Monitoring of some disinfection by-products in drinking water treatment plants of El-Beheira Governorate, Egypt

Two water treatment plants (Edfina and Kom-Hamada) in El-Beheira Governorate were selected to monitor disinfection by-products (DBPs) concentrations. A 12-month monitoring program from October 2011 to September 2012 was established for measuring some DBPs and some water quality parameters such as temperature, pH, turbidity, total organic carbon (TOC), ammonia and bromide. The concentrations of DBPs were determined by gas chromatography with ECD (GC-ECD). Trihalomethanes (THMs) and chloral hydrate (CH) were commonly seen in all samples collected from Plant 1 (Edfina) and Plant 2 (Kom-Hamada). THMs mean concentrations ranged from 34.5 to 64.6 μg/L and from 28.2 to 52.8 μg/L for Plant 1 and Plant 2. CH mean concentrations ranged from 3.3 to 6.76 μg/L and from 2.8 to 3.9 μg/L for Plant 1 and Plant 2, respectively. Dichloroacetonitrile (DCAN) mean concentrations ranged from 1.1 to 2.0 μg/L and from 1.2 to 2.1 μg/L for Plant 1 and Plant 2, respectively. Chloropicrin (CP) was detected in Plant 1 only with mean concentration ranging from 0.91 to 1.1 μg/L. Trichloroacetonitrile (TCAN) and dibromoacetonitrile (DBAN) were below the limit of quantification (LOQ) in all samples. Higher concentrations of THMs were measured in summer and spring as compared to winter. DBPs concentrations were higher in Plant 1 than in Plant 2. The DBPs levels in all samples collected from Edfina and Kom-Hamada were generally below the guideline values set by the Egyptian Health Minister in 2007.