Environment

Sustainable Environment

The theme of sustainable environment draws on research into sustainable water (focusing on the natural environment) and sustainable cities (focussing on the urban environment) and brings together experts across HKU from the Faculties of Engineering, Science, Architecture, Business and Economics, Arts, and Social Sciences. Keeping a healthy water environment and a safe water supply is crucial to any society, particularly with pressures such as population explosion and urbanisation. How cities are planned, designed and used will affect the health and quality of life of both current and future inhabitants.

Nature in the city

One approach to enhancing the quality of the urban environment is by promoting nature in the city through, for example, “greening" rooftops and walls, designing green spaces, and planting or preserving trees. Such greenery can improve the physical environment by reducing temperatures and improving air quality, facilitate storm water management, contribute to social integration by providing spaces for activities, and bring related economic benefits through enabling citizens to be healthier and offering cost effective ways to address pollution.

Compact cities such as Hong Kong are extremely high density and high rise, and therefore ground-level space for greening is limited. “So we are trying to convince people to use rooftops and vertical faces to add a new dimension to urban greening," said Professor C.Y. Jim of the Department of Geography. “We are undertaking research to demonstrate the actual environmental benefits and test the different plant species, soil types, and horticultural technology."

Green rooftops designed and developed by Professor Jim and his team are already being implemented in Hong Kong, including “sky woodland" on an electrical sub-station and grass roofs for schools to provide lawn recreation areas for the schoolchildren. As well as providing green space to play and reducing energy consumption through heat dissipation, the green roofs for schools will be used for environmental education.

Influence of water quality on housing prices

“A number of studies have looked at how air quality affects property prices and how the market prices clean air," said Professor K.W. Chau of the Department of Real Estate and Construction. Such research explores the issue of those suffering from the effects of pollution while not necessarily being the producers of the pollution. “But the effect of water quality has previously been very much ignored," Professor Chau said. A new water recognition scheme introduced in Hong Kong in January 2008 has increased the general public’s awareness of water quality issues, and it provides more information on the water quality of specific buildings. Such information can influence people’s decisions to rent or buy certain properties.

“This research aims to examine how people price water quality by developing a model to measure how much people are willing to pay for a housing unit with higher quality water," Professor Chau said. Developing an indicator of the market value of clean water will be an important variable in cost benefit analysis of large water improvement schemes and projects.

Converting wastewater to renewable energy

What if rather than just sending flushed wastewater away for costly treatment it could also be turned into a clean renewable fuel? A research team at HKU led by Professor H.H.P. Fang is doing just this in their work on converting organic pollutants in wastewater into a useful resource in the form of hydrogen.

“Hydrogen is the cleanest fuel you can have, because when you burn hydrogen you only get water," said Professor Fang of the Department of Civil Engineering. Using hydrogen, for example as a car fuel or to produce electricity, is an area being developed by research groups around the world. The work at HKU forms a fundamental stage at the front end by finding an innovative way to produce that hydrogen from a waste product. The group are international leaders in this area.

 “We use microorganisms and create the right environment in a ‘reactor’ that allows the bacteria to convert the waste into hydrogen, and then we harvest the hydrogen," Professor Fang explained. In addition, the anaerobic process (without the presence of oxygen) saves energy and produces only about 10% of the amount of waste sludge produced by the conventional aerobic process.

Managing resources to ensure future supply

In the late 1950s and early 1960s, Hong Kong experienced severe water shortages, with some areas only having freshwater for a few hours a week. Measures such as seawater flushing and building more reservoirs could not alleviate the problem, and in 1960 a long-term agreement was signed with China to provide water from Guangdong province.

Now, 80% of Hong Kong’s supply comes from China, in particular the East River section of the Pearl River Delta (PRD). “However, water resources in the PRD are under increasing pressure in terms of both quantity and quality because of rapid urbanisation in the past two decades," said Professor J.H.W. Lee of the Department of Civil Engineering. Professor Lee is leading a team of civil engineers, geographers, and earth scientists to investigate various problems related to water resources in the PRD.

“A number of issues have emerged, including expanding water demands from domestic, industrial, and agricultural sectors, whilst at the same time pollution, seawater intrusion into the estuary, and upstream soil erosion affect the water resources," Professor Lee said. Further pressures are created by more frequent and severe floods and droughts resulting from regional climate change, linked to urbanisation and global climate change.  

Convenor(s) and Key Members