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1.
基于活性污泥2号模型(ASM2)对快速易生物降解组分(SS)进一步划分为可发酵的易生物降解有机物(SF)和发酵产物(SA),本研究提出了一套科学的表征方法。该方法涉及SS与XS(慢速可生物降解组分)的好氧呼吸测量同时表征、SA组分的离子色谱测定以及物料衡算。应用这套方法对重庆市某2个城市污水厂隔栅井出水水样平行进行了4组实验,各种组分测量值序列的CV值在2.09%~6.18%之间。  相似文献   

2.
以颗粒活性炭(AC)和钛酸丁酯为原料,采用微波辐射法制备TiO2/AC复合光催化剂,并对制备的催化剂进行了表征;采用该催化剂对六氯苯进行光催化降解,确定了六氯苯降解的最佳工艺条件,并就几种外加试剂对TiO2/AC光催化降解六氯苯的强化作用进行了探讨。结果表明,制备的催化剂中TiO2均匀分布在活性炭表面、呈单一的锐钛矿晶型,晶粒生长完善。该催化剂催化降解六氯苯的最佳工艺条件为:pH值为5、TiO2负载量为18.2%、TiO2/AC投加量为0.4 g/L、反应时间为60 min。在此条件下,六氯苯降解效率达90.3%。添加适量的H2O2、AgNO3、K2S2O8、KIO4和KMnO4均能提高TiO2/活性炭对六氯苯的光催化降解效率。5种外加试剂的适宜添加量分别为0.3%、1.0、1.0、0.1和0.1 mmol/L,对TiO2/AC光催化效率的强化作用大小顺序为:H2O2>AgNO3>K2S2O8>KMnO4>KIO4。  相似文献   

3.
O3/BAF工艺系统中有机物生物降解数学模型   总被引:1,自引:1,他引:0  
研究臭氧预氧化/曝气生物滤池(O3/BAF)联合工艺深度处理实际城市污水二级出水过程中,后续BAF系统中有机物的生物降解数学模型。以有机底物浓度、填料层高度两个基本变量为控制条件,研究BAF的总体运行常数和填料特性常数,得出BAF有机物生物降解动力学方程为Se/S0=exp(-Kh/qSn0)。出水与进水COD浓度比值(Se/S0)的对数与反应器填料高度(h)之间可表达成一次函数关系。在不同的进水浓度(S0)下,根据ln(Se/S0)~h和关系式m=K/qSn0,得到方程ln(qm)=-nln(S0)+lnK。BAF总体运行常数K和填料特性常数n分别为1.708和0.5063。该模型对BAF工艺有如下指导意义:可以根据设计流量、进水有机物浓度和出水浓度,初步确定BAF的尺寸(如横截面积、高度等)。  相似文献   

4.
以SnO2为载体,Au为活性组分,采用真空浸渍法、共沉淀法、沉积沉淀法制备CO氧化的催化剂,同时还制备双金属体系催化剂Au-Pd/SnO2和Au-Pt/SnO2。用气相色谱对所制备的催化剂进行活性评价,运用DSC、SEM、XRD、BET等对催化剂进行表征。在本实验条件下,载体二氧化锡焙烧温度为500 ℃,催化剂成型温度为350 ℃,金负载量为3%(wt.)时,用沉积-沉淀法制备的Au/SnO2活性最好,在18 ℃,空速为24 000 h-1条件下就能将CO(浓度为4%)完全氧化为CO2;添加铂和钯可提高Au/SnO2对CO的催化活性。  相似文献   

5.
通过固定床实验系统研究烟气脱除零价汞的实验,首先研究了滤袋常用的聚苯硫醚(polyphenylene sulfide,PPS)以及活性炭纤维(activated carbon fiber,ACF)在不同温度、不同气体组分下负载V2O5-WO3/TiO2催化剂,对模拟燃煤烟气中零价汞(Hg0)的脱除效果。然后对比研究了活性炭纤维协同滤袋常用纤维负载催化剂后,对模拟燃煤烟气中Hg0的脱除性能。结果表明,在汞蒸气入口浓度为50 μg/m3,纯N2气氛下,当温度为25℃时,两者脱除率均能达到99%,当温度为200℃,负载催化剂的活性炭纤维脱除率在30%左右,PPS纤维仅为10%左右。在200℃情况下,模拟烟气的组分为N2+O2时,2种纤维的Hg0脱除率提高了10%~20%,当在混合气体中添加0.01‰后,负载催化剂的PPS纤维Hg0脱除率能达到80%,活性炭纤维Hg0脱除率能达到98%。当温度为200℃,模拟烟气的组分为N2+O2+HCl时,不同性能掺炭纤维负载催化剂后Hg0脱除率在69%~95%范围之间变化,其中PPS掺炭纤维对Hg0脱除效率最高达到95%,因此,负载V2O5-WO3/TiO2催化剂的PPS掺炭纤维能在高温烟气中保持较高的Hg0脱除率。  相似文献   

