Spatial variations of aluminum species in drinking water supplies in Xi'an studied applying geographic information system

This article aimed to investigate the variation of aluminum species and the effects of coagulant type and water quality on aluminum speciation in drinking water. Statistical analysis showed that the concentration of total aluminum （AlT） of drinking water in Xi＇ an ranged from 0.051 to 0.417 mg/L and the concentration of A1T in about 24.7% studied samples was higher than the currently recommended value （0.2 mg/L）. The areas fed by surface water plants had a larger portion （39.4%） of samples over the recommended value. In drinking water treated by alum coagulant, the average concentration of monomeric aluminum （Ala） was higher than that in water treated by poly aluminum chlorine （PACl） and poly aluminum ferric chloride （PAFC）. The average concentrations of polynuclear aluminum （Alb） and colloidal/suspended aluminum （Ale） in the drinking water treated by alum were lower than those in water treated by PACl and PAFC. There was a notable decrease in AlT along with the delivery pipeline away from the plants, with an average decline of about 36 μg/（L-km）. Besides coagulant type, water quality also could affect aluminum speciation. In drinking water without orthophosphate, the concentrations of Ala and AlT were positively correlated with pH; while, in drinking water with orthophospbate, the concentrations of Ala and AlT were negatively correlated with pH. The addition of orthophosphate salts in the drinking water treatment process would be an effective method for aluminum control in pH range 6.5-8.2.

Chemical Species of Aluminum Ions in Acid Soils *1

Soil samples collected from several acid soils in Guangdong, Fujian, Zhejiang and Anhui provinces of the southern China were employed to characterize the chemical species of aluminum ions in the soils. The proportion of monomeric inorganic Al to total Al in soil solution was in the range of 19% to 70%, that of monomeric organic Al (Al OM) to total Al ranged from 7.7% to 69%, and that of the acid soluble Al to total Al was generally smaller and was lower than 20% in most of the acid soils studied. The Al OM concentration in soil solution was positively correlated with the content of dissolved organic carbon (DOC) and also affected by the concentration of Al 3+ . The complexes of aluminum with fluoride (Al F) were the predominant forms of inorganic Al, and the proportion of Al F complexes to total inorganic Al increased with pH. Under strongly acid condition, Al 3+ was also a major form of inorganic Al, and the proportion of Al 3+ to total inorganic Al decreased with increasing pH. The proportions of Al OH and Al SO 4 complexes to total inorganic Al were small and were not larger than 10% in the most acid soils. The concentration of inorganic Al in solution depended largely on pH and the concentration of total F in soil solution. The concentrations of Al OM, Al 3+ ,Al F and Al OH complexes in topsoil were higher than those in subsoil and decreased with the increase in soil depth. The chemical species of aluminum ions were influenced by pH. The concentrations of Al OM, Al 3+ , Al F complexes and Al OH complexes decreased with the increase in pH.

Chemical species distribution and transformation in polyaluminum chemical solutions

The hydrolysis polymerization precipitation process of Al(III) was studied with pH titration method, and the prepared polyaluminum solutions were characterized by various experimental methods: acid depolymerization, timed complex-colorimetric procedure, ultrafiltration, X-ray diffraction and infrared absorption spectrum. The results showed that the chemical species transformation and distribution of Al(III) in the hydrolysis-polymerization process depended on B=(OH/Al) ratio, pH and other factors. By their structures, the chemical species can be divided into three categories of monomeric (Ala), polymeric (Alb), sol or gel precipitates (Alc) and the polymeric species may be further divided into three groups such as linear low polymer (Alb1), linear high polymer (Alb2) and high polymer with cyclic structure (Alb3). The nominal molecular weight of polymeric species obtained by ultrafiltration was about 1000-50000 and most of them failed into a range around 10000. A scheme for the chemical speciation model of Al(III) solution was suggested.

