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排序方式: 共有423条查询结果,搜索用时 15 毫秒
31.
针对进出水水质特点,经过技术经济分析,确定临汾市再生水厂采用曝气生物滤池、普通快滤池、连续微滤膜(CMF)和反渗透(RO)等工艺。经曝气生物滤池处理后,氨氮和总氮基本达到循环冷却水水质要求;CMF-RO工艺的应用则有效解决了总溶解性固体和总硬度问题。多种处理工艺的结合,既节约了工程投资,保证了出水水质稳定、可靠,又能够根据实际情况灵活调整,降低了运行、维护费用。 相似文献
32.
介绍了全膜水处理系统中超滤设备、反渗透设备、电去离子设备的工作原理,以及这些设备运行时主要参数的控制。阐述了进口全膜水处理系统在深南电有限公司除盐水处理中的运行情况,指出了设备运行过程中应注意的事项,提出了全膜水处理设备的保养、清洗和消毒的要求。 相似文献
33.
Seasonal fouling on seawater desalination RO membrane 总被引:1,自引:0,他引:1
A pilot study has been performed to investigate the seasonal characteristic of seawater reverse osmosis (RO) membrane fouling. Two batches of experiment during summer and winter were both performed 18 days to provide a clear picture on microbial population variability. The feed water of the pilot from seawater desalination plant has significant difference in temperature and silica content between the two seasons.In our experiments, scaling and biofouling are more serious in summer. And the permeate flux decline is closely related to the rise in microbial population, and it was dominated by cell multiplication rather than adhesion. In addition, the summer cell multiplication is much more abundant. Moreover, the extracellular polymeric substance (EPS) feature intensity detected by Fourier-transform infrared spectroscopy was also stronger in summer. The abundant EPS was one of the major reasons to cause the inorganic matter adsorption. Si, Al, Fe, Ca and Mg were found as the major inorganic foulants deposited on the Ro membranes. Silica and calcium in summer appeared obvious higher amounts than that in winter, which indicated that they should be affected by microbial action directly or indirectly more than other elements.In summary, there exists a seasonal effect on membrane scaling and fouling, and scaling is associated with biofouling in some degree. Further researches could be focus on actual association between microbial action and inorganic fouling. 相似文献
34.
The present study encompasses the application of electrolysis as novel treatment technique for the abatement of low-salinity concentrates generated from the filtrative treatment of water and wastewater. Four different materials have been tested as anode for a number of brine samples in a one-compartment electrolytic cell in galvanostatic mode. It was found that PbO(2) and SnO(2) anodes initiated electrochemical precipitation through an increase of the pH. Boron-doped diamond (BDD) and RuO(2) anodes successfully oxidised the pollutants in the brine and a linear removal of total ammonia nitrogen (TAN) and chemical oxygen demand (COD) was observed during the first phase of oxidation. Oxidation was predominantly achieved through indirect hypochlorite bulk oxidation; the higher oxidation rate and extent for the BDD anode was attributed to the higher selectivity and activity of the latter. Overall performance of the BDD electrode was higher than for RuO(2): higher rates for TAN (17.9 vs. 13.5mg/Ah) and COD (74.5 vs. 20.0mg/Ah) removal as well as higher overall current efficiencies (35.2% vs. 14.5%). Extensive colour removal was observed for both anodes (>90% decrease in absorbency at 455 nm). 相似文献
35.
Taiki Shimbo 《Soils and Foundations》2018,58(2):481-490
In this paper, we present an implicit stress-calculation algorithm for a multidimensional constitutive law using a one-dimensional skeleton curve and a hysteresis curve. To consider the hysteretic behavior of soils, one-dimension skeleton curves (e.g., the Hardin–Drnevich model, Ramberg–Osgood (RO) model, and general hyperbolic equation (GHE) model) are widely used. In a multidimensional analysis, there are several methods for extending a constitutive law using a skeleton curve into multiple dimensions. However, because these methods are suitable for an explicit integration stress-calculation scheme, a calculated stress does not satisfy the function of skeleton curve when a large incremental strain is imposed in one step. In this paper, to resolve this problem, a nonlinear stress–strain relation using a skeleton curve and an implicit stress-calculation algorithm is presented. In addition, we show an example of an application of the GHE/RO model to the proposed algorithm. 相似文献
36.
37.
Flux enhancement of thin film composite RO membrane by controlled chlorine treatment 总被引:2,自引:0,他引:2
A major stumbling block in polyamide thin film composite RO membrane performance is its incompatibility with chlorine and oxidizing agents. The amide bond of the membrane is highly vulnerable to chlorine attack. Two reactions are possible with chlorine exposure i.e. N-H bond chlorination and/or aromatic ring chlorination. In this way, chlorine may cause degradation/modification in the membrane leading to deterioration in performance.However, low concentration of chlorine up to a certain time may give synergistic effect on membrane and improve its performance. Chlorine solution, if exposed to membrane for certain time gives enhancement in trans-membrane flux of the membrane.The same solution if exposed for more time deteriorates ultra-thin polyamide layer of TFC membrane. Conspicuously, the membrane with poor salt rejection and flux benefited more as compared to the membrane with better performance. In the present study, membranes with different salt rejection and flux were taken and exposed to the inorganic chlorine solution. The inorganic chlorine solutions were made by dissolving sodium hypochlorite in pH buffer. The different solutions were made by varying pH to investigate the pH dependence. The membrane samples were kept in solution for different time durations. The exposure time was monitored and the exposure level was taken in terms of ppm h (ppm chlorine solution exposed to membrane for a fixed time in h). With the same chlorine concentration, effect of varying pH was studied. Spiral wound TFC membrane modules were also subjected to chlorine solution to study its effect. 相似文献
38.
根据现有反渗透(RO)工艺的运行管理经验,确定一级RO浓水的回收工艺仍为RO工艺,即二级RO工艺再处理一级RO浓水。通过对一级RO浓水水质的分析,提出了O3/BAC和粉末活性炭/GAC两种预处理工艺去除浓水中的有机物,两种工艺均可保证系统的出水COD30mg/L,满足RO膜对进水COD的要求。以NaOH为软化剂进行RO浓水的软化中试,在NaOH的投加量为400~440 mg/L、聚合氯化铝(PAC)的投加量为5 mg/L(在软化反应后期投加)、曝气量为0.1 m3/(h.m2)的条件下,软化装置对总硬度、COD、NH3-N的去除率分别约为80%、(7%~12%)、30%。 相似文献
39.
40.
《分离科学与技术》2012,47(8):1135-1145
Fluoride forms a common aqueous effluent in many chemical industries. Excess of fluoride in the effluent can cause a health hazard. So, effluent containing fluoride needs treatment to reduce its concentration to a disposable value before discharging into public sewage. Removal of fluoride ion from model water solutions was investigated using polyamide thin film composite reverse osmosis and nanofiltration membranes. The effects of feed pressure, concentration, ionic strength, nature of cation associated to fluoride, and pH on the retention of fluoride ions were studied. Membranes were used to reduce fluoride ions and total salinity of a metal packaging industrial effluent. The retention of fluoride exceeds 90% for both membranes. This was found to depend on feed concentration, ionic strength, pH, and applied pressure. The Spiegler-Kedem model was applied to experimental results to determine phenomenological parameters σ and Ps, the reflection coefficient of the membrane and the solute permeability coefficient of ions. The convective and diffusive parts of the mass transfer were quantified with predominance of the diffusive contribution. 相似文献