The growing water stress both in terms of water scarcity and quality deterioration promotes the development of reclaimed water as a new water resource use. This paper reviewed wastewater reuse practices in China, and the opportunities and challenges of expanding reclaimed water use were analyzed. Rapid urbanization with the increasing of water demand and wastewater discharge provides an opportunity for wastewater reuse. The vast amount of wastewater discharge and low reclaimed water production mean that wastewater reuse still has a great potential in China. Many environmental and economic benefits and successful reclamation technologies also provide opportunities for wastewater reuse. In addition, the overall strategy in China is also encouraging for wastewater reuse. In the beginning stage of wastewater reclamation and reuse, there are many significant challenges to expand wastewater reuse in China including slow pace in adopting urban wastewater reuse programs, the establishment of integrated water resources management framework and guidelines for wastewater reuse programs, incoherent water quality requirements, the limited commercial development of reclaimed water and the strengthening of public awareness and cooperation among stakeholders.

A majority of global secondary organic aerosol (SOA) comes from terpenoids. In this study, we carried out a 1 year nationwide observation of pinenes (α‐ and β‐pinene) and SOA tracers from monoterpenes (SOAM) and β‐caryophyllene (SOAC) over China for the first time. SOAM and SOAC tracers ranged from 9.80 to 49.0 ng m−3 and 1.72 to 7.72 ng m−3, respectively, with high levels in southern China. Pinenes ranged from 34 to 102 parts per trillion by volume, with α‐pinene dominant over β‐pinene. SOAM tracers were correlated between paired sites, suggesting a regional impact of SOAM, while pinenes were uncorrelated between sites due to their rapid oxidation. High levels of SOAM tracers were observed in spring and summer. However, at the Hailun site in Northeast China, SOAM tracers increased during winter. The positive correlation between SOAM tracers and the biomass burning (BB) tracer levoglucosan during winter at Hailun indicated that the unexpected increase of SOAM was associated with BB. The SOAC tracer, β‐caryophyllenic acid, increased during winter and was positively correlated with levoglucosan, suggesting substantial contributions from BB to SOAC production in wintertime. Together with SOA tracers from isoprene, these tracers were applied to estimate biogenic secondary organic carbon (BSOC) from isoprene, monoterpenes, and β‐caryophyllene. The annual average BSOC was 0.91 ± 0.41 μgC m−3,with the majority from monoterpenes and the highest level in Southwest China. BSOC was elevated from April to September and was lowest in January and February. BSOC composition dramatically changed from a monoterpene majority in fall‐spring to an isoprene majority in summer.

Public involvement is critical to the successful implementation of reclaimed water reuse programs. Based on the participatory research method, we studied the attitudes of the stakeholders who are involved in reclaimed water reuse in Beijing, China. Results showed that the general public's knowledge on water resources was poor, while their awareness on reclaimed water reuse was high. The general public showed a strong acceptance of non-contact and non-potable reclaimed water reuse, but their acceptance of the three major water reuse types of river water supplement, park water supplement, and agriculture irrigation was not high. The beneficial use of reclaimed water was admired by water resource managers, industrial sectors, and researchers, and these stakeholders strongly supported the advancement of reclaimed water reuse. However, some of the stakeholders showed concerns about the potential risks from reclaimed wastewater reuse. Among them, risks from waste water treatment facilities were the biggest concern. Stakeholders' perception of reclaimed water was influenced by their social-economic attributes. This study will enrich the current survey findings on public perception of reclaimed water reuse, particularly in developing countries. OPEN ACCESSSustainability 2015, 7 9697