活性白土对油脂溶液中叶绿素的吸附行为研究

利用活性白土(AAB)对油脂溶液中叶绿素进行吸附,深入探讨了叶绿素在AAB上吸附的动力学及热力学行为.结果表明,Freundlich等温吸附方程能够较好地拟合吸附等温线.叶绿素在AAB上的吸附能够在较短的时间内达到平衡,温度升高有利于提高吸附速率和吸附客量,动力学特性符合准二级动力学方程,此吸附是一个吸热的自发过程.     

改性伊利石对活性红KD-8B的吸附研究

用壳聚糖改性天然伊利石制备伊利石负载壳聚糖吸附剂,研究吸附剂对活性红KD-8B染料废水吸附。结果表明,最合适吸附条件为:溶液pH值5,壳聚糖负载量为1.3g,吸附剂量为0.6g。吸附过程动力学方程符合准二级反应动力学模型,吸附等温线用Langmuir方程的拟合效果优于Freundlich方程。     

改性粉煤灰吸附十二烷基硫酸钠的研究

通过对粉煤灰改性,研究改性粉煤灰对磷矿浮选药剂十二烷基硫酸钠的吸附性能,为磷矿浮选废水中有机药剂的去除提供依据。采用X射线衍射仪分析粉煤灰焙烧前后的成分,扫描电镜观察改性前后表面形貌,粉煤灰在350℃焙烧后形成更多的孔道。改性后的粉煤灰吸附十二烷基硫酸钠,进行用量、pH、温度和时间的吸附试验。采用准一级动力学模型、准二级动力学模型、Bangham孔道扩散模型和Weber and Morris（W-M）动力学模型进行吸附动力学分析,可知该吸附符合准二级动力学和W-M动力学模型。采用Langmuir和Freundlich等温模型对吸附等温线进行分析,可知粉煤灰表面具有不均匀性,该吸附属于优惠吸附。      

负载锰活性炭对苯酚吸附性能的研究

以高锰酸钾为浸渍液,采用浸渍法对果壳活性炭进行改性制备负载锰活性炭(Mn/AC),通过SEM、BET、FTIR等技术对负载锰前后活性炭进行表征,并考察了其对苯酚的去除率,通过单因素实验研究了Mn/AC投加量及p H值对苯酚吸附性能的影响,采用吸附等温线模型、动力学模型对Mn/AC吸附苯酚过程进行拟合,研究其吸附特性及机理。结果表明,Mn/AC对苯酚的去除率是负载前(NAC)的3.7倍,25℃,不调节p H值,Mn/AC的投加量为5 g/L时,对苯酚去除率为95.4%;Freundlich模型可较好地拟合Mn/AC吸附苯酚过程,吸附动力学符合拟二级动力学方程。     

四环素在改性凹凸棒土中的吸附

采用批实验的方法讨论了四环素在改性凹凸棒土中的吸附行为以及pH值和阳离子对吸附的影响.结果表明:四环素吸附初始速度较快,并在4h左右达到平衡,吸附体系符合准二级吸附动力学模型;吸附等温线可采用Freundlich方程进行较好的拟合;吸附过程为自发的吸热过程;四环素吸附量在pH值为3时达到最大,随着pH值的增加而降低;阳离子浓度越大,价态越高,吸附量越小.     

活性氧化铝对矿井水中Ca~(2+)的吸附研究

矿井水深度处理采用了反渗透工艺,为使出水能够作为煤矿生产和生活用水,分析了活性氧化铝的投加量、吸附时间、pH对Ca2+吸附的影响。结果表明:随着pH的增大、投加量的增加和时间的延长,Ca2+的去除率均增加,并到一定程度时达到吸附平衡。吸附等温线可用Langmuir等温线描述,用于去除矿井水中Ca2+,并为工业水处理中高钙离子的去除提供重要方法。     

CTAB吸附对褐煤亲水性抑制作用机理的研究

表面活性剂在褐煤表面的吸附特性对其亲水性抑制具有重要影响,在研究了阳离子表面活性剂十六烷基三甲基溴化铵(CTAB)在褐煤表面的吸附特性,并分析吸附等温线、吸附热力学和吸附动力学,通过润湿热测定考察了CTAB吸附量与褐煤表面亲水性抑制效率的相关性后,进一步探讨了褐煤吸附CTAB后表面含氧量和孔结构的变化对其亲水性抑制的影响。研究结果表明,CTAB在褐煤表面的吸附是放热过程,吸附量随着温度的升高而增大;吸附等温线较符合Freundlich模型,吸附速率可以用二级动力学方程描述;褐煤吸附CTAB后,其表面有序度增加,亲水性降低;在褐煤表面吸附的CTAB覆盖了其亲水含氧官能团,并且在褐煤的大孔中发生聚集,还可能引起小孔结构的堵塞;吸附表面活性剂对褐煤亲水性的抑制是表面含氧官能团含量和孔结构变化共同作用的结果。     

