration: Burns flammable organic vapours, dust, particulates
• Landfilling: Common method in Ireland, less preferred than others, licensed by EPA, for non-hazardous materials and treated wastewater sludge

Treatment of Solid Waste

• Recycling, chemical treatment, incineration, landfill are the main methods of disposal

Treatment of Wastewater

• Created as a byproduct of process/cleaning operation.
• May contain contaminants.
• IPC license condition: characterising and removing toxic contaminants, producing effluent.
• Wastewater treatment plants remove contaminants.

Wastewater Treatment Process

• Stages:
  • Preliminary treatment
  • Primary treatment
  • Secondary treatment
  • Advanced/Tertiary treatment

Physical and Chemical Methods for Wastewater treatment

• Filtration
• Sedimentation & clarification
• Centrifugation
• Neutralization
• Oxidation
• Precipitation
• Absorption

This quiz assesses your understanding of occupational safety and environmental practices within the food industry. It covers key topics such as hazard identification, risk assessment, biosafety regulations, and legal responsibilities for employees and employers. Prepare to demonstrate your knowledge of safety protocols and environmental management.