Drones for monitoring water quality
China could soon be using drones and remote sensing technology on a bigger scale to monitor water pollution. The gadget, developed by Chinese student Ke Shuai, has been successfully used in Wuhan, in southeastern China’s Hubei province. Wuhan is near the source of the middle route of China’s massive South to North Water diversion project, a scheme that pumps water to Beijing and other parched areas. Ke’s research was sponsored by the Ministry of Environmental Protection, where officials hope it can be used widely to monitor water quality across the country.
Rotterdam – floating communities
With nearly 80% of its urban area below sea level and home to one of the largest ports in the world, Rotterdam has created floating communities in its harbour which can move with the sea. The Dutch city has also pioneered “green” solutions on flood control. This has involved creating natural levies and flood plains that double up as urban parks, water plazas, rowing courses and roof gardens. These projects also aim to improve public spaces in rundown areas of the city. Such schemes could be particularly instructive in Asia’s low-lying cities, which are at increasing risk of massive and permanent flooding as sea levels rise in the wake of climate change.
Wastewater to energy in China
Mounting piles of by-product from wastewater treatment on the edge of China’s cities pose major pollution hazards for urban water supplies. A company in Xiangyang, Hubei province, has set up a plant to convert tonnes of toxic sludge into green biofuel. The company recycles sludge from one of the city’s wastewater treatment plants in bio-digesters to produce purified methane, which is then used as fuel to one-third of the city’s taxi fleet. Had it not done so, the methane, which is 25 times more potent than carbon dioxide over a 100-year timeframe, would have risen into the atmosphere.
The bio-digester system has also saved thousands of gallons of petrol from being consumed by the city’s public hire vehicles. In addition, the residue from the sludge treatment is a good organic compost, which nearby farms sell along with seedlings.This model can be used elsewhere in China, where over half of cities face water shortages and 90% of urban groundwater is polluted.
Renewable filter to remove e-waste
An American teenager has developed a US$20 (127 yuan) water purifier to filter heavy metal pollution from electronic goods. Discarded mobile phones and other electronic gadgets are leaving a legacy of toxic waste in countries such China and India, where factories source and recycle e-waste from around the world. This process discharges heavy metals and chemicals into local water supplies.The renewable heavy metal filter, designed by 18-year-old Perry Alagappan from Texas, uses nanotechnology to remove 99% of heavy metals from water that passes through it.
More significantly, Alagappan says he will keep the technology ‘open-source’, enabling it to be adapted without payment for patents. The young inventor says he developed the idea while visiting his grandparents in India, where he was shocked by the impact of electronic waste contamination on the environment.
A giant magnet maps groundwater 400 metres deep
Hydro-geologists in Denmark have developed a novel way to measuregroundwater more accurately and uses technology that could help revive depleted groundwater resources in water-stressed areas such as the North China Plain and Indus basin. Available data is scarce for groundwater worldwide, as mapping it is a notoriously difficult task. But countries are increasingly reliant on groundwater as they draw down or pollute surface rivers and lakes.
The Danes’ technique – known as SkyTM – uses a low flying helicopter and giant electro-magnet to detect water up to 300-400 metres deep. This technique also shows different types of sediments, sands and clays; varying degrees of water quality; and the water table. This will enable scientists to identify where resources are most depleted, and helps in the revival of underground waterways. The technology was developed by the Geoglogical Survey of Denmark and Greenland, and has been used already in Australia. The team is now discussing pilot projects with India and China, although the surveys are considered as expensive for many developing countries.
Space age showers
A Swedish start-up has designed the world’s most advanced and efficient shower, using a recycling technology similar to that used by astronauts on spacecraft. The household shower purifies any water that would usually go down the drain, and sends this back to the shower head, saving up to over 90% water and 80% energy. In Europe, a large proportion of water is used in personal hygiene. There’s no confirmation of an actual price on the company website, although it’s estimated to cost a hefty US$5,000 upfront. But the eco-shower would save households hundreds of dollars a year in energy and water bills.
At the other end of the spectrum, a group of Bangladeshi students has developed a low cost household water recycling system, which reuses water from sinks and showers and rainwater. The system runs from the basement of buildings and reduces dependence on groundwater by half. Households in Bangladesh mainly rely on groundwater, which is oftennaturally contaminated with arsenic, and has horrendous long-term health impacts for huge swaths of the population.