The total dissolved solids (TDS) in the CBM produced water are removed to meet the "drinking water standards" and "groundwater quality standards" of China and can be used as drinking water, irrigation water, and livestock watering. The cost for treatment of CBM produced water is also assessed, and the RO technology is an efficient and cost-effective treatment method to remove pollutants.

Furthermore, a model for the RO membrane separation process is developed to describe the quantitative relationship between key physical quantities - membrane length, flow velocity, salt concentration, driving pressure and water recovery rate, and the water recovery restriction equation based on mass balance is developed. This model provides a theoretical support for the RO system design and optimization.

Exposure of atmospheric aerosol is associated with many adverse health impacts, such as asthma, allergy and cardiovascular diseases. Fine particles, also called PM_2.5 due to their aerodynamic diameter are not larger than 2.5 um, are more dangerous because they can deeply arrive at alveolus thus directly induce toxicant to respiratory and circulatory systems. However, ambient aerosol sample collection is usually a long haul because most aerosol samplers are designed with heavy and big outlines, and don’t have adjustable flow rate thus don’t have applicability in different research regions.

A dual-channel aerosol sampler was recently designed and manufactured by Dr. ZHANG Yang in Professor ZHANG YuanXun's Group in the Division of Atmospheric Environmental Sciences, CRE, GUCAS. It is characterized by small volume, slight weight, easy carrying, simple and friendly operation, convenient observation and high precision. The application of advanced single chip microcomputer control and LCD Panel technique greatly optimized its operation interface making its function control and parameter display panel conveniently. The flow rate of each channel is accurately controlled by proportional valve and automatically corrected by pressure and temperature compensating. In addition, this sampler is available to collecting the aerosol sample of TSP, PM₁₀, and PM_2.5 via switching the particle size selector easily. Thus, it is very suitable for field sampling.

To give an insight into the bacterial diversity of biofilms from full-scale drinking water distribution systems (DWDSs), the bacterial community compositions of biofilms from two urban DWDSs were determined using a 16S rRNA gene library technique. Meanwhile, the occurrence and diversity of mycobacteria were also analyzed by a Mycobacterium-specific hsp gene assay. The biofilms from the full-scale DWDSs have complex bacterial populations. Proteobacteria was the common and predominant group in all biofilm samples, in agreement with previous reports. The community structures of bacteria at the three sites in the south urban DWDS were significantly different, despite the similar physicochemical properties of portable water. Some abundant and peculiar bacterial phylotypes were noteworthy, including Methylophilus, Massilia, and Planomicrobium, members of which are rarely found in DWDSs and their roles in DWDS biofilms are still unclear. The diversity of Mycobacterium species in biofilm samples was rather low. Mycobacterium arupense and Mycobacterium gordonae were the primary Mycobacterium species in the south and north urban DWDS biofilms, respectively, indicating that M. arupense may be more resistant to chloride than M. gordonae.

Those findings were observed by Dr. LIU Ruyin, assistant professor of CRE, who has spent almost two years on this research. He, as well as his group, will continue their research and are expected to identify some key factors associated with drinking water security.

Phylogenetic analysis of hsp gene sequences of Mycobacterium spp.