同步除碳脱氮BAF快速启动中试研究

为缓解同步除碳脱氮曝气生物滤池(BAF)启动过程中异养菌对硝化菌的抑制作用,提高硝化菌的竞争优势,提出了BAF低强度反冲洗与高浓度硝化污泥接种相结合的启动方法.试验结果表明,通过第一阶段闷曝接种和第二阶段小流量连续进水后,COD去除率达到80%以上,平均出水COD低于50mg·L-1,满足污水排放一级A要求;而NH4+-N去除率仅为20%左右.通过第三阶段的低强度反冲洗与高浓度硝化污泥接种,经过5个周期后,NH4+-N去除率提高至85%以上,出水NH4+N质量浓度低至5mg·L-1以下,满足污水排放一级A标准.该方法能使BAF的启动周期缩短为30d左右,并能够保证其长期稳定运行,平均出水COD和NH4+-N质量浓度分别为35.4mg·L-1和3.48mg·L-1,均能满足污水排放一级A要求.     

低基质厌氧氨氧化SBBR反应器启动研究

采用SBBR反应器,接种普通污水厂剩余污泥,以人工配制含NH4+-N和NO2--N的低氨氮废水为进水,NH4+-N、NO2--N分别为24.3~32.0 mg/L、31.9~37.5 mg/L,p H为7.60~7.75,水温为(32±1)℃,考察低基质条件下厌氧氨氧化反应器启动及稳定运行特征。结果表明:经100余天后,SBBR厌氧氨氧化反应器成功启动。进水TN为60.8~68.7 mg/L时,平均去除率为88.3%,NH4+-N和NO2--N的去除率均达到95%以上。稳定运行期间,NH4+-N去除量、NO2--N去除量和NO3--N生成量的质量浓度之比为1∶1.37∶0.27,出水p H略高于进水,稳定在7.95左右。     

MBBR—MBR组合工艺处理生活垃圾沥滤液的研究

室温下,采用缺氧/两级好氧MBBR—MBR组合工艺对厌氧处理后的垃圾焚烧厂沥滤液进行处理。实验结果表明:在进水pH约为7、进水流量1.0 L/d和总回流比400%的条件下,即使沥滤液的NH4+-N高约1 650 mg/L、COD约为6 500 mg/L时,组合工艺对COD、NH4+-N、TN的去除率仍达到80%、99%、81%左右,出水NH4+-N<15mg/L,该工艺能实现对高浓度NH4+-N的有效去除。另外,二级好氧MBBR和MBR中的亚硝氮积累率分别达到90%、80%左右。这两个反应器中亚硝酸菌的数量远多于硝酸菌。     

HRT对悬挂链曝气式接触氧化处理污染河水的影响

考察了不同水力停留时间(HRT)下,厌氧-缺氧-悬挂链曝气式接触氧化对重,轻度污染河水的净化效果.结果表明,HRT为2、4、8,12h时,在重、轻度污水水质COD为58.67～85.33mg·L-1、26.67～42.67mg·L-1;NH4+-N为5.20～11.30 mg·L-1、2.79～3.47 mg·L-1,TN为8.10～14.18 mg·L-1,3.15～3.38mg·L-1;TP为0.62～O.82 mg·L-1,0.135～0.39mg·L-1两种典型进水水质情况下,COD、NH+-N和TN的平均去除率都随HRT的增加而升高,但在HRT为8 h后,平均去除率的增幅都变小.TP在重、轻度污水时随HRT变化去除率差异不大.考虑节能与效率,该工艺适宜的HRT为8 h,此时重、轻度污染河水的主要污染指标平均去除率COD为61.87%、25.39%;NH4+-N为61.25%、51.04%;TN为37.66%、26.51%;TP为10.19%、8.77%.     

