复合型纳米TiO2降解甲醛多孔调湿材料研究

从改善室内空气品质角度出发,结合活性炭纤维负载纳米TiO2吸附降解甲醛、Gel树脂凝胶及沸石粉调节湿度的多种特性,制成复合型纳米TiO2降解甲醛多孔调湿材料,对其结构及性能进行了分析研究.结果表明,制成的调湿材料具有较好的调湿及吸附降解甲醛的作用.     

改性炭对磺胺甲噁唑的吸附及解吸特性

采用商品活性炭和金属氧化物改性炭作为吸附剂,研究了几种活性炭对磺胺甲噁唑(SMZ)的吸附及解吸特性。结果表明:SMZ在几种活性炭上的吸附动力学符合拟二级动力学方程;SMZ的吸附均可采用Freundlich、Langmuir和Langmuir-Freundlich模型进行拟合,Langmuir-Freundlich吸附模型能更好地描述活性炭和改性炭对SMZ的吸附行为;铁、锰氧化物的存在对活性炭的比表面或者孔结构影响不大,并且其对活性炭吸附水中SMZ的性能影响甚微;与AC-Fe和AC-Mn相比,AC-0上吸附的SMZ更易解吸,改性炭负载的金属氧化物与SMZ的表面络合作用增强了AC-Fe和AC-Mn对SMZ的化学吸附,并且改性炭的MnOx和FeOx能氧化降解部分SMZ。     

吸附法与喷涂法在室内环境治理中的对比研究

本文以室内环境治理中甲醛清除为例,分别采用数值模拟方法及实验方法,对比研究了活性炭吸附法与光触媒喷涂法的治理效果。研究表明,光触媒喷涂法对室内甲醛有明显的分解作用,在相同的时间段内,可大幅降低室内空气中甲醛浓度。相比之下,活性炭吸附法虽然价格便宜,设置位置灵活,但见效较慢,且只对吸附装置附近区域有较明显的效果。     

核空气净化用浸渍活性炭的性能鉴定

在核空气净化系统设计中,常使用浸渍活性炭来吸附去除放射性碘。浸渍活性炭必须进行放射性碘吸附性能鉴定,以证明其对放射性碘的去除能力。而通过对浸渍活性炭的物理性能鉴定,可以获得浸渍活性炭在粒径、硬度和燃点等方面的参数以及对实际装料和使用的影响。     

活性炭吸附法处理含铀放射性废水

研究了活性炭吸附法处理含铀放射性废水的最佳条件。试验结果表明,活性炭具有良好的除铀效果,在所选择的条件下,活性炭吸附法对铀的去除率≥96%,同时对重金属铬、镉、铅、铜也有一定的吸附作用。用活性炭吸附法除铀,方法简单,除铀率高,特别适合实验室含铀废水的处理。     

复合型纳米Ti02降解甲醛多孔调湿材料研究

从改善室内空气品质角度出发，结合活性炭纤维负载纳米TiO2吸附降解甲醛、Gel树脂凝胶及沸石粉调节湿度的多种特性，制成复合型纳米TiO2降解甲醛多孔调湿材料，对其结构及性能进行了分析研究。结果表明，制成的调湿材料具有较好的调湿及吸附降解甲醛的作用。     

活性炭颗粒过滤器在室内空气净化中的实验研究

利用活性炭颗粒过滤器可以有效地去除室内空气中甲醛等低浓度有机污染物.实验测试了不同实验条件下以及过滤器本身的一些因素时过滤器净化效率的影响.结果表明:过滤风量、污染物的初始浓度、活性炭颗粒用量、活性炭颗粒粒度、净化网的形状等因素时过滤器吸附效果均有影响.     