6.
溶胶-凝胶和浸渍相结合的方法制备锰掺杂WO3-TiO2复合光催化剂,RXD表征,考察WO3和Mn2+掺入量、焙烧温度、焙烧时间及催化剂用量对光催化降解甲基橙的影响。结果表明,500℃焙烧2h,掺杂量n(Mn2+n(WO3n(TiO2=0.8∶1∶100时,光催化活性最高,光催化降解甲基橙溶液,120min后,降解率达90%, 比单纯 TiO2的光催化活性提高81%。  相似文献   

7.
采用硼氢化钠还原法制备核-壳结构的Fe-FeOxH2x-3复合材料,研究了富里酸在UV/H2O2和UV/H2O2/Fe-FeOxH2x-3两种不同反应体系下的降解情况。结果表明,核-壳结构Fe-FeOxH2x-3的存在,提高了UV/H2O2降解富里酸的反应速率,TOC去除达到84%。采用XAD树脂吸附法对反应前后的富里酸进行化学分级表征,结果表明,富里酸经反应后憎水酸(HoA)、弱憎水酸(WHoA)和憎水中性物质(HoN)都有所减少,进而转化为亲水性物质(HiM);用超滤膜法对富里酸进行物理分级表征,考察了富里酸在反应前后分子量分布的变化情况。同时,富里酸经过反应后生成的中间产物降低了三氯甲烷生成趋势。  相似文献   

8.
以钛酸四丁酯为原料,空心微珠为载体,采用溶胶凝胶法制备TiO2/beads光催化剂载体,然后浸渍法制备出H4SiW12O40/TiO2/beads表面负载修饰型复合光催化剂,并运用SEM、XRD、FT-IR和DRS对催化剂进行表征和分析。研究了H4SiW12O40/TiO2/beads对亚甲基蓝降解的光催化活性,考察了光强度、pH值、曝气量、底物浓度和催化剂用量等对催化效率的影响。实验结果表明,在中性条件下,H4SiW12O40/TiO2/beads催化剂的投加量为0.25 g/L,浓度为7.5 mg/L的亚甲基蓝溶液在250 W的紫外灯和600 W的可见光灯下光照60 min降解率分别可达到94.5%和55%。  相似文献   

9.
以成型TiO2作为载体,通过浸渍法制备了Mn-Ce/TiO2低温SCR催化剂,并系统研究了制备方法、煅烧条件、活性组分担载量、Mn含量等参数对催化剂催化还原NO性能的影响。结果表明,煅烧温度的升高会促使活性组分结晶度的提高,从而引起催化活性的降低,在500℃和600℃下所得Mn-Ce/TiO2催化剂活性组分为无定型态,表现出较高的脱硝活性。活性组分担载量的增加有利于催化活性的提高。Mn含量对Mn-Ce/TiO2催化剂的活性有较大影响,当Mn/(Mn+Ce)摩尔比为40%和85%时,催化剂活性最高。  相似文献   

10.
活性污泥系统中自养菌浓度及生长动力学参数测定   总被引:4,自引:1,他引:3  
利用批式呼吸计量法测定了实际污水处理厂厌氧/缺氧/好氧工艺和小试装置厌氧/好氧工艺好氧池内自养菌(XA)的浓度及其最大比生长速率常数(μA)。结果表明,活性污泥系统中XA与混合液挥发性悬浮固体的比例为1.60%~2.34%,μA实测值为0.69~0.76 d-1,测定结果有较好的重现性,且与文献值非常接近,说明该方法具有较高的准确度和精密度。  相似文献   

