PDM复合混凝剂用于低温低浊水源水处理的研究——低浊度宁波姚江水处理

该文报道了用特征黏度系列化的有机阳离子高分子聚二甲基二烯丙基氯化铵(PDM)与无机混凝剂复合物对宁波低浊度姚江水的脱浊处理研究过程。通过混凝烧杯实验,考察了无机混凝剂的种类及其与PDM的复合配比对低浊度姚江水脱浊效果的影响。结果表明,对低浊度姚江水,要达到1.0~1.2 NTU的沉淀出水余浊,硫酸铝(AS)需5 mg/L左右的投加量,聚合硫酸铁(PFS)需8 mg/L左右的投加量,而聚合氯化铝(PAC)的投加量在10 mg/L左右;PDM对无机混凝剂强化混凝脱浊效果明显,无机混凝剂与PDM的复合配比越低,复合混凝剂混凝脱浊效果越好,在达到水厂沉淀出水浊度标准的前提下,AS/PDM复合药剂能比单独使用AS减少20%AS投加量;PFS/PDM复合药剂能比单独使用PFS减少30%~40%PFS投加量;PAC/PDM复合药剂能比单独使用PAC减少30%~50%PAC投加量。     

聚合硫酸铁复合混凝剂处理秋季长江水研究

通过混凝烧杯实验,考察了特征黏度系列化的聚合硫酸铁(PFS)/聚二甲基二烯丙基氯化铵(PDM)复合混凝剂在秋季长江水处理中的混凝处理效果.结果表明:对温度为16～18℃,浊度为57～62 NTU的秋季长江水,复合混凝剂脱浊效果明显,达到南京某水厂6 NTU的沉淀出水余浊标准时,可显著降低PFS的投加量,PFS/PDM复...     

复合聚铝用于冬季太湖水的混凝脱浊研究

将特征黏度系列化的聚二甲基二烯丙基氯化铵(PDM)与聚合氯化铝(PAC)复合用于冬季低温太湖原水强化混凝脱浊处理。由混凝烧杯实验,考察了PAC/PDM复合比例、PDM特征黏度对脱浊效果及絮团沉淀性能的影响,并与经预加氯处理的太湖水的相应处理结果作对比。结果表明,对浊度在24~26 NTU,温度为5~9℃,藻含量为8.01×103个/mL的太湖水,在与某市某水厂混凝强度相近的搅拌强度下,要达到其2 NTU沉淀池出水的余浊标准,PAC投加量3.28 mg/L,而复合比例分别为20∶1、10∶1、5∶1的PAC/PDM复合混凝剂所需PAC投加量随PDM特征黏度0.55、1.53、2.47 dL/g的增加,分别为2.93~2.83,2.70~2.60,2.62~2.51 mg/L,相应的PAC投加量减少的幅度分别为10.67%~13.72%,17.68%~20.73%,20.12%~23.48%;当沉淀出水浊度要求提高至1 NTU时,PAC需4 mg/L的投加量,复合混凝剂需3.77~3.04 mg/L的投加量,相对于PAC可减少投加量5.75%~24.00%。可见PDM明显提高了PAC的混凝脱浊效果,且PAC/PDM复合配比越低,PDM特征黏度越高,复合混凝剂的脱浊效果与沉淀性能越好。此外,PAC/PDM复合混凝剂有可能通过减少预加氯的投加量,来减少卤代有机物的形成机会,增强供水水质安全性。     

低温低浊河网水的有机高分子助凝处理研究

用不同特征黏度的聚二甲基二烯丙基氯化铵(PDM)与聚合氯化铝(PAC)、两种市售无机复合聚铝分别复合,用以改进无机混凝剂对低温低浊微污染河网水的混凝脱浊效果。考察了无机混凝剂的种类及其与PDM的复合配比对低温低浊微污染河网水脱浊效果的影响。结果表明,对温度为7～10℃,浊度为4.5～8NTU的低温低浊河网水,在与实际生产相近的混凝搅拌强度下,要达到2NTU左右的出水余浊标准,PAC、复合聚铝1、复合聚铝2分别需4.0、3.5、2.8mg/L的投加量。而用特征黏度分别为0.52、1.47、2.46 dL/g的PDM配制的、无机复合聚铝与PDM复合质量比为20:1、10:1、5:1的复合混凝剂PAC/PDM、复合聚铝1/PDM、复合聚铝2/PDM,比单独使用同种无机混凝剂,分别约能减少10%～25%、8.6%～28.6%、7.1%～28.6%的无机药剂投加量,无机复合聚铝与PDM复合比例越低、PDM特征黏度越高,复合混凝剂脱浊效果越好。因此,PDM对低温低浊河网水具有明显的强化混凝脱浊效果。     

