For a nation obsessed with cleanliness, the thought of drinking water sourced from sewage seems preposterous, but Thais must resign themselves to doing just that as water shortages become increasingly common, says a leading wastewater treatment manufacturer.
Aerowheel’s revolutionary process uses less than half the electricity and treats wastewater a third more quickly than other processes, Premier Products claims.
"In the future, we're surely going to face problems with freshwater shortages, so it's crucial now to figure out how we can reuse water at least two or three times," said Suradej Boonyawatana, the chief executive of Premier Products Plc (PP).
Drinkable water obtained from treated wastewater is nothing new for developed countries including nearby Singapore, which wanted to avoid reliance on Malaysia for fresh water.
Indeed, technology today can treat dirty water from kitchens and toilets to the extent of making it drinkable at no risk whatsoever to human health.
"The issue in Thailand is not sanitation engineering technology but rather people's mental block against drinking water originating from filthy sources," said Mr Suradej.
Established in 1975, PP has researched water treatment technology for years, spending 5 million baht annually on average. The company sells its own patented product called Aerowheel.
Through a more environmentally friendly process, the system purifies all household wastewater from toilets, washbasins and kitchens into clean water, suitable for use with plants, fish ponds, toilet flushing and _ if further treated _ even for drinking.
Aerowheel's revolutionary process uses less than half the electricity and treats wastewater a third more quickly than other processes," said Mr Suradej.
Electricity pumps oxygen into dirty water, whereby aerobic microorganisms present are activated to transform it biochemically into clean water.
Other systems take 12 hours to treat one cubic metre of water at an electricity fee of 1.70 baht per cubic metre per day.
Aerowheel treats the same amount of water in just 4 hours while slashing the cost to 80 satang per cubic metre per day.
Suradej: People have mental block
It is 5-10% more expensive than other systems and appropriate for buildings with more than 100 inhabitants.
"The trick of wastewater treatment systems lies in the manner in which the optimal amount of oxygen is infused," said Mr Suradej, adding that this is where the competition lies.
Furthermore, Aerowheel combines an aerobic system with an anaerobic wastewater treatment.
Wastewater is kept airtight before oxygen is added, thereby increasing the efficiency of oxygen absorption.
Water quality is measured by its biological oxygen demand level _ the higher the BOD, the higher the contamination.
Extremely dirty water can have a BOD level of 400 milligrammes per litre compared with 0 mg/l for drinking water.
Thai law stipulates the maximum acceptable BOD level in clean but non-potable water is 20 mg/l.
Some of PP's clients include universities, schools, hospitals and large development projects.
One of its biggest challenges over the years has been working with outdated laws and stubborn bureaucrats.
"It took years to convince bureaucrats and successive Bangkok leaders that the smelly water was coming from households, not industries," said Mr Suradej.
"Back in those days, people barely knew what wastewater treatment was about. The Chao Phraya River was contaminated, but people thought factories were to blame. "
However, up to 80% of water contamination results from uncontrolled household waste, he said, adding that most single houses, old buildings and small development projects still use outdated wastewater treatment systems.
Twenty years ago, the law stipulated only septic tanks had to be used to treat wastewater despite the fact that they do not function adequately in practice, leaving BOD levels of treated water as high as 40-50 mg/l.
Septic tanks separate solids from household sewage, with leftover liquids allowed to seep into the ground.
"But in a place like Bangkok, where groundwater levels are very high, it's impossible for the liquid to penetrate properly," said Mr Suradej.
"When toilets fill up, the wastewater is directed into drainage ditches along the roadside, which apart from being against the law also ends up contaminating the canals before finally ending up in the Chao Phraya. "
Recent changes to land law have made wastewater treatment compulsory for all new buildings, but monitoring and post-treatment water quality testing remain problems.
"The lack of post-treatment water testing enables products that are not up to proper industrial standards be widely sold nationwide, which eventually affects the environment," said Mr Suradej.
He said there is also has no industrial standard or certification for wastewater treatment products.
PP has a 30-40% market share in a business of 20 producers, of which only four or five make standardised goods.
Revenue growth from water treatment products averages 10% per year for the company, in line with new development projects.
The company plans to push provincial sales, especially in places with limited freshwater resources such as tourist islands.
The latest project undertaken was for a community in a drought-prone area in Sakon Nakhon province that wanted to obtain potable water from contaminated waste.
"Demand is increasing for household wastewater treatment systems as people become more environmentally aware," said Mr Suradej.
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- Writer: Soonya Vanichkorn