八羟基喹啉改性膨润土预处理养殖废水

以八羟基喹啉为改性剂,天然膨润土为原料,制备一种新型吸附剂,并将其应用于养殖废水的预处理中。确定了改性膨润土的最佳制备条件:土液比为4 g/L,改性剂浓度为0.3 g/L,改性时间为50 min,改性温度为50℃。并以扫描电镜方法对改性膨润土行进表征:八羟基喹啉已经有效进入层间,改变了膨润土的性状,提高了吸附效果。优化了改性膨润土处理养殖废水的工艺条件:投土量为1 g/L,pH为4,搅拌时间为30 min,搅拌速度为350 r/min,沉淀时间为40 min。在此优化条件下,改性膨润土对养殖废水的COD去除率最高可达79.18%,且吸附动力学结果满足二级动力学模型。     

微波强化有机改性膨润土对磷的吸附特性研究

利用十六烷基三甲基溴化铵(CTMAB)在微波辐射条件下对浙江临安膨润土进行改性,制得有机改性膨润土,利用其含磷模拟废水进行处理,考察了不同的工艺条件如有机改性剂用量、微波辐射强度、辐照时间、吸附时间、改性膨润土投加量、pH值对废水中磷去除效果的影响。结果表明:在有机改性剂用量为3 mmol/g,微波辐照强度为96 W/g,微波辐照时间8 min为最佳制备条件。改性膨润土用量为12 mg/L,反应时间为15 min,溶液pH为7及常温条件下,改性膨润土对浓度为50 mg/L的含磷废水去除率达到97.3%,吸附符合Freundlich吸附等温方程。     

有机改性膨润土的稳定性研究

利用十六烷基三甲基溴化铵(HDTMAB)对膨润土进行有机改性,研究了不同振荡时间、振荡强度、温度、pH以及盐溶液浓度下改性后有机膨润土的稳定性。结果表明,表面活性剂用量为0.6CEC时,改性的膨润土比较稳定。在同一环境因素下,当表面活性剂用量大于0.6CEC时,有机膨润土的稳定性均随着改性剂用量的增加而降低。振荡时间、振荡强度以及反应温度对有机膨润土稳定性影响不明显;酸性条件下会降低有机膨润土的稳定性,而中性、碱性条件下,有机膨润土的稳定性会提高;对于0.6CEC改性的有机膨润土,当NaC l、CaC l2的浓度由0.2 mol/L增加到0.6 mol/L时有机膨润土的稳定性得到了显著的提高,浓度继续增大,稳定性下降。所以当外界NaC l或CaC l2浓度为0.6 mol/L时,0.6CEC改性的有机膨润土相对0.8CEC以及1.0CEC改性的膨润土稳定,可用做废水处理的吸附剂,且无二次污染。     

改性壳聚糖处理污水中Ni(Ⅱ)的效果

通过丁二酸酐与γ-氨丙基三甲氧基硅烷改性后的纳米SiO2(即可分散的纳米二氧化硅,简称DNS)反应,合成了羧基化的DNS,再经过与壳聚糖脱水生成酰胺的过程,合成了改性壳聚糖。通过红外光谱和扫描电镜对改性壳聚糖进行表征。研究了壳聚糖及改性壳聚糖微粒吸附Ni2+时溶液pH值、时间、吸附剂用量和Ni2+初始浓度等对吸附率的影响,并确定了最佳条件为:pH=7,吸附时间为120 min,吸附剂的投加量为0.3 g。改性壳聚糖比壳聚糖具有更强的吸附Ni2+的能力,吸附率达67.01%。     

剩余污泥对酸性大红G的吸附

以剩余污泥为吸附剂,研究其对模拟废水中酸性大红G的吸附条件及吸附机理。结果表明,剩余污泥对酸性大红G的吸附是一个快速过程,吸附时间可控制在30 min;其吸附过程同时受液膜扩散和颗粒内扩散的影响,可以用假二级动力学模型进行描述和预测;Freundlich方程可以较好地描述剩余污泥对酸性大红G的吸附行为。污泥未调pH时,对pH<2的溶液中酸性大红G的吸附性能良好;污泥pH为1时,对实验范围(pH<11)溶液中的酸性大红G均可有效吸附;污泥投加量增加,酸性大红G去除率升高,但污泥对酸性大红G的吸附量下降。     