11.
废水COD 4种物化表征方法的比较与评估   总被引:1,自引:1,他引:0  
为了确定废水COD组分表征的物化分析方法,对0.1μm滤膜过滤、0.45μm滤膜过滤、絮凝和絮凝+0.45μm滤膜过滤4种方法进行了实验比较和评估。结果表明:某些材料的滤膜会因"COD溶出"而影响表征结果;4种方法分离废水的重现性都很好,相互没有明显区别;物化分离对废水快速可生物降解COD(SS)没有影响,但4种方法得到的处理液中可生物降解COD仍含降解速率明显不同的组分,其中SS仅占35%~45%。因此,物化方法不能合理表征SS;絮凝+0.45μm滤膜过滤速度快、干扰少、分离机理与活性污泥系统类似,更适用于废水溶解性惰性COD组分(SI)表征。  相似文献   

12.
A new simple method is proposed for identifying sources of small scale pollution, by determining the tissue concentrations of pollutants in terrestrial mosses. The method is based on spatial characterization of the processes that generate accumulation of pollutants in these organisms. The steps involved in implementing and applying the method are: (i) obtaining data on pollutants in moss samples collected at least at 35 pairs of sampling sites (SS) separated by 1 km distance; (ii) study of the distribution of the differences in concentration between the pairs of SS, eliminating pairs affected by foci that generate small scale processes; (iii) characterization of the resulting normal distributions and calculation, for different levels of significance, of the probability of a value lying within these distributions, and (iv) application of the calculated quantiles to data corresponding to the differences in concentrations between pairs of SS in the vicinities of foci of small scale pollution, to determine which elements can be considered as pollutants. Given the small number of data required once the distribution of the differences has been established, the method is an inexpensive, efficient way of establishing the probability that a pollutant is being emitted from a particular source. The method is very useful for verifying the results of pollution inventories, evaluating new technologies and improving the design of regional networks for biomonitoring of air quality with terrestrial mosses.  相似文献   

13.
Atmospheric aerosols were collected in separate coarse (2–10 μm diameter) and fine (diameter less than 2 μm) size fractions at Rukomechi Research Station (16.1°S, 29.4°E), Zimbabwe, in the central part of southern Africa, from September 1994 to January 2000. The samples were analysed for the particulate mass (PM), black carbon, and 47 elements. The overall data set and the separate wet and dry season data sets were examined with absolute principal component analysis (APCA). Natural and anthropogenic aerosol sources were identified in both seasons, but the sources and their contributions to the total PM were found to vary between seasons and between size fractions. Crustal matter, sea salt (SS), a mixed biogenic (BIO) emission/biomass burning (BB) component, and a copper component were identified for the coarse aerosols during the wet season. APCA attributed 29% of the total wet season coarse PM to the mixed BIO/BB component, and 32% to SS. The copper component is likely due to the copper smelters in the Zambian Copperbelt. The dry season coarse PM originated from crustal matter, BB, BIO, and SS sources, with the major contribution (32%) coming from BB. Four components (crustal matter, BB, non-ferrous smelters, and SS) were identified for the fine particles for both the wet and dry seasons. The BB component provided the major contribution to the total fine PM, accounting for 44% and 79% in the wet and dry seasons, respectively. The relative contributions to the total PM (both fine and coarse) for all sources were greater in the dry season than the wet season, except for SS.  相似文献   

14.
The guidelines regarding sampling terrestrial mosses for biomonitoring the atmospheric contamination in a region specifically recommend that sampling close to focal points of contamination (i.e. roads, populated areas, etc.) should be avoided for satisfactory characterization of general patterns of contamination. However, these recommendations cannot always be followed in many parts of the world with dense, highly dispersed populations. The aim of the present study was to determine how the distances between sampling sites (SS) and contamination foci such as roads, isolated houses and urban nuclei affect regular, large-scale sampling networks. Metal concentrations obtained in biennial sampling surveys carried out between 2000 and 2006 in Galicia (NW Spain) were used, and the relative proportions of the concentrations corresponding to small-scale and large-scale processes were calculated. The possible relationship between the mean concentrations corresponding to small-scale processes in the different sampling surveys and the distances from SS to roads, buildings and urban nuclei was established by a GIS. Outliers in the data were identified at many of the SS and frequency statistics revealed the absence of any relationship between the distance to these foci and the concentrations of metals in the moss. The method also revealed many instances of the influence of one or more small-scale contamination foci such as airports and railways (often not considered in the sampling recommendations) on SS. Relocation of such SS would improve the representativeness of the sampling grid.  相似文献   

