Adsorption Characteristics of Arsenite and Arsenate on Hydrous Ceric Oxide

以开发新型高效除砷吸附材料为目的 ,在室温 (2 5℃ ) ,初始浓度 0 .0 5～ 2 5 0mg/L ,pH4～ 11条件下 ,对稀土材料氢氧化铈 (HCO)进行了吸附除砷的性能评价 .实验结果表明 ,在实验条件下 ,HCO对亚砷酸和砷酸阴离子都显示了良好的吸附效果 ,其吸附等温线能很好地用Langmuir方程进行描述 .对于低浓度 (0 0 5～ 10mg/L)的砷溶液 ,HCO在所选 pH条件下对亚砷酸和砷酸阴离子的吸附率可达 10 0 % .对于高浓度的砷溶液 ,偏酸性 (pH 4 )条件有利于砷酸阴离子 ,而中性 /微碱性 (pH 7,8)条件最有利于亚砷酸阴离子的吸附 .HCO对 2种形态的砷阴离子的吸附效应在较宽 pH范围内同溶液的离子强度基本无关 ,常见阴离子 (Cl-,NO-3 ,SO2 -4)的存在对砷的吸附也未显示出干扰效应 .从实验结果推测 ,HCO吸附亚砷酸和砷酸阴离子的主要反应机理应属于专性吸附Seeking to develop novel adsorbents for arsenic removal from polluted water, adsorption isotherms of arsenite and arsenate in aqueous solutions at room temperature (25℃) onto hydrous ceric oxide (HCO), CeO 2·xH 2O, were studied over the arsenic concentration range 0.05～250 mg/L and the pH range 4～11. The HCO adsorbent proved to be effective to remove both arsenite and arsenate from water. These isotherms fit well in the Langmuir model of adsorption. At the lower concentration range of 0.05～10 mg/L As, adsorption of both arsenic anions was virtually independent of pH and up to 100% removal can be achieved. At higher concentrations, a pH of 4 is optimum for arsenate adsorption, whereas adsorption of arsenite goes through a maximum at approximately pH 7 to 8. Both adsorption processes were little influenced by changing ionic strength in a wide pH range. The presence of common anions such as Cl -, NO - 3, and SO 2- 4 had no interference in the removal processes. The principal adsorption mechanism is presumed that arsenite and arsenate are specifically adsorbed onto HCO surfaces

Adsorption Characteristics of Arsenic in Water by Cerous Hydroxide

研究了氢氧化铈对水中砷的吸附特性,结果表明:氢氧化铈对As(Ⅲ)和As(Ⅴ)均有良好的吸附效果,其吸附等温线能很好地用Langmuir方程描述。酸性条件下有利于As(Ⅴ)的吸收,而中性/微碱性条件下有利于As(Ⅲ)的吸收。氢氧化铈粉末粒径及共存离子对吸附效果影响甚微,通过TCLP测试可知吸附后的粉末对环境无二次污染。The adsorption characteristics of arsenic in water by cerous hydroxide were studied.The results showed that cerous hydroxide had well adsorption effect for trivalent arsenic and pentavalent arsenic.The adsorption isotherms fitted very well for Langmuir equation.It was more suitable to adsorb pentavalent arsenic in an acidic condition,whereas adsorb trivalent arsenic in neutrality/slightly alkaline conditions.The adsorption effect of particle diameter and the coexisted ions of cerous hydroxide were feeble.The powder after adsorption did not have secondary pollution to environment by TCLP test.福建省自然科学基金计划项目(D0510005

Heavy Metal Contamination in the Soil of a Copper Mine

通过对某铜矿区土壤重金属含量及化学形态分布进行分析,探讨了采矿过程中的重金属在土壤中的积累特征。结果表明,该矿区的Cu、zn、Pb、Cd、nI在土壤中的积累程度相当高。各采样点的重金属综合污染递减顺序依次为:堆浸泥>最后沉淀池>堆浸矿>堆浸土>金矿排污口污泥>原生土壤>铜矿区下游江边土壤。堆浸矿土壤的重金属以残渣态、水溶态、有机质硫化态这三种组分为主,而堆浸泥土壤则以fE-Mn氧化物结合态为主。Through analysis of heavy metals content and speciation in the soil of a copper ore area,accumulated characteristics of heavy metals in soil in the process of mining were discussed.Results indicated that copper,zinc,lead, cadmium and nickel have highly accumulated in the soil,with the descending order of the composite pollution degree of heavy metals in each sampling site as stack mud,final deposition,stack mine,stack soil,gold mine trough,natural soil and downriver of mining area.Heavy metals of stack mine were mainly in residual,aqueous and organic fraction,but heavy metals of stack mud were mainly in Fe-Mn oxides fraction.福建省自然科学基金项目资助(D0510005

