PMC:4160552 / 10273-12437
Annnotations
{"target":"https://pubannotation.org/docs/sourcedb/PMC/sourceid/4160552","sourcedb":"PMC","sourceid":"4160552","source_url":"https://www.ncbi.nlm.nih.gov/pmc/4160552","text":"Conclusions\nIn this paper, the behavior of hybrid membrane bioreactor in various loadings of oily pollutant was studied and the results were compared with the time when the rotating biological contactor performs without using a membrane.\nThe Attached growth bioreactor creates the biofilm on the support media that provide a better treatment efficiency than suspended growth bioreactor due to accumulation of high microbial population in a large surface area. Therefore, better performance can be achieved by combining such a biofilm reactor as RBC with a membrane compared to suspended growth bioreactors as the active sludge in convectional HMBRs.\nRBC requires a secondary settling tank which is accomplished by adding a membrane to the system. However, it has a smaller volume than the settling tank and the amount of suspended solids in its effluent is less than the effluent from the settling tank. The membrane can also separate the materials that cannot be settled in the settling tank from effluent. It is cost effective as well when there is space limitation or the land is expensive.\nComparison of two hydraulic retention times of 24 and 18 hours for both reactors showed that COD and TPH removal efficiency at 24 hrs HRT is higher than 18 hours.\nResults from tests of removing COD and TPH for various ratios of oily pollutant revealed that with the ratio of 0.6 at both HRTs, the amount of COD and TPH removal obtained while with ratios of higher than 0.6, this removal was reduced.\nThe highest removal efficiency of COD and TPH was 97.3% and 98.8%, respectively. These were obtained by the hybrid membrane bioreactor, with oily pollutant concentration of 700ppm , the ratio of TPH/COD molasses 0.6, at HRT of 24 hours.\nThe fouling is the major problem with membranes in separation processes. Nevertheless, RBC was used as a pre-treatment stage and the most of the wastewater was treated before entering into the membrane which results in the reduction of the fouling. Membrane fouling in this study took place after 120 hours from the beginning and after cleaning the membrane was reutilized. This is more than the time needed in previous studies [14].","divisions":[{"label":"title","span":{"begin":0,"end":11}},{"label":"p","span":{"begin":12,"end":237}},{"label":"p","span":{"begin":238,"end":649}},{"label":"p","span":{"begin":650,"end":1093}},{"label":"p","span":{"begin":1094,"end":1256}},{"label":"p","span":{"begin":1257,"end":1493}},{"label":"p","span":{"begin":1494,"end":1730}}],"tracks":[]}