[Occurrence Characteristics and Ecological Risk Assessment of Antibiotics in Reclaimed Water-receiving Rivers in Beijing].

Taking Liangshui River, the reclaimed water-receiving river in Beijing, as the research area, the types, detection frequencies, and concentrations of 16 antibiotics in water and sediment were analyzed, and their temporal-spatial variation and occurrence characteristics were discussed. The results showed that nine and 13 target antibiotics were detected in the water and sediment of Liangshui River, with the antibiotic concentration ranges of ND-116.68 ng·L and ND-235.

Ozonation of norfloxacin and levofloxacin in water: Specific reaction rate constants and defluorination reaction.

The degradation kinetics and mechanism of two typical fluoroquinolones (FQs), norfloxacin (NF) and levofloxacin (LOF), by ozone in water were investigated. Semi-continuous mode and competition kinetics mode experiments were conducted to determine the reaction rate constants of target FQs with ozone and OH, separately. Results indicate that both NF and LOF were highly reactive toward ozone, and the reactivity was strongly impacted by the solution pH.

Impacts of water quality on the corrosion of cast iron pipes for water distribution and proposed source water switch strategy.

Switch of source water may induce "red water" episodes. This study investigated the impacts of water quality on iron release, dissolved oxygen consumption (ΔDO), corrosion scale evolution and bacterial community succession in cast iron pipes used for drinking water distribution at pilot scale, and proposed a source water switch strategy accordingly. Three sets of old cast iron pipe section (named BP, SP and GP) were excavated on site and assembled in a test base, which had historically transported blended water, surface water and groundwater, respectively.

A comparison of disinfection by-products formation during sequential or simultaneous disinfection of surface waters with chlorine dioxide and chlor(am)ine.

The effect of chlorine dioxide (ClO2) oxidation on the formation of disinfection by-products (DBPs) during sequential (ClO2 pre-oxidation for 30 min) and simultaneous disinfection processes with free chlorine (FC) or monochloramine (MCA) was investigated. The formation of DBPs from synthetic humic acid (HA) water and three natural surface waters containing low bromide levels (11-27 microg/L) was comparatively examined in the FC-based (single FC, sequential ClO2-FC, and simultaneous ClO2/FC) and MCA-based (single MCA, ClO2-MCA, and ClO2/MCA) disinfection processes. The results showed that much more DBPs were formed from the synthetic HA water than from the three natural surface waters with comparative levels of dissolved organic carbon.

Kinetics and mechanism for omethoate degradation by catalytic ozonation with Fe(III)-loaded activated carbon in water.

The kinetics and mechanism for degradation of omethoate (OMT) by catalytic ozonation with Fe(III)-loaded activated carbon (Fe@AC) were investigated in this study with focus on identification of degradation byproducts. The rate constants of OMT reacting with ozone and hydroxyl radical ((·)OH) were determined to be 0.04 and 5.

Development of systems for detection, early warning, and control of pipeline leakage in drinking water distribution: a case study.

Water leakage in drinking water distribution systems is a serious problem for many cities and a huge challenge for water utilities. An integrated system for the detection, early warning, and control of pipeline leakage has been developed and successfully used to manage the pipeline networks in selected areas of Beijing. A method based on the geographic information system has been proposed to quickly and automatically optimize the layout of the instruments which detect leaks.