ABSTRACT
<p><b>OBJECTIVE</b>Since haloacetic acids (HAAs), which are nonvolatile and of high carcinogenic risk, are common species of chlorinated disinfection by-products(DBPs) in drinking water, and little has been known in China, it is necessary to make a survey about the kinds and levels of HAAs in drinking water of the nation.</p><p><b>METHOD</b>HAAs were analyzed using gas chromatography with electron capture detector(GC/ECD) and relatively complex pretreatment process of sample was applied. Five main cities in different areas of China were chosen in the survey.</p><p><b>RESULTS</b>Studies showed that the main species of HAAs in drinking water in China were DCAA and TCAA, ranging from 0.4 microg/L to 12.85 microg/L and from 0.56 microg/L to 10.98 microg/L, respectively. MBAA and DBAA were also detected in one city, ranging from 2.20 microg/L to 4.95 microg/L and 1.10 microg/L to 2.81 microg/L, respectively. Therefore, the contents of HAAs varied, usually no more than 25 microg/L. Based on the acquired data to date, it is known that the concentrations of HAAs in drinking water in China were surely under the limits of Sanitary Standard for Drinking Water Quality (China, 2001).</p><p><b>CONCLUSION</b>A wider survey of HAAs in drinking water should be conducted throughout the nation to get adequate data and information, the ultimate aim of which is to control HAAs pollution and keep the balance between microbiological safety insurance and chemical risk control, minimize the formation of DBPs and ensure the safety of water supply at the same time.</p>
Subject(s)
Humans , Acetates , China , Chlorine , Chemistry , Cities , Environmental Monitoring , Halogens , Chemistry , Seasons , Water Purification , Water SupplyABSTRACT
<p><b>OBJECTIVE</b>To investigate phosphorus limitation and its effect on the removal efficiency of organic matters in drinking water biological treatment.</p><p><b>METHODS</b>Bacterial growth potential (BGP) method and a pair of parallel pilot-scale biofilters were used for the two objectives, respectively.</p><p><b>RESULTS</b>The addition of phosphorus could substantially increase the BGPs of the water samples and the effect was stronger than that of the addition of carbon. When nothing was added into the influents, both CODMn removals of the parallel biofilters (BF1 and BF2) were about 15%. When phosphate was added into its influent, BF1 performed a CODMn removal, 6.02 percentage points higher than the control filter (BF2) and its effluent had a higher biological stability. When the addition dose was < 20 micrograms.L-1, no phosphorus pollution would occur and there was a good linear relationship between the microbial utilization of phosphorus and the removal efficiency of organic matters.</p><p><b>CONCLUSIONS</b>Phosphorus was a limiting nutrient and its limitation was stronger than that of carbon. The addition of phosphate was a practical way to improve the removal efficiency of organic matters in drinking water biological treatment.</p>
Subject(s)
Bacteria , Bioreactors , Filtration , Kinetics , Organic Chemicals , Chemistry , Phosphorus , Water Pollutants, Chemical , Water Purification , Methods , Reference StandardsABSTRACT
More and more importance has been attached to the problem of endocrine disrupting chemicals (EDCs) since 1960s. This article elaborates the recent research progress of EDCs in water and the trends in the near future in China.