Effluent organic nitrogen removal by magnetic ion exchange resin
Tutor / director / evaluatorPagilla, K
Document typeMaster thesis (pre-Bologna period)
Rights accessRestricted access - confidentiality agreement
An increase of the effluent quality from wastewater treatment plants (WWTP) is becoming of crucial importance to both reduce the environmental impact in the receiving waters and make possible the treated sewage reuse. In this eld, the effluent dissolved organic nitrogen (DON) is increasingly of concern, as it has an important environmental impact, and it has been proven to produce disinfection by-products (DPBs). The reduction of the effluent DON from WWTP is a great challenge, as not many technologies have been studied to this speci c purpose. In this research, ion exchange was shown to be an e ective method for the removal of the effluent DON. Two strong basic ion exchange resins were studied. First, Dowex 1-X8, a gel-type resin, was studied in a packed bed reactor. It was able to remove as much as 55% of the initial DON, and an average of 37%. Secondly, a magnetic ion exchange resin, MIEX R , a macroporous resin, was studied in a stirred tank reactor. This resin was speci cally designed to remove DOC from drinking water supplies. In this thesis, it has been shown its efficiency to remove as much as 58% of the effluent DON, and an average of 36%. Both regular ion exchange and MIEX R were shown to remove effluent dissolved organic phosphorus (DOP) to an average extent of 85%. These techniques are therefore able to target the removal of several effluent organic nutrients. The efficiency of ion exchange as a method to remove effluent DON indicates the anionic character of a fraction of the DON pool. The extent of removal achieved corresponds to the negatively charged DON species. However, an important variabil- ity was found in the extent of removal, which would imply an important variation of the DON pool speciation exiting the WWTP.