以牡蛎壳为填料的好氧与厌氧生物滤池的脱色特性

以牡蛎壳为生物滤池的填料,在好氧和厌氧条件下,结果表明对多种模拟印染废水具有较好的脱色效果。以活性红为目标污染物,好氧/厌氧生物滤池的脱色率可分别达到99.5%和100.1%;进水pH从3～11范围内,好氧/厌氧生物滤池出水pH分别维持于7～8和6～7;与厌氧生物滤池相比,好氧生物滤池对COD具有较好的去除率,可达到95.9%。福建省中青年教师教育科研项目(JAT160018

Removal of As(V) and As(III) from aqueous solution using hydrous ceric oxide

Removal of As(V) and As(III) from water using hydrous ceric oxide, CeO(2)center dot xH(2)O (HCO) was investigated under different pH and As loading conditions, using batch equilibrium adsorption and FTIR methods. Adsorption of both As(V) and As(III) anions was virtually independent of pH and up to 100% removal can be achieved in the lower concentration range 0.5 - 5.0 mg L(-1) As at sorbent dosage of 1.0 g L(-1). As the initial As concentration increased to 50, 100 or 250 mg L(-1) for the same sorbent dosage, distinct adsorption maxima of As(V) appeared and shift to lower pH, whereas that of As(III) was found at approximately pH 8. The effect of contact time was dependent on pH but adsorption equilibriums were reached after 6 h in all cases for the studied systems. The isotherms fit well in the Langmuir model of adsorption. Both As(V) and As(III) anions were adsorbed on HCO principally by forming inner-sphere complexes as revealed by the FTIR spectra

Content and partitioning and study on removal technology of heavy metals in tentative dredged sediments of Xiamen western harbor

着重研究了厦门西海域拟疏浚物中重金属的含量和赋存形态,探讨了化学试剂浸提和曝气法去除重金属的可行性,为建立后续的去污染方案提供科学依据。厦门西海域拟疏浚物枯洪两季沉积物中重金属含量变化不大,枯季稍高于洪季。从经济角度考虑,选用C2H2O4、(nH4)2C2O4、EdTA作为浸提剂结合曝气和TClP翻转实验对厦门西海域代表性拟疏浚物样品(X5站位)进行了重金属去除试验。结果表明,几种溶剂中,C2H2O4的效果最好;在相同溶剂条件下,对多数重金属元素,曝气处理可以有效地提高去除率。Total content and partition of heavy metals in the tentative dredged sediments of Xiamen western harbor were studied with the aim to development of conventional decontamination technology.The chemical extraction repair heavy metals polluted soil used the chemical medicament to exchange hydronium,dissolve(in acid or alkali) and complexation.The variety of content of heavy metals in Xiamen western harbor is not evident between dry season and rain season,content of heavy metals in dry season is comparatively higher.This experiment consider from economical,choose ammonium oxalate,oxalic acid and EDTA as the chemical medicament,combining aeration and TCLP upturning,carry though attempt on removing the heavy metals of X5 sample station of Xiamen western harbor.The results showed that the effect of oxalic acid is the best of several chemical medicaments.Using the same chemical medicament,remove the heavy metals much more effective with aeration for most heavy metals

同步脱氮除磷技术研究进展

为避免造成水体富营养化,污水排放前必须进行脱氮除磷处理。与传统技术相比,新型同步脱氮除磷技术具有能耗低、占地小等特点,是污水处理领域中新的工程应用方向。介绍了生物法、物理化学法、生物电化学法和生物诱导矿化法4类同步脱氮除磷技术的原理、特点及影响因素。其中,生物诱导矿化法作为新型的生物-矿物结晶耦合处理技术,在降低运行成本和磷资源回收方面具有较大的优势,成为污水脱氮除磷领域的研究热点。国家自然科学青年基金项目(51808473)国家科技攻关计划项目(2016YFC0502901)国家自然科学基金项目(41771500)中国博士后科学基金项目(2017M610397

地热水温下α型活性氧化铝对砷的吸附动力学研究

4个地热水温下α型活性氧化铝(α-AA)吸附砷的动力学研究表明当PH=4.6时,α-AA对AS(Ⅲ)/AS(V)的吸附都是初始吸附速率快,达到吸附平衡需时短的过程;随温度升高,α-AA吸附AS(Ⅲ)/AS(V)的4H平衡吸附容量QE,EXP都无明显变化;α-AA吸附AS(Ⅲ)/AS(V)全过程符合拟二级动力学方程,0.25~1MIn内,α-AA对AS(Ⅲ)/AS(V)的吸附均符合ElOVICH方程,1~5MIn内,α-AA对AS(Ⅲ)的吸附属于颗粒内部扩散过程。国家自然科学基金项目No.21077086的支

