08 Aug
2019

THERE ARE NO QUICK WAYS TO GET RID OF THE PILES OF LITTER THAT FOUL THE COUNTRYSIDE AND POLLUTE OUR OCEANS – BUT SOME NOVEL EXPERIMENTS ARE UNDERWAY, WRITES TONY CARNIE

Standing on the ramparts of a castle of rubbish, Andrew Venter looks quite majestic as he surveys a kingdom of discarded yoghurt tubs, bottles, tin cans, chip packets or cereal boxes.

His organisation has gone to great expense to collect this rubbish from several parts of KwaZulu-Natal, hoping to reduce waste and extract more value from the throw-away resources that pile up daily in local landfill sites or which end up polluting Durban’s holiday beaches and adjoining Indian Ocean.

While some is collected as litter, there is also a growing corps of shoppers who diligently drop off their waste at several suburban “recycling villages”.

Andrew, chief executive of the Pietermaritzburg-based WILDTRUST conservation and development group has been at the forefront of local efforts to clean up the environment and promote recycling – while also creating thousands of jobs for the unemployed.

The trust’s initial efforts to collect and recycle waste began about 10 years ago, but as Andrew and his colleagues have discovered, magic solutions are not always easy to find.

At the time, they thought that almost everything could be recycled – including plastic packaging waste. But it is not that simple, Andrew explains during a tour of the WILDTRUST waste-recycling centre near Midmar Dam.

Most plastics are derived from crude oil, but there is a wide variety ranging from ultra-thin clingfilm
to much thicker grades for plastic tables and chairs – all made with different additives, softeners or colourants.

Often, several types of plastic are used on a single consumer product (for example, a red twist-off cap on a clear plastic bottle, wrapped with a third type of thin plastic film for branding).

The result is that only some plastic waste has commercial value – either because it is too labour-intensive to separate and sort millions of tiny lids from the bottles and tubs, or because some plastics (like empty chip and snack packets) have little value.

Hanno Langenhoven, the trust’s recycling strategy manager, says some companies find it cheaper to produce new bottles and jars using virgin sands rather than recycled glass. Many paper and cardboard products are also dyed with bright inks and chemicals which contaminate and reduce the recycling value.

Now, in an effort to make sure nothing goes to waste, Hanno and his colleagues are trying to produce more value from what they refer to as “crap plastic” and other waste streams.

A few years ago they began to turn throw-away plastic into sturdy “timber” planks for school desks and benches. More recently they started to make “concrete” housing blocks made from a mixture of crushed-up bottles (70%) and crap plastic (30%). This is heated in a furnace to extrude a slushy mixture into metal moulds which then solidifies to produce a 14kg brick that is lighter and stronger than the conventional version.

Hanno says the machine can produce 200 building blocks a day, but the long-term vision is to distribute new “green brick” plants to places where the plastic litter problem persists, especially in poorer communities.

“Some of the glass goes into our bricks, but we are also exploring other potential uses such as a sand substitute for golf course bunkers, for sand-blasting or for chemical and water filtration.”

Another new innovation is “plastic petrol”, which is produced by treating polypropolene plastic in a reactor and heating it at high temperature in a hydrolysis machine to produce a liquid fuel to power diesel vehicles.

While turning plastic into fuel may sound like a magic solution, other environmental groups are concerned about the potential air pollution and health impacts of burning or heating plastic on a large-scale. Groups such as the Centre for International Environmental Law and GroundWork are strongly opposed to large-scale incineration of plastic, due to potential emission of toxic fumes. They also believe that burning plastic or using it for energy heating simply perpetuates the problem of global plastic pollution.

Hanno acknowledges that producing plastic fuel may be controversial, but he suggests that the trust is looking for interim solutions while efforts continue to reduce the scale of plastic pollution.

“It could take another 10 years to find global solutions, but what happens if we do nothing in the interim?” he asks.

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