15.
Multivariate characterization of 60 polycyclic aromatic hydrocarbons (PAHs) was performed using data from literature and semi-empirical molecular orbital calculations. This dataset was analyzed by principal component analysis and projections to latent structures by means of partial least square. The PAHs were found to distribute in the chemical domain in several groups mainly governed by the number of aromatic rings and the number of five-membered rings. The multivariate model and training set was used to predict GC retention times on a non-polar column (DB-5). Using a 2(4) experimental design on the principal components of the chemical characterization model, a test set of PAHs was selected dependent on the distribution in the chemical domain of the PAHs. Such a test set is expected to improve selection of PAHs for future testing and modeling of both biological and chemical responses. Although the model of GC retention times was good, the precision was however not good enough for practical use.  相似文献   

16.
活性污泥1号模型废水特性的测定研究   总被引:7,自引:0,他引:7  
废水的水质特性是活性污泥数学模型研究和应用的重要方面。采用呼吸计量法及常规化学分析法对污水处理厂的废水特性进行了测定,通过研究发现,污水处理厂的曝气沉砂池出水中SS占总COD的比例平均为10.49%;Xs占总COD的比例平均为14.24%;S1占总COD的比例平均为5.52%。初沉池出水中Ss占总COD的平均比例为9.62%;Xs占总COD的比例平均为16.97%;S1占总COD的比例平均为11.38%。  相似文献   

17.
Xu Z  Nakhla G  Patel J 《Chemosphere》2006,65(7):1171-1181
Tomato-processing wastewaters are typical of slowly biodegradable high strength wastewaters generated from the food canning industry. Three different samples of influent and three samples of anaerobic effluents corresponding to the three influents collected from an on-site pilot-scale anaerobic/aerobic system were characterized using respirometric methods. Respirometric studies demonstrated that the pretreatment in the anaerobic reactor of the pilot-scale system increased the readily biodegradable fraction from an average of 40% of the SCOD in the influent to 50% of the SCOD in the anaerobic effluent, improved kinetics from an average micro(max) of 1.5d(-1) in the influent to 3.5d(-1) in the anaerobic effluent, and eliminated nutrient deficiency. Furthermore, the system was calibrated and simulated by application of wastewater characterization and biokinetic data derived form respirometric tests of influent and anaerobic effluent in Activated Sludge Model no.1 (ASM1).  相似文献   

18.
The disposal of sewage sludge (SS) and reed straw (RS) has becoming a critical issue due to their rapid production. In this study, the SS-based activated carbon (SSC) was produced by introducing the RS as a component material. Properties including BET surface area, pore volume, surface chemical groups, and morphologies were characterized. The adsorption of 1-diazo-2-naphthol-4-sulfonic acid (1,2,4-Acid) and 2-Naphthol (2-Nap), which differs in their physicochemical properties, on as-prepared carbons were investigated. The overall adsorption was found to be jointly controlled by external mass transfer and intraparticle diffusion, and the optimal pH was found to be 5 due to their electrostatic attraction. Further study revealed that the SS- and RS-based carbons (SC and RSC, respectively) exhibited different adsorption behavior toward 1,2,4-Acid and 2-Nap. The calculated adsorption capacity from Langmuir–Freundlich model of SC and RSC for the two intermediates was 141.0, 84.6 mg g-1 and 48.2, 110.2 mg g-1, respectively, whereas their hybrid product (SSC) showed comparable capacity for 1,2,4-Acid (117.8 mg g-1), as well as higher capacity for 2-Nap (157.5 mg g-1). It was found that the presence of meso- or macropores facilitates the precipitation of mineral phases of inorganic substances during carbonization, attracting the molecules with polar functional groups, while the introduction of C-rich RS to SS enhances the adsorption of hydrophobic molecules.  相似文献   

19.
Marc I. Stutter 《Ambio》2015,44(2):207-216
Concerns about the sustainability of inorganic fertilizers necessitate the characterization of alternative P source materials for agronomic P-efficiencies and P losses via leaching. Firstly, this study examined nutrient compositions including P speciation of seven soil amendments: sewage sludge (SS), anaerobic digestate (AD), green compost (GC), food waste compost (FWC), chicken manure (CM), biochar, and seaweed. Secondly, soil P leaching and availability was studied on a subset of four materials (SS, AD, GC, and CM). Sorption of extracts onto columns of a test soil showed strong P retention for SS and compost, but weak P sorption for CM and especially AD, suggesting short-term leaching risks for soil applied AD. Limited P desorption with water or citrate indicated sorbed P was strongly fixed, potentially limiting crop availability. These data indicate that variation in P forms and environmental behavior should be understood to maximize P usage, but minimize leaching and soil P accumulation. Hence, different alternative P source materials need differing recommendations for their agronomic management.  相似文献   

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