Fenton试剂再生活性炭的试验研究

采用Fenton试剂再生被苯酚吸附饱和的活性炭,研究H2O2和Fe2+的投加量、pH值、温度、振荡速率、反应时间等因素对再生效果的影响,并确定最佳再生条件.试验结果表明,当H2O2投加量为7.5mL、FE2+投加量为400mg/L、反应pH值为3、温度为25℃、振荡速率300r/min、反应时间60min时,再生活性炭...     

镧改性磁性介孔二氧化硅对磷酸盐的吸附性能研究

针对高浓度含磷废水排放加剧水体富营养化的问题,制备了一种吸附容量高易于磁分离回收的镧改性磁性介孔二氧化硅纳米粒子(MMSNPs-La),考察投加量、pH值、初始浓度和吸附时间对磷酸盐吸附过程的影响。结果表明,MMSNPs-La对磷酸盐最佳投加量为0. 1 g/L,吸附pH为7. 0,吸附平衡时间为120 min,最大吸附容量为55. 8 mg/g;吸附符合Langmuir等温模型,拟合所得理论吸附容量qemax为57. 1 mg/g,吸附动力学过程遵循准二级动力学;吸附饱和MMSNPs-La可以用3 mol/L的Na OH溶液很好地解吸,5次吸附-脱吸后仍保持较好的吸附性能。     

粉煤灰基质滤料对Cu2＋吸附的关键参数研究

为了研究颗粒状粉煤灰基质滤料对于水体中的可溶性Cu2＋的吸附性能,主要探讨了滤料的投加量、吸附时间、操作温度等对吸附效果的影响。结果表明,在20℃,初始浓度为10 mg/L的含铜溶液中,当滤料投加量为800 g/L,振荡速率为110 r/min,经过25 min后,吸附率可达91.53%。温度升高有利于Cu2＋去除率的提高和单位吸附量增加,但超过65℃后变化不明显。     

粉煤灰滤料对水中Ni^2＋的吸附研究

通过静态吸附试验,研究了粉煤灰滤料对水中Ni^2＋的吸附作用,探讨了吸附剂投加量、吸附时间、溶液pH值以及初始浓度对Ni^2＋吸附效果的影响,拟合了吸附等温线。结果表明,当粉煤灰滤料投加量为30g／L,溶液初始浓度为10mg／L,pH=7时,在30℃、180r／min的转速条件下振荡90min,Ni^2＋的去除率可达到95．2％。经过拟合,粉煤灰滤料对水中Ni^2＋的吸附符合Freundlich和Langmuir吸附等温模型。     

镧改性磁性介孔二氧化硅对磷酸盐的吸附性能研究

针对高浓度含磷废水排放加剧水体富营养化的问题,制备了一种吸附容量高易于磁分离回收的镧改性磁性介孔二氧化硅纳米粒子(MMSNPs-La),考察投加量、pH值、初始浓度和吸附时间对磷酸盐吸附过程的影响。结果表明,MMSNPs-La对磷酸盐最佳投加量为0. 1 g/L,吸附pH为7. 0,吸附平衡时间为120 min,最大吸附容量为55. 8 mg/g;吸附符合Langmuir等温模型,拟合所得理论吸附容量qemax为57. 1 mg/g,吸附动力学过程遵循准二级动力学;吸附饱和MMSNPs-La可以用3 mol/L的Na OH溶液很好地解吸,5次吸附-脱吸后仍保持较好的吸附性能。     

赤泥对亚甲基蓝吸附性能研究

赤泥为氧化铝工业副产物,不仅量大而且污染环境。采用静态吸附实验确定赤泥吸附亚甲基蓝的适宜时间、温度、pH值、亚甲基蓝初始浓度、赤泥投加量范围,并考察了盐浓度对赤泥吸附亚甲基蓝的影响。结果表明,振荡时间5 min,赤泥投加量6 g/L,赤泥对40 mg/L亚甲基蓝的吸附率可达87%。亚甲基蓝浓度与赤泥吸附量符合Langmuir和Freundlich吸附等温式,最大吸附量为14.60 mg/g。赤泥吸附亚甲基蓝为放热反应,低温利于亚甲基蓝吸附。     

氧化石墨烯/二氧化锰的制备及应用

以氧化石墨烯、氯酸钡和硫酸锰为原料合成氧化石墨烯/二氧化锰(GO/MnO2).通过研究投加量、pH值、Pb2+的浓度对去除率的影响,探究材料对水体中Pb2+的吸附特性.结果表明,投加量为0.2g/L,pH=7时,GO/MnO2对20mg/L的Pb2+的去除效率最高达到96.92％.同时对GO/MnO2进行SEM和XRD...     

