Tesis doctoral de Gemma Ribera Simon
The present thesis is about membrane technology implementation for two cases of water processes: nanofiltration (nf) to produce drinking water and membrane bioreactor (mbr) to treat wastewater effluent. the first part has evaluated nf capacity to reduce contents of disinfection by-products precursors, especially for trihalomethanes (thm). On the other hand, the second part is focused to evaluate mbr capacity to treat winery industry effluents giving the required quality for wastewater reclamation and reuse. nf membranes have been studied in laboratory set-up (flat-sheet module) and in pilot plant (18 spiral-wound elements). Initially, laboratory results allowed to select two of the ten membranes tested at this scale, in function of the permeability and the reduction of trihalomethane formation potential (thmfp). Most of the membranes rejected thmfp at levels of 95%, however the separation capacities in front of inorganic salts were highly variable, which may have important consequences in permeability and energy demands for a full-scale system. This study also considered factors influencing feed water quality for the nf membranes, such as seasonal variations and different catchments of raw water. two nf membranes were selected in order to be compared simultaneously in a pilot plant. Under optimum conditions, good performances were obtained for both membranes. With the final aim to optimize treatment process, several aspects were evaluated simultaneously for each membrane: separation capacities for different inorganic and organic components, feed pressure requirements to operate with the same recovery for the same feed flow, pretreatment, initial flux decline and chemical cleaning efficiencies. Results obtained from both scales were compared to validate prediction for solutes rejection in a real plant from laboratory experiments, together with the calculations using suppliers¿ design software. finally, in this work environmental impact for this technology was also evaluated by means of life cycle assessment (lca), using pilot plant data and approximations for the nf implementation in a full-scale drinking water treatment plant (dwtp). Results indicated how increase the environmental impacts using nf in front of the current treatment, mainly as a result of higher energy demands during membrane process. These results have been correlated with results calculated by means of human health risk (hhr) assessment, developing a multicriteria tool in order to design a full-scale dwtp. Is important to note that carcinogenic risk index can be lowered near to 75%, associated to the reduction of thm precursor material (thmfp), if nf plant produces 100% of the final drinking water. on the other side, a mbr pilot plant was installed in the wastewater treatment plant (wwtp) to treat effluents of winery industry. Quality of effluents from the current conventional activated sludge (cas) plant and from the mbr pilot plant was compared during the experimental campaign, demonstrating that mbr effluent presented a higher quality that accomplished with legislated requirements for some reuse applications. In addition, mbr technology was able to maintain permeability although organic loads fluctuations in winery industry take place, what demonstrated its applicability in this sector. data obtained from mbr pilot plant were also employed to evaluate environmental impact associated to full-scale implementation of mbr technology, together with those obtained for the actual cas system. Among other environmental impact categories, observed impacts related to wastewater emissions into water bodies (freshwater eutrophication) were diminished while impacts on climate change and particulate material (or photochemical compounds) formation were increased as a result of energy consumption.
Datos académicos de la tesis doctoral «Technical and environmental viability of membrane technologies in water treatment: nf in drinking water process and mbr for watewater reuse.«
- Título de la tesis: Technical and environmental viability of membrane technologies in water treatment: nf in drinking water process and mbr for watewater reuse.
- Autor: Gemma Ribera Simon
- Universidad: Politécnica de catalunya
- Fecha de lectura de la tesis: 22/03/2013
Dirección y tribunal
- Director de la tesis
- Xavier Martínez Lladó
- Tribunal
- Presidente del tribunal: josep Caixach gamisans
- emile robin Cornelissen (vocal)
- (vocal)
- (vocal)