Study On Slightly Polluted Cellar Rainwater Treated By O₃-BAC Combined With Ultrafiltration

Rainwater is the only potential water resource in the rural area of the arid and semi-arid area, even the only source of drinking water in some northwest rural area.In order to solve the existing problems of drinking-water, some projects aiming at solving“the difficulty of drinking water for people ” are conducted. They have effectively solved the water shortage problem of this area, but there are serious risks of drinking water safety.Due to the different environment and the diversity of the rain collecting surface, increase the cellar water quality change of uncertainty and complexity, improve the purification difficult of cellar water. Some small towns in the area, water treatment technology and management level is relatively backward.The micro pollution water cellar as the research objectin this paper,research and developmentintegrated small water purification equipment combined with the ozone biological activated carbon and ultrafiltration, to purify water quality of cellar, solve the problem of "drinking water safety". Firstly, explore the filtering effect of the filter, through experiments to determine thefilter whether satisfy the requirements of pretreatment unit inthe integrated device. Secondly, three different activated carbon biofilm was observed during the experiment, the capacity of removal pollutantsmembrane hanging of three kinds of activated carbon, the removal efficiency of pollutants after the completion of the biofilm, choose the most suitable activated carbon for integrated device. In addition through experiments to verify the ozone treatment of cellar water in integrated water purifying device, if can delay the ultrafiltration membrane fouling. Finally, three different kinds of water cellar water sampling for integrated water purifying device, Testingthe removal effect of each unit and the final effluent quality detection.In the experiment of the filter turbidity removal, respectively 5μm and 1μm aperture filter cartridge filter at different speeds cellar water and change the water turbidity,testing water turbidity. The experimental results show that the filter surface: two aperture has a good removal effect on turbidity, so the device with pore size of 5μm filter. When the filter speed is 2.3m/h, the filter effluent turbidity is 0.65 NTU, the removal rate is 93.5%; when the filter speed is gradually increased to 20.22m/h, the removal rate decreased to 89.2%, the turbidity of effluent was 1.08NTU; the filtering effect of the filter decreased with increased turbidity water cellar, cellar water turbidity is high, large Particle Pollutant the higher the proportion of small particle size, the ratio after filter will increase of pollutants.Activated carbon biofilm experiments, coal quality, shell, coconut shell activated carbon material natural biofilm.The experimental results show that: the process of biofilm formation was about 35 days, coal activated carbon removal performance is better, the biofilm maturation of activated carbon on the cellar water average removal rates of CODMn, ammonia nitrogen, UV254 and turbidity were 81.02%, 77.21%, 65.18%, 78.02%; comparison of activated carbon on scanning electron microscope(SEM) membrane before and after photos to see, mature biofilm activated carbon surface is a layer of membrane covered with biofilm mass, flocculent and contour more smooth, transparency is not consistent. These oligotrophic microorganism membrane, has a large specific surface area, thickness is thin and has a high biological activity.In the ozonation of ultrafiltration membrane fouling control in the experiment, the change of ozone dosage, water changes of the activated carbon unit and its effect on membrane flux. The experimental results show that: the pre ozonation have a protective effect on membrane fouling, dosage the more effect is better, when the ozone dosage is more than 3mg/L, the flux of membrane effect is not obvious, the ozone device adopts the dosage was 3mg/L.In the experiment ofIntegrated device with practical operation of cellar water, with the water storage of three kinds of typical cell as raw water, treated by integrated device. The experimental results show that: the bacteria ofthree kinds cellars were exceed the standard, The water quality of rain collecting surface soil ground than the water of othertwo kinds was poor, ammonia nitrogen content of 0.24mg/L, CODMn content is 1mg/L, UV254 is 0.091cm-1, the turbidity of 6.12 NTU. Integrated device has a good removal effect on micro polluted water cellar for conventional pollutants, water treatment quality standards.Device required materials costs a one-time investment 630 yuan. Daily water production device for 70 L, the biological activity of carbon water purification unit operation cost is 0.146 yuan /m3; ozone generator operating cost is 0.3 yuan /m3; ultrafiltration integrated device operating costs 0.81 yuan /m3; Ozone biological activated carbon combined with total running ultrafiltration integrated device cost is above three and, therefore the total cost of operation of the device is 1.256 yuan /m3.