氧化石墨烯的合成及其对龙胆紫染料废水的净化研究

水体有机污染难以处理,制备吸附性能好、价廉易得、绿色高效的净化剂十分必要。采用改进的Hummers法制备GO,并研究了GO对染料污水的吸附性能。对比了该吸附剂对6种染料的吸附性能,得出对龙胆紫的吸附效果最好,故选取龙胆紫为研究对象。设计了单因素实验,系统研究了不同条件下氧化石墨烯对龙胆紫的吸附,并拟合吸附动力学和等温模型。探究发现,氧化石墨烯投加量0.03 g, pH=9,吸附时间30 min,转速1 200 r/min,染料质量浓度为50 mg/L时吸附最优,吸附率为98.36%,吸附量81.96 mg/g。等温模型符合Langmuir吸附,动力学模型符合准二级动力学吸附。实验结果显示了氧化石墨烯对龙胆紫染料具有较强的吸附能力,有望在水体染料污染处理上发挥巨大作用。     

改性粉煤灰处理生活污水中磷的试验研究

采用改性粉煤灰为吸附剂,对生活污水中磷进行吸附脱磷试验,并研究粉煤灰粒径、投加量、pH、温度、振荡强度以及吸附时间等因素对脱磷效果的影响。结果表明,在粉煤灰粒径为0.075～0.096 mm、投加量为25 g/L、溶液pH为3.5、水温为50℃的条件下,对磷质量浓度为6.0 mg/L的生活污水,以140 r/min的强度振荡吸附120 min,磷的去除率可高达94.5%,水样中的磷质量浓度降至0.5 mg/L以下。     

热改性铝污泥对水中磷的吸附性能

考察了接触时间、pH、投加量对热改性铝污泥吸附磷的影响,确定了其最佳吸附条件和影响因素顺序。结果表明,除磷影响因素依次为磷溶液初始浓度接触时间溶液pH投加量,改性铝污泥吸附除磷的最佳条件:初始磷浓度为60.00 mg/L,pH值为3.0,投加量为4 g/L,振荡反应时间为4 h,改性铝污泥对磷的最高去除率达77.2%。     

改性膨胀石墨对甲醛的吸附性能研究

对含甲醛的废气处理一般采用吸附法，本文以天然鳞片石墨、浓硫酸、浓硝酸、双氧水、重铬酸钾为原料，采用改进的二次氧化法制备膨胀石墨，并对所制得的膨胀石墨进行表面改性。运用改性后的膨胀石墨对甲醛进行静态和动态吸附实验，实验结果表明，改性后的膨胀石墨对甲醛气体的吸附能力有大幅度提高。研究了改性前后膨胀石墨孔结构的变化及其对饱和吸附量的影响，并对改性机理进行了初步探讨。     

Recovery of heavy oil from contaminated sand by using exfoliated graphite

Heavy oil was recovered from contaminated sand through capillary suction into exfoliated graphite with differentpacked densities by using model sands, alumina powders, with different particle sizes. For efficient recovery it was important to have an appropriate combination of average size of sand particles and packed density of exfoliated graphite. Pumping of heavy oil into exfoliated graphite occurs as a balance in an attracting capillary force between exfoliated graphite and sand, the former being stronger than the latter because of the hydrophobic nature of the surface of graphite.     

膨胀石墨对高分子吸附的研究

本文对膨胀石墨制备方法进行了研究,以及各种方法制得的膨胀石墨对油类物质及些有机物的吸附效果进行了比较。     

石墨烯气凝胶的制备及其对水中油分的吸附特性

以改性Hummers法制备出的氧化石墨（GO）为原料,乙二胺（EDA）为交联剂,通过液相化学交联法制备出以石墨烯为主体的多孔网状气凝胶（EGA）。利用电子扫描电镜（SEM）、电子透射电镜（TEM）及选区电子衍射（SAED）对其进行表征。以水中柴油为研究对象,考察所制EGA样品对水中柴油的吸附脱除效果。结果表明,石墨烯气凝胶对柴油的吸附量在前5 min上升迅速,在30 min左右达到吸附平衡。吸附过程遵循准二级动力学模型,且吸附速率随温度的升高而增加,体系的表观活化能E_a=23.94 kJ·mol^-1。颗粒内扩散模型拟合结果表明,EGA对水中柴油的吸附分为表面孔道吸附、气凝胶内部孔道扩散以及石墨烯片层间小孔道扩散。石墨烯气凝胶对柴油的吸附等温线与Freundlich模型较为吻合。     

Sorption and recovery of heavy oils using exfoliated graphite Part IV: Discussion of high oil sorption of exfoliated graphite