Effects of Tannic Acid on Active Aluminum Species Distribution in Various Tea Soils

Effects of tannic acid on active aluminum species distribution in different pH tea soils in Yunnan and Jiangxi tea gardens were studied by field observation and laboratory analysis.There were 4 species of active aluminum in the tea soil,i.e.,exchangeable aluminum Al3 +,unimer hydroxyl aluminum Al(OH)2 +Al(OH)+2,acid-soluble aluminum Al(OH)03and humic-acid aluminum Al-HA.Experimental results showed that tannic acid at levels 0 ~0.4 mmol/kg and 0 ~ 2.0 mmol/kg,with the rising of soil pH value,the content of exchangeable aluminum decreased significantly,hydroxyl aluminum,acid-soluble aluminum and humic-acid aluminum were increased gently.When the concentration of tannic acid increased to above 2.0 mmol/kg,the inhibition of higher concentration of tannic acid on content of active aluminum was strengthened with the rising of soil pH value and variation law of 20 ~ 40 cm soil layer was similar to 0 ~ 20cm soil layer.Generally speaking,the content of active aluminum in upper layer of soil were more than subsoil and total content of active aluminum in Yunnan tea soils were higher than Jiangxi tea soils.The correlation analysis showed that the soil pH were positively correlated with hydroxyl aluminum,humic-acid aluminum,pHBC(r = 0.796,0.960,0.852;p < 0.01,0.01,0.01) in 0 ~ 20cm soil layer.pHBC were significant negative correlated with exchangeable aluminum(r =- 904,p < 0.01),hydroxyl aluminum(r =- 645,p < 0.05),and with humic-acid aluminum have a positive correlation,correlation coefficient was0.795(P < 0.05).Meanwhile,the tannic acid addition concentration were 0 ~ 0.4 mmol/kg soils pH were increased significantly,while samples attains a peak pH value afterwards decrease continuously,the relationship between the pH and the concentration of tannic acids accords with the equation:Y pH=- 0.04C DN+3.82(R2= 0.95,P < 0.01).When the concentration of tannic acid up to about 8.0 ~ 12.0 mmol/kg,soil pH keep unchanged.Therefore,we can clearly draw that effects of tannic acid on active aluminum content of the inflection point is not the same in different region of tea garden soil.Low concentration tannic acid can improve the soil content of various forms of aluminum,but with the increase in the amount of tannic acid,the various forms of aluminum content are inhibited.With the soil pH increased,high concentrations tannic acid on the inhibition of the release of active aluminum increased.pH and tannic acid on the total amount of active aluminum garden soil was mutual weakening effect relationship.

Effects of fulvic acid and humic acid on aluminum speciation in drinking water

This article focused on the influences of fulvic acid and humic acid on aluminum speciation in drinking water. Factors including the concentration of residual chlorine and pH value had been concerned. Aluminum species investigated in the experiments included inorganic mononuclear, organic mononuclear, mononuclear, polymer, soluble, and suspended forms. It was found that the effects of fulvic acid and humic acid on aluminum speciation depended mainly on their molecular weight. Fulvic acid with molecular weight less than 5000 Dalton had little influence on aluminum speciation; while fulvic acid with molecular weight larger than 5000 Dalton and humic acid would increase the concentration of soluble aluminum significantly even at concentration below 0.5 mg/L （calculated as TOC）. Aluminum species, in the present of fulvic acid with molecular weight larger than 5000 Dalton and humic acid, were more stable than that in the present of fluvic acid with molecular mass less than 5000 Dalton, and varied little with reaction time. Within pH range 6.5-7.5, soluble aluminum increased notably in water with organic matter. As the concentration of residual chlorine increased, the effects of fulvic acid and humic acid became weak. The reactions between humic acid, fulvic acid with large molecular weight, and aluminum were considered to be a multi-dentate coordination process. With the consideration of aluminum bioavailability, reducing the concentration of fulvic acid and humic acid and keeping the pH value among 6.5-7.5 were recommended during drinking water treatment.

