Technical and Economic Viability of Distributed Recycling of Low-Density Polyethylene Water Sachets into Waste Composite Pavement Blocks

Abstract

In many developing countries, plastic waste management is left to citizens. This usually results in landfilling or hazardous open-air burning, leading to emissions that are harmful to human health and the environment. An easy, profitable, and clean method of processing and transforming the waste into value is required. In this context, this study provides an open-source methodology to transform low-density polyethylene drinking water sachets, into pavement blocks by using a streamlined do-it-yourself approach that requires only modest capital. Two different materials, sand, and ashes are evaluated as additives in plastic composites and the mechanical strength of the resulting blocks are tested for different proportion mix of plastic, sand, and ash. The best composite had an elastic modulus of 169 MPa, a compressive strength of 29 MPa, and a water absorptivity of 2.2%. The composite pavers can be sold at 100% profit while employing workers at 1.5× the minimum wage. In the West African region, this technology has the potential to produce 19 million pavement tiles from 28,000 tons of plastic water sachets annually in Ghana, Nigeria, and Liberia. This can contribute to waste management in the region while generating a gross revenue of 2.85 billion XOF (4.33 million USD).

The Potential of Replacing Concrete with Sand and Recycled Polycarbonate Composites: Compressive Strength Testing

“…In these future tests, it is worth exploring alternative mixing strategies that could be employed to promote a more homogenous sample. Alternative research approaches have used an external mixing chamber to introduce the plastic to preheated sand under continuous agitation [50]. Once the mixture is homogenous, it can be poured directly into the mold and stamped down.…”

“…This behavior is critical in determining their efficacy in northern communities and supporting their use as solar rack footings. Additional tests that can be run to maintain the standard tests upheld by other researchers on plastic sand bricks include a hardness test, thermal resistance test, efflorescence test, and 3-point bending test [22,50]. Finally, a full life cycle analysis must be run on the system to quantify the environmental benefits of using this composite as an alternative to concrete.…”

The Potential of Replacing Concrete with Sand and Recycled Polycarbonate Composites: Compressive Strength Testing

“…In these future tests, it is worth exploring alternative mixing strategies that could be employed to promote a more homogenous sample. Alternative research approaches have used an external mixing chamber to introduce the plastic to preheated sand under continuous agitation [51]. Once the mixture is homogenous, it can be poured directly into the mold and stamped down.…”

“…This behavior is critical in determining their efficacy in northern communities and supporting their use as solar rack footings. Additional tests that can be run to maintain the standard tests upheld by other researchers on plastic sand bricks include a hardness test, thermal resistance test, efflorescence test, and 3-point bending test [22,51]. Finally, a full lifecycle analysis must be run on the system to quantify the environmental benefits of using this composite as an alternative to concrete.…”

Improvement of Age-Resistance of LDPE-Based Nanocomposite Films by Addition of a Modified Layered Double Hydroxide with an Anionic UV Screener

“…This plastic is especially used in the manufacturing of disposable bags, packaging, and greenhouse applications. UV irradiation [16], thermo-oxidation [17], and chemical oxidation [18] are the most common degradation mechanisms of polyethylene, which is a non-biodegradable plastic that causes environmental problems [19]. For outdoor applications, polyethylene-based materials suffer from photodegradation.…”