捕收剂K64与辉钼矿吸附等温模型及吸附动力学研究

针对辉钼矿与捕收剂K64的作用机理进行研究,以Mo S2含量为96%的纯矿物作为捕收剂K64的作用对象。使用紫外光谱仪进行测试研究,得到不同浓度捕收K64的吸光度,从而获得其标准曲线y=0.654x+0.0226其中R2=0.99694。在此基础上进行了捕收剂K64与辉钼矿表面吸附等温线模型的研究,分别研究了Langmuir、Freundlich、Temkin三种吸附等温线模型,获得捕收剂K64与辉钼矿矿物颗粒之间的吸附作用可以按照Freundlich吸附等温线模型来进行解释的结论。并对三种不同浓度的捕收剂K64与辉钼矿矿物颗粒表面的吸附动力学进行了计算,分别计算了一级吸附动力学、二级吸附动力学、颗粒内扩散动力学,获得二级动力学模型比一级动力学模型和颗粒内扩散动力学模型更加能准确说明K64与辉钼矿矿物颗粒之间的吸附行为。     

辉钼矿与捕收剂K64的作用机理研究

针对辉钼矿与捕收剂K64的作用机理进行研究,以Mo S2含量为96%的纯矿物作为捕收剂K64的作用对象。使用紫外光谱仪进行测试研究,得到不同浓度捕收K64的吸光度,从而获得其标准曲线y=0.654x+0.0226其中R2=0.99694。在此基础上进行了捕收剂K64与辉钼矿表面吸附等温线模型的研究,分别研究了Langmuir、Freundlich、Temkin三种吸附等温线模型,获得捕收剂K64与辉钼矿矿物颗粒之间的吸附作用可以按照Freundlich吸附等温线模型来进行解释的结论。并对三种不同浓度的捕收剂K64与辉钼矿矿物颗粒表面的吸附动力学进行了计算,分别计算了一级吸附动力学、二级吸附动力学、颗粒内扩散动力学,获得二级动力学模型比一级动力学模型和颗粒内扩散动力学模型更加能准确说明K64与辉钼矿矿物颗粒之间的吸附行为。     

改性海泡石对有机污染物氯苯的吸附研究

本文研究了经过酸热改性的海泡石对氯苯的吸附特性,在pH值为6～7,吸附1h条件下,氯苯去除率可达80%左右.同时探讨了改性海泡石对氯苯的吸附等温线,经过对吸附等温方程的拟合可知,符合Freundlich吸附等温方程式,其改性海泡石吸附氯苯为表面不均匀吸附.其吸附动力学符合二级反应动力学模型.     

Mercury Partitioning and Behavior in Streams and Source Areas Affected by the Novo-Ursk Gold Sulfide Tailings (West Siberia,Russia)

We studied the behavior of mercury in acid mine drainage (AMD) and in portions of the Ur River affected and non-affected by AMD near the Ursk sulfide tailings (Siberia) before (2007–2009) and after (2011–2019) the beginning of tailings reprocessing operations. Mercury occurs in water as dissolved plus colloidal (Hg_dc) and colloidal (Hg_C) species or is adsorbed on suspended particles (Hg_susp). The mercury species were classified as either reactive (Hg_R) or non-reactive (Hg_NR), depending on their capacity to reduce to Hg⁰ by reacting with SnCl₂. The composition and pH of the AMD and river waters change downstream of the AMD input. Mercury concentrations ranged from 1.8 to 89 μg/L (for the entire monitoring period) and increased with AMD pH. High-pH conditions are unfavorable for the precipitation of jarosite, which can adsorb Hg from water, and thus mercury remains mobile. Hg_NR is more abundant than Hg_R in the river and in AMD particulates. Non-reactive mercury in the river water is associated with CH₃Hg⁺, which correlates with total organic carbon (TOC), while Hg in the AMD samples is bound to HgS_(s), m-HgS_(s), HgSe_(s), and Hg-jarosite. Hg_R species are associated with particulates in all water bodies as Hg⁰_(liq), Hg(OH)_2(aq), HgCl_2(aq), and Hg²⁺ adsorbed by OH groups on the surfaces of mineral grains. Judging by the TOC concentration and the pH and Eh of river water, which local people use for fishing, Hg is prone to methylation upstream and downstream of the AMD input. The Hg enrichment of local surface waters is due to both a naturally elevated background in a Hg-rich province and to the mining and processing operations.