铁镍改性膨润土对废水中有机污染物的吸附性能研究

以钠基膨润土为原料,制备了铁镍无机改性土和铁镍有机复合改性土,并应用于造纸废水的处理,探讨了改性土用量、废水pH值、搅拌时间等因素对COD去除率的影响,通过正交实验对实验条件进行了优化.结果表明:铁镍有机复合改性土和铁镍元机改性土对废水的处理效果明显好于原土;膨润土的用量、废水的pH对COD的去除率影响较大;对于铁镍无机改性土,吸附剂用量为12g/L,溶液pH=2,吸附时间为10 min时,对废水中COD的去除率为54.06%;对于铁镍有机复合改性土,吸附剂用量为14g/L,溶液pH=3,吸附时间为20 min时,对废水中COD的去除率为70.10%.     

铁镍改性膨润土对废水中有机污染物的吸附性能研究

以钠基膨润土为原料,制备了铁镍无机改性土和铁镍有机复合改性土,并应用于造纸废水的处理,探讨了改性土用量、废水pH值、搅拌时间等因素对COD去除率的影响,通过正交实验对实验条件进行了优化.结果表明：铁镍有机复合改性土和铁镍元机改性土对废水的处理效果明显好于原土;膨润土的用量、废水的pH对COD的去除率影响较大;对于铁镍无机改性土,吸附剂用量为12g/L,溶液pH=2,吸附时间为10 min时,对废水中COD的去除率为54.06%;对于铁镍有机复合改性土,吸附剂用量为14g/L,溶液pH=3,吸附时间为20 min时,对废水中COD的去除率为70.10%.     

改性膨润土对水体中多环芳烃的吸附

改性膨润土被广泛地应用于吸附水体中重金属离子和有机污染物,但关于改性膨润土吸附水体中多环芳烃混合物的动力学研究鲜见报道。利用十二烷基三甲溴化铵和十二烷基磺酸钠对膨润土进行改性,并将之应用于吸附水体中萘、蒽、菲和芘4种多环芳烃,考察了吸附剂投加量、时间和温度等条件对吸附效果的影响。实验结果表明,在25℃、吸附时间40 min、起始浓度为1.25 mg/m L、改性膨润土的投加量为4 g/L的条件下,该吸附剂对萘、蒽、菲和芘的吸附率分别为99.1%、99.6%、98.7%和98.9%。改性膨润土对水体中4种多环芳烃的吸附机理服从准二级动力学方程,该吸附剂吸附等温线服从Langmuir方程。     

CTAB改性膨润土制备及其对海洋溢油的吸附

利用室内吸附实验,以钙基膨润土和改性后的CTAB-膨润土为研究对象,研究了改性前后的膨润土在海洋环境条件下对石油的吸附性能。结果表明,CTAB已经成功地插层到钙基膨润土层间,使其表面形貌更加蓬松,层间距增大为2.04 nm,改性后膨润土由亲水性变为疏水性。改性前后的膨润土对海洋溢油的吸附率均随着膨润土浓度的增加及粒径的减小而增加,改性后膨润土的吸油率比改性前提高了13.1%,最高达到59.5%。临界颗粒物浓度为1 000 mg·L~(-1),最佳颗粒物粒径范围为100μm。CTAB-膨润土对委内瑞拉原油的吸附过程较好地符合准二级动力学模型和Freundlich吸附等温线模型,吸附的最佳时间为240 min,最佳温度为30℃,饱和吸附量约为526 mg·g~(-1)。改性前后的膨润土在海洋环境条件下对石油的吸附性能有明显变化,CTAB-膨润土对海洋溢油的吸附优势较为显著。     

PDMDAAC改性膨润土对石油类污染物脱附行为的研究

石油类污染是水体环境主要的污染源之一,并且石油是不可再生资源,用吸附法处理含有石油类污染的废水有较好的处理效果。膨润土是一种优良的吸附剂,对其进行改性能提高其吸附石油类污染物的性能。改性膨润土在在含油废水处理方面得到广泛的应用,但其对石油类污染物脱附行为的研究还较少。本实验考察了搅拌时间、搅拌速度、p H、温度和盐度的变化对饱和吸附含油废水的聚二甲基二烯丙基氯化铵(PDMDAAC)改性膨润土脱附行为的影响,并通过正交实验优化了最佳脱附条件:搅拌时间为25 min,搅拌速度为200 r/min,p H为3,温度为35℃,在此条件下,脱附率可达92.05%。在最佳脱附条件下使其再生,并和原土进行了比较,通过脱附动力学研究了其脱附的过程。结果表明,饱和吸附含油废水的PDMDAAC改性膨润土在最优条件下,脱附率可达92.05%,可以用来回收石油;再生得到的改性膨润土用于处理含油废水,去除率在82.84%左右,可以重复使用来处理含油废水;准二级脱附动力学能较好地描述脱附过程。旨在探索改性膨润土的吸附及脱附的规律,为膨润土用于含油废水处理奠定基础。     

