活性炭负载TiO_2光催化杀菌研究

研究了溶胶-凝胶法制备活性炭颗粒负载TiO2的光催化杀菌作用,探讨了光催化剂的最佳制备条件。实验结果表明,光催化杀菌效果明显好于单独紫外光的杀菌效果,当钛酸丁脂与无水乙醇比例为1:8制备TiO2溶胶,活性炭颗粒浸涂凝胶一次、在450℃煅烧2h,20min的杀菌率可达88%,在溶胶中掺杂Fe3+的杀菌率可达到95%,提高了活性炭负载TiO2的光催化活性。     

Carbon nanotubes and cyclodextrin polymers for removing organic pollutants from water

Some organic compounds are major water pollutants. They can be toxic or carcinogenic even at low concentrations. Current technologies, however, fail to remove these contaminants to parts per billion (ppb) levels. Here we report on the removal of organic pollutants from water using cross-linked nanoporous polymers that have been copolymerized with previously functionalized carbon nanotubes. These novel polymers can remove model organic species such as p-nitrophenol by as much as 99% from a 10 mg/L spiked water sample compared to granular activated carbon and native cyclodextrin polymer that removed only 47 and 58%, respectively. These polymers have also demonstrated the ability to remove trichloroethylene (10 mg/L spiked sample) to non-detectable levels (detection limit <0.01 ppb) compared to 55 and 70% for activated carbon and native cyclodextrin polymers, respectively.     

Removal of congo red dye from water using carbon slurry waste

A cheaper adsorbent has been prepared from carbon slurry waste obtained from National Fertilizer Limited (NFL), Panipat and investigated for the removal of congo red, an anionic dye. Its adsorption on prepared carbonaceous adsorbent was studied as a function of contact time, concentration and temperature. The results have shown that carbonaceous adsorbent adsorbs dye to a sufficient extent (272 mg g^-1). A comparative study of adsorption results with those obtained on activated charcoal shows that the carbonaceous adsorbent is ~95% efficient as compared to activated charcoal. Thus, it can be fruitfully used for the removal of dyes from wastewaters.This work has been presented at the National Symposium on Biochemical Sciences: Health and Environmental Aspects (BSHEA—2003), Agra, India (2003).     

催化氧化CS2的催化剂及其性能研究

以ＣＳ２作为含硫废气的处理对象，研究了Ｐｔ－Ｍｏ负载，在改性天然丝光沸石上对ＣＳ２的催化氧化活性，以及添加Ｖ对催化剂活性的影响。研究表明，Ｐｔ－Ｍｏ－Ｖ和改性载体之间存在着共催化作用，在Ｐｔ－Ｍｏ－Ｈ＾＋Ｍ催化剂上由于Ｖ的添加，使催化剂处理ＣＳ２的浓度和ＳＤＹ值明显提高。在反应温度３１０℃，空速５００ｈｒ＾－１和ＣＳ２浓度为３７０ｍｇ／ｍ＾３转化率达到１００％，ＳＯｘ放出率接近９５％－１００％。     

Landscape visualisation and climate change: the potential for influencing perceptions and behaviour

The urgent need to mitigate and adapt to climate change is becoming more widely understood in scientific and policy circles, but public awareness lags behind. The potential of visual communication to accelerate social learning and motivate implementation of the substantial policy, technological, and life-style changes needed, has begun to be recognised. In particular, realistic landscape visualisations may offer special advantages in rapidly advancing peoples’ awareness of climate change and possibly affecting behaviour and policy, by bringing certain possible consequences of climate change home to people in a compelling manner. However, few such applications are yet in use, the theoretical basis for the effectiveness of visualisations in this role has not been clearly established, and there are ethical concerns elicited by adopting a persuasive approach which deliberately engages the emotions with visual imagery. These questions and policy implications are discussed in the context of a theoretical framework on the effects of landscape visualisation on a spectrum of responses to climate change information, drawing in part on evidence from other applications of landscape visualisation. The author concludes that the persuasive use of visualisations, together with other approaches, may be effective, is justified, and could be vital in helping communicate climate change effectively, given ethical standards based on disclosure, drama, and defensibility.     