硝酸改性香榧果壳活性炭的制备及对甲醛的吸附性能

以香榧果壳为原料,经炭化、氢氧化钾活化、硝酸改性处理,制备硝酸改性活性炭。通过氮气吸附和X-射线光电子能谱测活性炭的孔隙结构和表面元素含量。用硝酸改性的活性炭对空气中的甲醛进行吸附,以水解吸后,采用气相色谱进行分析,并确最佳的甲醛色谱分析条件。结果表明,硝酸改性活性炭对甲醛的吸附容量为414.12 mg/g,在4.00～400μg/mL范围内甲醛的峰高与浓度呈良好的线性关系,相关系数(R2)为0.999 4。     

粉末活性炭去除水中阴离子合成洗涤剂的试验研究

在实验室磁力搅拌条件下,研究了活性炭吸附对阴离子合成洗涤剂吸附效果的影响。结果表明:活性炭对阴离子合成洗涤剂的吸附效果良好。在活性炭投炭量为20mg/L条件下,活性炭对阴离子合成洗涤剂的快速吸附阶段大约需要30min,可以达到约75%的吸附容量;2小时后其对纯水中阴离子合成洗涤剂的去除效率达到了95.3%。实验结果表明活性炭吸附方法是一种有效的去除阴离子合成洗涤剂的应急处理技术。     

合成锰氧化物氧化水中苯酚的研究

在实验室条件下制备出了合成锰氧化物(结构类似于δ-MnO2),研究了锰氧化物对水中微量苯酚的氧化效果,并对影响因素进行了分析.实验结果表明:合成锰氧化物对水中微量苯酚具有很好的氧化能力.在pH=3,合成锰氧化物投加量为10mg,反应720min时,合成锰氧化物对200mL质量浓度为5mg/L的苯酚去除率达到86.8%,随着pH值的升高,合成锰氧化物对苯酚的氧化能力逐渐降低,在pH=3时最大;一定范围内,随着合成锰氧化物投加量的增加以及苯酚初始浓度的增加,苯酚的氧化去除率也随之增加;合成锰氧化物对苯酚的氧化受环境中金属离子的抑制作用,其中,Na+、Ca2+、Mg2+离子的抑制效果较弱,而Pb2+、Mn2+等离子抑制作用较强,具体抑制效果为:Na+Ca2+≈Mg2+Zn2+Cu2+Ba2+Mn2+Pb2+.     

Selection of an adsorbent for lead removal from drinking water by a point-of-use treatment device

The removal of lead from drinking water was investigated to develop a point-of-use water filter that could meet the regulation imposed by the new European Directive 98-83 lowering lead concentration in drinking water below 10 μg L⁻¹. The objective of this research was to assess the potential of different adsorbents (zeolites, resins, activated carbon, manganese oxides, cellulose powder) to remove lead from tap water with a very short contact time. To begin, the repartition of the lead species in a tap water and a mineral water was computed with the computer model CHESS. It showed that in bicarbonated waters lead is mainly under lead carbonate form, either in the aqueous or in the mineral phase. Batch experiments were then conducted to measure the equilibrium adsorption isotherms of the adsorbents. Then, for five of them, dynamic experiments in micro-columns were carried out to assess the outlet lead concentration level. Three adsorbents gave rise to a leakage concentration lower than 10 μg L⁻¹ and were then selected for prototypes experiments: chabasite, an activated carbon coated with a synthetic zeolite and a natural manganese oxide. The proposed method clearly showed that the measurement of equilibrium isotherms is not sufficient to predict the effectiveness of an adsorbent, and must be coupled with dynamic experiments.     

两种碳基材料对二级出水中有机物的去除特性

针对活性炭与活性焦两种碳基吸附材料,分别开展静态吸附与动态过滤实验,考察了两者对城镇再生水厂二级出水中有机物的去除效果。结果表明:活性焦介孔及大孔丰富,对应孔体积为0.436 cm³/g,为活性炭的1.6倍;准二级动力学模型更适用于两种材料对COD的吸附动力学拟合,活性焦动力学吸附速率常数k₂为活性炭的2倍;水温为22℃时,活性焦与活性炭对COD的Langmuir饱和吸附量分别为230.38、94.14 mg/g。在近4个月的连续运行中,活性焦滤柱对有机物的去除效果全程优于活性炭滤柱,尽管两滤柱在由单纯吸附向生物吸附降解转化的过程中对有机物的去除率有所降低,但对COD的去除率仍可分别稳定在28.43%和22.26%。活性焦颗粒与活性炭颗粒表面ATP含量最高分别为7032.94、5753.52 ng/g。此外,活性焦滤柱对1~10 ku有机物组分,以及腐殖酸类物质、溶解性微生物代谢产物等不同荧光特性有机物均有较好的去除效果。与活性炭相比,活性焦对再生水厂二级出水中有机物的去除效果更优。     

