New framework for automated article selection applied to a literature review of Enhanced Biological Phosphorus Removal

RESEARCH ARTICLE New framework for automated article selection applied to a literature review of Enhanced Biological Phosphorus Removal Minh Nguyen Quang1, Tim Rogers2, Jan Hofman ID1, Ana B. Lanham ID1* 1 Water Innovation and Research Centre, Department of Chemical Engineering, University of Bath, Bath, United Kingdom, 2 Centre for Networks and Collective Behaviour, Department of Mathematical Sciences, University of Bath, Bath, United Kingdom a1111111111 a1111111111 a1111111111 a1111111111 a1111111111 * Abstract Aims OPEN ACCESS Citation: Quang MN, Rogers T, Hofman J, Lanham AB (2019) New framework for automated article selection applied to a literature review of Enhanced Biological Phosphorus Removal. PLoS ONE 14(5): e0216126. https://doi.org/10.1371/journal. pone.0216126 Editor: Nicolas Roche, Aix-Marseille Universite, FRANCE Received: July 6, 2018 Accepted: April 15, 2019 Enhanced Biological Phosphorus Removal (EBPR) is a technology widely used in wastewater treatment to remove phosphorus (P) and prevent eutrophication. Establishing its operating efficiency and stability is an active research field that has generated almost 3000 publications in the last 40 years. Due to its size, including over 119 review articles, it is an example of a field where it becomes increasingly difficult to manually recognize its key research contributions, especially for non-experts or newcomers. Therefore, this work included two distinct but complementary objectives. First, to assemble for the first time a collection of bibliometric techniques into a framework for automating the article selection process when preparing a literature review (section 2). Second, to demonstrate it by applying it to the field of EBPR, producing a bibliometric analysis and a review of the key findings of EBPR research over time (section 3). Published: May 9, 2019 Copyright: © 2019 Quang et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: Data used in the analysis presented in this manuscript are provided in the Supporting Information files. The raw Web of Science metadata are not available in the Supporting Information files, as legal restrictions have been imposed on publicly sharing these data. These legal restrictions are detailed in Clarivate Analytics’ terms of use. Interested readers may find the search terms used to access these data within the paper. The authors do not have special access to these data and confirm that they were accessed in the manner described. Findings The joint analysis of citation networks, keywords, citation profiles, as well as of specific benchmarks for the identification of highly-cited publications revealed 12 research topics. Their content and evolution could be manually reviewed using a selection of articles consisting of approximately only 5% of the original set of publications. The largest topics addressed the identification of relevant microorganisms, the characterization of their metabolism, including denitrification and the competition between them (Clusters A-D). Emerging and influential topics, as determined by different citation indicators and temporal analysis, were related to volatile fatty acid production, P-recovery from waste activated sludge and aerobic granules for better process efficiency and stability (Clusters F-H). Conclusions The framework enabled key contributions in each of the constituent topics to be highlighted in a way that may have otherwise been biased by conventional citation-based ranking. PLOS ONE | https://doi.org/10.1371/journal.pone.0216126 May 9, 2019 1 / 42 New framework for automated article selection applied to a literature review of EBPR Funding: MNQ acknowledges support from the Engineering and Physical Sciences Research Council (EPSRC, UK) in the form of his PhD studentship. TR acknowledges support from the Royal Society (UK). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Further, it reduced the need for manual input and a priori expertise compared to a traditional literature review. Hence, in an era of accelerated production of information and publications, this work contributed to the way that we are able to use computer-aided approaches to curate information and manage knowledge. Competing interests: The authors have declared that no competing interests exist. 1 Introduction Eutrophication—the over-abundance of certain nutrients in water bodies, unbalancing local ecosystems—is a major environmental concern. To prevent this, numerous technologies have been developed to remove phosphorus from wastewater [1]. Of these technologies, Enhanced Biological Phosphorus Removal (EBPR) is perhaps one of the most popular choices in wastewater treatment plants (WWTP), especially for those with larger capacities. It is essentially a variation of conventional Activated Sludge (AS). By engineering alternating anaerobic, aerobic and often anoxic conditions, the resulting community of microorganisms removes phosphorus (P) by intra-cellular accumulation. Primarily, EBPR offers an alternative to chemical precipitation for P-removal. However, it also became an extremely interesting model of microbial ecology applied to complex engineered environmental systems. Since its inception in 1975 [2], close to 3000 articles have been published on EBPR and the field continues to grow with many emerging questions (e.g., the most recent paper by Barnard and colleagues in 2017 [3]). Almost 40 years later and with such a rich and multidisciplinary body of work [4], it is an example of a field where it becomes increasingly time-consuming for a non-expert or a newcomer (e.g., a new PhD student or postdoctoral researcher) to manually review all the existing literature and identify key research highlights, as well as new opportunities for further research. With advances in bibliometric techniques, i.e., the statistical analysis of literature, in particular via citation analysis, it is now timely and possible to develop for the first time a suitable bibliometric framework that can systematically identify EBPR’s key areas of research and/or publications. The aim of this framework is to reduce the manual intervention needed to review a specific research area, in this case applied to EBPR. Such a framework can be interesting to EBPR scientists but also to anyone exploring other research fields and searching for ways to reduce manual input when conducting a literature review. In addition, the resulting bibliometric analysis and review of EBPR’s key areas of research, exemplifies what sort of information can be obtained. While primarily intended for researchers new to the field, the framework may also prove useful to specialists already knowledgeable of the ava (...truncated)