聚硅硫酸铝处理造纸废水的研究

以硫酸铝、硅酸钠为原料合成了具有不同Al^3 ／SiO2摩尔比的聚硅硫酸铝(PASS)混凝剂。通过对造纸废水的混凝实验，确定了PASS的Al^3 ／SiO2最佳配比为1／1，适用pH值范围为5～11，与硫酸铝的混凝对比实验表明，PASS具有更好的处理效果。对PASS的混凝机理进行了分析、探讨。     

聚硅酸硫酸铝处理低温低浊水分析

文章阐释了低温低浊水对于混凝效果的影响与聚硅酸硫酸铝的制备方法,围绕SIO2质量分数、硅酸活化pH值、硅酸活化时间、Al/Si摩尔比等层面,试分析不同制备条件对聚硅酸硫酸铝混凝效果的影响,并依托实验比较得出不同絮凝剂对于低温低浊废水的处理性能,证实聚硅酸硫酸铝具备良好的混凝效果。     

聚硅酸铝镁絮凝剂制备及其对印染废水脱色处理研究

以硅酸钠、硫酸镁和硫酸铝为原料,制备出聚硅酸硫酸铝镁(PAMSS)絮凝剂,将其用于对染料废水的脱色研究.结果表明,SiO2浓度为0.3mol/L,硅酸活化pH=3,活化时间30min,n(Mg)∶n(Si)=1.25,n(Al)∶n(Si)=0.5时,其对活性染料脱色率可达到90%以上.实际废水处理结果表明,PAMSS处理印染废水具有良好的脱色效果,是一种高效的无机高分子絮凝剂.     

高浊度选矿废水混凝实验研究

采用混凝法对某铜镍矿高浊度选矿废水进行除浊实验,结果表明聚合硫酸铝铁为最佳混凝剂,最佳加药量为86g/m3,添加助凝剂PAN 0.57g/m3,最佳pH值为7-9,沉降时间在15min左右取得较好的混凝效果。     

新型絮凝剂PAMSS的应用研究

用正交试验的方法，对新型无机高分子絮凝剂聚硅硫酸铝镁处理污水的过程进行了分析和研究，探讨了有关因素对絮凝效果的影响。通过试验认为，这种絮凝剂对污水的最佳处理工艺条件为：Mg／Al／Si为1．0：1．0：1；投加量约为100mg／L；pH在6．5～7．5之间；搅拌时间10～13min。此时，浊度和CODCr的去除率分别达到91．98％和82．85％，并优于聚合硫酸铝(PAS)和聚合硅酸硫酸铝(PASS)的絮凝效果。     

芬顿正交法深度处理棕榈CTMP生化出水的研究

对COD为682mg/L的棕榈CTMP生化出水进行混凝,随着Al2(SO4)3用量的增加,COD值先降低后增加;用量为1kg/t时,COD降至最低值92mg/L。混凝放大实验时,废水量增加,处理效果增强至89.61%。对COD为94.1mg/L的混凝出水,采用芬顿高级氧化工艺进行深度处理,正交实验知,依据影响程度,以COD为指标的优组合条件为:H2O2为0.05kg/t,p H为3,Fe2+为1.20kg/t,Time为40min;以色度为指标的优组合条件为H2O2为0.15kg/t,p H为3,Fe2+为1.20kg/t,Time为40min。在优组合条件下进行验证实验,COD为48mg/L,色度为12度,达到废水排放标准。     

涤纶织物掺杂La~(3+)的TiO_2/SiO_2水溶胶抗静电整理

采用掺La3+-TiO2/SiO2复合水溶胶对涤纶织物进行抗静电整理。测试了整理后织物的感应电压、半衰期和摩擦电荷面密度,优化了整理工艺,并探讨了掺La3+-TiO2/SiO2复合水溶胶的抗静电机理。结果显示,TiO2/SiO2复合水溶胶整理涤纶织物的抗静电性能大大提高,不同配比TiO2/SiO2复合水溶胶整理织物的抗静电效果差别不大;掺杂La3+的复合水溶胶能进一步提高涤纶织物的抗静电性能;当水溶胶的浓度为0.1 mol/L以上,掺La3+量为0.3%,采用轧烘沸煮工艺,涤纶织物的抗静电性能最佳,织物经20次皂洗后仍具有一定的抗静电性能。     

化学絮凝法在造纸白水处理中的应用

造纸白水用絮凝剂处理后CODCr、浊度去除明显,通过对比聚合碱式氯化铝(PAC)、聚合硫酸亚铁(PFS)、聚硅硫酸铝(PASS)3种不同的絮凝剂与助凝剂阳离子聚丙烯酰胺(PAM)配合处理造纸白水的结果发现,PASS絮凝效果最佳.研究表明,PASS与PAM配合处理白水的最佳条件:PASS用量100 mg/L,PAM用量2 mg/L,pH值7.0,在最佳絮凝条件下,CODCr、浊度的去除率分别为93%、98.2%.     

