● Traditional wastewater treatment technology purifies wastewater, but pollutes the atmosphere. Are there any such technologies that can make the water quality up to standard, but also can protect the atmosphere from pollution, thereby realizing the sustainable development of the entire human environment.
● Phosphorus is a non-renewable resource, and the current global reserves would only last for 100 years. And the water pollutant is just the carrier of such non-renewable resources. In conventional wastewater purification processes, phosphorus is unreservedly removed along with the water pollutant.
● Beijing has too little water and the quality of the water is not satisfactory.
Reporter: What is the sustainable wastewater treatment technology you have pioneered around the world? What does it mean to be "sustainable"?
What does it mean to be "sustainable"?
Mark: The sustainable wastewater treatment technology has two levels of meanings. First, regard the pollutants in the wastewater as a carrier of resources and energy, thereby innovating the traditional "removal" method, which is replaced by modern "transformation" or "recovery" methods. Second, the "conversion" or "recovery" technologies used inherently feature low energy and high material consumption.
The meaning of sustainable can be interpreted in two ways. First, sustainable recycling of non-renewable resources such as phosphorus, which recycles organic materials and converts them into a resource carrier, methane, as phosphorus is a limited earthly resource that will last for only 100 years of human use. Second, traditional wastewater treatment focuses solely on water purification and water quality standards, without considering how much energy is consumed in the wastewater purification process, how much resources are wasted, and without considering the relationship between wastewater treatment and air quality. In traditional wastewater treatment, the organic matters in the water are oxidized through energy consumption with oxygen, and the organic matters in the water are precisely the carrier of energy. Therefore, it is in nature equivalent to energy consumption, which is very unreasonable. To take a simple example, the higher the degree of treatment of wastewater, the higher the energy consumption. In the northern areas, coal is used to generate energy for wastewater treatment. The process consumes a lot of energy and requires burning a lot of coal, resulting in the release of large amounts of carbon dioxide into the air and air pollution thereof. Such traditional energy-intensive approach for wastewater treatment is therefore essentially a form of pollution transfer, where water purification is based on air pollution, and is therefore unsustainable. The sustainable wastewater treatment technology can both satisfy water quality standards and protect the atmosphere from pollution, thereby guaranteeing a sustainable improvement in overall environmental quality.
Reporter: Which one has less investment and lower cost, sustainable wastewater treatment technology or traditional wastewater treatment method?
Mark: It can't simply be calculated based on a one-time investment in building a wastewater treatment plant. Instead, multiple factors have to be considered. In terms of the investment in building a wastewater treatment plant alone, the application of sustainable wastewater treatment technologies may require the construction of several more treatment ponds, which is about 10 per cent more than the application of conventional technologies. However, in terms of energy and resource savings, the application of sustainable wastewater treatment technologies significantly reduces CO2 emissions, which means a reduction of the "greenhouse effect". In addition, by considering a combination of factors such as phosphorus recovery and reuse of treated water, sustainable wastewater treatment technologies are less expensive than conventional technologies, rather than more expensive. Especially, the recycling of phosphorus by sustainable wastewater treatment technologies is for the benefit of future generations, as phosphorus is a non-renewable resource that can be recycled profitably.
Reporter: Has sustainable wastewater treatment technology been widely applied in the Netherlands? What is the role of the Netherlands government in the construction and management of wastewater treatment facilities?
Mark: Sustainable environmental biotechnology was initiated 6 or 7 years ago in countries such as the Netherlands, Germany, Denmark and Sweden, and in recent years there has been more emphasis on sustainability issues and such countries have started to widely accept this new concept and apply the corresponding technologies.
The management and control of water resources in the Netherlands falls under the responsibility of the Water Authority. The Netherlands, with its low terrain and numerous rivers, is prone to flooding if there are poor drainage channels throughout the country and the water volume of the rivers is not well controlled. The Water Authority of the Netherlands has a history even longer than that of Parliament with the main task to effectively control the quality and quantity of water within the territory. The Water Authority is not under the control of the government and is an independent, not-for-profit agency distributed in every region of the Netherlands. The Government of the Netherlands is responsible for setting standards of wastewater treatment and river water volume control, which are enforced by the Water Authority. The wastewater treatment plants in the jurisdiction of the Water Authority of the Netherlands are publicly owned rather than privately owned as in other European countries and in the United States. Public wastewater treatment plants are open to the public and are funded directly by corporate taxation and citizen taxation, in other words, whoever discharges wastewater pays for it, with an average wastewater tax of 40 Euros per person per year (1:1 exchange rate with the US dollar).
Reporter: What do you think of the water environment in Beijing?
Mark: When I arrived in Beijing, I felt like there was so little water in Beijing, and the water quality seemed unsatisfactory. Europe had been in wastewater treatment and water control for over 20 years, while China is just starting in this area, but this is precisely the advantage of China, as it is no longer necessary to go down the traditional path of Europe. Instead, China should leapfrog development by directly utilizing the current high technology in the field of wastewater treatment.
Reporter: Your sustainable wastewater treatment technology is in line with the goal of Beijing Green Olympics, do you have any project cooperation intention with Beijing?
Mark: In China, we are proposing to work with the Sustainable Environmental Biotechnology Research and Development Center led by Doctor Hao Xiaodi from the Beijing Civil Engineering Institute. This R&D Center will bring the latest international wastewater treatment technologies into China in time to improve the water environment in Beijing and to serve the Beijing Green Olympics. Meanwhile, we also plan to develop joint doctoral and master's degree programs in the field of sustainable wastewater treatment with the Beijing Civil Engineering Institute, which will provide an opportunity to carry out a full range of cooperative research projects.
Mark van Loosdrecht: Internationally renowned environmental biotechnologist. Professor of the Biotechnology Laboratory at the Delft University of Technology NL, Academician of the Royal Netherlands Academy of Sciences, Chairman of the International Water Association Expert Group on Biological Nutrient Removal (Nitrogen and Phosphorus Removal), Biofilm Processes. His pioneering researches in fields of environmental biotechnology, such as wastewater treatment, soil treatment, inorganic compounds and microbial conversion, biopolymer formation, biofilm processes as well as mathematical modelling of activated sludge and biofilms, have led to academic achievements that have been widely followed by his peers worldwide. In particular, he pioneered the sustainable wastewater treatment technology, which revolutionized traditional pollution control approaches, and he is regarded as one of the few "highlighted" ones in the field of wastewater treatment.
Liu Qiong
Links: Guangming Daily December 6, 2002 Global Technology Weekly