Using hydrochars as template, TiO2 photocatalysts were prepared by the sol-gel method. The samples were characterized with X-ray diffraction (XRD), Fourier infrared spectrum (FT-IR), scanning electron microscope (SEM) and BET specific surface area measurement. The photocatalytic activity was investigated by degradation of methyl orange (MO) as target pollutant in the solution. The results showed that HTC-TiO2 remained anatase type at high calcination temperature due to the higher thermal stability than TiO2. The TiO2 particles were almost uniformly dispersed on the surface of HTC. HTC-TiO2 had smaller crystal sizes, bigger specific surface area and the flake structure, which had the same structure character as the hydrochars micro-structure and was beneficial to improve the photocatalytic activity. The degradation rate of MO under 550 W iodine-tungsten lamp illumination for 2 hours was 40.6% in presence of HTC-TiO2 calcined at 450ºC, which increased by 1.5 times more than those in presence of TiO2 (16.2%).
For better understanding the global trend in wastewater resource recovery and reflecting major nation’s scientific capability and influences on the world’s science community in the field, a bibliometric analysis was conducted using the literatures in the Science Citation Index (SCI) database during the period 1995–2014. Results indicate that: 1) among all articles included by the SCI, water recovery from wastewaters account for the largest percentage with 72.0% of all related research fields. 2) The mainly involved subject areas are Environmental Sciences, Engineering Environmental, Water Resources, Engineering Chemical, Biotechnology Applied Microbiology, and so on. The number of the Environmental Sciences articles has the largest annual growth. 3) The topranked countries of both the total number of articles and the average impact factor are USA, Spain, and India. However, China has the fastest growth rate of publishing articles only. 4) Three research institute including University of California System, India Institute of Technology, and Consejo Superior De Investigaciones Cientificas are the most abundant research institutes in this field. The Chinese Academy of Sciences and Tsinghua University were the two toppest institutions in China that have advance its international influence in recent years.