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Water
and Wastewater Treatment
A.
Summary of activities
The Water and Wastewater Group was established to be a
focus for inter-disciplinary research and consultancy in water and wastewater
treatment technology within the Department of Civil and Structural Engineering,
The Hong Kong Polytechnic University, and the wider community.
The
Group conducts research in the areas of biological wastewater treatment
technology, physico-chemical wastewater treatment technology and potable water
treatment technology. In a number
of these areas, the Group has been in collaboration with local and overseas
research institutes, and local and overseas government departments, in the drive
towards research excellence. The
Group also promotes its consultancy services and facilities available to the
industry and Government bodies.Members
from the Group have acted as consultants for a wide variety of clients, ranging
from such Government bodies as the Environmental Protection Department, Drainage
Services Department and Airport Authority, to environmental consulting
and industry based companies.
B. Representative projects
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Industrial and trade
effluent treatment technology
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Implementation
of stringent water pollution control legislations has led to an urgent demand
for appropriate onsite wastewater pre-treatment facilities at commercial and
industrial production sites. Advanced
biological and physico-chemical technology for industrial and trade effluent
treatment has been a main focus of our research and development.
Examples include the modular anaerobic-oxidation-sedimentation (AOS)
system that capitalises on state-of-the-art anaerobic hybrid reactor for
treating food-processing and livestock industrial wastewaters, the
photocatalytic oxidation and electrocoagulation systems for treating persistent
and toxic pollutants in textile dyeing industrial and agro-industrial effluents.
A number of these technologies have been on full-scale operation in their
respective target industries. The
Group has also been actively engaged in consultancy works on assessing the
operation and performance of various existing on-site wastewater treatment
facilities at commercial and industrial sites.
The
novel AOS system developed for treating food–processing wastewater
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Municipal sewage treatment technology
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In
line with the effort to upgrade communal municipal sewage treatment facilities
in Hong Kong, a major research area of the Group is in developing novel
techniques that improve the operation efficiency and solving common operation
problems in municipal sewage treatment works. On-going projects include
identification of causative microbes and the specific organic precursors of
foaming and bulking problems in activated sludge processes.
Elucidation of the process biochemical kinetics and formulation of
effective foam control measures improve the efficiency of process operation and
the treated effluent quality. Years
of experience in these areas have led to the development of a "Feast-Fast
Process" as a foam prevention and control strategy for activated sludge
processes, which is currently on a full-scale operation in Singapore as part of
our research collaboration with the Ministry of Environment of Singapore.
The Group has also provided related consultancy services to the Drainage
Services Department of the Hong Kong Government and the Hong Kong Airport
Authority.
Sewage
and sediment sampling from Chak Lap Kok Airport sewer system
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Sewage
sludge and waste management
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Reduction
and management of the massive quantity of sludge generated from biological
sewage treatment have been given much attention. On the other hand, development
of environment-friendly plastic substitutes to solve the ever
increasing plastic wastes problems has been another main direction of our
research effort.
Microbial culture facilities
in the Water and Waste Laboratory
The Group is
attempting to solve these two seemingly unrelated problems at the same time.
Activated sludge bacteria in conventional wastewater treatment systems
are induced to accumulate storage polymers which can be extracted as a low-cost
source of biodegradable plastics. While reducing the costs of environment-friendly biodegradable plastics, this technique will also
substantially reduce the amount of excess activated sludge generated from the
biological wastewater treatment process. The
team has been in collaboration with the Department of Biology of Tsinghua
University and the local plastics industries to optimise the polymer production
without significantly affecting the normal treatment performance of the
activated sludge process.
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Advanced
potable water treatment
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The
group has recently driven into a new direction, in collaboration with the
Tianjin University, in advanced potable water treatment in built-up areas.A compact nanofiltration membrane system, integrated with microfiltration,
microflocculation, ozonation and biological filtration, is being developed for
likely installation in hotels and residential buildings to improve the drinking
water quality.In the past five years, the Group has also been actively
serving the Water Supply Department of the Hong Kong Government, through a
number of consultancy firms, in assessing the hygiene standards of various water
supply facilities.
Apparatus for assessing the biodegradability and
hygiene standards of various water supply facilities
C. Major facilities
The
Water and Waste Laboratory is composed of a monitoring laboratory, an instrument
laboratory, a process laboratory and a prototype development laboratory, and is
served by a team of experienced research and technical staff.
The laboratory is equipped with state-of-the-art chromatographic,
spectrophotometric and many other automated analytical measuring instruments.
The instrument laboratory also includes a microbiology section that is
well equipped and capable of carrying out aerobic and anaerobic microbial works.
Finally, the laboratory is complete with sampling equipments, a walk-in
chemical store and a walk-in sample cold store.
