Font Size: a A A

The Study On Optimum Combination Of Ozone/Biological Activated Carbon Further Treatment Process And Water Quality In Qiantang River Water Source Water Treatment Plants

Posted on:2006-09-10Degree:DoctorType:Dissertation
Country:ChinaCandidate:S C ChenFull Text:PDF
GTID:1102360182978572Subject:Municipal engineering
Abstract/Summary:PDF Full Text Request
Based on ozonation, traditional treatment, Biological activated Carbon filter, this article mainly studied different optimum combinations of these units treating micro-polluted raw water, including optimum operational factors, pollutant-removal effect and duration variation curve of columnar carbon and crushing carbon, biological stability, removal effect of endocrine interfering matter, etc. through pilot scale experiment and full-scale experiment in Hangzhou Qiantang River water treatment plant, the following conclusions are drawn:1. The pilot scale experiment indicated: O3—BAC process and single BAC process have closer removal effects of Turbidity, CODMn , TOC, UV254, NH4+—N and NO2-—N;Crushing carbon's pollutant removal effect was apparently higher than columnar carbon's;water temperature, hydraulic load, turbidity affected dramatically BAC filter's pollutant-removal effect.2. Study on carbon's regenerate cycle indicated: Adding O3 and biological reclaiming action can all relay carbon's operational life span;columnar carbon's life is longer than crushing carbon;In actual production process, crushing carbon's operational life span is about 6.19 year, 2 month shorter than carbon's life in pilot scale test.3. Process operation parameters Optimizing indicated: pre-03, post-O3's optimum dosage was 0.55mg/l and 1.60mg/l respectively, Pre-03 can also save 20 percent alum consumption, 1.5m carbon thickness is enough to meet effluent water quality, BAC filter's optimum hydraulic load was 10 m3/m2.h.4. Optimum study on different process combination shows: when raw water's CODMn ≤4.5 mg/L, combination of traditional process and O3—BAC (flow 1), combination of pre-O3, traditional process, and O3—BAC (flow 2), combination of pre-O3, traditional process and BAC (flow 3), all can meet effluent water quality, but the flow 3 is the most economic process. The manufacturing cost is 643.6yuan/m3, 650.8yuan/m3 and 638.6yuan/m3 respectively, unit water treatment cost is0.555yuan/ m3,0.563yuan/ m3,0.535yuan/ m3.5. Raw water from Qiantang river is worse biologically stable. Using traditional water treatment process, effluent water's AOC concentration increased by 26 percent, its biological stability became worse. Using further treatment process (pre-03 + traditional process + O3-BAC + chloramine disinfection), effluent water's AOC concentration increased by 70 percent, biological stability also became worse. Although sand filter and BAC filter can remove AOC effectively, however, post- O3 and chloramines disinfection will enhance AOC concentration (enhance 2.99 fold and 1.57 fold). So it is essential to reduce post-O3 dosage or using single BAC process and decrease disinfectant's dosage, so that AOC concentration is controlled, and better effluent water biological stability is gotten.6. In water supply pipe network, AOC concentration declined in turn from water treatment plant effluent to pipe network to user, average rate of decline is 27 percent and 67 percent.7. Water from Qiantang River has strong Ames mutagenicity. Mutagen is mainly TA98 indirect phase shift mutant. Traditional treatment process can't remove mutagen, and effluent water appears positive. O3—BAC process and single BAC process all can remove mutagen, under maximum dosage(7L/mi> 5L/HIL), effluent water appears negative.8. Traditional treatment process has limited removal effect of Endocrine interfering matter. But O3—BAC further treatment process has a significant removal effect, can reduce endocrine interfering matter to prescribed limit.9. Combination process of activated carbon and diatomite has a obvious removal effect of Turbidity, CODMn , TOC, UV254 and Mutagen , can meet water quality's need. Contrast to using activated carbon as filter media, cost of filter media can save 25.9 percent.
Keywords/Search Tags:Qiantang River water source, O3—BAC, BAC, further treatment, process combination, optimum, water quality
PDF Full Text Request
Related items