复合聚铝处理秋季长江水脱浊研究

通过混凝烧杯实验,探讨了特征黏度系列化的聚二甲基二烯丙基氯化铵(PDM)与液体聚合氯化铝(PAC)复合得到的稳定型复合混凝剂用于对秋季微污染长江水强化混凝处理效果。结果表明,对温度为16～18℃,浊度为70 NTU左右的秋季长江水,沉淀池出水在达到6 NTU的南京某水厂现行浊度标准的情况下,PAC需1.66mg/L的投加量,质量配比分别为20∶1、10∶1、5∶1的PAC(以Al2O3计)/PDM复合混凝剂所需投加量随特征黏度变化为1.38～1.26、1.19～1.14、1.16～1.13 mg/L,相对于PAC可减少投加量16.87%～24.10%、28.31%～31.32%、30.12%～31.93%。复合混凝剂还提高了絮体密实度与沉淀性能。由此可见,PDM明显改善了PAC的混凝脱浊效果,PAC/PDM复合比例越低,PDM特征黏度越高,脱浊效果与沉淀性能越好。考虑未来社会对水质的要求,若使沉淀池出水达到2 NTU左右,则PAC需3.35 mg/L左右的投加量,而复合比例分别为20∶1、10∶1、5∶1的复合混凝剂仍能比单独使用PAC减少19.10%～30.45%的投加量。     

复合硫酸铝用于冬季太湖水的混凝脱浊研究

用特征黏度系列化的聚二甲基二烯丙基氯化铵(PDM)与硫酸铝(AS)复配制得稳定的复合混凝剂,用于冬季低温太湖水强化混凝脱浊处理.通过混凝烧杯实验.考察了AS/PDM复配比例、PDM特征黏度对脱浊效果的影响.结果表明,对浊度28～30 NTU、温度5～9℃、藻含量7.57×103mL-1的太湖水,要达到2 NTU的余浊标准.仅用AS需投加质量浓度4.29 mg/L,而采用m(AS):m(PDM)分别为5:1、10:1、20:1的复合混凝剂所需投加质量浓度随PDM特征黏度(0.55～2.47 dL/g)的增加分别为2.40～2.29、2.98～2.84、3.49～3.17 mg/L,相对于AS投加量减少44.06%～46.62%、30.54%～33.80%、18.65%～26.11%.PDM提高AS的混凝脱浊效果,并且AS/PDM复合配比越低,PDM特征黏度越高,则该复合混凝剂的脱浊效果越好.     

聚二甲基二烯丙基氯化铵对聚合硫酸铁处理冬季长江水的助凝效果

采用聚二甲基二烯丙基氯化铵(PDM)与聚合硫酸铁(PFS)复合制得的稳定型复合混凝剂,用于冬季低温长江水强化混凝脱浊处理。通过混凝烧杯试验,考察了PDM对PFS在脱浊效果和沉淀性能上的改进程度。结果表明:对温度为5～7℃,浊度为45 NTU左右的冬季长江水,PDM助凝效果明显,同时PFS与PDM的复配比例越低,复合混凝剂混凝脱浊效果越好。复合混凝剂中PFS的用量比单独使用PFS时的少。复合混凝剂能增大絮团的沉淀速度,克服冬季低温条件下单独使用PFS时絮体轻而细小、沉淀慢、破碎现象严重的问题,从而使沉淀出水水质能够迅速稳定地达标,同时,还可明显改善PFS处理时出水带色、腐蚀设备等问题。     

污水处理厂出水的聚硅硫酸铝铁混凝除磷研究

研究新型混凝剂聚硅硫酸铝铁(PSFA)对城市污水处理厂出水中磷的混凝去除效果,考察了混凝剂投加量、原水pH、与聚丙烯酰胺(PAM)复配等因素对混凝除磷效果的影响,同时进行了聚合氯化铝(PAC)、聚合硫酸铁(PFS)和Al2(SO4)3混凝除磷效果的比较试验。结果表明,PSFA可有效降低城市污水处理厂出水TP含量,当投加量为36mg·L-1时,可以使出水TP的质量浓度从1.51mg·L-1下降到0.32mg·L-1,出水达到上海市地方标准DB31/199-2009规定的TP排放一级标准;PSFA混凝除磷适宜pH为6～10;PAM可以有效提高PSFA混凝除浊和除磷效果,减少混凝剂投加量;PSFA比PAC、PFS、Al2(SO4)3具有更好的混凝除磷效果,具有很好的应用前景。     

PAC/PDM复合混凝剂用于春季长江水制水生产研究

在某市日均12×104m3水量规模的水厂对聚合氯化铝(PAC)-聚二甲基二烯丙基氯化铵(PDM)复合混凝剂用于春季长江水制水生产的总体应用效果进行了考察,并通过混凝烧杯实验对生产应用结果进行了分析验证。结果表明:在复合混凝剂应用过程中,对浊度25～40NTU,水温15～20℃的长江水,在沉淀池出水与出厂水均满足水厂工艺要求的情况下,总体运行情况良好,复合混凝剂相对于现有混凝剂PAC可起到相同铝盐投加量下降低沉淀池出水浊度、达到相同沉淀池出水浊度时减少混凝剂铝盐用量、相同铝盐投加量下耐水量突增冲击能力增加的效果。     

橡胶促进剂NS废水预处理实验研究

橡胶促进剂NS生产废水采用酸化吹脱-混凝法进行预处理,考察废水pH、吹脱时间以及混凝剂种类、投加量、助凝剂投加量和混凝pH等对COD去除率的影响。结果表明,酸化吹脱-混凝法处理该废水的最佳酸化pH值为3,吹脱时间为120 min;最佳混凝剂为PFS(聚合硫酸铁),投加量1 400 mg/L,混凝pH值为7,助凝剂PAM 14 mg/L。酸化吹脱及混凝处理后,出水COD去除率值为53.75%。     

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.     

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。     

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…     

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。