Waste management and reuse of landfill

‘Locked down’ due to Covid-19 and going through some of my old collections, I came across an interesting publication as titled above. As this subject is relevant today, concerning climate change and renewable sources of energy, I quote the 11 suggestions made in the introduction, for the information of the authorities interested.

1. Total landfill management concept – With available space for landfills declining daily and concerns over population and dwindling natural resources; a Total Landfill Management Concept covering handling, recycling, composting, extraction and use of gases and maintenance and re-use of sanitary landfills is becoming vital.

2. Landfill gas – Anaerobic decomposition of organic solid waste in the landfill environment produces landfill gas [LFG]. LFG mainly consists of methane and carbon dioxide, both of which are odorless, Trace concentrations of other volatiles, often maladdress or toxic gases, are also found in LFG. LFG can migrate through soil into structures located on or near landfills. Since methane presents a fire or explosive threat, LFG must be controlled to protect property, and public health and safety. Also, many jurisdictions require landfill owners/operators to reduce reactive organic gas emissions to improve regional air quality, Thus, engineered solutions are needed to efficiently and safely monitor, collect, and process landfill gas.

3. Solid waste management planning – As existing landfills near capacity, as less land becomes available for the siting of new municipal solid waste [MSW] landfills, and regulatory agencies adopt stricter rules on waste disposal, or jurisdictions are facing the need to have a solid waste management plan. Unlike plans in the past, these plans are focusing on more than just collection and disposal of MSW, such as recycling, resources recovery, waste-to-energy and incineration, and examine other methods for reducing waste at the beginning of the cycle – i.e. less packaging, requiring biodegradable wrappings [bottle bills etc.

4. Waste composition studies – Waste composition studies are performed for a number of reasons, one of which is the most common – as a start towards recycling programs. Waste composition studies can assist solid waste management departments

5. Recycling – With available space in landfills declining daily, and concerns over population and dwindling natural resources growing, many communities are looking for recycling as one way to ease the strain created by increasing solid waste. Assisting communities in determining the most economically feasible and efficient method of handling recyclable materials. Several steps are involved in determining what recyclables exist in the waste stream. Evaluating the market to discover what are the current and projected needs for recyclables, comprehensive planning so implementation of a recycling plan goes smoothly and fits in with the overall goals of the community, and siting design of the recycling facility.

6. Material Recovery Facilities [MRFs] – Material recovery facilities, also sometimes called separation facilities, can be multi-million dollar installations with sophisticated, automated sorting, baling, crushing , wash-down machines or an empty building renovated with a conveyor and magnetic separator. The size and types of equipment of a MRF is determined by the usage – is the facility only used by the residents of a town, by a large city or country, or is it regional?. Much of what a MRF accepts is dictated by supply and demand and recycler’s requirements. One of the keys for designing a MRF is to design the flexibility as the demand for different types of recyclable grows.

7. Patented Technology for Conversion of Non-Organic Waste [Plastics etc] into Composite Structural Material – This process uses polypropylene, plastic and similar waste materials combined with chain fibers from biomass [wood, straw etc] to produce lightweight composites, which can be used for earth filling, building construction etc. The chemical and mechanical action of the process leads to steam explosion of the biomass material, through exposing more surface area to the melting polymers which promotes entanglement and adhesion. This allows for use of 65% biomass, 25% polypropylene,1 to 2% Epolene and 2 to 3% fly ash. Together, these longer chain fibers create an improved matrix with more flexibility at lower costs due to the wide variety of biomass which may be used. By using more fiber and less polymers, a lighter weight composite results and particle size is larger due to the chain fibers. Where waterproofing and external use are the prime concerns or where Maximum strength is desired, more plastic and finer particles can be incorporated. Color can be added to assimilate natural woods such as redwood or yellow pine.

8. Transfer Stations – The siting, design and permitting of a transfer station, or a network of transfer stations in densely populated areas, can be difficult. Emotionally-charged issue for a community. Environmental , financial, legal, noise, traffic, aesthetics, public resistance, and health and safety concerns are some of the issues that must be dealt with when siting and designing a transfer station. Other considerations include hauling distances, collection vehicle arrival times and discharges rates, the needed tipping floor and loading area, etc. As the transfer station is one component in a solid waste management program, other vehicles, such as combining a waste transfer station with a recycling/or resource recovery facility must be taken into account.

9. Composting- Composting is becoming an important part of the recycling programme. Communities are finding it a useful tool to both keep yard waste out of the land fill, and to promote natural, and economic fertilisation of vegetable and flower gardens in urban and suburban areas. A plant of the solid waste management plan being conducted, strategy. The USEPA has conducted studies to determine if different types of composts [yard wastes, sewage, sludge, water waste sludge, food waste] can be processed for land cultivation and land reclamation purposes

10. Landfill Engineering – Landfill engineering assignments typically involve many elements, including – Siting of new landfills, – Geological and hydrogeological investigations. Environmental studies [ecology. Wetland, etc], Concept designs – Design [including leachate and landfill gas migration control and cap and cover plans]; – Operation plan – Preparation of permitting application packages and negotiations with regulatory officials. Environmental impact assessments and preparation of environmental impact reports. Closure and post-closure plans and Remedial action investigations and design.

11. Landfill Gas -Landfill gas [LFG] migration investigations, control and recovery design and continuing monitoring is absolutely necessary.

G. A. D. SIRIMAL

Boralesgamuwa