Global trends and performances of publication on sewage sludge from 1991 to 2012

This study is a bibliometric analysis of sewage sludge researches to quantitatively and visually evaluate the global publication trends and research emphases using the Science Citation Index Expanded (SCI-Expanded) database from 1991 to 2012. Both "evaluative bibliometrics" and social network analysis methods were used to analyze the following aspects: publication characteristics, publication performances and collaborations of countries/ territories and research emphases on author keywords, words in title and hotspots. An evaluating indicator, a-index, was applied to value the journals. The most productive country were USA, while the most productive journal was Bioresource Technology. Based on the network analyses of author keywords and words in title and the analysis of hotspots, "compost" and "anaerobic digestion" were the most popular disposal and treatment methods. "Heavy metals" were the contaminants with the greatest concerns. "Organic matters" such as "PPCPs" (abbreviation of pharmaceuticals and personal care products) and "PBDEs" (abbreviation of polybrominated biphenyl ethers) attracted comprehensive attention in recent years. "Soil" owned the most intimate relationship with sewage sludge due to its frequent appearance in titles and abstracts as an important approach for sewage sludge disposal. (C) 2016 The Authors. Published by Elsevier B.VCPCI-S(ISTP)yshliu@pku.edu.cn65-743