Another Grand Challenge: Diversity in Environmental Engineering

© Copyright 2018, Mary Ann Liebert, Inc. 2018. As efforts to address grand challenges in engineering move forward, one important challenge has been conspicuously absent - improving diversity in science, technology, engineering, and math fields. Previous research has shown that diverse teams perform better in a range of output measures and are better equipped to objectively and creatively evaluate problems. Here, we make the case for including diversity as a critical component of our ability to enable transformative solutions to the grand challenges in environmental engineering

Trends in Population and Demographics of U.S. Environmental Engineering Students and Faculty from 2005 to 2013

Copyright © 2016 Mary Ann Liebert, Inc. Although modern environmental engineering was established in the mid 1900s, the field has arguably evolved into its own professional discipline only in the past 3-4 decades. During this time, the number of environmental engineering students, faculty, and practitioners has grown dramatically, and many environmental engineering BS degree programs were established. To better assess this growth, we have conducted an analysis of the demographics of environmental engineering students and faculty using the American Society for Engineering Education (ASEE) Engineering Data Management System. One limitation of the ASEE database is that only students and faculty primarily associated with environmental engineering degrees and programs, respectively, are counted; therefore, students and faculty related to environmental engineering tracks within civil and chemical engineering programs are excluded from this analysis. From 2005 to 2013, the number of BS, MS, and PhD degrees awarded rose by 90%, 27%, and 39%, respectively; furthermore, these growth rates exceeded those of civil and chemical engineering at all levels. As a consequence, the BS student-to-faculty ratio rose from 8 in 2005 to 35 in 2013. Hispanic American, African American, and Native American students are underrepresented in environmental engineering programs at all levels. Representation and retention of African American students is particularly concerning, since this group exhibited negative retention trends from the 2006 to 2010 BS cohorts. Gender demographics were reasonably representative with 46% of all environmental engineering degrees awarded to women in 2013. Some gains were found in representation of ethnic and racial minorities and women in environmental engineering faculty at the associate professor level. Minimal gains were observed at the assistant professor rank. However, 88% of full professors are Caucasian, and 85% are men. These findings suggest that increased efforts are needed to recruit and retain students from underrepresented groups to environmental engineering and encourage them to pursue careers in academia

A protocol for the use of computational fluid dynamics as a supportive tool for wastewater treatment plant modelling

To date, computational fluid dynamics (CFD) models have been primarily used for evaluation of hydraulic problems at wastewater treatment plants (WWTPs). A potentially more powerful use, however, is to simulate integrated physical, chemical and/or biological processes involved in WWTP unit processes on a spatial scale and to use the gathered knowledge to accelerate improvement in plant models for everyday use, that is, design and optimized operation. Evolving improvements in computer speed and memory and improved software for implementing CFD, as well as for integrated processes, has allowed for broader usage of this tool for understanding, troubleshooting, and optimal design of WWTP unit processes. This paper proposes a protocol for an alternative use of CFD in process modelling, as a way to gain insight into complex systems leading to improved modelling approaches used in combination with the IWA activated sludge models and other kinetic models

Assessing the impact of the 4CL enzyme complex on the robustness of monolignol biosynthesis using metabolic pathway analysis

<div><p>Lignin is a polymer present in the secondary cell walls of all vascular plants. It is a known barrier to pulping and the extraction of high-energy sugars from cellulosic biomass. The challenge faced with predicting outcomes of transgenic plants with reduced lignin is due in part to the presence of unique protein-protein interactions that influence the regulation and metabolic flux in the pathway. Yet, it is unclear why certain plants have evolved to create these protein complexes. In this study, we use mathematical models to investigate the role that the protein complex, formed specifically between Ptr4CL3 and Ptr4CL5 enzymes, have on the monolignol biosynthesis pathway. The role of this Ptr4CL3-Ptr4CL5 enzyme complex on the steady state flux distribution was quantified by performing Monte Carlo simulations. The effect of this complex on the robustness and the homeostatic properties of the pathway were identified by performing sensitivity and stability analyses, respectively. Results from these robustness and stability analyses suggest that the monolignol biosynthetic pathway is resilient to mild perturbations in the presence of the Ptr4CL3-Ptr4CL5 complex. Specifically, the presence of Ptr4CL3-Ptr4CL5 complex increased the stability of the pathway by 22%. The robustness in the pathway is maintained due to the presence of multiple enzyme isoforms as well as the presence of alternative pathways resulting from the presence of the Ptr4CL3-Ptr4CL5 complex.</p></div

CFD for wastewater treatment : an overview

Computational fluid dynamics (CFD) is a rapidly emerging field in wastewater treatment (WWT), with application to almost all unit processes. This paper provides an overview of CFD applied to a wide range of unit processes in water and WWT from hydraulic elements like flow splitting to physical, chemical and biological processes like suspended growth nutrient removal and anaerobic digestion. The paper's focus is on articulating the state of practice and research and development needs. The level of CFD's capability varies between different process units, with a high frequency of application in the areas of final sedimentation, activated sludge basin modelling and disinfection, and greater needs in primary sedimentation and anaerobic digestion. While approaches are comprehensive, generally capable of incorporating non-Newtonian fluids, multiphase systems and biokinetics, they are not broad, and further work should be done to address the diversity of process designs. Many units have not been addressed to date. Further needs are identified throughout, but common requirements include improved particle aggregation and breakup (flocculation), and improved coupling of biology and hydraulics

Good modelling practice in applying computational fluid dynamics for WWTP modelling

International audienceComputational fluid dynamics (CFD) modelling in the wastewater treatment (WWT) field is continuing to grow and be used to solve increasingly complex problems. However, the future of CFD models and their value to the wastewater field are a function of their proper application and knowledge of their limits. As has been established for other types of wastewater modelling (i.e. biokinetic models)​, it is timely to define a good modelling practice (GMP) for wastewater CFD applications. An International Water Association (IWA) working group has been formed to investigate a variety of issues and challenges related to CFD modelling in water and WWT. This paper summarizes the recommendations for GMP of the IWA working group on CFD. The paper provides an overview of GMP and, though it is written for the wastewater application, is based on general CFD procedures. A forthcoming companion paper to provide specific details on modelling of individual wastewater components forms the next step of the working group

Contour plot showing the variation of steady state flux (V₇) as a function of Ptr4CL3 and Ptr4CL5 concentration in the presence of a complex.

<p>The axis values represents the percentage of the protein concentration as a function of the wild type concentration. The color bar represents the flux values (μM/min).</p