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Social Innovation

Reaching the city limits on resources

Cities are filling up with people and waste, so how does technology help keep a lid on it?

Cities are filling up with people and waste, so how does technology help keep a lid on it?

Cities are growing at a faster rate than ever before. Today, 55% of the world’s population live in urban areas. This is set to increase to 68% by 2050. We are having to learn how to support a larger population with the same land mass, natural resources and public services.

How does a growing city stay within its limits? The answer lies in new technology which is being used to help re-use resources and recycle waste.

Talking a load of rubbish

One issue faced by growing cities is the accumulation of rubbish and overflowing landfill sites. To combat this problem Ljubljana, the capital of Slovenia, has started to view waste as a resource.

City officials invested in a modern waste plant which turns 95% of the supposedly useless waste into recyclable material or fuel. The system is ingenious; biowaste is turned into high-quality compost for the area’s parks and rainwater is reused for street-cleaning. The plant, alongside regulations on waste sorting in home, has resulted in a dramatic improvement in recycling. In 2008 Ljubljanaians’ only recycled 29.3% of waste, today the figure is 68%.

New tech to solve modern habits

Hubbub, an environmental behaviour change organisation, has introduced recycling reward machines to the UK city of Leeds to help curb the amount of waste going directly to landfill. Users find special bins using a digital map and receive reward vouchers for each piece of recyclable material deposited. Some bins even blow bubbles after receiving a deposit!

The scheme has resulted in a marked rise in local recycling rates, and further rollouts are planned later this year.

According to the common proverb, necessity is the mother of invention and this is certainly the case when it comes to urban living. As more people move to urban environments, new technology is helping us to re-use our waste products and improve quality of life in cities.

Protecting a precious resource

Saudia City in Jeddah, Saudi Arabia, is an enclosed compound which houses 9,000 Saudi Airline employees. The community, situated in a highly water-stressed region, relies on effective water management to survive. However, after 25 years, the sewage treatment facility had become outdated and inefficient. The structure was far too large for the small space and inhabitants were being subjected to mosquitoes, bad odours and poor water quality. To solve the problem, Hitachi designed a new a plant made up of Membrane Bio-Reactor (MBR) units. The new plant uses less than one fifth of the original space and has eliminated the previous sanitary issues.

The new membrane bioreactor is making the area more pleasant to live in; recycling the precious water and putting it to good use is helping to make the desert region a little greener.