[Study on the optimization of monitoring indicators of drinking water quality during health supervision].

Objective: To optimize non-regular drinking water quality indices (except Giardia and Cryptosporidium) of urban drinking water.

Methods: Several methods including drinking water quality exceed the standard, the risk of exceeding standard, the frequency of detecting concentrations below the detection limit, water quality comprehensive index evaluation method, and attribute reduction algorithm of rough set theory were applied, redundancy factor of water quality indicators were eliminated, control factors that play a leading role in drinking water safety were found.

Results: Optimization results showed in 62 unconventional water quality monitoring indicators of urban drinking water, 42 water quality indicators could be optimized reduction by comprehensively evaluation combined with attribute reduction of rough set.

Formation and modeling of disinfection by-products in drinking water of six cities in China.

Water quality parameters including TOC, UV(254), pH, chlorine dosage, bromide concentration and disinfection by-products were measured in water samples from 41 water treatment plants of six selected cities in China. Chloroform, bromodichloromethane, dibromochloromethane, dichloroacetic acid and trichloroacetic acid were the major disinfection by-products in the drinking water of China. Bromoform and dibromoacetic acid were also detected in many water samples.

Factors influencing disinfection by-products formation in drinking water of six cities in China.

Based on the measured chemical and physical data in drinking water from six cities in China, the factors including total organic carbon (TOC), ultraviolet absorbance at 254 nm (UV(254)), pH, applied chlorine dosage, temperature, concentrations of bromide ion and several chemical elements which possibly affect the formation of trihalomethane (THM) and haloacetic acid (HAA) have been studied. The results showed that: in all factors, TOC and UV(254) have definite correlations with total THM, but have nonsignificant relationships with total HAA. In the studied pH range of 6.

[Study for distribution level of disinfection byproducts in drinking water from six cities in China].

Objective: To find the distribution level and geographical variations of disinfection by-products (DBPs) in drinking water.

Methods: The samples were selected from water utilities in six cities (Daqing, Beijing, Tianjin, Zhengzhou, Changsha and Shenzhen) of China. The water source and technology of water treatment were investigated and the indices including trihalomethanes (THMs) and haloacetic acids (HAAs) in main DBPs and natural organic materials (NOM), pH, chlorine dosage and temperature were determined.

[Determination of trace bromate in drinking water by ion chromatography with suppressed conductivity detection].

Bromate is a common disinfection by-product produced from the ozonation of source water containing bromide. An ion exchange chromatographic method with suppressed conductivity detection for the determination of trace bromate in drinking water was developed. The separation of the bromate in drinking water was achieved on a Metrosep A Supp 5 anion exchange column and a Metrosep A Supp 4/5 Guard column with a carbonate eluent.

[Rapid detection of toxic substances in water with ToxY-PAM].

A new type of dual-channel PAM fluorometer (ToxY-PAM) was developed for highly sensitive detection of toxic substances in water samples. In conjunction with suspension of unicellular algae as the biotest material, the ToxY-PAM provided a highly rapid and sensitive bioassay test system for the detection of toxic substances in water samples, which could directly or indirectly produce the inhibition of photosynthetic activity in algae. The development process of the detection of toxic substances in water with fluorescence technique, the basic principle and operation of the ToxY-PAM were reviewed in this paper.

[Determination of chlorophenols in drinking water by headspace solid phase microextraction and gas chromatography].

Objective: To study the method for determination of chlorophenols in drinking water by headspace solid phase microextraction and gas chromatography.

Methods: Chlorophenols in water samples was extracted using optimized SPME technology, separated by HP-5 chromatigraphic column and the concentration of chlorophenols was determined by electron capture detector (ECD).

Results: The detection limit of MCP, DCP, TCP, PCP were 60.