The autumn of recycling: Why science and sociology must meet

Battling negative perceptions surrounding food waste collections can prove challenging. Some members of the public view it as messy and problematic. However, Keith Riley argues that there is a solution to this problem - a new innovation that combines science with sociology. Here, he unpicks the issue.

Food waste can represent anything from 16% to 19% of the waste produced by householders, according to Riley.


As autumn sets in, we can now only reflect on the long, glorious summer of 2014, that stretched itself all the way to October. The economy turned into the long hoped for growth and an aura of anticipation has emerged for the future growth of the economy. It has not necessarily been so good for the UK's environmental performance, however.

As soon as elected, the coalition Government took its foot off the peddle and "localism" was the excuse that led to both targets and funding being removed, with waste management disappearing almost completely from the political agenda. Over this summer it has become clear that the growth in recycling is slowing down, heralded in May by the Telegraph's spectre of "green fatigue".

Politics aside, the fact is that the UK's approach to recyclable collection has always been disparate with little common approach across the country and different collection systems in different places.

This, coupled with the fact that we are a nation whose unwritten constitution is based on reasonableness, do not like being told what to and dislike rules in general, when something like recycling is left to whatever the householder wants to do, it is not surprising that we revert to the easiest path and just throw everything in the same bin.

Consequently, the growth in recycling is slowing down and unless things change, it looks like the UK will miss its 50% target for 2020.

Waste revolution

With the spectre of complicating the collection system even more, it is not surprising, therefore, that despite all the noise and publicity food waste collection has received, it is still the poor relation of the recycling world, and often only introduced reluctantly. Yet separation of food from the residual and the dry recycling streams is important if we are to revolutionise waste management in the UK and achieve what the Waste Framework Directive says we have to.

Food waste can represent anything from 16% to 18% of the waste produced by householders, and if the 50% target is to be reached, its separate collection must be a feature. But more than that, removing food waste and treating it appropriately could have a major impact on the success of our waste management future.

Unlike the rest of Europe, the UK is facing a major shortfall in its energy needs and any future development in how we treat our waste must consider this. Residual waste cannot close the UK's energy gap, but it can make a serious contribution to it.

Food waste can contain up to 60% water and hence does not make a good fuel for the energy-from-waste thermal treatment plants. Removing food waste from the residual stream will raise its calorific value and benefit the performance of those plants.

Meanwhile, the UK has seen a burgeoning of anaerobic digesters, well suited to treat food waste, but unable to get enough of it. Collecting food waste will not only be beneficial to both methods of treatment, but will also remove most of the contamination that occurs in both residual and recycling streams, and if well developed, one could imagine a situation ultimately where the collection system could be simplified to just wet (food waste and organics) and dry (everything else) steams.

The concept of the residual stream - which already primarily plastic film, trays and card - could disappear and the dry stream sorted and recovered using the nIR (near-infrared) and scanning methods available today. This would simplify collection and raise the capture of materials for recycling.

Counting costs

There is a strong perception, however, that segregated collection of food waste is not a cost effective method of meeting the waste management challenges faced by local authorities.

Although many authorities have adopted food waste collections, and these comply with the legal duty to apply the waste hierarchy, they are finding that such collections are not very effective. Traditional thinking is that because food waste is putrescible, is messy and smells, the only option is to collect it once a week - and that's expensive.

As part of a large research programme funded by the European Community called Valorgas (, Southampton University found that in the five European countries investigated, even after food waste collections were introduced, most food waste is still found in the residual waste stream.

So the perception that food waste collection is not effective is correct - and the lack of participation by residents makes it an expensive service to operate. Having to carry it out weekly over and above what may be a two-weekly based collection service just exacerbates the problem.

So the issue is how can participation be raised, and with local authorities having to cut costs, how can it be done as cheaply as possible whist remaining effective. Whilst the standard answer is more communication and education, it is unlikely that just having more leaflets and logos is not the answer. What is needed is something that engages with the psyche of the householder and makes disposing of food an almost natural thing to do.

Public engagement

Whilst it is not yet fully proven, there is a novel technology that may overcome most or all of these issues. Known as the 'Aerobic Bin', this as yet little known development could transform the storage and collection of food waste. Following three years of research at Imperial College, London, the Aerobic Bin combines science with sociology.

It consists of a unique ventilated bin that holds a specially designed paper liner. The bag is waterproof and will contain liquid, but will allow vapour and air to pass through the fibres in the paper, keeping the food waste in aerobic and stopping the problem of odour which attracts flies.

The waste mass in the bag becomes subject to aerobic microbial activity, which causes the temperature to rise, thus evaporating the moisture content and drying the food waste. Not only does the waste not smell, it reduces in weight as it is stored.

This means that food waste can easily be kept in an Aerobic Bin for two weeks and collected with the alternate weekly collection, reducing the cost of vehicles, crews and disposal. Collection advantages aside, perhaps the most interesting aspect of the Aerobic Bin is the human interface.

This is different to what has gone before, and if local authorities are to re-launch their education and behaviour change campaigns, they need something different. The design of the bin is important, but the paper bag is key. It is required to allow the biodrying process to take place, but also keeps everything clean.

The most interesting feature, however, is that it seems to be better in engaging the user than a plain plastic bin. It may be coincidence, but in the Valorgas study, the best performing collection recorded was in Sweden and used a paper bag.

Early trials carried out in Bexley, London, also indicated that there was a better engagement by the users than other collection systems. Maybe a clean paper bag liner makes the difference. It avoids the mess and the need to wash the bin every week. It seems to have a positive effect on the user participation and improve food waste capture rates.

Of course, the Aerobic Bin may only be a small part of the answer, but if we can establish what really lies behind the psychology of waste collection, whilst putting more orderliness into the way we manage our waste at large, it will open up the future of recycling at large.

A two-stream waste collection system may be a dream, but if we can get the people to engage with their waste, progress can be made. This beautiful summer must not be allowed to become the autumn of recycling in the UK. Let's not let the fatigue set in.

Keith Riley is founder and chief executive of waste and environment consultancy Vismundi Consultancy.

This article first appeared in the November issue of edie sister title Local Authority Waste & Recycling.



Waste & resource management