Adsorption behavior of Fe-Mn binary oxide towards As(Ⅲ) and As(Ⅴ) and its application in biogas slurry

研究了铁锰复合氧化物(fMbO)吸附去除AS(Ⅲ)、AS(V)的性能。结果表明fMbO对AS(Ⅲ)、AS(V)均具有较好的吸附能力,其饱和吸附量分别为111.10、71.40 Mg·g-1。AS(Ⅲ)和AS(V)是通过与fMbO表面的fE—OH基团进行交换并形成内层络合物的形式被fMbO吸附,且AS(Ⅲ)的吸附是吸附和氧化共同作用的结果。另外,沼液中共存离子对AS(Ⅲ)和AS(V)的吸附有不同的影响。zn2+能够增加fMbO对AS(Ⅲ)、AS(V)的吸附量,且增加幅度随着zn2+浓度的增加而增加;磷酸根对AS(Ⅲ)、AS(V)的吸附有明显的抑制作用,当磷与砷的分子摩尔比为1时,fMbO对AS(Ⅲ)、AS(V)的吸附量分别降低了34.70%、31.50%;但是有机物(腐殖酸、动物蛋白及尿素)对fMbO吸附AS(Ⅲ)、AS(V)的影响不大。利用fMbO对实际沼液中的砷进行吸附,结果表明砷的去除率平均达到65%左右,使吸附后某些沼液中砷的浓度达到生活饮用水标准和地表水排放标准。因此,将fMbO用于砷污染的沼液及水体的治理具有很好的应用前景。The adsorption behavior of arsenite(As(Ⅲ)) and arsenate(As(Ⅴ)) by Fe-Mn binary oxide(FMBO) was studied.The results indicated that FMBO had strong adsorption ability to both As(Ⅲ) and As(Ⅴ) and the maximum adsorption capacity was 111.10, 71.40 mg·g-1 respectively.As(Ⅲ) and As(Ⅴ) were adsorbed on FMBO surface through forming inner-sphere surface complexes by ligand exchange with hydroxyl groups, and As(Ⅲ) removal by FMBO was through an oxidation and adsorption combined process.In addition, the influences of co-existing substances generally present in biogas slurry were examined.Zinc ion could promote As(Ⅲ) and As(Ⅴ) adsorption on FMBO and the adsorption capacity increased with increasing zinc ion concentration.Phosphate had significant effect on As(Ⅲ) and As(Ⅴ) removal.When P/As ratio was equal to 1, the adsorption capacity of As(Ⅲ) and As(Ⅴ) was reduced by 34.70%, 31.50%, respectively.However, organics, such as humic acid, animal protein and carbamide had no significant effect on As(Ⅲ) and As(Ⅴ) removal.Moreover, FMBO as adsorbent for removal arsenic of actual biogas slurry was investigated.The average removal rate of arsenic of actual biogas slurry was about 65%, decreasing the arsenic concentration of some biogas slurry to the drinking water and surface water discharge standard.Therefore, FMBO could be an attractive adsorbent for both As(Ⅴ) and As(Ⅲ) removal from biogas slurry.国家重点基础研究发展计划项目(2013CB733505); 国家自然科学基金项目(21077086)~

Utilization of Ce(IV)/La(III) Hydroxide as Recovery of Waste Ceria Polishing Powder from Glass Polishing for Removal of Phosphate

探讨了废弃稀土抛光粉的改性方法以及改性后材料对磷酸根离子的吸附特性.结果表明,改性稀土抛光粉对磷酸根阴离子显示了良好的吸附效果,改性后的磷吸附量是改性前的100倍,在室温(25℃),初始浓度5~150 mg/L,pH为3、5、7、9、11的条件下,其吸附等温线能很好地用Langmuir方程进行描述.对于低浓度(5~10 mg/L)磷溶液,改性后材料在所选pH条件下对磷的去除率可达100%,表明将废弃稀土抛光粉改性成磷吸附剂是可行的.This research has investigated the possibility of converting waste polishing agent(mainly a mixture of Ce(IV)/La(III) oxide) into an adsorbent for phosphate removal from water.The phosphate adsorption capacity of the resultant adsorbent was 100 times higher than that of the raw material.The adsorption isotherm fitted well to the Langmuir isotherm at room temperature in an initial concentration range of 5 mg/L to 150 mg/L and at selected pH of 3、5、7、9、11,respectively.In the low phosphate concentration range(5~10 mg/L),100% phosphate removal could be achieved at the selected pH.It proves that it's feasible to remove phosphate in water using the modified waste ceria polishing powder.教育部留学回国科研启动基金(2005383)资