聚硅酸铝铁絮凝剂在造纸废水深度处理中的应用

研究了以硫酸铝、硫酸铁、硅酸钠、浓硫酸和氢氧化钠等为原料制备的无机高分子絮凝剂聚硅酸铝铁(Polysilicate Ferro-Aluminum Sulfate,简称PSAF)对废纸造纸废水三级出水深度处理的效果。考察了n(Si)/n(Al)/n(Fe)、pH和PSAF用量等因素对去除造纸废水的色度及COD Cr处理效果的影响,并且与PAC进行了处理效果对比。结果表明:Si/(Al3++Fe3+)=1.5:1、Al3+/Fe3+=2:1、废水pH=6,温度为40℃,PSAF投加量200mg/L时,PSAF对废水的色度和COD Cr有比较好的去除效果。同样的投加条件下,PSAF效果优于PAC。     

淀粉接枝聚丙烯酰胺用于漂白废水处理

研究了淀粉接枝聚丙烯酰胺作为絮凝剂对漂白废水进行处理,通过实验比较了淀粉接枝聚丙烯酰胺絮凝剂与其他絮凝剂对漂白废水的絮凝效果,确定了淀粉接枝聚丙烯酰胺絮凝剂和明矾[Al2（SO4）3]配合使用的合适比例。结果表明：不同絮凝剂对漂白废水的絮凝效果好坏依次是Al2（SO4）3/St-PAM、St-PAM、PAM、Al2（S04）3。采用Al2（SO4）3和St-PAM混合使用时,Al2（SO4）3和St-PAM的最佳配比为1：1。     

Arsenate and arsenite adsorption and desorption behavior on coprecipitated aluminum:iron hydroxides

Although arsenic adsorption/desorption behavior on aluminum and iron (oxyhydr)oxides has been extensively studied, little is known about arsenic adsorption/desorption behavior by bimetal Al:Fe hydroxides. In this study, influence of the Al:Fe molar ratio, pH, and counterion (Ca2+ versus Na+) on arsenic adsorption/desorption by preformed coprecipitated Al:Fe hydroxides was investigated. Adsorbents were formed by initial hydrolysis of mixed Al3+/ Fe3+ salts to form coprecipitated Al:Fe hydroxide products. At Al:Fe molar ratios < or = 1:4, Al3+ was largely incorporated into the iron hydroxide structure to form a poorly crystalline bimetal hydroxide; however, at higher Al:Fe molar ratios, crystalline aluminum hydroxides (bayerite and gibbsite) were formed. Although approximately equal As(V) adsorption maxima were observed for 0:1 and 1:4 Al:Fe hydroxides, the As(III) adsorption maximum was greater with the 0:1 Al: Fe hydroxide. As(V) and As(III) adsorption decreased with further increases in Al:Fe molar ratio. As(V) exhibited strong affinity to 0:1 and 1:4 Al:Fe hydroxides at pH 3-6. Adsorption decreased at pH > 6.5; however, the presence of Ca2+ compared to Na+ as the counterion enhanced As( retention by both hydroxides. There was more As(V) and especially As(III) desorption by phosphate with an increase in Al:Fe molar ratio.     

聚合硅酸硫酸铝的铝形态及其水解稳定性

利用２７Ａｌ核磁共振技术分析了聚合硅酸硫酸铝的铝形态,发现铝单双核组分随碱化度的提高和硅铝比的降低而增加,表明硅的引入相对降低了聚合硅酸硫酸铝的聚合程度。但未发现Ａｌ１３的存在。聚合硅酸硫酸铝的水解稳定性随其聚合程度的提高及水解ｐＨ值的增加而下降。     

Impact of interactions between metal oxides to oxidative reactivity of manganese dioxide

