Distinguished Visiting Professor Dr John Cherry has won the 2020 Stockholm Water Prize
Distinguished Visiting Professor Dr John Cherry from Department of Earth Sciences has won the 2020 Stockholm Water Prize – the first groundwater expert receiving this honour. Dr Cherry is named the Laureate for discoveries that have revolutionised our understanding of groundwater vulnerability. Being a world-renowned hydrogeologist and a leading authority on the threats to groundwater from contamination, Dr Cherry is the creator of the academic field contaminant hydrogeology who has changed the scientific paradigms of groundwater research. His research has raised awareness of how groundwater contamination is growing across the world and has led to new and more efficient methods to tackle the problem. The Stockholm International Water Prize Nominating Committee said, “with the Stockholm Water Prize, John Cherry is recognised for his contributions to science, education, practice and for translating his well-earned stature into a passionate and highly effective advocacy for groundwater science to inform current and future policies, laws and collective deliberations that governments must establish to protect water, our most essential and yet most imperilled resource.” Contaminant hydrogeology studies how chemicals and waste leaches into the groundwater. A geological engineer by training, Dr Cherry has pioneered in-depth systematic approaches, including measurement tools and deep insights into groundwater transport processes. Through highly collaborative field experiments, he has developed new ways to monitor, control and clean up contaminated groundwater. Stockholm International Water Institute’s (SIWI) Executive Director Torgny Holmgren commented, “Dr Cherry has made us aware of how much we depend on groundwater and that it is all too often threatened by contamination. We are very grateful for his invaluable contributions in helping us understand how we can protect the world’s groundwater from the threats it faces”. More about Stockholm Water Prize The Stockholm Water Prize is an international water award presented annually since 1991. For 30 years, the world’s most prestigious water award, the Stockholm Water Prize, has honoured women, men and organizations for extraordinary water-related achievements. Stockholm Water Prize is awarded by SIWI in cooperation with the Royal Swedish Academy of Sciences and presented by the Swedish King H.M King Carl XVI Gustaf, the official patron of the Prize.
HKU researchers develop novel wastewater treatment process to effectively remove health hazardous chemical contaminants
Globally, there is a growing concern regarding the presence of trace emerging contaminants such as retinoids and oestrogenic endocrine disrupting chemicals (EDCs) in aquatic environments. Retinoids such as retinoic acids and their metabolites, which are the derivatives of vitamin A, can cause abnormal morphological development in amphibians, fish, and snails at elevated levels. Oestrogenic EDCs like alkylphenols and bisphenol A are environmental oestrogens that can induce feminization of male fish and abnormal development in aquatic organisms. Sewage effluents are a significant source for the continuous input of these contaminants into the aquatic environment. High levels of these chemical contaminants are commonly found in sewage effluents discharged from conventional sewage treatment plants (STPs). An interdisciplinary team led by the University of Hong Kong (HKU) has developed a novel wastewater treatment system that can effectively remove conventional pollutants, and recover valuable resources such as phosphorus and organic materials (i.e., carbon fibres and volatile organic acids). This novel system combines chemically enhanced primary sedimentation (CEPS) of sewage with acidogenic fermentation of sludge in tandem (Image 1). A series of laboratory experiments were conducted to prove that this novel system can effectively remove trace emerging chemical contaminants from wastewater and is more cost effective compared with conventional wastewater treatment systems. The results of this study have been recently published in Water Research and Environment International. Moreover, in collaboration with the Nanshan Sewage Treatment Plant in Shenzhen, a pilot wastewater treatment system adopting the novel treatment process has been under construction in Shenzhen since 2019. It will come into operation and testing by this summer if the COVID-19 outbreak subsides (Image 2). Background In the past few years, Professor Xiao-Yan Li of the Department of Civil Engineering who led the interdisciplinary research project, has been collaborating with Professor Kenneth Leung from HKU School of Biological Sciences and the Swire Institute of Marine Science to examine the levels and removal efficiencies of retinoids and oestrogenic EDCs from wastewater by the novel wastewater treatment process developed by the research team, and to compare that with the conventional STPs. The research team first examined the levels and removal efficiencies of retinoids and oestrogenic EDCs in Shatin, Stanley and Stonecutters Island STPs in Hong Kong by collecting wastewater and sludge samples from different stages of the treatment process, and analyzing the samples for retinoids and oestrogenic EDCs using liquid chromatography with tandem mass spectrometry (LC-MS/MS). Secondly, a series of laboratory experiments were conducted using a small-scale pilot plant of the novel wastewater treatment process. Samples of wastewater and sludge were taken for the chemical analysis using the protocols developed by Professor Leung’s team. Key Findings The results indicated that the three STPs can only remove an average of 57% of retinoids (range: 41-82%) and an average of 54% of oestrogenic EDCs (range: 31-79%) from wastewater influents (this work was published in Environment International). Using the novel treatment system operated under laboratory conditions, the CEPS process alone was demonstrated to be 16 - 19% more effective in removing retinoids and EDCs than the conventional STPs. 65 - 80% of retinoids and 72 – 73% of EDCs can be removed