Species distribution of polymeric aluminium ferrum——timed complexation colorimetric analysis method of Al-Fe-Ferron

The effects of the calorimetric buffer solutions were investigated while the two colorimetric reactions of AI-ferron complex and Fe-ferron complex occurred individually, and the effects of the testing wavelength and the pH of the solutions were also investigated. A timed complexatian colorimetric analysis method of Al-Fe-ferron in view of the total concentration of {AI + Fe} was then established to determine the species distribution of polymeric Al-Fe. The testing wavelength was recommended at 362 net and the testing pH value was 5. With a comparison of the ratios of n(Al)/n(Fe), the standard adsorption curves of the polymeric Al-Fe solutions were derived from the experimental results. Furthermore, the solutions' composition were carious in both the molar n(Al)/n(Fe) ratios, i.e. 0/0, 5/5, 9/1 and 0/10, and the concentrations associated with the total ( Al + Fe which ranged from 10(-5) to 10(-4) mol/L..

骨粉生物质炭对酸性土壤的改良作用

以猪、鸡、牛和羊骨为原材料厌氧热解制备成生物质炭(骨炭)作为改良剂,探究骨炭最佳制备条件及其对酸性土壤改良效果,并从土壤固相和液相二个角度探究骨炭对酸性土壤铝(Al)形态的影响。结果表明:高温厌氧热解制备的骨炭富含CaO、CaCO_(3)和Ca_(5)(PO_(4))_(3)(OH),同时含有NaO、MgO等碱性物质及-OH等多种官能团。但骨炭碱含量受热解温度影响较大,鸡骨和牛骨在800℃、猪骨和羊骨在900℃时其炭碱含量接近峰值并保持稳定,约为生石灰的90%,是最佳制备温度。此温度下制备的四种骨炭均可有效地提高pH<6.0的酸性红黏土、红砂土和砖红壤pH。骨炭中的碱性物质主要以H+缓冲剂的形式存在,从而导致其提高土壤pH的幅度与初始土壤pH成反比。pH=4.40的红黏土中添加5 g·kg^(-1)猪、鸡、羊和牛骨炭后土壤溶液Al浓度分别较对照降低33%、34%、47%和41%,固相有机结合态Al含量无显著变化(P>0.05)。骨炭增加了酸性土壤阳离子交换量,并通过促进活性Al向土壤固相吸附态羟基Al和更稳定态Al转化从而降低土壤溶液Al及交换态Al含量。骨炭富含植物生长所需营养元素,具备无机和有机改良剂的双重特性,是可替代传统石灰作为酸性农田土壤改良剂的优质材料。

4种乡土树种幼苗对酸铝胁迫的响应差异分析

【目的】酸铝毒害是南方人工林培育中常见的生产性问题。本文旨在探究乡土树种对酸铝胁迫的抗性差异,为人工林高效栽培提供参考。【方法】本试验以红锥、荷木、樟树、火力楠4种南方主要乡土造林树种为研究对象,在人工控制环境条件下,通过水培法,分析了不同酸铝处理下,各树种幼苗生长生理方面的变化。【结果】在pH 5.0、无铝添加处理下,供试树种幼苗均遭受到了酸胁迫伤害,幼苗存活率下降,叶绿素含量、净光合速率(Pn)、水分利用效率(WUE)、气孔导度(Gs)降低,蒸腾速率(Tr)、丙二醛(MDA)含量升高,POD、SOD活性增大。在pH 5.0+0.5~1.5 mmol·L^(-1)硫酸铝复合胁迫下,随着铝添加浓度增加,幼苗存活率减小,叶绿素含量、Pn、WUE、Ci降低,MDA含量增大,Gs先下降后上升,POD、SOD活性先增大后减小的趋势。通过主成分分析评价,在无铝添加的酸胁迫下,以荷木的抗性最强,其次为火力楠、樟树、红锥,而在酸铝复合胁迫下,供试4个树种的抗性表现为:火力楠>荷木>红锥>樟树。【结论】相较樟树、红锥,火力楠、荷木抗酸铝毒害能力较强。