Manganese oxides typically exist as mixtures with other metal oxides in soil-water environments; however, information is only available on their redox activity as single oxides. To bridge this gap, we examined three binary oxide mixtures containing MnO(2) and a secondary metal oxide (Al(2)O(3), SiO(2) or TiO(2)). The goal was to understand how these secondary oxides affect the oxidative reactivity of MnO(2). SEM images suggest significant heteroaggregation between Al(2)O(3) and MnO(2) and to a lesser extent between SiO(2)/TiO(2) and MnO(2). Using triclosan and chlorophene as probe compounds, pseudofirst-order kinetic results showed that Al(2)O(3) had the strongest inhibitory effect on MnO(2) reactivity, followed by SiO(2) and then TiO(2). Al(3+) ion or soluble SiO(2) had comparable inhibitory effects as Al(2)O(3) or SiO(2), indicating the dominant inhibitory mechanism was surface complexation/precipitation of Al/Si species on MnO(2) surfaces. TiO(2) inhibited MnO(2) reactivity only when a limited amount of triclosan was present. Due to strong adsorption and slow desorption of triclosan by TiO(2), precursor-complex formation between triclosan and MnO(2) was much slower and likely became the new rate-limiting step (as opposed to electron transfer in all other cases). These mechanisms can also explain the observed adsorption behavior of triclosan by the binary oxide mixtures and single oxides.     

聚合硅酸硫酸铝的动电特性

利用微电泳技术对聚合硅酸硫酸铝的动电特性研究表明：聚合硅酸硫酸铝的等电点和硫酸铝相近,约为pH值5,但其所带电荷的绝对值高于硫酸铝,且碱化度和硅铝比提高,均可不同程度地提高其可测Zeta电位的绝对值;水解过程中的搅拌作用可增加聚合硅酸硫酸铝的可测Zeta电位的绝对值,但不会改变其等电点;水中杂离子使聚合硅酸硫酸铝稀释后的pH值较高,所带电荷的绝对值降低,但却使其等电点向高pH值方向移动;水解时间对聚合硅酸硫酸铝Zeta电位的测定影响不大。     

Ceramsite made with water and wastewater sludge and its characteristics affected by SiO2 and Al2O3

To solve the disposal problems of residual sludges, wastewater treatment sludge (WWTS) and drinking-water treatment sludge (DWTS) were tested as components for production of ceramsite. SiO2 and Al2O3 were the major acidic oxides in WWTS and DWTS, so their effect on characteristics of ceramsite was also investigated to optimize the process. Results show that WWTS and DWTS can be utilized as resources for producing ceramsite with optimal contents of SiO2 and Al203 ranging 14-26% and 22.5-45%, respectively. Ceramsite within the optimal SiO2 and Al2O3 contents ranges was characterized using thermal analysis, X-ray diffraction (XRD), morphological structures analyses, and compressive strength measurements. Significant weight loss below 600 degrees C is through the release of structural water and gases. Bloating and crystallization in ceramsite above 900 degrees C are caused by the oxidation and volatilization of inorganic substances. Higher strength ceramsite with less Na-Ca feldspars and amorphous silica and more densified surfaces can be obtained at 18% < or = Al203 < or = 26% and 30% < or = SiO2 < or = 45%, while porous ceramsite with complex crystalline phases and lower strength can be obtained at 14% < or = Al2O3 < 18% and 22.5% < or = SiO2 < 30%. This revolutionary technology of utilization of WWTS and DWTS can produce high performance ceramsite, in accordance with the concept of sustainable development.     

Analytical methods for SiO2 and other inorganic oxides in titanium dioxide or certain silicates for food additive specifications

An analytical method has been developed for the detection of SiO(2) and other oxides in titanium dioxide and certain silicates used in food additives using inductively coupled plasma (ICP) atomic emission spectrometry without hydrofluoric acid. SiO(2) and other oxides in titanium dioxide or certain silicates were resolved by alkali fusion with KOH and boric acid and then dissolved in dilute hydrochloric acid as a test solution for ICP. The recovery of SiO(2) and Al(2)O(3) added at 0.1 and 1.0%, respectively, in TiO(2) was 88-104%; coefficient of variation was <4%. The limit of determination of SiO(2) and Al(2)O(3) was about 0.08%, and the accuracy of the ICP method was better than that of the Joint FAO/WHO Expert Committee on Food Additives (JECFA) test method. The recovery of SiO(2) and other oxides in silicates was 95-107% with a coefficient of variation of <4%. Using energy dispersive X-ray fluorescence spectrometry (EDX) with fundamental parameter determination, the content of SiO(2) and other oxide in titanium dioxide and silicate showed good agreement with the ICP results. ICP with alkali fusion proved suitable as a test method for SiO(2), Al(2)O(3) and other oxides in titanium dioxide and certain silicates, and EDX proves useful for screening such impurities in titanium dioxide and componential analysis of certain silicates.     

