改性钢渣处理低浓度氨氮废水

采用正交实验法,以氨氮去除率为指标,设计5因素4水平正交实验;采用恒温振荡方法对高温活化改性钢渣做了吸附低浓度氨氮影响因素的研究;得出以下结论：改性钢渣吸附低浓度氨氮影响因素的重要性顺序为：氨氮初始质量浓度〉钢渣粒度〉改性方法 〉溶液pH〉吸附时间,经过改性,提高了钢渣处理低浓度氨氮废水的能力,其中经过700℃高温活化改性效果最佳;高温改性钢渣对低浓度氨氮的吸附过程符合Langmuir方程,相关系数为0.9993,作用机理为表面吸附,即单层吸附,理论饱和吸附量为2.8491 mg/g。     

适宜处理分散性生活污水的人工湿地除磷填料的筛选及改性

为提高人工湿地除磷效能,从沸石、陶粒、萤石、膨胀蛭石、石灰石、麦饭石、火山岩、牡蛎壳、钢渣和废砖块这10种具有较高磷素饱和吸附量的填料中,筛选出钢渣、沸石和石灰石3种适宜处理分散性生活污水的人工湿地填料,并分别使用不同浓度梯度的酸(碱)、盐对3种填料进行改性,以增强其除磷能力。研究结果表明,钢渣、沸石和石灰石分别经2 mol/L AlCl3、2 mol/L NaOH及2 mol/L AlCl3、0.5 mol/L AlCl3溶液改性后,磷素吸附量达到最高值(0.272、0.0801和0.351 mg/g),而双常数方程能更好地描述优选填料对生活污水中磷的吸附动力学过程,综合考虑填料的吸附效果、成本及来源,改性石灰石是人工湿地处理分散性生活污水时较为理想的除磷填料;此外,填料经铝改后,氮磷吸附效果普遍优于其他改性条件,且Al-P有利于植物直接吸收利用,含铝废水来源广泛,故利用铝改液处理人工湿地填料具有较高的应用推广价值。     

方沸石水质净化剂的制备及其除氟研究

通过微观分析方法,在鄂尔多斯盆地白垩系钻孔岩样中首次发现方沸石类矿物.就地取材,对方沸石岩进行提纯和改性,制成多孔方沸石球,用于含氟水的处理,取得了明显的效果.对于100 mL起始浓度3 mg/L的含氟水,方沸石球较佳的水处理工艺条件为:用量1.5 g,搅拌后静置48 h,直径3 mm.对于起始浓度3 mg/L的含氟水,方沸石球一次水处理后氟离子浓度就低于国家标准值.对于起始浓度3～10 mg/L的含氟水,经方沸石球几次水处理后氟离子浓度也低于国家标准值.方沸石球对氟离子吸附等温线符合Langmuir吸附等温式,为:qe=0.243ce/1 0.433ce;吸附速度符合斑厄姆公式,为:dq/dt=4.482×10-3(qe-q)/t0.176.用过的方沸石球再生处理后活性基本恢复,多次再生后除氟效果有所下降.     

改性活性碳毡电吸附污水中的Zn2+

用20%硝酸改性活性碳毡,利用扫描电镜和傅里叶红外光谱等技术对其改性后的结构进行了表征;利用改性活性碳毡作为吸附电极,进一步研究了其应用于电吸附的除盐效果和影响因素.结果表明,改性后的活性碳毡上的羰基和羧基增多,比表面积增大了32.2%,平均孔径提高了2.5%,微孔体积增大了23.1%.在电压为1.2V,pH值为6~8,极板间距为5mm时电吸附装置对水中Zn²⁺的吸附效果最优,动力学分析表明改性活性碳毡吸附Zn²⁺更符合准二级动力学方程,吸附等温线符合Langmuir等温吸附模型,除此以外,电吸附循环实验表明用20%硝酸为再生液,通过电极反接,改性活性碳毡的再生率> 74%,说明在电吸附Zn²⁺过程中改性活性碳毡具有良好的再生性.     

废轮胎热解炭黑制备活性炭及处理染料废水

分别采用H₂SO₄和NaOH对废轮胎热解炭黑进行改性处理,考察炭黑与改性剂固液比对染料废水脱色率的影响.实验结果表明,炭黑与H₂SO₄固液比1g/15mL时得到HBC（酸改性活性炭）处理酸性湖蓝溶液,脱色率最高;炭黑与NaOH固液比1g/10mL时得到NBC（碱改性活性炭）处理碱性湖蓝溶液,脱色效果最好.溶液的酸性越强,越有利于HBC对酸性湖蓝溶液的脱色效果;而溶液的碱性增大,有助于提高NBC对碱性湖蓝的脱色率.此外,HBC对酸性湖蓝与NBC对碱性湖蓝的吸附反应变化趋势非常接近,整个吸附反应迅速,20min后基本达到吸附反应平衡.HBC吸附酸性湖蓝和NBC吸附碱性湖蓝的过程均符合准二级动力学方程.对改性前后的固体物质进行了扫描电镜,红外光谱及比表面积分析.     

