Tham khảo tài liệu 'wiley wastewater quality monitoring and treatment_19', khoa học tự nhiên, công nghệ môi trường phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | The Water Reclamation Technology Involved 337 or without nutrient removal tertiary with attached bar for main tertiary treatment processes or quaternary multi-barrier systems including a double membrane unit -attached to them in different regions of the world Bixio et al. 2005 . For each treatment process there are typically well-defined standard Quality As-surance Quality Control QA QC practices to assure that the system is functioning as designed Bixio and Wintgens 2006 . While their description goes beyond the scope of this document it is worth mentioning that on-line real-time water quality monitoring is extensively used for this purpose and that the degree of satisfaction of the respondents of the Aquarec questionnaire with on-line sensors is very high. Such indirect indicators that detect on-line possible integrity defects are particularly desired for those parameters that cannot be monitored directly on-line or in rapid repetition . hygienic parameters. Moreover some technologies can introduce additional water quality concerns. For instance by-products of disinfection processes DBP may yet prove to be among the greatest chemical concerns in reclaimed water. In recent years attention has been given to the detection of the potent carcinogen nitrosodimethylamine NDMA in chlorinated sewages intended for reuse. Besides we have seen that chloride levels can be of concern also for certain reuse application for instance in irrigation because high levels are toxic to many plants. Dechlorination is sometimes required. The type of distribution system also contributes to the setting of the appropriate monitoring strategy. For instance long distribution systems may need a disinfection residual or contamination in the distribution system or cross-connections may negate any of the benefits of the water reclamation step. Many respondents of the Aquarec questionnaire gave particular importance to the control of reticulation systems especially where reclaimed water is .
