高铝粉煤灰基NaP1型沸石/水合金属氧化物的制备及其对亚甲基蓝的吸附

以高铝粉煤灰为原料,通过水热法制备沸石,然后在室温下,采用沉淀法在其表面负载水合金属氧化物,分别得到了沸石/水合氧化锆和沸石/水合氧化铁.通过XRD、SEM、BET对吸附剂进行表征,并对沸石及负载型沸石吸附亚甲基蓝的吸附动力学和吸附等温线进行研究.结果 表明,粉煤灰基沸石为NaP1型,比表面积为50.88 m2/g,平均孔径为8.01 nm.沸石及负载型沸石吸附亚甲基蓝过程均符合准二级动力学模型,以化学吸附为速率控制步骤,吸附等温线均更符合Langmuir方程.其中,沸石/水合氧化铁的理论饱和吸附量高达185 mg/g,并且在无需调节溶液的pH值条件下,再生后的样品对亚甲基蓝的去除率仍然达到90％以上.因此,高铝粉煤灰基沸石原位负载水合金属氧化物材料是一种新型高效、绿色环保的吸附剂.     

活性炭负载Fe(III)吸附剂去除饮用水中的As(V)

利用活性炭负载水合铁氧化物制备了复合吸附剂,并用于饮用水中As(V)的去除. 研究了活性炭种类、粒度、溶液pH值、Fe(III)盐浓度和干扰离子等对As(V)去除的影响. 结果表明,煤质活性炭作为基质负载水合铁氧化物比椰壳炭和果壳炭具有更好的除砷效果. 随着炭粒度降低,除砷效率显著增加. 在pH 3~9范围内,活性炭负载水合铁氧化物可有效吸附As(V). F-, Cl-, SO42-的加入对As(V)的去除效率基本无影响,而SiO32-和PO43-则明显抑制As(V)的去除. Langmuir模型比Freundlich模型能更好地描述复合吸附剂对As(V)的吸附平衡. 动力学研究表明,As(V)吸附反应可用二级速率方程描述.     

载银沸石吸附去除水中溴离子的特性研究

将天然沸石依次使用1 mol/LNaCl溶液、1moL/LHCl溶液、0.2 mol/LAgNO3溶液改性并于马弗炉中450℃焙烧2h制得载银沸石吸附剂.采用静态吸附方法,探讨了溴离子浓度、吸附时间、吸附剂用量、溶液pH值等因素对溴离子去除效果的影响.载银沸石投加量为0.9 g/L,溶液pH值为7,吸附时间为90 min时,溴离子去除效果达97％以上.拟二级动力学模型可以很好地描述载银沸石对溴离子的吸附动力学过程,其吸附平衡规律符合Langmuir等温线模型.     

蜂巢石负载纳米水合氧化铁吸附氮磷的性能研究

制备了蜂巢石纳米水合氧化铁复合吸附剂(PUMICE-NHFO),研究投加量、溶液pH和共存阴阳离子对PUMICE-NHFO同时吸附氮和磷性能的影响;采用吸附等温线和吸附动力学模型研究PUMICE-NHFO的吸附特征。结果表明,纳米水合氧化铁成功地负载到蜂巢石上。当PUMICE-NHFO投加量为7.5 g/L、溶液pH为7时,氮和磷被吸附的效果较好,共存阴阳离子与氮和磷竞争吸附位点,降低氮磷吸附效率。PUMICE-NHFO对氮和磷的吸附过程更符合Langmuir吸附等温线模型,氮和磷的最大吸附量分别为3.09 mg/g和5.12 mg/g。准二级动力学模型可准确描述PUMICE-NHFO吸附氮和磷的过程,R²可分别达到0.992和0.996,吸附过程主要受化学吸附控制。经过5次吸附-解吸循环后,PUMICE-NHFO对氮和磷的吸附容量仍保持在初次吸附容量的68%以上,表现出较好的可重复利用性。     