Analytical
facilities in the Water and Waste Laboratory
D. Selected recent outputs
| Chu, W., Dye Removal from Textile Dye Wastewater Using Recycled Alum
Sludge, Water Research, (In press). |
| Chu, W., Tsui, S. M., Photoreductive Model of Disperse Orange 11 in
Aqueous Acetone and Triethylamine, J. Environ. Eng.-ASCE, (In press). |
| Ma, C. W., Chu, W., Photodegradation Mechanism and Rate Improvement of
Chlorinated Aromatic Dye in Non-ionic Surfactant Solutions, Water Research,
(In press). |
| Choy W. K., Chu, W., The Modeling of Trichloroethene Photodegradation in
Brij 35 Surfactant by Two-Stage Reaction, Chemosphere, Vol. 44, No. 2,
pp.83-87, 2001. |
| Chu, W., Ma, C. W., Quantitative Prediction of Direct and Indirect Dye
Ozonation Kinetics, Water Research, Vol. 34, No. 12, pp3153-3160, 2000. |
| Chu, W., Chan, K. H., The Prediction of Partitioning Coefficients for
Chemicals Causing Environmental Concern, Science of Total Environ., Vol.
248, No. 1, pp.1-10, 2000. |
| Chu, W., Choy W. K., The Study of Lag Phase and Rate Improvement of TCE
Decay in UV/Surfactant System, Chemosphere, Vol. 41, No. 8, pp.1119-1204,
2000. |
| Chu, W., Tsui, S. M., Photo-Sensitization of Diazo Disperse Dye in Aqueous
Acetone, Chemosphere, Vol. 39, pp1667-1677, 1999. |
| Chu, W., Photodechlorination Mechanism of DDT in UV/Surfactant System,
Environ. Sci. Technol., Vol. 33, No. 3, pp421-425, 1999. |
| Chu W., Jafvert, C. T., Diehl C. A., Marley K., and Larson, R. A.,
Phototransformations of Polychlorobiphenyls in Brij 58 Micellar Solutions,
Environ. Sci. Technol., Vol. 32, No. 13, pp1989-1993, 1998. |
| Chua, H. and Yu, P.H.F., Production of biodegradable plastics from
chemical wastewater - A novel method to reduce excess activated sludge
generated from industrial wastewater treatment, Water Science and
Technology, 39(10), pp.273-280, 1999. |
| Chua, H., and Hua, F.L., Effects of trace chromium on organic adsorption
capacity and organic removal in activated sludge, Science of the Total
Environment, Vol. 214, pp.239-245, 1998. |
| Chua, H., Degradation pathway of persistent fatty acids in natural
anaerobic ecosystem, Chemosphere, (in press). |
| Chua, H., Liu, X.H., and Kuang, Y.H., Bio-accumulation of environmental
residues of rate earth elements in aquatic hora eichhormia crassippes
(mart.) solms in Guangdong Province China, Science of the Total Environment,
Vol. 214, pp.79-85, 1998. |
| Chua, H., Lu*, Y.J. and Wong, P.K., Changes of cell surface dielectric
constant in biosorption of nickel ion (Ni2+) by Enterobacter sp. 4-2, Enzyme
and Microbial Technology, 23, pp. 403-407, 1998. |
| Chua, H., Yu, P.H.F. and Sin, S.N., Sub-lethal effects of heavy metals on
activated sludge microorganisms, Chemosphere, (in press). |
| Ma, J. and Graham, N.J.D., Degradation of Atrazine by Manganese-Catalysed
Ozonation: Influence of Humic Substances, Water Research, Vol. 33, no. 3,
pp. 785-793, 1999. |
| Paraskeva, P., Lambert, S.D. and Graham, N.J.D., Ozone Treatment of Sewage
Works Final Effluent, Journal of the Chartered Institution of Water and
Environmental Management, Vol. 13, no. 6, pp. 430-435, 1999. |
| Graham, N.J.D., Removal of Humic Substances by Oxidation/Biofiltration
Processes - A Review, Water Science and Technology, Vol. 40, no. 9, pp.
