Evolution of struvite research and the way forward in resource recovery of phosphates through scientometric analysis

Abstract

The alarming decline in phosphate raw materials and increase in eutrophication has escalated interest in struvite research. This manuscript presents scientometric analysis on struvite for fertilizing applications to comprehend the evolution and transformation of the field, investigate the existing challenges, research gaps, and developments to gain insights on the emerging trends for further studies. A total of 1550 scientific documents, between the years 1999–2020, were collected from Scopus® and PubMed® using an appropriate trail of keywords and analyzed using CiteSpace 5.7. R2. Ten attributes such as annual publication output and types, co-authorship network, co-occurring author keywords, the network of authors’ countries and institutions, author co-citation network, document co-citation network, journal co-citation network, and co-occurring subject categories were investigated. Based on the distinct network patterns generated by the software, progress of the field, paradigm shifts, knowledge gaps, and scientific frontiers were identified and mapped. The literature on struvite research was found to have bloomed in the early 2000s and accelerated significantly until now, with maximum contribution from China and United States. Journal of cleaner production ranks 5th with 3.35% share of the total contribution according to journal co-citation analysis. Cluster analysis of co-occurring author keywords revealed the research progression through the expanse, knowledge gaps, disciplinary and inter-disciplinary advancements, and future exploration trends. The research has evolved from evaluating the process influencing parameters and developing suitable reactor designs to installation of pilot-scale plants for commercialization. However, lack of experiments on real-time wastewater, plant growth studies and the underlying nutrient uptake mechanisms persist as major research gaps. Focussing on these aspects along with integrated advanced technologies such as microbial fuel cells, microbial electrolysis cells, electrochemical precipitation of struvite and wider application of struvite can pave way for enormous progress of this field.