甘蔗渣基水合氧化铁对源水中单宁酸的吸附特征

利用甘蔗渣(BR)、甘蔗渣水合氧化铁(HFO-BR)和甘蔗渣水合氧化锆(HZO-BR)三种材料对源水中单宁酸进行吸附去除,探讨其吸附特征。试验结果表明:甘蔗渣水合氧化铁(HFO-BR)和甘蔗渣水合氧化锆(HZO-BR)具有较宽的pH适用范围,当吸附剂剂量为1.6g/L、反应时间为180min时,两种复合材料对50mg/L单宁酸的去除率分别为96.54%和97.89%,比甘蔗渣对单宁酸的去除率分别提高10.56%和11.91%。准二级动力学方程能较好的拟合三种材料对单宁酸的吸附动力学过程,揭示其吸附以离子交换吸附为主。Langmuir和Freundlich方程均能较好地拟合单宁酸等温吸附试验数据,表明三种材料对单宁酸的吸附既有单分子层吸附,又有多分子层吸附。     

沼泽红假单胞菌对Zn^2＋的吸附性能研究

采用沼泽红假单胞菌为生物吸附剂,研究了锌离子初始浓度、pH值、吸附剂用量、菌龄、吸附时间等因素对沼泽红假单胞菌生物吸附模拟废水中锌的影响,探讨了吸附动力学特征。结果表明,沼泽红假单胞菌在Zn2＋初始质量浓度为200 mg/L、吸附剂用量0.5 g/L、菌龄32 h、pH=7、吸附时间80 min的条件下,对Zn2＋的吸附量为88.23 mg/g;其吸附行为可以用Langmuir和Freundlich吸附等温方程描述,但更符合Freundlich吸附等温方程。对Zn2＋的吸附过程符合二级动力学特征。     

AlCl_3改性柿叶对苯酚废水的生物吸附性能

以柿叶为原料,采用硫酸-甲醛和AlCl_3进行改性制备新型吸附剂硫酸甲醛改性柿叶(SCLAl)。研究了SCL-Al对苯酚的吸附性能,探讨了吸附剂用量、吸附时间、初始浓度、pH值、温度等因素对吸附性能的影响。结果表明:pH值、吸附剂用量和吸附时间对吸附率的影响较明显;温度对吸附率的影响较小;SCL-Al吸附1g/L苯酚时,在pH≥7,1L苯酚溶液中吸附剂用量为15g/L,室温条件下吸附60min基本达平衡,吸附动力学符合准二级动力学方程;吸附行为符合Freundlish吸附等温式。     

麸皮去除废水中Cr(VI)的实验研究

以麸皮为生物吸附剂,考察麸皮用量、废水pH、时间、Cr(Ⅵ)初始浓度对废水中Cr(Ⅵ)去除率的影响。结果表明,麸皮作为生物吸附剂可有效去除废水中的Cr(Ⅵ),麸皮用量200 g/L,pH=2、Cr(Ⅵ)初始浓度为5 mg/L,吸附240 min时,Cr(Ⅵ)去除率为99.31%。麸皮对Cr(Ⅵ)离子的吸附过程接近准二级动力学方程,吸附符合Freundlich等温模型,饱和吸附量为55.44 mg/kg。     

磁性多孔Fe(OH)3微球制备及其在含磷废水处理中的应用

利用诱导成球法制备磁性Fe3O4粒子为核的Fe(OH)3多孔微球,以X射线衍射(XRD)和扫描电镜(SEM)等对其进行结构表征,采用静态吸附法对磁性多孔微球去除水中H2PO4-的性能进行了实验研究,考察了吸附剂用量、H2PO4-初始浓度、溶液pH值等因素对吸附的影响,分析了其吸附等温线及对H2PO4-的吸附动力学. 结果表明,Langmuir方程能较好地描述吸附平衡,其吸附动力学符合Lagergren二级方程. 磁性多孔微球对H2PO4-有很强的去除能力,在吸附剂用量0.8 g/L,pH 2.5~9,吸附时间150 min的条件下,磁性多孔微球对H2PO4-的去除率可达98%以上.     