Transfer and transport of aluminum in filtration unit

Aluminum salt coagulants were used prevalently in various water works. In this article, the effects of filtration on residual aluminum concentration and species distribution were researched by determining the concentration of different aluminum species before and after single layer filter, double layer filter, and membrane filtration units. In the research, size exclusion chromatography （SEC） was used to separate colloidal and soluble aluminum, ion exchange chromatography （IEC） was used to separate organic and inorganic aluminum, and inductivity coupled plasma-atomic emission spectrometry （ICP-AES） was used to determine the aluminum concentration. The results showed that the rapid filtration process had the ability of removing residual aluminum from coagulant effluent water, and that double layer filtration was more effective in residual aluminum removal than single layer filtration, while nano filtration was more effective than micro filtration. It was found that when the residual aluminum concentration was below lmg/L in sediment effluent, the residual aluminum concentration in treated water was above 0.2 mg/L. The direct rapid filtration process mainly removed the suspended aluminum. The removal of soluble and colloidal aluminum was always less than 10% and the natural small particles that adsorbed the amount of soluble or small particles aluminum on their surface were difficult to be removed in this process. Micro filtration and nano filtration were good technologies for removing aluminum; the residual aluminum concentration in the effluent was less than 0.05 mg/L.

Effect of Electrolyte on the Dissolution of Aluminum from Acid Soils and the Distribution of Aluminum Forms inSoil Solution

KCl, CaCl2, NH4Cl, NaCl, K2SO4 and KF solutions were used for studying the effects of canons and anions on the dissolution of aluminum and the distribution of aluminum forms respectively. Power of exchanging and releasing aluminum of four kinds of canons was in the decreasing order Ca2+ >K+ >NH+4 >Na+.The dissolution of aluminum increased with the canon concentration. The adsorption affinity of various soils for aluminum was different. The aluminum in the soil with a stronger adsorption affinity was difficult to be exchanged and released by canons. The Al-F complexes were main species of inorganic aluminum at a low concentration of canons, while Al3+ became major species of inorganic aluminum at a high concentration of canons. The results on the effect of anions indicated that the concentrations of total aluminum, three kinds of inorganic aluminum (Al3+, Al-F and Al-OH complexes) and organic aluminum complexes (Al-OM)when SO2-4 was added into soil suspension were lower than those when Cl- was added. The dissolution of aluminum from soils and the distribution of aluminum forms in solution were edicted by the adsorption of Fon the soil. For soils with strong affinty for F- , the concentrations of the three inorganic aluminum species in soil solution after addition of F- were lower than those after addition of Cl-; but for soils with weak affinity for F- , the concentrations of Al3+ and Al-OM were lower and the concentrations of Al-F complexes and total inorganic aluminum after addition of F- were higher than those after addition of Cl-. The increase of F- concentration in soil solution accelerated the dissolution of aluminum from soils.

靛蓝废水无机盐环境下铝极板溶解与电化学行为分析

为提升靛蓝染色废水电絮凝效率,确定电絮凝过程中最佳水解金属盐形态形成条件,采用Al-Ferron逐时络合比色法探讨电絮凝过程中初始pH、共存阴离子种类、电流密度对铝盐形态分布的影响,同时监测絮体Zeta电位、终止pH、体系电流密度与电导率的变化。通过显微镜观察电极溶解腐蚀情况,利用电化学工作站测定电极的极化曲线与电化学阻抗谱,分析其电化学行为。结果表明,靛蓝废水电絮凝过程中,最佳初始pH范围为6~7,此时具有优势絮凝形态的中聚合态铝(Al_(b))含量较高;Cl–的加入可抑制电极钝化,提升电絮凝反应速率;低电流密度有利于电极均匀腐蚀和Al_(b)的存在,当电流密度为15 m A/cm(2)时体系内Al_(b)含量达4.76 mg/L,可产生较好的絮凝效果。