     

高锰酸钾改性对颗粒活性炭吸附Cu2+的影响

采用KMnO₄溶液在回流状态下对颗粒活性炭进行了改性。考察了KMnO₄ 溶液浓度对Cu²⁺吸附率-pH曲线及pH的影响,并研究了KMnO₄ 改性对颗粒活性炭吸附和解吸Cu²⁺性能的影响。结果表明,KMnO₄ 改性使颗粒活性炭对 Cu²⁺吸附率-pH曲线及pH向低pH偏移。当KMnO₄溶液浓度为0.03 mol/L时,改性颗粒活性炭效果最好;KMnO₄ 改性提高了颗粒活性炭对Cu²⁺的吸附速率,使其投加量节省约3倍;Cu²⁺在改性及未改性活性炭上的吸附遵循Freundlich等温吸附方程,在相同Cu²⁺平衡浓度下,KMnO₄改性活性炭对 Cu²⁺的吸附量提高约 2.7倍;使用 0.35 mol/L的HCl溶液作解吸液,Cu²⁺从KMnO₄改性活性炭上的解吸率为 91.1%,而Cu²⁺从未改性活性炭上的解吸率仅为8.8%。KMnO₄ 改性提高了颗粒活性炭从水中吸附重金属离子的能力,并促进了其解吸再生性能。     

煤粉对焦化废水二级出水中有机物的吸附动力学研究

研究了煤粉对模拟焦化废水二级出水中苯酚、喹啉的吸附,考察了pH、煤粉投加量、吸附反应时间等因素对吸附效果的影响。实验表明：煤粉对模拟废水中有机物的吸附去除率焦煤略高于肥煤,煤粉(-0.5 mm)吸附容量为0.109 4～0.154 4 mg/g;焦煤吸附苯酚、肥煤吸附喹啉符合Freundlich吸附等温式,焦煤吸附喹啉则符合Langmuir等温式;不同煤种和不同粒度煤粉吸附有机物的反应动力学特性相似,均较好符合二级反应动力学模型,R²=0.990±0.008;吸附过程以液膜扩散为速率控制步骤;在不同温度下得到了焦煤吸附苯酚的速率常数方程lnk=188.54e^-11.64/(RT),吸附活化能E_a=11.64 kJ/mol。     

Removal of Mn2+ from aqueous solution by manganese oxide coated zeolite

The preparation, characterization, and adsorption properties of Mn²⁺ by manganese oxide coated zeolite (MOCZ) and its ability in removing Mn²⁺ by adsorption were investigated. Characterization analyses were used to monitor the surface properties (and their changes) of the coated layer and metal adsorption sites on the surface of MOCZ. The adsorption experiments were carried out as a function of solution pH, adsorbent concentration and contact time. Binding of Mn²⁺ ions onto MOCZ was highly pH dependent with an increase in the extent of adsorption with the pH of the media investigated. After the Mn²⁺ adsorption by MOCZ, the medium pH decreased and enhanced with increasing adsorbent concentration. The pseudo-second-order model fitted better among all the kinetic models suggesting that the adsorption mechanism might be a chemisorption process. The equilibrium data showed excellent correlation for both Langmuir and Freundlich isotherm model and this implies both monolayer adsorption and a heterogeneous surface existence in MOCZ. At pH = 6, the Mn²⁺ uptake by MOCZ attained as high as 1.1 meq Mn²⁺ g^?1 at equilibrium. The results suggested that MOCZ presents a fairly good potential as an adsorbent for an efficient removal of Mn²⁺ ions from aqueous solution.     

Mercury speciation and removal across full-scale wet FGD systems at coal-fired power plants

The Ontario Hydro Method (OHM) recommended by the United States Environmental Protection Agency (EPA) was used to determine mercury speciation in the combustion flue gas across wet FGD systems. Four coal-fired units with wet FGD systems were chosen to evaluate mercury speciation and mercury removal efficiencies through these wet FGD systems. Chlorine content in coal had been suggested as a main factor that affects mercury speciation in flue gas. It is shown that the higher the chlorine concentration in coal is, the higher the percentage of oxidized mercury (Hg²⁺) is removed in wet FGD systems, which can increase overall mercury removal efficiencies through wet FGD systems. The selective catalyst reduction (SCR) system has a function of oxidizing elemental mercury (Hg⁰) to oxidized mercury. A higher percentage of oxidized mercury in the total vapor mercury at the FGD inlet is observed when SCR is in service. Therefore, higher overall mercury removal efficiencies through wet FGD are attained. Because of different wet FGD operating conditions, there are different mercury removal efficiencies in different units. Elemental mercury reemission took place when a fraction of oxidized mercury absorbed in the slurry is reduced to elemental mercury, and Hg⁰ is reemitted from stack, which results in decreases in mercury removal efficiencies through wet FGD systems.     

