Environmental Science: Water Research & Technology blog

Dr. Xin Yang is now a professor at the School of Environmental Science and Engineering at Sun Yat-sen University. She received a B.S. in Environmental Science from Nankai University in 2002 and obtained her M.Phil. and Ph.D. degree in Environmental Engineering from the Hong Kong University of Science & Technology at 2004 and 2007, respectively. She was a postdoctoral fellow, working with Prof. Philip C. Singer at University of North Carolina at Chapel Hill. Her research focuses on the formation mechanisms and control strategies of disinfection byproducts in water treatment and the fate of emerging micropollutants in aqueous environments.

Read Xin’s Emerging Investigators article ‘disinfection by-products in mixed chlorine dioxide and chlorine water treatment’.

– How has your research evolved from your first to your most recent article?
My first research article was on disinfection byproducts formation during chlorination during my MPhi study at the HKUST. My current paper is also on disinfection byproducts, but from chlorine dioxide disinfection. Over the years, my research has been focused on disinfection and the byproducts formation with expansion toward emerging contaminants, such as pharmaceuticals and personal care products and persistent organic pollutants. My research has always aimed at drinking water safety.

– What aspect of your work are you most excited about at the moment?
The most exciting thing is to bridge the knowledge or results from the laboratory work with the real application. As my research has been focusing on drinking water treatment, we have good connections with water companies serving drinking water. It is great to apply what have learned from the laboratory work to guide the real application in water treatment. This is not easy, but we are trying.

– What would be the ideal ratio of chlorine dioxide:chlorine for water treatment?
From the tests, we find that the presence of some chlorine in chlorine dioxide solution may be effective in control certain groups of disinfection byproducts. It is difficult to give an ideal ratio as the water qualities vary. Meanwhile, the valuation of the formation of disinfection byproducts is just one aspect of the mixing solution, the other aspects such as inactivation capability may also be considered for further study.

– What do you find most challenging about your research?
I am working on pollutants or products with trace concentrations and the instruments such as GC-MS/MS and LC-MS/MS are often used. As the exploration of the reaction pathway is often one major objective, the mass spectral analysis from tons of peaks obtained from MS is very challenging.

– In which upcoming conference or events may our readers meet you?
I will be attending the Gordon Conference on Drinking Water Disinfection By-Products in July 2017 in South Hadley, MA, USA. The other conferences I often attend are the International Water Association conferences.

– Which profession would you choose if you were not a scientist?
I have been enjoying so much as a teacher and researcher in the university. If I had not gone into science, I would like to be an engineer.

– Can you share one piece of career-related advice or wisdom with other early career scientists?
Work on something that needs to be worked on. Research is not just paper publication. It will be very exciting and important to solve real-application problems.

Christopher M. Sales is a Tenure-Track Assistant Professor in the Civil, Architectural, and Environmental Engineering Department of Drexel University. He is an environmental engineer with research interests in molecular environmental microbiology related to the biodegradation of environmental contaminants and biotechnologies for energy and resource recovery from waste. His research group, who you can follow on twitter @SalesLaboratory, applies a combination of high-throughput and advanced molecular biology, analytical chemistry, and bioinformatics techniques to study microbial systems in natural and engineered environments.

Christopher received his Ph.D  in Civil and Environmental Engineering from the University of California, Berkeley, in 2012. His dissertation focusing on the functional genomics of the biodegradation of the emerging water contaminants, 1,4-dioxane and N-nitrosodimethylamine (NDMA). Prior to this, he worked as a post-doctoral researcher with Dean Joseph B. Hughes in the Civil, Architectural, and Environmental Engineering Department at Drexel University concentrated on the bioremediation of soils contaminated with nitroaromatric compounds, the environmental impacts of hydraulic fracturing in the Marcellus Shale, and the development of combined algae-bacteria biotechnologies for the conversion of wastes to energy and valuable products.

Read Chris’ Emerging Investigators article ‘untangling the microbial ecosystem and kinetics in a nitrogen removing photosynthetic high density bioreactor’.

– How has your research evolved from your first to your most recent article?
This most recent article in ES:WR&T blends together aspects of research that I did as an undergraduate and then as a doctoral student. As an undergraduate at the University of Pennsylvania, I performed research in the laboratory of Wen Kang Shieh (who is a co-author on this most recent article) that mainly focused on the design and kinetics of bioreactors for wastewater treatment. Through this undergraduate research, I was fortunate enough to publish a manuscript on the performance of a novel continuous bioreactor system that had high mean cell residence times without a biomass-liquid separation unit (see DOI:10.1016/j.watres.2006.01.043). While I knew microbes were involved in the treatment of synthetic wastewater in the bioreactors that I operated as an undergraduate, I was not able to fully grasp or appreciate–at that time–the complex microbial processes responsible for removing pollutants from wastewater in these systems. This undergraduate research experience propelled me on a journey to pursuing a graduate degree with Lisa Alvarez-Cohen at the University of California at Berkeley, where I applied functional genomics to understand microbial degradation of environmental contaminants.  This recent article on untangling the microbial ecology and kinetics in a nitrogen removing photosynthetic bioreactor of algae and bacteria showcases my ambitions as an Assistant Professor at Drexel University, where I am aiming to utilize molecular biology techniques, such as high-throughput genomic sequencing, to shed light on the microbial processes that dictate the function and performance of environmental biological processes in order to inform how we design and engineer them.

– What aspect of your work are you most excited about at the moment?
The most exciting–and also the most daunting and challenging–aspect of incorporating meta-omics and high-throughput chemical techniques to studying the kinetics and microbiology of environmental biological processes is the collection, handling, and analysis of such large datasets. This influx of data has the potential to vastly improve our understanding and ability to engineer biological processes but realization of this potential will depend largely on advances in data sciences and computational modeling to analyze the large amounts of high-dimensional data and draw meaningful relationships from these system within an engineering context.

– What do you see as the biggest benefit of using 3D visualization methods for water research?
The 3D visualization method gave us a new perspective, beyond single-variate regressions, to determine how more than one predictor variables could interact to affect the performance of a system. The 3D visualization methods will allow water researchers to examine how two predictor variables could work in tandem to affect the performance of a treatment process.

– What is the most useful application for these membranes?
With its enhanced removal of organic compounds, this membrane can be potentially used for wastewater reuse, as wastewater often contains harmful organic contaminants, such as pharmaceuticals and personal care products, and endocrine disrupting compounds.

– In which upcoming conference or events may our readers meet you?
I will be at the upcoming 16th International Symposium for Microbial Ecology (ISME) in Montreal, Canada from August 21-26, 2016 with my PhD student and co-author on this recent article in ES:WR&T, Jacob Price.

– Which profession would you choose if you were not a scientist?
I love cooking and being in a kitchen, so I’d say a chef.

– Can you share one piece of career-related advice or wisdom with other early career scientists?
Surround yourself with a strong support system of peers and mentors–they will help you gain confidence to navigate through difficult times and will always be there to champion and celebrate your successes.