from the CEPS process (Image 3). After acidogenic fermentation of the CEPS sludge, 50 – 58% of retinoids and 47 – 50% of EDCs were further removed from the supernatants of sludge (this work has been recently published in Water Research). Compared to the conventional STPs, the novel treatment system integrating CEPS with acidogenic fermentation of sludge is comparatively more efficient in removing emerging chemical contaminants from wastewater, and hence could reduce their environmental impacts. In terms of cost effectiveness, the CEPS process has been shown, by other studies, to be more cost-effective than the conventional wastewater treatment process. For instance, the cost of CEPS for wastewater treatment is less than a half of that of the secondary wastewater treatment (i.e., activated sludge process). On one hand, acidogenic fermentation of CEPS sludge can further reduce the treatment cost by recovering organic carbon and phosphate resources from the sludge as the harvested organic carbon and phosphate can be utilized to produce carbon fibers and fertilizers respectively. On the other hand, the acidogenic fermentation of CEPS sludge can provide additional removal of pollutants. The novel treatment process, therefore, offers win-win outcomes. The Way Forward Professor Li, who led the study, said: “When the pilot wastewater treatment system in Shenzhen comes into operation and testing, we hope to demonstrate that this innovative technology will use less energy, generate cleaner effluent and recover more useful materials from the sludge.” Professor Leung said, “We are very pleased to gather evidence for supporting our hypothesis that our novel sewage treatment system can effectively remove the emerging chemical contaminants. With the scaled-up pilot plant in Shenzhen, we will further investigate the removal efficiency of other classes of common pollutants by this novel treatment system.” Regarding its potential application in Hong Kong, Professor Li added, “Our system can be easily retrofitted onto the existing STPs in Hong Kong, like add-on units. For instance, the pilot system will be connected to the existing Nanshan STP in Shenzhen to test its performance. If successful, this will pave the way for advancing wastewater treatment in China and beyond.” This innovative research is funded by Theme-based Research Scheme of Research Grants Council of the Hong Kong SAR. The published articles: Zhou G.J., Lin L., Li X.Y., Leung K.M.Y. 2020. Removal of emerging contaminants from wastewater during chemically enhanced primary sedimentation and acidogenic sludge fermentation. Water Research 175: 115646. Link to the article: https://www.sciencedirect.com/science/article/pii/S0043135420301822 Zhou G.J., Li X.Y., Leung K.M.Y. 2019. Retinoids and oestrogenic endocrine disrupting chemicals in saline sewage treatment plants: Removal efficiencies and ecological risks to marine organisms. Environment International 127:103-113. Link to the article: https://www.sciencedirect.com/science/article/pii/S0160412018327570 Image 1: The novel wastewater treatment system developed by the Theme-based research team led by HKU: Fe-based CEPS with side-stream sludge acidogenesis in relation to the conventional wastewater treatment process. Image 2: The HKU research team’s pilot wastewater treatment plant adopting the novel treatment process under construction in Shenzhen, including the control system, a CEPS tank, an acidogenic fermenter and a moving bed biofilm reactor (MBBR) and carriers. Image 3: The novel wastewater treatment process and removal of emerging contaminants during this process. Image 4: Prof. X.Y. Li (Left) and Prof. Kenneth Leung (Right) taking this picture with the HKU Distinguished Visiting Professor John Giesy from Canada.
HKU chemical scientist Professor Che Chi Ming receives First Class Award of 2019 Shenzhen Science and Technology Prize
Professor Che Chi Ming Professor Che Chi Ming, Chair Professor and Zhou Guangzhao Professorship in Natural Sciences at the Department of Chemistry of Faculty of Science, the University of Hong Kong (HKU) has received the First Class Award of 2019 Shenzhen Science and Technology Prize from the Shenzhen Science and Technology Innovation Commission (SZSTIC). Professor Che specialises in synthesis of inorganic and organic chemistry, inorganic and metal organic photochemistry, photocatalysis and bioinorganic medicine, and has significant achievements in the studies of high-valent metal ligand multiple bond complex, inorganic and metal organic light emitting materials, photo-induced electrons and atom transfer reaction, as well as asymmetric olefin epoxidation. Professor Che thanks his research team members including Dr Cheng Gang, Dr To Wai Pong, Dr Lok Chun Nam and Dr Zou Taotao for their dedicated hard work to make the research a success. Professor Che has made innovative discoveries in inorganic photochemistry, electron transfer in multinuclear compounds and atom transfer chemistry. In particular, his outstanding contribution to the study in reactive metal-ligand multiple bonded complexes won him the First Class prize of the State Natural Science Award in 2007. He is the first Hong Kong scientist to have received the honour. The Shenzhen Science and Technology Prize was established in accordance with the Shenzhen Science and Technology Prize Incentives and related implementing rules. It is seen as the important window for the scientific and technological development in Shenzhen, which provides the essential motivation for the realisation of innovative breakthroughs in the city. Professor Che is the first HKU scholar to receive the award. Professor Che was elected to the Chinese Academy of Sciences as academician in 1995, the US National Academy of Sciences as foreign associate in 2013, the Hong Kong Academy of Sciences as founding member and vice president in 2015. Professor Che is now the Director of the Synthetic Chemistry State Key Laboratory, HKU-CAS Joint Laboratory on New Materials and Shanghai-Hong Kong Joint Laboratory in Chemical Synthesis. He also serves the editorial board for Chemical Review and other internationally recognised academic journals.