活性炭催化氧化烟气中SO_2的研究

为了有针对性地寻找有实际应用价值的炭系脱硫剂 ,以活性炭为研究对象 ,较深入地研究了影响其脱硫性能的因素。通过对活性炭脱除烟气中SO2 的实验研究 ,得出了活性炭脱硫效果的关键是活性炭的催化活性 ,在催化活性一定的条件下 ,O2 浓度、水蒸汽浓度、炭床层温度等影响脱硫效率的结果。并由此得出寻找具有较高催化活性的炭系脱硫剂 ,是保证脱硫效率 ,使炭系脱硫剂得以推广应用的关键的结论     

电渗析法再生CO_2碱吸收液的初步探讨

以Na2CO3和NaHCO3的混合液作为用碱液吸收CO2气体的模拟液,用两室单阴膜电渗析装置对其在小于5V的低电压下进行脱碳处理,并且得出电渗析的方法可以增加回收液中Na2CO3和NaHCO3的浓度比,减少碳的总浓度,起到了对CO2的碱吸收液再生利用的作用。     

First in vitro use of the phenylphosphate carboxylase enzyme in supercritical CO2 for the selective carboxylation of phenol to 4-hydroxybenzoic acid

A new biotechnological synthetic approach to 4-hydroxybenzoic acid is reported. Thauera aromatica cells produce the phenylphosphate carboxylase enzyme that selectively carboxylates phenylphosphate in the para position, without any formation of the ortho isomer. Here we show that the enzyme also works in supercritical carbon dioxide, opening a new technological solution to the recovery of the products that is a key problem when aqueous media are used. The enzyme shows an activity comparable with that shown under CO₂ pressure in aqueous media and does not require the presence of NaHCO₃.     

Recycling greenhouse gas fossil fuel emissions into low radiocarbon food products to reduce human genetic damage

Radiocarbon from nuclear fallout is a known health risk. However, corresponding risks from natural background radiocarbon incorporated directly into human genetic material have not been fully appreciated. Here we show that the average person will experience between 3.4 × 10¹⁰ and 3.4 × 10¹¹ lifetime chromosomal damage events from natural background radiocarbon incorporated into DNA and histones, potentially leading to cancer, birth defects, or accelerated aging. This human genetic damage can be significantly reduced using low radiocarbon foods produced by growing plants in CO₂ recycled from ordinary industrial greenhouse gas fossil fuel emissions, providing additional incentive for the carbon sequestration.     

Life cycle assessment of a pulverized coal power plant with post-combustion capture, transport and storage of CO2

In this study the methodology of life cycle assessment has been used to assess the environmental impacts of three pulverized coal fired electricity supply chains with and without carbon capture and storage (CCS) on a cradle to grave basis. The chain with CCS comprises post-combustion CO₂ capture with monoethanolamine, compression, transport by pipeline and storage in a geological reservoir. The two reference chains represent sub-critical and state-of-the-art ultra supercritical pulverized coal fired electricity generation. For the three chains we have constructed a detailed greenhouse gas (GHG) balance, and disclosed environmental trade-offs and co-benefits due to CO₂ capture, transport and storage. Results show that, due to CCS, the GHG emissions per kWh are reduced substantially to 243 g/kWh. This is a reduction of 78 and 71% compared to the sub-critical and state-of-the-art power plant, respectively. The removal of CO₂ is partially offset by increased GHG emissions in up- and downstream processes, to a small extent (0.7 g/kWh) caused by the CCS infrastructure. An environmental co-benefit is expected following from the deeper reduction of hydrogen fluoride and hydrogen chloride emissions. Most notable environmental trade-offs are the increase in human toxicity, ozone layer depletion and fresh water ecotoxicity potential for which the CCS chain is outperformed by both other chains. The state-of-the-art power plant without CCS also shows a better score for the eutrophication, acidification and photochemical oxidation potential despite the deeper reduction of SO_x and NO_x in the CCS power plant. These reductions are offset by increased emissions in the life cycle due to the energy penalty and a factor five increase in NH₃ emissions.