间歇运行的MBR工艺处理农村生活污水的中试研究

采用间歇运行的一体化膜生物反应器(MBR)处理农村生活污水,对此工艺的技术可行性进行分析.试验结果表明,出水COD平均值为46 mg·L-1,平均去除率为68.3％,出水NH4+-N质量浓度平均值为323 mg· L-1,平均去除率为65.3％,出水TN质量浓度平均值为712 mg·L-1,平均去除率为65.8％,所测各指标均满足北京市水污染物排放标准( DB11/307-2005)中一级B的排放标准,中试系统未设置严格的厌氧区,反硝化效果不明显,出水TN以NH4+-N和NOx-N为主.试验对膜通量变化和膜污染情况进行了观察,结果表明经过反冲洗后的膜组件,膜通量可以维持在35 L·m2·h-1以上,跨膜压力可保证在0.02 MPa以下.     

溶解氧对长距离输水管道水质影响

为保证长距离输水管道输送水水质,采用管道模拟反应器考察了溶解氧(DO)对输水管道水质影响以及曝气充氧后水质恢复情况。结果表明:DO降低影响氨氮(NH+4-N)的去除,DO浓度越低越不利于NH+4-N的去除,且曝气充氧后恢复越缓慢,DO=0.5 mg·L-1和DO=1.5 mg·L-1的反应器在运行95 h后,NH+4-N去除率分别由90%降到21%和85%,曝气充氧54 h和3 h后恢复;DO浓度降低导致亚硝酸氮(NO-2-N)积累明显增加,DO浓度越低,NO-2-N的积累越严重,且曝气充氧后恢复越缓慢,DO=0.5 mg·L-1的反应器在运行95 h后,出水NO-2-N由0.02 mg·L-1增加到0.354 mg·L-1,曝气充氧54 h后恢复,DO=1.5 mg·L-1的反应器在运行32 h后,出水NO-2-N达到最大值0.112 mg·L-1,曝气充氧4 h后恢复;DO浓度降低使水中UV254升高,DO=0.5 mg·L-1和DO=1.5mg·L-1的反应器在运行2 h后,出水UV254分别增加了70.8%和20.8%,均在运行32 h后恢复,且曝气充氧后保持稳定。因此,DO对长距离输水管道水质具有重要影响,可采用DO实现对水质的调控。     

O/A/O工艺处理化工综合含氮废水运行优化研究

采用初曝池-兼气池-好氧池( O1/A/O2)工艺处理化肥、季戊四醇生产综合含氮废水,在进水COD、NH4+-N的质量浓度平均分别为624和59.3 mg·L-1时,出水COD在100 mg·L-1以下,平均为34.5 mg· L-1,去除率达93.2％;出水氨氮的质量浓度在15 mg·L-1以下,平均为0.8 mg·L-1,去除率高达98.7％;达到了GB 8978- 1996的一级标准.分析了系统反硝化能力较差、TN去除效率较低的原因,提出应减小硝化液回流比、适当调低O1池DO含量、充分利用厂区季戊四醇废液作为外加碳源等措施.     

厌氧折流板反应器-生物接触氧化池联合工艺处理新兴农村生活污水试验

采用厌氧折流板(ABR)-生物接触氧化(BCO)工艺处理新兴农村生活污水,试验研究了COD去除率、pH、挥发性脂肪酸(VFA)、碱度等随水力停留时间(HRT)的变化情况以及BCO中氮的转化。试验停留时间经过20、16、12、8、4、3、2 h的连续改变,最终确定最佳停留时间是4 h。试验进水COD平均为1 530 mg.L-1,经过ABR处理之后,出水COD降为119 mg.L-1,经过BCO工艺处理后,COD降为9 mg.L-1。ABR工艺COD的平均去除率为92%,总COD去除率为98%。同时,进水NH4+-N经过ABR-BCO工艺处理以后,平均质量浓度由93 mg.L-1降为0.52 mg.L-1,NH4+-N去除率为99%,总氮去除率在40%左右。     

