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Air desiccant cooling systems are burgeoning. Their major advantage is the use of water alone as a refrigerant. Pairing with efficient solar panels looks promising. Much research is underway to improve the techniques and performances of installations. In this article, we present the results of a calculation code that we developed from experimental data. It studies the conditions of air treatment by desiccation according to three different techniques with wide intervals of climatic conditions in order to point the limits of applicability. The objective is to precisely define the area in which each type of handling system can be used. We started by simulating the treatment of the air in the desiccant handling system (DHU) operating according to four techniques in order to choose one for the Algerian climate. A validation of the results with the experimental data was made. According to our calculations, DHU using Pennington cycle are not able to achieve satisfactory comfort conditions. An improvement in the Pennington cycle is proposed. It consists in adding an exchanger cooled by the water leaving the heating circuit and which is used to cool the fresh air. This solution seems effective and gives clearly acceptable results for the climatic conditions studied. In the last part of this article, we present the calculation results relating to the sensitivity of each technique to variations in temperature and humidity conditions. We have thus successfully delimited the climatic zones of applicability of each system from the process of the evolution of the air inside the building (coefficient ɛ). It has been confirmed that the improved Pennington cycle is the system best suited to Algerian climatic conditions.

Invasive fungal infections incidence in patients with hematological malignancies is increasing. Air treatment remains an essential preventive measure. Guidelines state that high-risk patients should be housed in units equipped with High-Efficiency Particulate Air filtration. Mobile air-treatment devices may be considered as alternatives or as a complement to the ventilation system. We assessed the decontamination performances of a new mobile air-treatment device in a conventional hematology room. This device connected or not to a plenum combining Ultra-Low Particulate Air filtration and non-thermal catalysis process has been evaluated with or without healthcare activities (one sampling at-rest and triplicate samplings in activity). Environmental particulate, airborne and surface fungal and total mesophilic flora (TMF) samplings were performed with a total of 1800 min of particles counting, 144 air and 240 surface samplings. At-rest, both devices achieved a 2-log decrease of airborne particles, ISO 4 being the maximal particle class reached under the plenum. Whatever the healthcare activities and the location in the room, ISO 7 was the maximal particle class reached. TMF and fungal air contamination were lower during healthcare activities when the air portable cleaners were running. The bed was the area the least contaminated in the room. No differences were observed for surface contamination. This work provides arguments of the efficacy of a new mobile air-treatment device to decrease particle counts and airborne bioburden in real-life conditions. Studies have yet to be conducted to document the impact of these devices on the risk of invasive aspergillosis in immunocompromised patients.

The fabrication of hierarchical layered TiO2/graphene/chitin composite membranes from the liquid crystal (LC) self-assembly of graphene oxide (GO) nanosheets, chitin nanospindles, and peroxotitanate is presented. The multilayer co-assembly evolves the lamellar arrangement to mimic a fascinating nacre’s structure in the solidified graphene/chitin composites. The core of our routine is the self-assembly of both GO LCs and chitin LCs into a flexible nacre-mimicking membrane structured by graphene-wrapped chitin layers. The intrinsic electron mobility of graphene nanosheets and mechanical toughness of chitin nanocrystals endow these reinforced membranes with functions in catalyst supports and electronics. The nacre-mimicking composite homogeneously incorporates with TiO2 nanoparticles by simultaneous LC co-assembly of GO, chitin and peroxotitanate to afford layered TiO2/graphene/chitin composites that can function as a photocatalytic membrane for the mineralization of organic compounds. The LC integration creates hierarchical assemblies to increase the permeability of the TiO2/graphene/chitin nanohybrid membranes, offering its potential use for developing photocatalysis and separation for water and air treatment. The work not only presents the implementation of the nacre-mimicking LC self-assembly but also presents the sustainable materials as promising precursors for further investigation in energy storage and conversion and gas sensing.

