At present, with more and more attention paid to the impact of buildings on the health and well-being of occupants, sick building syndrome (SBS) has become a global concern. Since the introduction of SBS by the World Health Organization (WHO) in 1983, thousands of research literatures have been published in this field. This paper systematically arranges knowledge development of SBS through bibliometric analysis, exploring the most influential countries, institutions, journals and scholars, as well as the main subject categories and keywords. Main path analysis (MPA) was used to list development trajectory under inheritance relationship of SBS knowledge, including symptom analysis, risk factors of SBS and the improved impact of ventilation on SBS and productivity. Furthermore, it is an emerging research trend to propose SBS solution in the building design stage.

The Internet of Things (IoT), as an important technical domain in the future, has received wide attention globally from different disciplines. The research output in this domain, therefore, grew rapidly in the past 10 years. This study deeply investigates the knowledge base and knowledge development trajectory of the domain since the IoT was proffered in 1999. By adopting basic statistical and keyword co-occurrence methods, the most influential countries, institutions, journals and scholars in the domain, as well as the division of core, hot keywords and subdomains, are investigated. By using the main path analysis method, a survey is conducted on the development trajectory of the domain on the basis of knowledge inheritance; the four core branches-industry, big data, cloud computing and IoT security; and the three application studies of industry, healthcare and smart city.

Pro-environmental behaviors related to reclaimed water reuse are regarded as important motivations for both environmental protection and the use of reclaimed water, and these motivations could affect the citizens’ decision whether they will accept reclaimed water reuse. A hypothesis model was developed as the NAM (Norm Activation Model) has changed, and this hypothesis model was used to explore the factors that affect the citizen’s decision about the reclaimed water reuse, and obtain a better understanding of the mechanism of urban citizens in environmental protection and the related outcomes. First, 584 samples were used to verify the reliability and validity of data, and AMOS21.0 was used to test the goodness-of-fit between the sample data and the hypothesis model. Based on this, the applicability of the improved NAM was verified through the study of recycled water reuse. The hypothesis model was used to analyze its direct influences, showing that environmental motivation has positive influences on the citizens’ acceptance toward recycled water reuse. Besides, Bootstrap method was used to verify the mediation effect, proving that awareness of consequences regarding environmental pollution caused by human activities and ascription of responsibility could strengthen the citizens’ motivation to protect the environment.

Reclaimed water is an important component of available water resources, and public acceptance of reclaimed water is a key factor influencing the implementation of reclaimed water reuse projects. For this reason, it has received attention from different scholars in the international community. Based on the literature data on public acceptance of reclaimed water, this study analyzes the development status of research results and explores the knowledge evolution path with the help of bibliometric methods. Our results show that the field of research on public acceptance of reclaimed water began to grow rapidly after 1990, and identify influential countries, institutions, authors, and journals in the field. In addition, “water quality”, “public health”, and “irrigation” are themes that run throughout the research, and “sustainable development” and “potable reuse” are the emerging research hotspots. As research progresses, the scope of research on reclaimed water reuse and its influencing factors continues to expand, and reclaimed water management policies and standards continue to improve. In the future, in order to improve public acceptance, finding how to improve the public’s risk perception and trust in reclaimed water will become a central research focus.