外加剩余污泥水解酸化液碳源时曝气生物滤池的生物脱氮性能

利用剩余污泥水解酸化液作为外加碳源研究中部曝气和底部曝气曝气生物滤池(BAF)处理低碳氮比生活污水时的生物脱氮性能。结果表明,碳源与污水投配的流量比以及是否回流对BAF生物脱氮效果影响明显,气水流量比和回流流量比对BAF生物脱氮效果有一定影响;进水NH4+-N、TN质量浓度和COD分别为43.11、45.07、29.2mg.L-1时,中部曝气BAF的NH4+-N和TN去除率分别为99.04%和78.32%,出水COD为32.4 mg.L-1;底部曝气BAF的NH4+-N和TN去除率分别为98.61%和68.99%,出水COD为28.4 mg.L-1。研究表明,BAF在2种运行方式下可获得良好的硝化与反硝化性能,且不会引起二次污染。     

ANAMMOX反应器快速启动及对反硝化聚磷的影响研究

硝化菌的生长快于厌氧氨氧化菌,通过培育硝化生物膜,利用硝化菌的基质多样性和代谢多样性,可使生物膜由催化硝化反应过渡到催化厌氧氨氧化反应,加速ANAMMOX反应器的启动。经过2个月的运行,成功地启动了ANAMMOX反应器,而且反应器运行性能稳定。将厌氧氨氧化引入反硝化聚磷系统中,试验结果表明,在COD和TP的去除率保持基本不变的情况下,NH4+-N的去除率从23%上升到87%,TN的去除率从88%提高到93%,出水NH4+-N和NO2--N的质量浓度均低于2mg/L。     

氢气纯度分析方法准确性的探讨

ONACCURACYOFANALYSISOFOFHYDROGEN1前言我公司目前应用的氢气纯度分析方法有两种,一种是爆炸反应法,另一种是焦性没食子酸吸收法。几年来,人们对两种分析方法的准确性曾有过褒贬不一的评论。这里我们也谈谈自己粗浅的观点。2爆炸法测定氢气纯度一定量的氢气样品与适量的空气之均匀混合物因反应后生成液体水而引起气体体积减少,减少的体积等于参加反应气体体积之和。其中l／3为氧气,2／3为氢气。根据氢气取样量和反应前后混气体体积之差,以及氢气在反应中的体积比例关系,可计算出样品的氢气纯度。计算公式式中：A一混…     

COMPARISON OF METHODS OF ANALYSIS OF GYPSUM1

The different analytical methods proposed for the evaluation of gypsum have been subjected to an experimental test. A combination method, consisting of a fusion with KHCO₃ and determination of CaO by KMnO₄ titration, the SO₃ by Andrews method of titration of BaCrO₄ has been found to give very reliable results with the least consumption of time.     

SEDIMENTATION OF BINARY MIXTURES OF PARTICLES OF UNEQUAL DENSITIES AND OF DIFFERENT SIZES

A model is developed for the sedimentation from a suspension of two particle species of unequal densities and of different sizes. The composition and the thickness of various layers in the sediments are predicted using graphical and analytical methods. The model predictions were in excellent agreement with experimental results, when the particle size ratio was ≥ 108. When size ratio of the particles was 2.60 and 4.31 the agreement occurred in about 50 percent of the cases.     

HEASUREHENT OF INSTANTANEOUS RATES OF LOSS OF VOIATILE COMPOUNDS DURING DRYING OF DROPS

A novel technique serves to monitor instantaneous rates of loss of a volatile solute from a suspended drop during drying. A highly sensitive electron capture detector is used to monitor concentrations of SF6 released into a flowing gas stream from a suspended, drying drop. Simultaneously, the appearance and morphological development of the drop are monitored with a video camera. This provides the wherewithal of relating instantaneous rates of loss of the volatile solute to particular events during the development of particle morphology.

Initial experiments have been carried out with drops of aqueous solutions of glucose, sucrose, maltodextrin and coffee extract. The results clearly display the onset of the volatiles-retentive selective diffusion phenomenon. There is also substantial loss of the volatile component later in the drying process, when the drops undergo repeated ex ansion, bursting and cratering due to the formation of internaf bubbles. These experiments appear to be the first quantitative demonstration of major losses accompanying changes in drop morphology.     