Use of spectroscopic techniques for uranium(VI)/montmorillonite interaction modeling

To experimentally identify both clay sorption sites and sorption equilibria and to understand the retention mechanisms at a molecular level, we have characterized the structure of hexavalent uranium surface complexes resulting from the interaction between the uranyl ions and the surface retention groups of a montmorillonite clay. We have performed laser-induced fluorescence spectroscopy (LIFS) and X-ray photoelectron spectroscopy (XPS) on uranyl ion loaded montmorillonite. These structural results were then compared to those obtained from the study of uranyl ions sorbed onto an alumina and also from U(VI) sorbed on an amorphous silica. This experimental approach allowed for a clear determination of the reactive surface sites of montmorillonite for U(VI) sorption. The lifetime values and the U4f XPS spectra of uranium(VI) sorbed on montmorillonite have shown that this ion is sorbed on both exchange and edge sites. The comparison of U(VI)/clay and U(VI)/oxide systems has determined that the interaction between uranyl ions and montmorillonite edge sites occurs via both [triple bond]AlOH and [triple bond]SiOH surface groups and involves three distinct surface complexes. The surface complexation modeling of the U(VI)/montmorillonite sorption edges was determined using the constant capacitance model and the above experimental constraints. The following equilibria were found to account for the uranyl sorption mechanisms onto montmorillonite for metal concentrations ranged from 10(-6) to 10(-3) M and two ionic strengths (0.1 and 0.5 M): 2[triple bond]XNa + UO2(2+) <==> ([triple bond]X)2UO2 + 2Na+, log K0(exch) = 3.0; [triple bond]Al(OH)2 + UO2(2+) <==> [triple bond]Al(OH)2UO2(2+), log K0(Al) = 14.9; [triple bond]Si(OH)2 + UO2(2+) <==> [triple bond]SiO2UO2 + 2H+, log K0(Si1) = -3.8; and [triple bond]Si(OH)2 + 3UO2(2+) + 5H2O <==> [triple bond]SiO2(UO2)3(OH)5- + 7H+, log K0(Si2) = -20.0.     

Aluminum control of phosphorus sorption by lake sediments

Release of reactive (phosphate-like) phosphorus (P) from freshwater sediments represents a significant internal P source for many lakes. Hypolimnetic P release occurs under reducing conditions that cause reductive dissolution of ferric hydroxide [Fe(OH)3]. This hypolimnetic P release may be naturally low or artificially reduced by sediment with naturally high or artificially elevated concentrations of aluminum hydroxide [Al(OH)3]. We presentfield and laboratory data for a common extraction analysis of sediments from 43 lakes differing in trophic status, pH regime, climate, and P loading. The results indicate that a simple sequential extraction of sediment may be a useful predictor of sediment's ability to release P. Sequential extractions of sediment P, Al, and Fe by water (H2O), bicarbonate-dithionite (BD), and NaOH (at 25 degrees C) showed that negligible amounts of P would be released from lake sediments during hypolimnetic anoxia if either (1) the molar Al(NaOH-25):Fe(BD) ratio is > 3 or (2) the molar Al(NaOH-25):P(H2O+BD) ratio is > 25. These ratios can be used as operational targets for estimation of sediment P release potential and Al dosing of P-rich sediment to prevent hypolimnetic P release under anoxic conditions.     

纳米复合磷钨酸催化合成琥珀酸二乙酯的研究

以纳米型H3PW12O40/SiO2为催化剂,琥珀酸和乙醇为原料合成琥珀酸二乙酯。实验结果表明,纳米复合磷钨杂多酸是合成琥珀酸二乙酯的良好催化剂,适宜的工艺条件为酸醇物质的量比为1∶6、催化剂用量为5%、反应时间为5h,此时酯化率可达92%。     

磁性催化剂Na2O·SiO2/Fe3O4的制备及其催化酯交换反应

以Na2SiO3为活性物质,以纳米Fe3O4为磁核制备磁性固体碱催化剂Na2O·SiO2/Fe3O4,通过正交实验,得到催化剂的最佳制备条件为：硅与铁的摩尔比2.5,晶化时间2h,煅烧温度350℃,煅烧时间2.5h,并通过震动样品磁强计（VSM）对催化剂的磁性进行表征。结果表明,所制备的催化剂Na2O·SiO2/Fe3O4具有较好的磁性和顺磁性,抗水性能优于传统均相碱催化剂;将其应用于棉籽油酯交换反应制备脂肪酸甲酯的最优工艺参数为：醇油摩尔比7：1,催化剂加入量5%,反应温度65℃,反应时间1h,搅拌速度400r/min,在此条件下,催化棉籽油酯交换反应转化率为99.6%,连续使用11次后活性仍在90%以上。