| Pharmaceuticals and personal care products (PPCPs), as a massly-used and potentially physiological effective, new chemicals, has received a common attention by scientific field as well as society. Major sources of PPCPs in the environment are release from incomplete treatment of the wastewater in Sewage Treatment Plants caused by human or animal medication.In recent years, the application of Membrane Bioreactor (MBR) combining process in wastewater recycling and refractory organic wastewater treatment has generally got constant attention from researchers and businessmen. However, it's seldom to find researches focusing on MBR's removal effects on PPCPs and PPCPs'influence on MBR's running condition.In view of this situation, this thesis puts forward the application of integrated MBR combining process in overall research of the removal efficiency on domestic sewage containing typical PPCPs (Norfloxacin and Naproxen) as well as researching on influencing factors on MBR, which provides the theoretical foundation of domestic sewage's removal property in MBR process and MBR's performance changing trend, thus fills the vacant area of this kind of research.It was found that, although in the high organic load (COD = 600 mg/L), MBRs carrying two commonly used flat membrane materials called Polyvinylidene fluoride(PVDF) and Poly tetra fluoro ethylene (PTFE) behaved not so bad on treating domestic sewage containing typical PPCPs (Norfloxacin and Naproxen)when compared with whose behavior in low organic load, not only did membranes pollution become more serious but also the treatment duration decreased. Therefore, considering the high price of the high polymer membranes, people shall control the organic load of the practical inlet water around COD=300mg/L.Through the comparison of PTFE membrane bioreactor's and PVDF membrane bioreactor's treatment capabilities on the domestic sewage containing typical PPCPs (Norfloxacin and Naproxen) under the same inlet water condition, it was found that PTFE membrane bioreactors performed better than the PVDF membrane bioreactor in removing COD and typical PPCPs (Norfloxacin and Naproxen). However, when there existed Naproxen, PTFE membrane bioreactor's ammonia nitrogen concentration in drainage only could reach national urban wastewater discharge secondary standard and the cleaning of PTFE membrane was more difficult. According to different demands on ammonia nitrogen discharge index of relevant departments and economical consideration, people can choose the domestic PTFE membrane, whose comprehensive capability proves slightly lower than imported PVDF membrane, in future practical use. Using control Varian method, the thesis analyzed different PPCPs'influences of membrane bioreactor's removal trend and mechanism. Results indicated that the existence of Norfloxacin brought out negative effect on the removal of COD while Naproxen poisoned more heavily on nitrification/denitrifying bacteria. However, generally speaking, the existence of the two PPCPs has less influence on the removal effect of membrane bioreactor on COD than on ammonia. In addition, study also found that as time passing, the membrane bioreactor's removal capability of each index of domestic sewage containing typical PPCPs increased. While in contrast, the existence of PPCPs shorten the treatment duration of membrane bioreactor, increased the generation of partial overcritical on membrane surface, and reduced the sludge activity; Particularly speaking,the existence of Norfloxacin caused greater negative effect on the running of PTFE membrane, however PVDF membrane's condition proved the opposite. Naproxen harmed more heavily on the health of sludge system.According to the exploration of membrane bioreactor's removal effect on domestic sewage containing typical PPCPs with the absence of sludge, it was found that when PPCPs existed, membrane bioreactor's removal of organic matters was mainly realized through the biodegradation way of activated sludge; While in the membrane bioreactor removal process of PPCPs, the average contribution rate of the membrane was> 50%; This result indicated activated sludge had limited adsorptable and biodegradable role in removing PPCPs.After exploring the treatment performance of New type of stainless steel membrane bioreactor, it was found that although its treating capability of domestic sewage containing typical PPCPs was slightly lower than traditional flat membrane bioreactor, it dominated advantages over more quantities of water management, convenient cleaning ,lower frequency of changing membranes and moderate price., thus makes it a wide foreground in practical use and valuable to further studied in the future. |
PDF Full Text Request