磷酸铁锂正极废粉提锂后的硫酸锂除磷和除氟研究

针对废旧磷酸铁锂正极粉经硫酸浸出后得到的硫酸锂中氟、磷含量高的问题,开展了水合金属氧化物吸附除杂工作,重点研究了吸附剂种类、吸附剂用量、溶液pH、吸附温度、吸附时间、共存阴离子浓度等因素对F-、PO43-吸附规律的影响.结果表明,La(OH)3的吸附效率优于Zr(OH)4或Ce(OH)4.随着吸附剂用量或溶液pH的提高...     

改性粉煤灰处理含磷废水的研究

采用浓硫酸固相反应法对粉煤灰进行改性用于含磷废水的净化,考察了pH值,吸附剂用量,磷初始浓度,反应时间对净化过程的影响。通过实验发现溶液pH值在4-10范围内对磷的吸附过程影响不显著,改性粉煤灰可以在较宽的pH值范围内进行脱磷处理;随着粉煤灰加入量的增加和初始溶液中磷酸根浓度的降低,磷的净化率逐渐增加。对于含磷50 mg/L的溶液,当粉煤灰的投加量为1.5%时,磷的吸附效率可达99.66%,净化后水中含磷量为0.17 mg/L。改性粉煤灰对水中磷的净化过程速度较快,5 min可达到最大净化率。改性粉煤灰对磷的吸附等温线符合Freudlich方程。     

Study on the phosphate removal from aqueous solution using modified fly ash

In this work the fly ash was modified by sulfuric acid for the removal of phosphate. It was found that modification of fly ash could significantly enhance the phosphate immobilization ability of the fly ash. The specific surface area of the fly ash increased from 8.8 to 32.5 m²/g after treated with sulfuric acid. The modification of the fly ash also resulted in the mobilization of acid-soluble metal ions due to partial or complete dissolution of the metals under the acidic conditions. Both adsorption and precipitation contributed to the removal of phosphate by the modified fly ash but precipitation was a major mechanism of phosphate removal. The experimental results showed that adsorption of phosphate by the modified fly ash was rapid, the removal percentage of phosphate could reach maximum in 5 min. In the range of 5–9, pH did not significantly affect the removal of phosphate and the removal percentage of phosphate increased with the increase of adsorbent dosage. The adsorption of phosphate by the modified fly ash could be described well by Langmuir isotherm equation, the Langmuir constant Q₀ was 9.15 mg g⁻¹. The XRD patterns and the SEM images of modified fly ash after sorption revealed that CaHPO₄·2H₂O was formed in the removal of phosphate. In addition, phosphate also formed precipitate with aluminum and iron.     

用硫酸改性粉煤灰处理含磷废水的研究

以硫酸对粉煤灰进行改性用于含磷废水的净化,考察了pH值,吸附剂用量,磷初始浓度,反应时间、反应温度对净化过程的影响。通过实验发现溶液pH值在8~11范围内对磷的吸附过程影响不显著,改性粉煤灰可以在较宽的pH值范围内进行脱磷处理;随着粉煤灰加入量的增加和初始溶液中磷酸根浓度的降低,磷的净化率逐渐增加。对于含磷<80 mg/L的溶液,当粉煤灰的投加量为3%时,反应温度40℃,磷的吸附效率可达97.6%。改性粉煤灰对水中磷的净化过程速度较快,30~40 min可达到最大净化率。     

粉煤灰合成沸石除磷机理研究

利用粉煤灰合成沸石，考察了其对模拟废水中磷酸盐的去除效果，并着重研究了其除磷机理。结果表明，粉煤灰合成沸石有优良的除磷效果，其磷酸吸收系数几乎是原料粉煤灰的4倍，比原料粉煤灰有更高的吸附磷的潜力。粉煤灰合成沸石对磷酸盐的去除机理包括化学沉淀作用和吸附作用，且吸附作用随着平衡溶液的pH值的增大而减弱。粉煤灰合成沸石中沸石成分的骨架结构没有磷吸附作用，粉煤灰只能通过化学沉淀作用去除磷酸盐，粉煤灰合成沸石对磷的吸附作用主要来源于粉煤灰合成沸石过程中产生的无定型非晶体的中间体物质。     

