Process Operation Characteristic Test Research Of Flotation- Carbon Sand Filtration

The studies made for South- to -North Water Diversion project Shandong section mixing water to provide security, the subject carry out "flotation-charcoAl sand filter" as the core purification process of research. The subject is sixth sub-topics of the country’s major science and technology "Drinking water safety technology and research Conditions pollution mechanism and switch of South-to-North Water Diversion project", "Adaptability evAluation and research of existing tapping process operation optimization".South- to -North water after mixing water in Shangdong with a blend of perenniAl water reservoir turbidity change more, there is a tendency to eutroPhication。 Because cited as the Changjiang river, Along the wide acrossing geograPhicAl, as reached Shandong section after mixing water with the water quAlity characteristics that summer high Algae High organic matter and winter low temperature and turbidity. ConventionAl processes often do not have the ability to deAl with changing water present study was to blend the South- to -North Water Diversion mixing Shandong section for the study, for the typicAl characteristics we independently developthe flotation-sand filter carbon as the core of the purification process, the treatment capacity is 0.5 m3/h.The study includes three aspects:(1) Flotation-charcoAl sand filter process performance evAluation and decontamination effectiveness research; (2) The process water conditions in different operation modes to switch; (3) A combination process’s effect and mechanism of removAl of organic matter and nitrate synergistic.Process parameter optimization experiments show that by turbidity, CODMn, UV254 and DOC as indicators of water control. Preferred process flocculant PAFC (PFAC), and preferably suitable dosage of flotation-charcoAl sand filter equipment is PFAC and the best dosage is 5mg/L (to Al3+ count); suitable level flocculation G is 63 s-1,second flocculation G is 22 s-1; soda dissolved air flotation unit suitable reflux ratio of 12%; filtration unit surface load control under 8m3/(m2 · h).Processes to flotation- sand filter carbon decontamination effect test run showed that in low temperature and turbidity during this process the finAl effluent turbidity is less than 0.1 NTU, turbidity removAl is up to 99% of the whole process,the totAl number of particle concentration is less than 500/ml, can better ensure water quAlity. In high summer Algae water during this process,in outlet the CODMn, UV254, DOC levels is 1.9 mg/L,0.023 cm-1,2.85 mg/L, water quAlity can meet drinking water heAlth standards requirements.Process running as Flotation-charcoAl sand filter way in conditions of high Algae in summer, the totAl average removAl of Algae and chloroPhyll a content were 98.99%,88.18%, stable process uptime, better flotation process can be extended high Algae during the filtration cycle. Water-induced olfactory substances are mainly resulted from the MIB, MIB removed by flotation unit is lower than before and the content is 10.80 ng/L, the removAl rate is 46.95%, the average content of water filtration unit MIB was 0.9845 ng/L, the water removAl rate was 95.14%, the finAl result has a good effect. The main components of the raw water is THFMP CHC13 and CHC12Br, accounting for about 70% THMFP totAl. Due to THMFP having low levels in the relatively raw water,so the whole process of removAl is not relatively obvious, but water quAlity in THFMP content is below the limit of "drinking water heAlth standards"(GB5749-2006). THMEP in raw water is 88.8μ.g/L, finAl effluent THMEP is67.1μg/L, totAl removAl is 24.43%.Process running as Direct filtration process way in conditions of the period of low temperature and turbidity, the entire process omitted intermediate flotation unit, sand filter effluent turbidity averages charcoAl filtration column runs directly below 0.3NTU, and the average effluent turbidity is 0.15NTU. Water outlet’s CODMn, UV254, DOC is 1.84mg/L,0.03 cm-1,4.31 mg/L, CODMn, UV254, DOC average removAl is 40%,35%,25%, confirming the direct filtration viable way resistance。The preferably suitable PAFC dosage for direct mode is lmg/L, The preferably granular activated charcoAl type is effective particle size in the range between 1.6-2.3mm.Water quAlity switching tests showed that, through water quAlity and drug、energy consumption etc.Test results suggest that the process is running with direct filtration as inflow turbidity is under 5NTU, as the turbidity is higher than 5NTU, for the protection of water quAlity, the proposed process running with Flotation-filter mode.The process running by two ways in purification of high ammonia high organic source water,results showed that as the effluent organic matter and ammonia indicators is controlled factor, flotation-filtration mode have a lot better than the direct-filtration mode, according the two Ways deAling NH3-N, CODMn, and UV254 removAl anAlysis, flotation- .filtration respectively than direct filtration improves 33.2%,43.3% and 32.9%.Dissolved air flotation unit for ammonia removAl of organic carbon sand filtration columns impact tests showed that flotation-filtration process for treatment of organic matter and ammonia nitrogen concentration is relatively high micro-polluted water, dissolved air flotation unit can promote carbon sand filter biologicAl role for the influent ammonia treatment under the conditions and the relatively high concentration of organic matter, air filtration units and water purification unit capable of full collaboration capabilities.Process water for extended range of DO, NH3-N, NO2-N, NO3-N, CODMn, UV254 and biomass index anAlysis showed that the higher flotation unit for ammonia removAl, three processes for the removAl of ammonia nitrogen flotation anAlysis, flotation remove ammonia relies mainly on micro-bubbles blown off, scum contribution for the removAl of ammonia nitrogen Secondly, the role of smAll redox indicators in for ammonia removAl filtration units, mainly that the biologicAl effect is greater than the adsorption, and the entire filter works basicAlly no denitrification. Floatation-filtration process can better handle influent ammonia content of 3mg/L of micro-polluted water, effluent NH3-N, NO2-N to meet water quAlity requirements. For organics index CODMn, UV254 removAl, filtration unit for CODMn, rely mainly on UV254 removAl is to remove the activated carbon layer. And filtration column for the entire filter layer anAlysis can be concluded that the biologicAl carbon layer is greater than the biomass of sand and charcoAl upper layer is greater than the lower organisms.Activated carbon adsorption rate test anAlysis charcoAl sand filtration column except ammonia organics study suggest that further tests anAlyzed by activated carbon adsorption rate flotation-filtration anAlysis of organic nitrate removAl process can be obtained for the removAl of ammonia nitrogen, activated carbon adsorption is greater than the biologicAl role for the CODMn of The biologicAl effect of activated carbon to remove more than adsorption.