膨润土吸附-微波催化氧化协同处理葡萄酒废水

采用膨润土吸附-微波催化氧化技术处理葡萄酒生产废水,考察了膨润土用量、H2O2用量、微波辐照时间、微波功率、pH等5个单因素对葡萄酒生产废水处理效果的影响。确定了最终反应条件为:膨润土用量2.6 g、H2O2用量2.1mL、功率720 W、加热时间25 min、pH为3.5。在此条件下,COD去除率达到了80%以上。结果表明,该方法可快速有效地处理葡萄酒生产废水。     

吡啶改性膨润土对直接耐晒翠蓝染料废水脱色性能研究

为了解决日益严重的水污染问题,用吡啶作改性剂,对膨润土进行有机改性,制得一种新型水处理剂,用于直接耐晒翠蓝染料废水的处理。研究了处理废水的最佳工艺条件。结果表明,投土量为10g／L,pH=3．5,搅拌速度为175r／min,搅拌时间25rain,离心时间为2min,吡啶改性土对直接耐晒翠蓝染料废水的脱色率可达80％。改性土对直接耐晒翠蓝的吸附过程可用准二级速率方程较好地描述。     

纳米有机膨润土对苯酚的吸附性能研究

通过对天然膨润土改性,制备纳米有机膨润土并用于吸附苯酚,探讨了吸附时间、溶液pH、纳米有机膨润土投加量等因素对苯酚吸附的影响。结果表明,吸附在5 min内快速达到平衡,溶液pH可以影响苯酚在溶液中的状态,是影响苯酚吸附性能的重要因素。纳米有机膨润土吸附苯酚的过程可用伪二级反应动力学方程来描述,伪二级吸附速率常数为1.3 g/(mg.min)。吸附等温线符合Langmuir等温方程,在25℃时,Langmuir理论最大吸附容量可达到536.32 mg/g,吸附热力学参数表明吸附过程是自发的、放热的物理吸附过程。     

掺Al-TiO2改性膨润土去除微污染水中COD和NH4-N

采用掺Al-TiO2作为改性剂制备改性膨润土,考察了微波辐射功率、辐射时间、TiO2改性剂用量、铝盐掺杂量、pH值对微污染水中COD和NH4-N去除效果的影响。实验表明,微波辐射功率为460 W,辐射时间为8 min,TiO2改性剂用量为1.3 mmol/g,铝盐掺杂量为0.2 mmol/g为最佳制备条件。pH值为6.0,改性膨润土投加量为40 mg/L,沉淀时间为30min时,对微污染水中初始浓度15 mg/L的COD和5 mg/L的NH4-N去除率分别达到92%和59%以上。     

壳聚糖混凝处理丁腈橡胶废水的实验研究

利用壳聚糖作混凝剂处理丁腈橡胶废水。对投加量、pH、搅拌速率和沉降时间四因素进行L₉(3⁴)正交实验,确定壳聚糖混凝处理丁腈橡胶废水的最佳实验条件。结果表明,壳聚糖投加量为100 mg/L, pH为6,搅拌速率为200 r/min,沉降时间为5 min,COD去除率达96.7%,出水COD降为276 mg/L,达到国家三级排放标准。     

Removal of phenols from water accompanied with synthesis of organobentonite in one-step process

A novel technology of wastewater treatment was proposed based on simultaneously synthesis of organobentonite and removal of organic pollutants such as phenols from water in one-step, which resulted that both surfactants and organic pollutants were removed from water by bentonite. The effects of contact time, pH and inorganic salt on the removal of phenols were investigated. Kinetic results showed that phenols and cetyltrimethylammonium bromide (CTMAB) could be removed by bentonite in 25 min. The removal efficiencies were achieved at 69%, 92% and 99%, respectively, for phenol, p-nitrophenol and beta-naphthol at the initial amount of CTMAB at about 120% cation exchange capacity of bentonite. Better dispersion property and more rapid bentonite sedimentation were observed in the process. The results indicated that the one-step process is an efficient, simple and low cost technology for removal of organic pollutants and cationic surfactants from water. The proposed technology made it possible that bentonite was applied as sorbent for wastewater treatment in industrial scale.     

