Applied Mechanics and Materials Vols. 361-363

Abstract: Test using CS-type UV sterilizer to do experimental study on the urban sewage , mainly research the influence of the placement time under natural light and the UV dose on photoreactivation. The results show that when disinfection ultraviolet dose is equal, bacteria photoreactivation phenomenon is more obvious with the increase of the placement time of water samples under natural light . When the placement time reaches at 3h, bacteria photoreactivation phenomenon is the most obvious. Under the same placement time, the ratio of bacteria photoreactivation decreases gradually with the increase of UV dose. When UV dose reaches at 80mJ /cm2 or the higher doses, the bacteria does not basically happen photoreactivation phenomenon. Photoreactivation phenomenon in E. coli is more obvious than that in bacteria under the same conditions.

Abstract: By treating the secondary effluent of Sanbaotun sewage treatment plant in Fushun with the CS type UV Sterilizer, the experiment researches the influence on the removal rate which includes the factors of turbidity, chromaticity, initial E.coli concentration of raw water, UV dose. The results show that the turbidity does not influence on UV disinfection efficiency with the turbidity from 1.5NTU to 3.8NTU. In the low-dose UV disinfection process, the influent sewage turbidity should under 4NTU to ensure the disinfection efficiency. Low chromaticity does not affect the UV disinfection efficiency, with the influent sewage chromaticity is under 15 degrees.The initial E. coli has a certain impact on little doses of UV disinfection with the concentration from 175 × 10⁴ A/ L to 230 × 10⁴ A/ L, no impact on high doses of UV disinfection。

Abstract: Groundwater is always one of the main source of drinking water. But due to the vast use of nitrogenous fertilizer and irrationally discharge or utilization of animal wastes, domestic sewage and nitrogen-contained industrial waste drainage, the groundwater in the rural area is seriously polluted by Nitrate to varied degree.

Abstract: Development of a MBBR-MBR has been investigated combining a moving bed biofilm reactor with a submerged membrane biomass separation reactor. Treatment efficiencies were found to be high with the production of a consistent high-quality effluent, irrespective of media fill ratio of MBBR or membrane reactor operating modes. There had some obvious fouling in MBR, MBBR and IFAS 3000, while no fouling were detected in IFAS 1500. The great difference indicated the media filling fraction have an important role and effect on membrane fouling. Traditional MBR and IFAS 3000 have more non-flocculating microorganisms in most time due to the mixed liquor suspended solids (MLSS) concentration. There had almost the same MLSS on media surface, independent of the volume of media and the MLSS concentration in each tank. The MBBR had more biomass enriched on membrane surface due to the dead end system.

Abstract: Heavy oil wastewater must be pretreated if membrane technology was used to treat it. According to the quality analysis of heavy oil wastewater, the processes of silica removal by magnesia agent, filtration by fiber ball and adsorption by activated carbon were employed to treat heavy oil wastewater so that treated water could meet the demand of feed for membrane.

Abstract: To satisfy the requirements of high speed, large volume and high water quality for fracture-karst aquifer recharge by roofwater, sand filtration column was designed. Lab experiment of roof rainwater treatment by sand column was conducted to study the effect of roof rainwater purification in Jinan as pretreatment for fracture-karst aquifer recharge. The results show that the sand filtration column is effective in removing pollutants in roof rainwater. The average removal rate of turbidity reaches 87%, and the average removal rate of suspended solids is above 70%; the sand column is also effective in removing chroma, volatile phenol, Pb and Zn to a certain degree. However, it has a poor effect in removing ammonia nitrogen and nitrite nitrogen. In addition, the removal of most pollutants such as turbidity, chroma and suspended solids mainly take palce in the upper layer, which needs to be replaced regularly.

Abstract: The paper used the fluorescence staining method to study the effect of O₃ inactivating Cryptosporidium and Giardia in water. The results indicated that O₃ had the stronger inactivating ability. When the dosages of O₃ were above 3.0 mg /L and exposure time was 7 min, the extinct rate can be achieved 99.9%. The turbidity and concentration of organics were found to be statistically significant in artificial water. With the increasing of turbidity and temperature, the inactivating effect decreased. The inactivating ability of O₃ was stronger under acidic conditions than in alkalic circumstance. When the concentration of the organic in the reaction system is high, competition between Cryptosporidium, Giardia and organics with O₃ which reduced inactivation ratio might take place.

Abstract: Absract: the article touches upon the main discovers some issues on construction and reconstruction of waste water treatment plants in Russia. It also shows some typical problems which specialists faced with and the ways to solve it.

Abstract: the article touches the advantages of the use of immobilized sludge and describes various types of technological application.

Abstract: In order to develop realistic water resources strategy, we initially analyze the situation of water resources in the United States which present a significant regional difference. Then on the basis of previous studies, we propose the cost formulas of water storage, movement and desalinization. By analyzing the practical application, along with pros and cons of the above three solutions accordingly, we consider that a comprehensive utilization of these measures will be the best water strategy for America to solve the water shortage problem. Later we apply the conclusion to a case study of Southern California, we propose an optimization model which aims to minimize the total cost of the water strategy, and then use Lingo to solve the problem. Results show that 5.946 billion cubic meters of water by transferring is the best way to make up for the water use gap in 2025 and the total cost is 2.94 billion dollars. Finally, we summarize the strengths and weaknesses of our paper. What needs to be emphasized is that our model can also be adapted into the analysis of other states, which shows great flexibility.