Adsorption kinetics of fluoride on low cost materials

Adsorption is one important technique in fluoride removal from aqueous solutions. The viability of adsorption techniques is greatly dependent on the development of adsorptive materials. A large number of materials have been tested at a fluoride concentration greater than 2 mg/l, and the lowest limit for fluoride reduction by them is about 2 mg/l. Decreasing the fluoride concentration to less than 2 mg/l, most of the tested materials displayed a very low capacity of fluoride removal.

This paper has concentrated on investigating the adsorption kinetics and adsorption capacity of low cost materials at a low initial fluoride concentration. The experiments were carried out at a natural pH, and radioisotope ¹⁸F rather than ¹⁹F was used since ¹⁸F can be rapidly measured by measuring the radioactivity with a resolution of 1×10⁻¹³ mg or 0.01 μCi. The tested materials are hydroxyapatite, fluorspar, calcite, quartz and quartz activated by ferric ions. Their adsorption capacities follow the order:

Hydroxyapatite>Fluorspar>Quartz activated using ferric ions>Calcite>Quartz

The uptake of fluoride on hydroxyapatite is an ion-exchange procedure and follows the pseudo-first- and second-order equations, while the uptake of fluoride on the others is a surface adsorption and follows the pseudo-second-order equation. Calcite has been seen as a good adsorbent in fluoride removal and has been patented. However, our data suggested that its adsorption capacity is only better than quartz.

The external mass transfer is a very slow and rate-determining step during fluoride removal from the aqueous solution. Under static conditions, there was no relative movement between adsorbents and solutions, the fluoride uptake was at a very slow rate and the adsorbent properties did not significantly affect the fluoride uptake. Under shaken conditions, the adsorption of fluoride was controlled by the adsorbent structure and chemical properties.     

聚吡咯改性碳纳米管的设计及性能研究

通过对碳纳米管（CNT）两步改性得到富含P，N元素的磷腈单元接枝聚吡咯外壳包裹的有机无机杂化结构（HPCNT），将其作为填料添加进PP基体中。相对于纯CNT，杂化结构表面的包裹层与基体间具有更强的界面作用力以及界面相容性，呈现出良好的分散状态，继而能够有效地形成物理阻隔网络。同时，其丰富的P、N元素自身会提供一定的阻燃作用，且能促进成炭。加入3%HPCNT后，PHRR和THR相应的变为987 kW/m²和111 MJ/m²，分别下降了31.6%和15.3%。PCOY以及PCO₂Y相应的变为0.57 mg/m³和11.44%，分别下降了20.8%以及31.7%。     

Gaseous formaldehyde removal: A laminated plate fabricated with activated carbon,polyimide, and copper foil with adjustable surface temperature and capable of in situ thermal regeneration

Formaldehyde is one of the most common indoor air pollutants in Chinese residences. This study introduces a novel laminated plate with adjustable surface temperature to remove gaseous formaldehyde. The plate is fabricated with activated carbon, polyimide, and copper foil via thermal compression. The plate can be regenerated in situ by applying a direct current to the copper foil. Adsorption‐regeneration cycle tests were conducted to evaluate the plate's formaldehyde removal performance. The overall removal efficiency of the fabricated laminated plate with glue mass fraction of 25% and thickness of 1.5 mm was about 30% at the face velocity of 0.8‐1.2 m/s. The pressure drop was about 5 Pa. Its removal ability can be regenerated in situ in 8 minutes by increasing the surface temperature to 80°C. The fabricated laminated plate showed good durability after 52 cycles of adsorption‐regeneration tests. The results indicate that the proposed laminated plate can enhance the purifying efficiency and enlarge the life span of ordinary, cheap sorbents. It makes cheap materials with low performance suitable for air purification.     