铝胁迫下不同小麦基因型根尖多胺含量变化与耐铝性的关系

为探明铝胁迫下多胺种类和含量变化与小麦耐铝性的关系,以小麦耐铝基因型西矮麦1号和铝敏感基因型扬麦5号为试验材料,分析了对照和铝胁迫(30μmol·L^(-1) AlCl 3)条件下,两个小麦基因型幼苗根尖多胺种类和含量、根系伸长、氧化损伤和活性氧产生等指标的差异。结果表明,随铝胁迫时间的延长,小麦幼苗根系伸长量逐渐降低,但西矮麦1号显著高于扬麦5号。铝胁迫24 h后,2个小麦基因型根尖铝含量、膜脂过氧化程度、Evans blue吸收量、活性氧含量均显著升高,且西矮麦1号各指标均显著低于扬麦5号。铝胁迫下2个小麦基因型根尖腐胺总量随铝胁迫时间的延长均不同程度增加,西矮麦1号根尖腐胺总量增加时间明显早于扬麦1号,且前者增加幅度明显高于后者。相反,根尖亚精胺总量随铝胁迫时间的延长显著降低,西矮麦1号的降幅明显小于扬麦5号。添加腐胺合成抑制剂(D-Arg)显著加剧了铝诱导的氧化损伤,且对西矮麦1号的加剧作用较明显。这说明铝诱导的小麦多胺水平变化与耐铝性密切相关,腐胺总量的增加可能是耐铝的重要机制,而亚精胺总量的降低可能与小麦铝敏感性有关。

水处理工艺中铝盐水解物的毒性、形态及控制研究进展

铝盐混凝剂因其形成絮体大而密实,具有较好的除浊脱色性能,在混凝领域广泛应用,但却存在处理水铝残留问题。本文为更好地促进铝盐混凝剂在水处理领域的应用,详细介绍了铝盐水解物对人体的毒性效应、对输配水管网系统和饮用水深度处理工艺的影响。总结了残留铝生成机理和形态分析方法,阐述了优势形态Al_(13)和Al_(30)的水解过程以及其发挥优势混凝作用的原因。分析了原水水质条件、化学条件、水力条件和前期预处理对残留铝含量的影响。最后,点明了未来控制残留铝的策略和技术。指出未来应结合人工智能复配合成纳米级新型混凝剂,关注混凝过程中水力条件对残留铝的影响,并开发能够精准测量分析水中各类铝形态的方法,不断创新强化净水工艺,进一步完善残留铝控制措施,保障出水水质安全。

Profiles of and variations in aluminum species in PAC-MC used for the removal of blooming microalgae

Polyaluminum chloride modified clay(PAC-MC)is a safe and efficient red tide control agent that has been studied and applied worldwide.Although it is well known that the distribution of hydrolytic aluminum species in PAC affects its flocculation,little is known about the influence of particulars aluminum species on the microalgae removal efficiency of PAC-MC;this lack of knowledge creates a bottleneck in the development of more efficient MCs based on aluminum salts.The ferron method was used in this study to quantitatively analyze the distributions of and variations in different hydrolytic aluminum species during the process of microalgae removal by PAC-MC.The results showed that Ala,which made up 5%–20%of the total aluminum,and Alp,which made up 15%–55%of the total aluminum,significantly affected microalgae removal,with Pearson’s correlation coefficients of 0.83 and 0.89,respectively.Most of the aluminum in the PAC-MC sank rapidly into the sediments,but the rate and velocity of settlement were affected by the dose of modified clay.The optimal dose of PAC-MC for precipitating microalgae was determined based on its aluminum profile.These results provide guidance for the precise application of PAC-MC in the control of harmful algal blooms.