Livestock production is associated with several gaseous pollutant emissions to the environment. These emissions can degrade local and regional air quality, contribute to surface water eutrophication and acid rain, and contribute to the greenhouse gas footprint of the production sector. Modern production systems must balance animal welfare and environmental pollution potential with economic reality, which is a great challenge to maintain as global demand for animal protein increases. Accordingly, gaseous emission technologies were the main target for this research, in which mitigating gas emissions of ammonia, nitrous oxide, and methane from pig production facilities via slurry aeration system was tested. Five treatments with different airflow rates in the test room were examined continuously over a period of 6 weeks and the results were compared with the control room. Test results indicate that the highest mitigation potentials were 12, 57.6, and 10.4% for nitrous oxide, methane, and ammonia, respectively. Subsequently directing exhaust air into a sulfuric acid air scrubber at 3.0 pH further reduced total ammonia emissions by 80 to 87%.

Environmental remediation is a research field transformed over the past two decades by the integration of engineered nanoscale materials. The market for nanotechnology in environmental applications is rapidly growing, signifying the importance of such advancements in practice as well as research. Most nano-enabled remediation challenges in water, soil and air treatment are addressed by two primary phenomena—contaminant degradation by reduction/oxidation reactions or contaminant sequestration through adsorption processes. Despite the scientific accessibility of these fields by virtue of their shared treatment mechanisms, the unique engineering and physical challenges associated with implementation require field-specific solutions and create research bubbles where scientists and engineers may be unfamiliar with current research in parallel areas. Consequently, this review is focused on summarizing the key nano-enabled technologies and their mechanisms in the fields of water, soil and air treatment, as well as describing recent advances and highlighting areas with clear direction for further development. This review covers nano-enabled processes including photocatalysis in air and water treatment, nZVI-mediated reduction and adsorption processes in soil and water treatment, and CO2 capture and reduction including the state-of-the-art materials driving research focused on improving these technologies. This review is intended as a platform for researchers to understand how their expertise fits into the larger community of remediation technology as well as to provide direction for literature review of parallel fields suiting their interest. We conclude by identifying core research focuses and underdeveloped research directions in each of the three areas, most notably, a need for guided evaluation of meaningful composite materials for next-generation catalysts.

A range of different studies has been performed in order to design and develop photocatalysts that work efficiently under visible (and near-infrared) irradiation as well as to improve photons absorption with improved reactor design. While there is consensus on the importance of photocatalysis for environmental applications and the necessity to utilized solar irradiation (or visible-light) as driving force for these processes, it is not yet clear how to get there. Discussion on the future steps towards visible-light photocatalysis for environmental application is of great interest to scientific and industrial communities and the present paper reviews and discusses the two main approaches, band-gap engineering for efficient solar-activated catalysts and reactor designs for improved photons absorption. Common misconceptions and drawbacks of each technology are also examined together with insights for future progress.

Pulse bruchid-infested samples of green gram (Vigna radiata) and chickpea (Cicer arietinum) having different moisture contents (7.5–9.5% wb) (1 cm bed depth) were exposed to microwave–hot air treatment for different exposure times (3 min 20 s to 6 min) and hot air temperatures (40–60 °C). Protein content, cooking time, textural kinetics, color and viability of the treated samples were analyzed, and techno-economic feasibility analysis was carried out for the process. Hundred percent mortality of adult insect (Callosobruchus maculatus) was achieved immediately, at an air temperature of 60 °C with microwave exposure period of 6 min at 2900 W power level. All the three processing parameters, i.e., moisture content, period of exposure and hot air temperature, were found to have significant effect on the mortality of pulse bruchids for both chickpea and green gram. Negligible differences were observed between the control and treated samples with respect to protein content for both chickpea and green gram. Cooking time, textural hardness, L value, greenness and viability of treated samples were lower than control sample. Cost of the treatment works out to be INR 6.28–7.07 per kg which is likely to come down with economics of scale.

The analysis of the two-level multi-channel cyclone operation requires the investigation of the treated air flow movement. The two-level multi-channel cyclone was designed for separating solid particles from the air flow and constructed at the Institute of the Environmental Protection of Vilnius Gediminas Technical University. The study was aimed at determining airflow distribution in a two-level six-channel cyclone and measuring air treatment efficiency. To determine the velocity of airflow in the channels, a multi-functional measuring instrument Testo-400 and the dynamic Pitot tube were used. The concentration of particles in the air inlet and outlet ducts was determined by the weight method. The obtained results showed that the same air volumes on both cyclone levels are equal and the velocity of the airflow was uniformly distributed in the channels. The maximum airflow velocity was recorded in the first channel. The mean airflow velocity in the channels did not differ significantly.

