The Environmental Engineering Laboratory (LA311) is managed by Dr. Dong Chen. The lab is well equipped for conducting experiments and analyses of water and environmental samples. State-of-the-art laboratorial equipment is available to support both teaching and research in water and wastewater treatment technologies and environmental chemistry. The course of Environmental Engineering Laboratory (CE366) is offered every fall semester. Water and wastewater quality analyses can be performed including metals, dissolved organic matter, molecular weight of natural organic matter, acidity, biochemical oxygen demand, chemical oxygen demand, total suspended solids, dissolved oxygen, color, turbidity, conductivity, alkalinity, hardness, pH, and heterotrophic plate count of bacteria.
- Atomic absorption (AAnalyst 200 from PerkinElmer)
- UV-Vis spectrometer (Lambda 25 from PerkinElmer)
- Auto-titrator (DL15 from Mettler Toledo)
- 20 kHz ultrasonic probe system (Digital Model 450 from Branson)
- Stirred-cell membrane filtration system (Amicon from Millipore)
- Size exclusion chromatography
- Culture incubator
- BOD incubator
- Jar test system
- COD testing system
- pH meters
- Dissolved oxygen meter
- Turbidity meter
- Conductivity meter
- Oven and furnace
Water Filtration Membrane Processes and Fouling Control
Membrane filtration plays a critical role in advanced water and wastewater treatment practices, because of the technology’s high removal capacity, ability to meet stringent treatment goals and small footprint. Depends on the membrane pore size, the common contaminants in water such as particles, organic matters, bacteria, viruses, and dissolved salts can be removed in a single step. Consequently, high purity water can be produced. However, one of the main barriers to membrane technology is membrane fouling. Generally, membrane fouling is caused by the accumulation of water impurities (i.e., membrane foulants), such as colloidal particles, organic matters, microorganisms and scales on the membrane surface and/or within the membrane pores. As a result, membrane gets clogged over filtration time. Membrane fouling causes a significant decline of the permeate flux. Current research project is using cutting-edge techniques such ultrasound, advanced oxidation, and enzymes to mitigate membrane fouling, based on a mechanistic understanding of physical and chemical properties of the foulants and the membranes.
Chemistry of Natural Organic Matter (NOM)
NOM is ubiquitous and present in natural waters as a result of microbial degradation of plant and animal debris. It is a complicated, ill-defined, dark-colored and refractory natural organic and a significant global carbon pool. In drinking water treatment, the presence of NOM may result in color and bad tastes. More importantly, NOM is a precursor of toxic or carcinogenic disinfection byproducts when it reacts with chlorine. In addition, NOM can undergo a variety of reactions in natural and engineered systems and often interferes with treatment processes, including particle coagulation, filtration, bioavailability, as a nutrient for microorganisms, toxicity of trace metals, mobility of contaminants through complexation, and scavenging reactive species in water. NOM typically contains aromatic, aliphatic, carboxylic, phenolic, and amine functional groups. Current research is investigating the interactions among different functional groups of NOM and water filtration membranes to better understand the fouling behaviors of NOM and to provide control strategies.
Selected Recent Publications
Books and Book Chapters
- D. Chen, D.D. Sun, J.H. Tay, "Effects of property changes of natural organic matter via photooxidation on RO membrane fouling reduction", in T.C. Zhang, R.Y. Surampalli, S. Vigneswaran et al. (Ed.), Membrane Technology and Environmental Applications, ASCE, chapter 19, pp. 581-602, 2012 (ISBN: 9780784412275) (invited chapter).
- D. Chen, S.K. Sharma, A. Mudhoo (Ed.), Handbook on Applications of Ultrasound: Sonochemistry for Sustainability, CRC Press/Taylor & Francis Group, 2011, ISBN: 9781439842065.
- D. Chen, "Applications of Ultrasound in Water and Wastewater Treatment", in D. Chen, S.K. Sharma, A. Mudhoo (Ed.), Handbook on Applications of Ultrasound: Sonochemistry for Sustainability, CRC Press/Taylor & Francis Group, 2011.
- D. Chen, Ultrasonic Control of Ceramic Membrane Fouling: Sono-physical and Sono-chemical Effects, VDM Verlag, Saarbrücken, Germany, ISBN: 9783639209051, 2009.
- D. Chen, P. Szostak, "Factor analysis of H2S emission at a wastewater lift station: a case study", Environmental Monitoring and Assessment, DOI: 10.1007/s10661-012-2809-4, pp1-10, 2012.
- D. Chen, C.J. Lin, R.G. Jones, S. Patel, R. Smith, K. Simons, J.L. Davis, and S.A. Waisner, "A deployable decentralized biofilm system for degrading organic carbon and benzene in wastewater", Environmental Progress & Sustainable Energy, DOI: 10.1002/ep.11650, pp1-7, 2012.
- Y. Gao, D. Chen, L.K. Weavers, H.W. Walker, "Ultrasonic control of UF membrane fouling by natural waters: effects of calcium, pH, and fractionated natural organic matter", Journal of Membrane Science, 401-402, pp232-240, 2012.
- D. Chen, M. Columbia, "Enzymatic control of alginate fouling of dead-end MF and UF ceramic membranes," Journal of Membrane Science, 381, pp118-125, 2011.
- S. Shirazi, C.J. Lin, D. Chen, "Inorganic fouling of pressure-driven membrane processes --- a critical review", Desalination, 250, pp236-248, 2010.
- Y. Chen, D. Chen, L. Peng, S. Fu, H. Zhan, "The microorganism community of pentachlorophenol (PCP)-degrading coupled granules", Water Science & Technology, 59(5), pp987-994, 2009.
- D. Chen, K. Howe, J. Dallman, B. Letellier, "Corrosion of aluminum in the aqueous chemical environment of a loss of coolant accident at a nuclear power plant," Corrosion Science, 50, pp1046-1057, 2008.
- D. Chen, "Enzymatic Treatment of Alginate to Reduce Membrane Fouling for Municipal Wastewater Treatment,” US patent pending, 2012.
- L. Weavers, H. Walker, M. Lamminen, D. Chen, 'Ultrasonically Cleaned Membrane Filtration System," U.S. patent #7008540, 2006.