异养硝化菌强化饱和基质材料降解水体氨氮的研究

将优势菌技术运用于饱和基质材料中,考察基质材料对水中氨氮的吸附特性以及微生物原位强化饱和基质材料后对氨氮的降解效果。试验结果表明,沸石对氨氮的吸附量高于活性炭。对氨氮含量为110mg／L的模拟富营养化水体进行360h动态吸附后,沸石和活性炭吸附后出水中氨氮平均含量分别为73．3l和89．18mg／L,沸石显示出作为基质材料的优越性。对饱和基质材料进行异养硝化茵强化96h后,沸石柱和活性炭柱出水氨氮平均含量分别降低8．58和17．31mg／L,并且活性炭和沸石表面形成稳定的生物膜。因此,对富营养水体在基质吸附基础上进行微生物降解的方法是可行的。     

Role of the physico-chemical factors in the purification process of water from surface-active matter by biosorption

Activated carbon adsorption with attached microorganisms (biosorption) has been studied. The approaches available do not account for an efficient role of activated carbon under a steady state of purification, considering it (carbon) as a carrier of biofilm only. This paper considers the role of physico-chemical factors in order to clear up and assess a contribution of both physical adsorption and biodegradation (influencing effectiveness of the biosorption process) into the cumulative effect of the biosorption. The nonionic and anionic surfactants as well as phenol were used as sorbates. The impact of such essential physico-chemical factors of the adsorption process as the change in the Gibbs free energy (−ΔG_a⁰) and the porous structure of the activated carbon on the effectiveness of the biosorption process has been established. The lower the contribution of the biological degradation into the biosorption process, the higher the −ΔG_a⁰. As a result of the biodegradation process, products differing in their −ΔG_a⁰ are generated on the active carbon. Separation of the biodegradation products characterized by different −ΔG_a⁰ in the biosorption column filled by active carbon results in redistribution of contributions of physical adsorption and biodegradation into a cumulative effect. The micropores of the active carbon in the course of the biosorption/bioregeneration process are occupied by adsorbed molecules and are not subjected to biological regeneration.     

Anchorage of iron hydro(oxide) nanoparticles onto activated carbon to remove As(V) from water

The adsorption of arsenic (V) by granular iron hydro(oxides) has been proven to be a reliable technique. However, due to the low mechanical properties of this material, it is difficult to apply it in full scale water treatment. Hence, the aim of this research is to develop a methodology to anchor iron hydro(oxide) nanoparticles onto activated carbon, in which the iron hydro(oxide) nanoparticles will give the activated carbon an elevated active surface area for arsenic adsorption and also help avoid the blockage of the activated carbon pores. Three activated carbons were modified by employing the thermal hydrolysis of iron as the anchorage procedure. The effects of hydrolysis temperature (60-120 °C), hydrolysis time (4-16 h), and FeCl₃ concentration (0.4-3 mol Fe/L) were studied by the surface response methodology. The iron content of the modified samples ranged from 0.73 to 5.27%, with the higher end of the range pertaining to the carbons with high oxygen content. The materials containing smaller iron hydro(oxide) particles exhibited an enhanced arsenic adsorption capacity. The best adsorbent material reported an arsenic adsorption capacity of 4.56 mg As/g at 1.5 ppm As at equilibrium and pH 7.     

Complexation of copper in the effluent of a sewage treatment plant and an estimate of its influence on toxicity to coho salmon

Measurements by cupric ion electrode of the complexing capacity of the effluent from a sewage treatment plant (STPE) averaged 0.300 mg 1⁻¹. Of the complexed Cu 67% was due to compounds of 10,000 MW. Organic compounds removable by activated carbon composed 88% of the total organic carbon and were responsible for 87% of the complexation. Complexation of Cu²⁺ by STPE diminishes the toxicity from total Cu to juvenile coho salmon; the LC₅₀ was 0.164 mg 1⁻¹ for river water vs 0.286 mg 1⁻¹ for 40% STPE. The LC₅₀ of Cu²⁺ was approximately the same (0.017 vs 0.022 mg 1⁻¹) in both matrices; this species thus appears to play a toxic role. The mean survival time in diluted STPE with added Cu was inversely proportional to the Cu²⁺ concentration.