ENVIRONMENTAL WASTE MANAGEMENT BEN202

Open Learning Course -Waste Management

Lesson Structure

There are 6 lessons in this course:

1. Domestic Waste
   • Definitions
   • The Earths environment
   • Conservation and use of resources
   • Value of resources: economic, ecological and aesthetic
   • Damage being caused
   • UrbanisationThe impact of humans
   • Seweage and it's treatment
   • Characteristics of Sewage
   • Components of Sweage -solids, organic material, industrial waste
   • Decomposition of Sweage
   • The nitrogen cycle
   • Classification of Seweage Systems
   • Storm Water Systems and Management
   • Dry Rubbish
   • Nature of Refuse
   • Placement and protection of nins
   • Trade waste
   • Refuse Collection Systems
   • Refuse Collection vehicles
   • Salvage materials
   • Safe disposal of household chemicals
2. Street Cleaning & Disposal Of Refuse
   • Types of Street Refuse
   • Methods of street cleaning -gritting, sanding, sweeping, washing, etc
   • Cleaning storm water pits
   • Managing snow
   • Refuse disposal-separation, controlled tipping, combustion, pulversisation, etc
   • Refuse for fertiliser
   • Methods of Refuse Sorting -screening, magnetic, hand sorting
   • Types of incinerators
   • Vacuumn systems for refuse collection -garchey system, gandillon
   • Harvesting energy from combustion.
3. Industrial Waste
   • Types of industrial pollution
   • The greenhouse effect
   • Ozone depletion
4. Toxic and Nuclear Waste
   • Nuclear power
   • Nuclear fission
   • Mining nuclear fuel
   • Uranium enrichment
   • Gas Diffusion
   • Gas centrifuge
   • Nuclear waste
   • Transporting nuclear waste
   • Reprocessing
   • Health risks of nuclear waste
5. Water Quality and Treatment
   • Industrial effluent
   • Pricing control compared with direct control
   • Types of water impurities
   • Scope of purification
   • Managing water for public supply
   • Water treatment methods
   • Purification methods -sedimentation, filtration, disinfection, aeration, screening, etc
   • Recycling sewage water
   • Recycling waste water
   • Reed bed treatment
   • Improving water quality from any source -physical, chemical, biological impurities
   • Water borne diseases
6. Recycling Waste
   • Scope and nature of recycling
   • Rubbish tips (dumps)
   • Recycling plastics
   • Recycling metals
   • Recycling glass
   • Recycling paper
   • Recycling rubber
   • Actions by individuals (at home or work) -reducing, reusing and recycling waste

Aims

• Explain the nitrogen cycle and how it relates to waste treatment.
• Determine the economic considerations of different waste disposal systems.
• Compare industrial waste management with domestic waste management procedures.
• Determine the principles of "polluter pays" legislation and how it is applied.
• Describe how a budget is applied to managing a specific waste management enterprise.
• Discuss issues in nuclear power and nuclear waste technology (including hospital waste).
• Explain the cyclic nature of the water system and its relationship to environmental waste management.
• Monitor and recommend improvements to a specified recycling enterprise.

• Separation followed by composting or incineration.
• Controlled tipping.
• Incineration.

Under modern conditions, less separation is carried out than was done in previous times, although this is changing, with recycling being widely promoted in many countries. The degree of separation is dependent on the method of disposal and the saleability of the materials that can be salvaged. Salvage tends to be limited to those materials that have a ready sale and which can be salvaged economically and safely.

Before composting takes place, metal items must be removed. This is normally done by magnetic separation, although with the advent of aluminium tins, a certain amount of hand sorting may need to take place. In many areas separate recycling bins are provided to local residents so that salvageable items are kept separate from other refuse right from the start. After separation the bulk of the refuse may be pulverised, although a modern tendency is for ‘all in’ pulverisation.

Before incineration, it is usual to separate the fine dust, which has a low calorific value and impedes combustion. It is also usual to remove tins and other metals, and very often glass, some plastics and clean paper. After pulverisation the pulverised refuse is sometimes compounded with sewage sludge and the resulting fertiliser is sold to the public.

Tipping of waste at dump sites is often the most economical method and usually has fewer disadvantages than other methods. Where suitable land is within easy reach, a properly organised system of refuse tipping provides an economical means of refuse disposal, which is probably less costly than incineration, which also produces smoke and obnoxious gases.

For many waste sites, provisions have been made for tippers to deposit salvageable material at designated spots before disposing of the rest of their refuse at the tip face. This might include places to deposit plant material (except things such as noxious weeds, or rose prunings), which can easily be turned into useable mulch, or wood that can be salvaged for firewood, or metal, plastic and paper products that can be recycled. This can greatly reduce the amount of material being deposited in the tips.

Pulverisation can assist the hygienic tipping of refuse and it reduces the bulk by about sixty percent. In addition, the volume of covering material required is reduced.  In areas where tipping facilities are not readily available, transfer depots may be created, where local residents can deposit refuse into large bins transported by prime movers, which then transport the refuse to a suitable disposal point, such as a tip or incinerator, outside of the immediate area. These depots may have facilities for compaction of the refuse, thus reducing the number of bins that need to be transported.

The main problems associated with tipping are that dangerous chemicals may eventually leach out of the tip into nearby streams, or into groundwater supplies. The physical appearance of tips can also be poor, and they should ideally be located a suitable distance from residential areas, and be well screened by plantings. Tips can also provide a haven for pests, such as scavenging birds, foxes, feral cats and rats.

Once tips are filled and adequately covered, they are often converted into valuable recreation and parkland. Before this occurs many tips also sink pipes down through the deposited landfill, which act as collectors of methane, given off by decomposing refuse. The collected methane can be piped to a central point where it is used to power generators to produce electricity. Some tips may produce sufficient methane for electricity generation for decades.

In some situations, incineration is the only practicable method of refuse disposal, particularly where tipping facilities are unavailable, or to costly to provide (e.g. transfer of refuse over long distances). In the past incineration was usually associated with screening and separation before incineration. However, the modern trend is towards all-in incineration, with the extraction of tins and metals after burning.

• keep your skills current to the industry you are or wish to work in
• get experience - be it paid or unpaid, it looks good on a CV
• networking - join networking groups with people already in the field, these can be great contacts for finding work.