Low cost adsorbents obtained from ash for copper removal

We investigated the utilization of ash and modified ash as a low-cost adsorbent to remove copper ions from aqueous solutions such as wastewater. Batch experiments were conducted to determine the factors affecting adsorption of copper. The influence of pH, adsorbent dose, initial Cu²⁺ concentration, type of adsorbent and contact time on the adsorption capacity of Cu²⁺ from aqueous solution by the batch adsorption technique using ash and modified ash as a low-cost adsorbent were investigated. The optimum pH required for maximum adsorption was found to be 5. The results from the sorption process showed that the maximum adsorption rate was obtained at 300 mg/L when a different dosage of fly ash was added into the solution, and it can be concluded that decreasing the initial concentration of copper ion is beneficial to the adsorption capacity of the adsorbent. With the increase of pH value, the removal rate increased. When the pH was 5, the removal rate reached the maximum of over 99%. When initial copper content was 300 mg/L and the pH value was 5, the adsorption capacity of the zeolite Z 4 sample reached 27.904 mg/g. The main removal mechanisms were assumed to be the adsorption at the surface of the fly ash together with the precipitation from the solution. The adsorption equilibrium was achieved at pH 5 between 1 and 4 hours in function of type of adsorbent. A dose of 1: 25 g/mL of adsorbent was sufficient for the optimum removal of copper ions. For all synthesized adsorbents the predominant mechanism can be described by pseudo-second order kinetics.     

不同钙含量粉煤灰合成沸石对污水中磷的去除

进行了以不同钙含量的粉煤灰为原料合成的3种沸石对污水中磷去除的试验,探讨了表面交换性阳离子种类、投加量以及磷浓度对除磷的影响。结果表明：最佳投加量为8g／L,磷去除率可达到70％以上合成沸石除磷能力均高于粉煤灰,钙饱和处理又可明显进一步提高粉煤灰合成沸石的除磷效果。粉煤灰合成沸石钙含量越高,对磷的去除率越高。因此,采用高钙粉煤灰为原料合成沸石并进行钙饱和处理,可以获得除磷能力强的合成沸石材料。     

改性粉煤灰除去废水中的磷

利用水泥对电厂粉煤灰进行改性,并将改性粉煤灰应用于去除废水中的磷,探讨了吸附平衡时间、吸附剂用量、颗粒的大小、pH值以及初始浓度等对吸附效率的影响。在最佳条件下,磷的去除率可以达到98％以上。     

粉煤灰的混酸改性及吸附性能研究

以粉煤灰为原料,用混酸酸溶制取改性粉煤灰吸附剂,并处理生活污水。结果表明：最佳酸溶时间为3h,其固体溶出率约25wt％;当改性粉煤灰的用量为100g／L时,吸附效果最佳,COD的吸附率达到75．4％,出水达到《城市污水处理厂污染物排放标准》（GB18918—2002）中的二级标准限值（100mg／L）;改性后吸附能力提高了近三倍。     

Removal of Phosphate from Aqueous Solution Using Zeolite Synthesized from Fly Ash by Alkaline Fusion Followed by Hydrothermal Treatment

The removal of phosphate from aqueous solution by the adsorption process using zeolite synthesized from fly ash was investigated in this study. The XRD patterns revealed that the major crystalline phase of the synthesized zeolite was gismondine. The phosphate immobilization capacity (PIC) increased significantly from 52.7 mg/g of fly ash to 102.9 mg/g of synthesized zeolite after conversion. The batch experiments were conducted to investigate the effect of pH, initial phosphate concentration, and adsorbent amount. The maximum adsorption capacity was obtained at the pH value of 7.0. The adsorption process followed Ho' pseudo-second-order model, and both liquid film and intra-particle diffusion were the rate-controlling step for the process. The adsorption equilibrium data had been analyzed by Langmuir, Freundlich, Radlich-Peterson, Koble-Corrigan, Tempkin, Dubinin-Radushkevich, and Generalized models. The results showed that the Langmuir model gave the best fit. The process was also found to be endothermic. The maximum phosphate adsorption capacity obtained was 132.02 mg/g (30°C), 156.36 mg/g (40°C) and 184.17 mg/g (50°C), respectively, suggesting that the synthesized zeolite is a promising material and can be used to remove phosphate from wastewater.