Here we are in front of the Chinese University Sewage Pumping Station. It is not your typical tourist stop but this station plays a vital role in Hong Kong’s infrastructure. Let’s dive into the world of wastewater treatment. This is a story of innovation and environmental responsibility.
Hong Kong deals with huge amounts of wastewater daily. Edmond Ho Wai-kwong at the Shatin Sewage Treatment Works states they treat 2.9 million cubic meters each day. That is enough to fill 1,160 Olympic-sized swimming pools. The Chinese University Sewage Pumping Station is one small part of this mammoth undertaking.
Before modern treatment, Tolo Harbour was a dead zone says Kenneth Leung Mei-yee. Pig farm runoff polluted the water. This caused algal blooms that depleted oxygen. Without oxygen, marine life could not survive. Thankfully, those pig farms are gone.
But modern life brings its own challenges. Our wastewater now contains a cocktail of chemicals. These come from detergents, sunscreens, pharmaceuticals and personal care products. These pollutants can disrupt marine ecosystems. Nonylphenols found in some detergents can change the sex of fish. Antibiotics also pass through our bodies and end up in wastewater. This allows bacteria to develop resistance to life-saving drugs.
Treatment plants like the Chinese University Sewage Pumping Station combat these issues. They use several processes to clean the water. Screening removes large solids. Degritting removes sand. Primary sedimentation removes suspended solids. Biological treatment uses bacteria to remove organic content. Final sedimentation separates the activated sludge from the treated water. UV disinfection uses ultraviolet light to kill pathogens.
These plants rely on tiny organisms. Amoeba, protozoa, worms and bacteria all work together. They break down harmful chemicals into nitrogen, carbon dioxide and other basic elements. Oxygen is pumped into tanks to encourage these microorganisms. The balance is delicate and requires constant monitoring.
The team at the Chinese University Sewage Pumping Station takes samples regularly. They monitor how well the organisms are removing pollutants. A healthy plant has a slightly acerbic smell. It reminds one of a high school chemistry lab.
The Sha Tin plant can clean up to 90 percent of pollutants. But only a small percentage of Hong Kong’s sewage undergoes this secondary treatment. Most of the rest is simply screened or chemically treated. It is then released into the surrounding seas.
The government is working to improve this situation. They are considering upgrading the Stonecutters Island facility. The goal is to provide secondary treatment for more of Hong Kong’s wastewater.
Turning wastewater into drinkable water is possible. According to Professor Chen Guanghao the technology exists. The problem is the cost. Treating water to pristine condition is very expensive.
Despite the challenges, Hong Kong is making progress. The Chek Lap Kok airport uses a triple water supply system. This system uses seawater for cooling and toilet flushing. It also reuses treated grey water for irrigation. This has significantly reduced freshwater demand.
Researchers are also developing new technologies. Professor Chen’s SANI process uses seawater to minimize sludge production. This could revolutionize sewage treatment. A larger plant using this technology is being built in Sha Tin.
So the next time you flush a toilet, remember the Chinese University Sewage Pumping Station. It is a crucial part of Hong Kong’s effort to manage its wastewater. It is a story of innovation, environmental responsibility and a commitment to a cleaner future.