活性炭纤维的改性及对Cu~(2+)吸附性能影响的研究

采用硝酸、磷酸、磷酸二氢铵和硝酸铜水溶液对聚丙烯腈基活性炭纤维(PAN-ACF)进行浸渍改性,制备了4种改性活性炭纤维(ACF1-ACF4)。测定了改性活性炭纤维表面含氧酸性官能团、零电荷点、比表面积和孔容,评价了改性纤维对铜离子的吸附性能。结果表明改性后活性炭纤维表面含氧酸性官能团明显增加,其零电荷点相应降低,比表面积和微孔孔容增大。改性活性炭纤维对Cu2+的吸附容量显著提高,其中ACF2吸附性能最佳,其吸附容量从改性前的4.80 mg/g增加到17.32 mg/g,提高了3.6倍。     

环境矿物材料在水体污染治理进展中的研究

环境矿物材料在水体污染治理中的应用受到了人们的广泛关注.本文综述了环境矿物材料的改性方法,主要介绍了物理改性,主要有水热改性和焙烧改性,化学改性主要有无机改性和有机改性,探讨了在水体污染治理中的应用研究现状,主要包括去除重金属离子、去除有机污染物、去除无机阴离子和去除其他污染物,给出了环境矿物材料的发展趋势,主要包括加强环境矿物材料的研究、加强改性方法的研究和拓展与其他方法的联用等方面的应用研究.     

Interaction between Cu2+ and different types of surface-modified nanoscale zero-valent iron during their transport in porous media

This study investigated the interaction between Cu²⁺ and nano zero-valent iron (NZVI) coated with three types of stabilizers (i.e., polyacrylic acid [PAA], Tween-20 and starch) by examining the Cu²⁺ uptake, colloidal stability and mobility of surface-modified NZVI (SM-NZVI) in the presence of Cu²⁺. The uptake of Cu²⁺ by SM-NZVI and the colloidal stability of the Cu-bearing SM-NZVI were examined in batch tests. The results showed that NZVI coated with different modifiers exhibited different affinities for Cu²⁺, which resulted in varying colloidal stability of different SM-NZVI in the presence of Cu²⁺. The presence of Cu²⁺ exerted a slight influence on the aggregation and settling of NZVI modified with PAA or Tween-20. However, the presence of Cu²⁺ caused significant aggregation and sedimentation of starch-modified NZVI, which is due to Cu²⁺ complexation with the starch molecules coated on the surface of the particles. Column experiments were conducted to investigate the co-transport of Cu²⁺ in association with SM-NZVI in water-saturated quartz sand. It was presumed that a physical straining mechanism accounted for the retention of Cu-bearing SM-NZVI in the porous media. Moreover, the enhanced aggregation of SM-NZVI in the presence of Cu²⁺ may be contributing to this straining effect.     

Ti02光催化剂的掺杂改性和固定化研究

纳米TiO2作为光催化剂,由于其化学性质稳定、无毒、价廉等优点,使得纳米TiO2光催化氧化技术在环境领域具有广阔的应用前景,而针对其对可见光利用率低,光生电子一空穴对易复合,在使用过程中回收难,光催化效率不高等问题,近年来科研人员致力于Ti02光催化剂的改性和固定化研究。本文介绍了掺杂改性的不同方法及负载技术的研究进展,其中包括贵金属沉积、金属离子掺杂、非金属掺杂、共掺杂、表面光敏化、复合半导体等,并提出了TiO2光催化剂今后的研究方向及存在的问题。     

Efficient visible light photo-Fenton-like degradation of organic pollutants using in situ surface-modified BiFeO3 as a catalyst

The visible light photo-Fenton-like catalytic performance of BiFeO₃ nanoparticles was investigated using Methyl Violet (MV), Rhodamine B (RhB) and phenol as probes. Under optimum conditions, the pseudo first-order rate constant (k) was determined to be 2.21×10^-2, 5.56×10^-2 and 2.01×10^-2 min^-1 for the degradation of MV (30 μmol/L), RhB (10 μmol/L) and phenol (3 mmol/L), respectively, in the BiFeO₃-H₂O₂-visible light (Vis) system. The introduction of visible light irradiation increased the k values of MV, RhB and phenol degradation 3.47, 1.95 and 2.07 times in comparison with those in dark. Generally, the k values in the BiFeO₃-H₂O₂-Vis system were accelerated by increasing BiFeO₃ load and H₂O₂ concentration, but decreased with increasing initial pollutant concentration. To further enhance the degradation of pollutants at high concentrations, BiFeO₃ was modified with the addition of surface modifiers. The addition of ethylenediamineteraacetic acid (EDTA, 0.4 mmol/L) increased the k value of MV degradation (60 μmol/L) from 1.01×10^-2 min^-1 in the BiFeO₃-H₂O₂-Vis system to 1.30 min^-1 in the EDTA-BiFeO₃-H₂O₂-Vis system by a factor of 128. This suggests that in situ surface modification can enable BiFeO₃ nano-particles to be a promising visible light photo-Fenton-like catalyst for the degradation of organic pollutants.