141-148, 1999. |
| Paraskeva, P. and Graham, N.J.D., Microbial Reduction in a Secondary
Effluent by Ozonation, UV Irradiation and Microfiltration, 14th IOA World
Ozone Congress, 22-26 August, Dearborn, USA, 1999. |
| Ojha, C.S.P. and Graham, N.J.D., Numerical Assessment of Filtration
Equations, Environmental Engineering Research, Vol. 5, no. 1, pp. 11-21,
2000. |
| Ma, J. and Graham, N.J.D., Degradation of Atrazine by Manganese-Catalysed
Ozonation: Influence of Radical Scavengers, Water Research, Vol. 34, no. 15,
pp. 3822-3828, 2000. |
| Campos, L.C., Chu, R.K.Y., Chapra, S.C. and Graham, N.J.D., Developments
in Slow Sand Filter Modelling, 8th World Filtration Congress 2000, 3-7
April, Brighton, U.K., 2000. |
| Graham, N.J.D., Chen, X.G. and Jeyaseelan, S., The Potential Application
of Activated Carbon Prepared from Sewage Sludge to Organic Dyes Removal, 1st
International Water Association (IWA) World Congress, 3-7 July, Paris,
France, 2000. |
| Jiang, J., Andre, C., Graham, N.J.D., Kelsall, G. and Brandon, N.,
Evaluation of an Electro-Flotation Reactor for Water Treatment, IWA
International Conference on Innovations in Classic and Conventional Water
Treatment Processes, 26-29 September, Amsterdam, The Netherlands, 2000. |
| Graham, N.J.D., Martyn, H., Day, M. and Cooper, P., Minimising Wastewater
Sludge Production by Use of a Novel Membrane Bioreactor, 3rd Asia Pacific
Conference on sustainable Energy and Environmental Technologies, 3-6
December, Hong Kong, 2000. |
| Fung, P.C. and Tsui, S.M., Cleaner Technologies of Organic Wastewater in
Hong Kong Dyeing and Finishing Factories, Proceeding of the Water
Environment Federation Technical Conference and Exhibition, WEFTEC Asia,
March 1998, Singapore, Vol. 1, pp. 631-638, 1998. |
| Fung, P.C. and Tsui, S.M., Cleaner Wastewater Treatment Technologies for
Garment Industry, Journal of Asia Water Environment, Water Environment
Federation, USA, pp. 22-24, Oct, 1998. |
| Poon, C.S., Fung, P.C. and Huang, Q., Degradation Kinetics of Cuprophenyl
Yellow RL by UV/H2O2/Ultrasonication (US) Process in Aqueous Solution,
Chemosphere, Vol. 38, No. 5, pp. 1005-1014, 1999. |
| Fung, P.C., Poon, C.S. and Huang, Q. and Tsui, S.M., Treatability Study of
Organic and Colour Removal in Desizing/Dyeing Wastewater by UV/US System
combined with Hydrogen Peroxide, Water Science & Technology, Vol. 40,
No. 1, pp. 153-160, 1999. |
| Fung, P.C., Poon, C.S. and Chu, C.W. and Tsui, S.M., Degradation Kinetics
of Reactive Red by UV/H2O2/US Process under continuous mode operation,
Proceeding of IWA Conference: Manageing Water & Waste in the New
Millennium, -Challenges for Development Areas, May 2000, Johannesburg, South
Africa, 3C-7, pp.1-6. |
| Fung, P.C., Sin, K.M., and Tsui, S.M., Decolorization and Degradation
kinetics of reactive dye wastewater by a UV/ultransonic/peroxide system,
Journal of the Society of Dyers and Colourists, Vol 116, pp. 170-173,
May/June 2000. |
| Li, X.Z., Zhao, Q.L., Ammonium removal from landfill leachate by chemical
precipitation, Waste Manage., 19(6), 409-415, 1999. |
| Li X.Z., Zhao, Y.G., Advanced treatment of dyeing wastewater for reuse,
Water Sic. & Technol., 39(10-11), 249-255, 1999. |
| Li X.Z., Zhao Q.L., Inhibition of microbial activity of activated sludge
by toxicity of ammonia-nitrogen in landfill leachate, Environment
International, 25(8), pp. 961-968, 1999 |
| Zhao Q.L., Li X.Z., Chemical precipitation of ammonia-nitrogen removal
from the landfill leachate in Hong Kong (in Chinese), Environmental Science,
20(5), 90-92, 1999. |
| Li X.Z., Hao X.D., Zhu D.Y., A modified aeration process for promoting
nutrient removal using water hyacinth to treat sewage, Environ. Technol.,
21(5), 525-534, 2000. |
| Li X.Z., Liu H.L., Yue P.T., Sun Y.P., Photoelectrocatalytic oxidation of
rose Bengal using a Ti/TiO2 mesh electrode, Environ. Sci. & Technol.
34(20), 4401-4406, 2000. |
| Li X.Z., Yu B.T., Mak C.K., Photooxidation of wool dye and TCP in aqueous
solution using an innovative TiO2 mesh electrode, Water Sci. & Technol.,
42(12), 181-188, 2000 |
| Li X.Z., Sun J.M., Further formation of THMs in drinking water during
heating, Int. J. Environ. Health Res. 11(3) 2001 (in press). |
| Li, X.Z., Zhao Y.G., Efficiency of biological treatment affected by high
strength of ammonium-nitrogen in leachate and chemical precipitation of
ammonium-nitrogen as pretreatment, Chemosphere 2001 (in press) |
| Li X.Z. and Li F.B. (2001): Study of Au/Au3+-TiO2 photocatalysts toward
visible photo-oxidation for water and wastewater treatment, Environ. Sci.
Technol. (in press) |
E. Contact person
Dr.
W. Chu, Associate Professor
Tel:
(852) 2766 6075; Fax: (852) 2334
6389; E-mail: cewchu@polyu.edu.hk
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