几种针状焦性能对比

针状焦分石油系和煤系两大类,这主要取决于针状焦的原料来源。在同一系列中由于原料不同和工艺条件不同 ,针状焦的各自性能也不相同。针状焦是生产超高功率石墨电极和高功率石墨电极的主要原料 ,针状焦的性能对石墨电极的质量有至关重要的影响。所以对针状焦性能以及其对石墨电极质量影响的研究十分必要的。以下是常用的几种进口针状焦和国产针状焦的性能对比。１原料性能分析对比原料试样包括４种针状焦 ,其中两种为进口针状焦：三菱针状焦和新日化针状焦;另两种为国产针状焦：鞍山针状焦和锦州针状焦。其中除锦州针状焦是石油系针状焦外…     

茶多酚提取方法进展

本文综述了国内外现有茶多酚提取方法的现状以及近期的研究进展，并对其优缺点进行了评价。这将有助于中低档茶的综合利用和茶多酚的进一步开发应用。     

ANALYSIS OF RECENT MEASUREMENTS OF THE VISCOSITY OF GLASSES

Viscosity of Simple Soda-Silicate 500° to 1400°C Comparison of the results given by English with those of Washburn, Shelton and Libman, indicates a discrepancy in the absolute values of log₁₀ viscosity amounting to 0.6, those of Washburn et al., being relatively too high. If correction for this is made, the isothermal curves of log₁₀ viscosity as a function of soda content are smooth up to 50% Na₂O, showing no inflection. The observations as a function of temperature T are all represented within accidental error by an equation of the type where all three constants vary regularly with the composition. Change of Viscosity of Glass (6SiO₂, 2Na₂O) due to Molecular Substitution of CaO, MgO and Al₂O₃ for Na₂O The effect is clearly brought out by plotting (from the results of English) the change of log₁₀η due to the substitution as a function of temperature. The curves each show a sharp bend at a temperature between 840° and 1050°C, which is designated the aggregation temperature T_a. If we divide these curves by the corresponding percentage substituted, we get curves for each oxide which are straight and parallel below the aggregation temperatures, the slopes (increase of change of log₁₀η per 100°C) being −0.056 (CaO), −0.055 (MgO), −0.018 (A1₂O₃) per per cent oxide substituted. For substitution of 1/2 molecule the slopes are −0.325 (CaO), −0.23 (MgO) and −0.18 (Al₂O₃) per 100°. At the aggregation temperature the change of log₁₀η per per cent is a minimum, 0.03 to 0.06 for CaO, 0.12 for MgO, 0.07 for Al₂O₃. Evidence of Aggregation in Glasses, from viscosity Measurements The sharp bends in the plots of change of log₁₀η due to substitution of an oxide for Na₂O, suggest the beginning of molecular aggregation at these temperatures. These aggregation temperatures are close to the devitrification temperatures, but the effect on the viscosity curves cannot be due to actual devitrification since it does not change with time. Taking the aggregation temperatures as equal to devitrification temperatures, additional isotherms are roughly sketched into the equilibrium triangle of the system Na₂O-CaO-SiO₂. Change of Viscosity of Glass (4SiO₂, 2Na₂O) due to of Substitution of B₂O₃ for SiO₂ The change of log₁₀η (from the results of English) is plotted as a function of temperature, and also the change of log₁₀η per per cent B₂O₃. The curves are more complex than for the substitution for Na₂O.     

环氧树脂羟基值测定方法的研究

利用乙酸酐、吡啶和浓硫酸混合的乙酰化试剂测定环氧树脂中羟基值含量的方法具有操作简便、滴定终点明显和分析结果误差小等优点。     

骑式摩托车油箱喷涂工艺的改进

面对日益激烈的市场竞争,摩托车油箱外观质量越来越成为影响销售的因素之一。文章介绍了改进工艺后的油箱涂装,该涂装体系提高了油箱外观的丰满度,降低了油箱涂装的生产成本。     

聚酰亚胺的合成法

本文评述了缩聚型聚酰亚胺的主要合成方法和近年来国际上在合成中所做的探索。