The correlation between sorption capacity for heavy oil with a viscosity of 0.004 kg/m s and pore volume measured by a mercury porosimeter was studied on exfoliated graphite samples with different bulk densities. Pore volume measured by using the conventional dilatometer (N-type cell), which gives information on the pore size from 0.004 to 4 μm, was too low to explain the sorption capacity measured. However, pore volume measured by a special dilatometer (U-type cell) for large pore sizes up to 600 μm was very closed to sorption capacity. Pore volume measured by this U-type cell showed a linear relation to sorption capacity of exfoliated graphite samples, of which the slope was the same value as the density of heavy oil used (860 kg/m³). Therefore, large pores, which are reasonably assumed to be inter-particle pores among entangled worm-like particles of exfoliated graphite, were responsible for the large sorption capacity of heavy oils. Intra-particle pores inside and cleavage-like pores on the surface of worm-like particles were assumed to assist the capillary pumping of heavy oil.     

A rapid and efficient method to prepare exfoliated graphite by microwave irradiation

Exfoliated graphite materials had been rapidly and efficiently prepared by microwave irradiation in a short time (about 4 min including 3 min mixing and 1 min microwave irradiation). The promotion of the intercalation by microwave irradiation was proven by X-ray diffraction. With increasing content of oxidant and intercalation agent, the expanded volume of exfoliated graphite increased at first and then decreased. When the weight ratio of natural graphite and nitric acid to potassium permanganate was set at 1:2:1, the expanded volume of exfoliated graphite reached the maximum value (312 mL/g) and sorption capacity of this exfoliated graphite was 56 g of engine oil and 32 g of kerosene per 1 g of exfoliated graphite.     

Surface features of exfoliated graphite/bentonite composites and their importance for ammonia adsorption

Commercial graphite intercalated with sulfuric or nitric acid was exfoliated by rapid heating at 800 °C, homogenously mixed with bentonite water suspension and then dried at 120 °C. Dynamic ammonia adsorption was then measured on the prepared samples, the as received intercalated graphite, the expanded graphite, and the as received bentonite. The surface of the materials before and after exposure to ammonia was characterized using adsorption of nitrogen, XRD, SEM, FTIR, TA, and potentiometric titration. The results showed that mixing exfoliated graphite with clay leads to formation of layered composites on which enhanced amount of ammonia is retained. It is likely there are three types of active sites for ammonia adsorption. The first group consists of acidic functional groups formed on the edges of graphite flakes during exfoliation. The second groups are Brønsted or Lewis acidic centers of clay origin, and the third category includes unique features of the composite structure and chemistry. When a composite is formed metal cations from the clay interlayer space react with carboxylic groups of graphite flakes, as a result, the layer charge has to be balanced by additional adsorption of ammonia, which results in an enhancement in the performance of these materials as ammonia removal media.     

膨胀石墨的化学制备法和影响其质量的因素

膨胀石墨作为新型炭素密封件材料广泛用于石油、化工、电力、冶金、医药、食品、机械等行业。介绍了用化学法制备的膨胀石墨的过程中石墨的粒度、酸化液配比、pH、膨胀温度对膨胀石墨质量的影响。     

柴油电催化加氢与氧化脱硫的系统集成

柴油中硫和多环芳烃含量要求越来越严,由于二苯并噻吩类硫化物的空间位阻导致传统的催化加氢难以实现以上目标。本文以泡沫铅为阴极,以石墨为阳极,在CH₃CN+EtOH+H₂O+Bu₄NBr电解体系中可以将柴油中多环芳烃的电解加氢和含硫化合物的电解氧化脱除集成。在该电解体系中泡沫铅电极上柴油电解加氢主要是温和的加氢,电解加氢后氢含量增加了1.1%,三环芳烃蒽类和菲类减少3.3%,但是总芳烃含量变化不大,十六烷值增加3.9。在石墨阳极上柴油中硫化物容易电解氧化,氧化产物砜类不能完全由电解体系萃取脱除,进一步通过活性炭吸附可以将柴油硫含量由884 μg·g^-1降低至44 μg·g^-1。     

Preparation and characterization of graphite nanosheets from ultrasonic powdering technique

Natural flake graphite was exfoliated into exfoliated graphite via an acid intercalation procedure. The resulting exfoliated graphite was a worm-like particle composed of graphite sheets with thickness in the nanometer scale. Subjecting it to ultrasonic irradiation, the exfoliated graphite was effectively further foliated into isolated graphite nanosheets. SEM, TEM, SAD, laser counting, and BET measurements revealed that the graphite nanosheets prepared with 10 h irradiation were about 52 nm in thickness and 13 μm in diameter. FTIR examination showed that there were oxygen-containing groups presented on the surface of the exfoliated graphite. This result substantiated the statement reported in the literature that acid treatment could result in oxidization of carbon bonds on graphite surface.