Review Phosphorous recovery through struvite crystallization: Challenges for future design Bing Li a,b , Irina Boiarkina a , Wei Yu a, ⁎, Hai Ming Huang c , Tajammal Munir a , Guang Qian Wang b , Brent R. Young a a Department of Chemical & Materials Engineering, The University of Auckland, New Zealand b Department of Hydraulic Engineering, Tsinghua University, China c School of Environmental and Chemical Engineering, Yanshan University, China HIGHLIGHTS • A trend analysis of current research on struvite crystallization was performed. • All factors affecting struvite crystalliza- tion were reviewed. • Current gaps and future research direc- tions were identified. • A conceptual struvite crystallization process design was proposed. GRAPHICAL ABSTRACT abstract article info Article history: Received 29 May 2018 Received in revised form 13 July 2018 Accepted 13 July 2018 Available online 05 August 2018 Editor: Frederic Coulon Phosphorous (P) is an essential element for living organisms and is predicted to be depleted within the next 100 years. Across the world, significant phosphorous losses due to its low utilization efficiency become one of the main reasons for water pollution. Struvite crystallization has been found to be a promising recovery technique to mitigate these problems, as the recovered precipitate can be used as a slow release fertilizer or raw material for chemical industry. Although this technique has been widely investigated over the past two decades, there are cur- rently few real applications in industry. This paper addresses this issue by reviewing key aspects relevant to pro- cess design to pave the way for future application. It will help to narrow down struvite process design options and thus reduce the voluminous calculations for a detailed analysis. Struvite process development, research trend, product application and process economics are reviewed and a conceptual process design is provided. This analysis provides comprehensive information that is essential for future industrial struvite crystallization process design. © 2018 Elsevier B.V. All rights reserved. Keywords: Struvite Phosphorus recovery Process design Product application Product quality Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1245 2. An overview of research activity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1245 Science of the Total Environment 648 (2019) 1244–1256 ⁎ Corresponding author. E-mail address: w.yu@auckland.ac.nz (W. Yu). https://doi.org/10.1016/j.scitotenv.2018.07.166 0048-9697/© 2018 Elsevier B.V. All rights reserved. Contents lists available at ScienceDirect Science of the Total Environment journal homepage: www.elsevier.com/locate/scitotenv