氢氧化镁吸附处理水中三价砷的研究

通过研究氢氧化镁吸附处理含As³⁺模拟废水,考察了振荡反应时间、氢氧化镁用量、反应温度及溶液pH值对As³⁺去除效果的影响。研究结果表明：氢氧化镁处理含As³⁺的废水,操作简便,去除率高,可达99%以上。吸附等温线符合Langmuir 等温方程,吸附容量为4.04 mg/L。     

准东低阶煤孔隙特征及对气体传质方式的影响

进行探讨。结果显示：褐煤以中大孔为主,微小孔发育有限,主要储集空间孔径在0.1~2.0 μm;长焰煤以微小孔为主,孔容主要来自微小孔,其单位孔容远小于褐煤。在多级孔隙配置的煤储层中划分出达西流、滑脱流、过渡流和分子扩散4种传质方式。褐煤孔隙连通性好,以达西流、滑脱渗流为主;长焰煤微小孔发育,各级孔隙连通性差,以达西流、过渡流及分子扩散为主。相比较而言,纳米级孔隙中吸附甲烷分子层厚及滑脱效应对长焰煤单孔渗流能力的影响更显著,其将会在气藏开发过程中对增产稳产提供有益的支持。     

红黄土对水中Cr~(3+)和Cd~(2+)的吸附性能

用天然红黄土作为吸附剂进行了去除水中Cr3+和Cd2+的试验研究,考察了pH值、吸附时间、红黄土投加量对吸附效果的影响,测定了不同pH和不同温度下的吸附等温线。结果表明:红黄土对Cr3+的吸附能力高于对Cd2+的吸附能力,一定条件下,Cr3+的去除率可达99.5%,而Cd2+的去除率最高约63%;吸附行为均符合Lang-muir单分子层吸附模型。根据试验结果,认为红黄土有望成为处理含重金属离子废水的新型吸附材料。     

Investigations of accelerating parameters for the biooxidation of low-grade refractory gold ores

This research was designed to accelerate the biological oxidation rate of low-grade suphidic gold ores. The biological oxidation by tamed Thiobacillus ferrooxidans bacteria with a mixed low-grade refractory gold ore was investigated. These bacteria could well tolerate up to 18.0 g/L of arsenic (III). The effect on the oxidation rate due to the presence of a magnetic field on the culture medium was examined as well as the influence of surfactants (tween-80, tween-20 and emulsifier-OP) and selected ionic metals such as Ag⁺, Bi³⁺, Co²⁺ and Hg²⁺. The results showed that, based on a 60% oxidation rate for arsenic, the oxidation time was shortened by 83 hours, 90 hours, 98 hours and 100 hours under the optimal conditions of tamed bacteria, magnetized water, concentrations of tween-80 and Ag⁺ respectively. Under the combination of the above parameters, the biooxidation rate was shortened by 120 hours to achieve a 60% oxidation rate for arsenic. However it did not produce a simple additive effect on the biooxidation.     

Heavy metals removal from solution by palygorskite clay

The possible use of palygorskite clay, mined in the Dwaalboom area of the Northern Province of South Africa, as an adsorbent for the removal of metal ions such as lead, nickel, chromium and copper from aqueous solution, was investigated. In this work, adsorption of these metals onto palygorskite has been studied by using a batch method at room temperature. The results of adsorption were fitted to both the Langmuir and Freundlich models. Satisfactory agreement between experimental data and the model-predicted values was expressed by the correlation coefficient (R²). The Langmuir model represented the sorption process better than the Freundlich one, with correlation coefficient (R²) values ranging from 0.953 to 0.994. The adsorption capacity (Q₀) calculated from the Langmuir isotherm was 62.1 mg Pb(II) g⁻¹, 33.4 mg Ni(II) g⁻¹, 58.5 mg Cr(VI) g⁻¹ and 30.7 mg Cu(II) g⁻¹ at a pH of 7.0 at 25 ± 1 °C for a clay particle size of 125 μm. Kinetic investigations were performed to investigate the rate of adsorption of metal ions. The Lagergren’s first-order rate constants were calculated for different initial concentrations of metal ions. In batch mode adsorption studies, removal increased with an increase of contact time, adsorbent amount and solution pH. Adsorption of metals from the single-metal solutions was in the order: Pb > Cr > Ni > Cu. Data from this study proved that metal cations from aqueous solution can be adsorbed successfully in significant amounts by palygorskite. This opens up new possibilities and potential commercial uses in the palygorskite market.