土壤酸化及天然土壤溶液中铝的形态

采用真空式土壤溶液采样器收集了宜昌、巫山松树林中天然土壤溶液，采用高效液相色谱法Ａｌ－Ｌｕｍｏｇａｌｌｉｏｎ柱后荧光检测，分析测试了土壤溶液中可溶性铝的形态，研究了由于土壤酸化引起天然土壤溶液中不同形态铝的迁移转化结果表明，天然土壤溶液中含有不同形态的铝，主要是有机铝、 ＡＩＳＯ４＋、 ＡＩＦ２＋、 Ａｌ（ＯＨ）２＋、 Ａｌ３＋等．宜昌、巫山地区土壤溶液中活性铝（Ａｌ３＋、 ＡｌＯＨ２＋）的含量比较低．土壤的酸化使得天然土壤溶液中总铝含量增加、铝形态的优势态发生变化，即土壤的酸化使得天然土壤溶液中活性铝－Ａｌ３＋、ＡｌＯＨ２＋含量和比例增加．土壤酸化还降低了大然土壤溶液中的ＢＣ／Ａｌ比值，这些变化的结果都增加了对森林潜在的危害．

羟基聚合氯化铝铁溶液的形态转化规律

采用改进的 Al- Fe- Ferron逐时络合比色法和酸滴定实验研究了典型羟基聚合铝铁 (n Al/n Fe=9∶ 1 ,5∶ 5)溶液的形态转化 .结果表明 ,羟基聚合铝铁的形态转化主要由 n Al/n Fe值、碱化度和熟化等因素决定 ;羟基聚合铝铁的形态转化特征是优势形态之间的转变 ;当 n Al/n Fe>5∶ 5,随碱化度的升高 ,[Al+Fe]a和 [Al+Fe]b 2类形态逐渐占优势 ;随 n Al/n Fe值的减小 ,[Al+Fe]a和 [Al+Fe]c增加 ,而 [Al+Fe]b 减少 .讨论了羟基聚合铝铁的形态转化规律 .

PSAA水溶液中铝形态分布研究

ＰＳＡＡ是一种含有铝离子的聚硅酸絮凝剂。本文用２７Ａｌ－ＮＭＲ法和Ａｌ－Ｆｅｒｒｏｎ逐时络合比色法研究了ＰＳＡＡ水溶液中铝的形态分布情况，考察了ＳｉＯ２／Ａｌ３＋摩尔比，温度及稀释作用对铝的形态分布的影响。结果表明，ＰＳＡＡ水溶液中的铝主要是以单核羟铝络合物形式存在，聚硅酸的存在对铝的形态分布影响不大，温度对铝的形态分布无影响，稀释作用对铝的形态分布有一定的影响。

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。

Al-Ferron逐时络合比色法研究PACS中铝的水解聚合形态

制备了碱化度(B)及不同Al^(3+)/SO_4^(2-)摩尔比的系列PACS,用Al-Ferron逐时络合比色法研究了铝的形态分布,考察了碱化度(B)、Al^(3+)/SO_4^(2-)摩尔比、稀释作用及pH值对铝的形态分布的影响.实验结果表明,Al^(3+)/SO_4^(2-)摩尔比及溶液的pH值对铝的形态分布有较大的影响,稀释作用对铝的形态分布影响较小.Al^(3+)/SO_4^(2-)摩尔比愈小,pH值愈高,铝的水解聚合大分子及胶体粒子所占的比例就愈大.

聚合氯化铝混凝性能的影响因素研究

聚合氯化铝是目前最广泛使用的高效混凝剂,它具有用量少、污泥少、除浊高、对出水pH影响小等优点。聚合氯化铝是一系列介于Al3+和氢氧化铝之间聚合物的复合体,对于何种物种起到决定性的混凝效果,目前尚没有公认的结论。通过对不同生产工艺得到的商品聚合氯化铝进行聚合物种类的研究,并结合混凝实验,发现高分子聚合氯化铝对混凝效果发挥了更大的作用。