Dissolved organic matter effects on the performance of a barrier to polycyclic aromatic hydrocarbon transport by groundwater

In order to contain the movement of organic contaminants in groundwater, a subsurface sorption barrier consisting of sand or clay minerals coated with a cationic surfactant has been proposed. The effectiveness of such a sorption barrier might be affected by the presence of dissolved organic matter (DOM) in the groundwater. To study the impact of DOM on barrier performance, a series of batch experiments were performed by measuring naphthalene and phenanthrene sorption onto sand coated with cetylpyridinium chloride (CPC) and bentonite coated with hexadecyltrimethylammonium bromide (HDTMA) in the presence of various concentrations of DOM. The overall soil-water distribution coefficient (K*) of naphthalene and phenanthrene onto CPC-coated sand decreased with increasing DOM concentration, whereas the K* of the compounds onto HDTMA-coated bentonite slightly increased with increasing DOM concentration. To describe the overall distribution of polycyclic aromatic hydrocarbons (PAHs) in the systems, a competitive multiphase sorption (CMS) model was developed and compared with an overall mechanistic sorption (OMS) model. The modeling studies showed that while the OMS model did not explain the CPC-coated sand experimental results, a model that included competitive sorption between DOM and PAH did. The experimental results and the modeling study indicated that there was no apparent competition between DOM and PAH in the HDTMA-coated bentonite system, and indicated that in groundwater systems with high DOM, a barrier using HDTMA-coated bentonite might be more effective.     

负载TiO2/Fe^3＋的玻璃纤维反应器光催化苯酚

以玻璃纤维为载体,将TiO2负载到其表面形成了空间玻璃纤维反应器,引入Fe3＋作为掺杂改性离子,形成了负载TiO2/Fe^3＋的空间玻璃纤维光催化反应器,并以高压汞灯为光源进行了光催化降解水中苯酚的实验研究,考察了影响苯酚光催化降解的因素,确定了在UV365-250 W光源照射下,pH为3-5,O2通入量1.0 L/（min.L）,反应器内上升流速为0.7 m/min等实验条件下,初始浓度为30 mg/L的苯酚废水经120 min光催化反应后,降解率可达到85%,矿化率可达80%。     

负载TiO2/Fe3+的玻璃纤维反应器光催化苯酚

以玻璃纤维为载体,将TiO2负载到其表面形成了空间玻璃纤维反应器,引入Fe3+作为掺杂改性离子,形成了负载TiO2/Fe3+的空间玻璃纤维光催化反应器,并以高压汞灯为光源进行了光催化降解水中苯酚的实验研究,考察了影响苯酚光催化降解的因素,确定了在UV365～250 W光源照射下,pH为3～5,O2通入量1.0 L/(min.L),反应器内上升流速为0.7 m/min等实验条件下,初始浓度为30 mg/L的苯酚废水经120 min光催化反应后,降解率可达到85%,矿化率可达80%。     

Preparation of alginate-chitosan hybrid gel beads and adsorption of divalent metal ions

Naturally occurring polysaccharides such as alginic acid and chitosan have been recognized as one of the most effective adsorbents to eliminating low levels of heavy metal ions from waste water stream. The present study intended to use alginic acid and chitosan simultaneously, which are expected to form a rigid matrix structure of beads due to electrostatic interaction between carboxyl groups on alginic acid and amino groups on chitosan, and to prepare alginate-chitosan hybrid gel beads. This could be achieved for the first time by using water-soluble chitosan, which was obtained by deacetylating chitin to 36-39% degree. The water-soluble chitosan dissolved in water could remain in solution in the presence of sodium alginate, and the homogeneous solution of chitosan and alginate was dispensed into a CuCl2 solution to give gel bead particles. The resultant beads were then reinforced by a cross-linking reaction of aldehyde groups on glutaraldehyde with amine groups on the chitosan. The cross-linking reaction made the beads durable under acidic conditions. The adsorption of Cu(II), Co(II), and Cd(II) on the beads was significantly rapid and reached at equilibrium within 10 min at 25 degrees C. Adsorption isotherms of the metal ions on the beads exhibited Freundlich and/or Langmuir behavior, contrary to gel beads either of alginate or chitosan showing a step-wise shape of adsorption isotherm.