In this study, hot air heat treatments of larch (Larix kaempferi) wood specimens were conducted at various temperatures (160–220 °C) and times (1–12 h) to classify the degree of hot air heat treatment using near-infrared (NIR) spectroscopy. NIR reflectance spectra were acquired from specimen cross-sections and were then preprocessed using the standard normal variate. Hierarchical clustering analysis (HCA) using the complete linkage and squared Euclidean distance was conducted to classify the three degrees of heat treatment. A principal component score plot of the NIR spectra was well grouped by the HCA grouping result, and the first component reflected the cluster analysis grouping well. A partial least squares discriminant analysis was performed to develop the discriminant regression model of the three heat treatment degrees. The R2 and root mean square error of validation were 0.959 and 0.191, respectively. NIR is considered to be a good candidate to routinely measure the degree of hot air treatment for larch wood.

The Asian papaya fruit fly, Bactrocera papayae Drew and Hancock, was treated with hot-water immersion and forced hot air to develop a phytosanitary heat treatment schedule. Hot-water immersion tests were conducted with 12- and 24-h-old eggs and with first and third instar larvae to compare the relative thermotolerances of this fruit fly among these life stages. The 24-h-old eggs, the most thermotolerant among the four life stages tested, were subjected to time and temperature tests using cage-infested papaya fruits in a forced hot-air chamber. Heating the papayas to a minimum core temperature of 47.7 °C (95% confidence interval 47.2–48.3 °C) was estimated to induce probit-nine mortality based on a probit analysis of the data. Confirmatory tests in which papayas infested with 24-h-old eggs were heated to a minimum fruit core temperature of 47.2 °C that was maintained for 0–30 min followed by hydrocooling to a fruit core temperature of ≈25 °C resulted in the complete mortality of an estimated treated population of 43,425 eggs aged 24 h (99.9931% mortality at the 95% confidence level). Therefore, heating the papaya fruits to a core temperature of 47.2 °C for a minimum dwell time of 30 min, which was the longest dwell time in the confirmatory tests, may serve as a phytosanitary heat treatment schedule for the control of B. papayae in papaya fruits.

The photocatalytic treatment of gaseous benzene under visible light irradiation was developed using electrospun carbon nanotube/titanium dioxide (CNT/TiO2) nanofibers as visible light active photocatalysts. The CNT/TiO2 nanofibers were fabricated by electrospinning CNT/poly(vinyl pyrrolidone) (PVP) solution followed by the removal of PVP by calcination at 450 °C. The molar ratio of CNT/TiO2 was fixed at 0.05:1 by weight, and the quantity of CNT/TiO2 loaded in PVP solution varied between 30 and 60 % wt. CNT/TiO2 nanofibers have high specific surface area (116 m2/g), significantly higher than that of TiO2 nanofibers (44 m2/g). The photocatalytic performance of the CNT/TiO2 nanofibers was investigated by decolorization of 1 × 10−5 M methylene blue (MB) dye (in water solution) and degradation of 100 ppm gaseous benzene under visible light irradiation. The 50-CNT/TiO2 nanofibers (calcined CNT/TiO2 nanofibers fabricated from a spinning solution of 50 % wt CNT/TiO2 based on PVP) had higher MB degradation efficiency (58 %) than did other CNT/TiO2 nanofibers and pristine TiO2 nanofibers (15 %) under visible light irradiation. The photocatalytic degradation of gaseous benzene under visible light irradiation on filters made of 50-CNT/TiO2 nanofibers was carried out in a simulated air purifier system. Similar to MB results, the degradation efficiency of gaseous benzene by 50-CNT/TiO2 nanofibers (52 %) was higher than by other CNT/TiO2 nanofibers and pristine TiO2 nanofibers (18 %). The synergistic effects of the larger surface area and lower band gap energy of CNT/TiO2 nanofibers were presented as strong adsorption ability and greater visible light adsorption. The CNT/TiO2 nanofiber prepared in this study has potential for use in air purifiers to improve air treatment efficiency with less energy.

Immobility of photocatalysts on substrates is a vital factor for the practical application of photocatalysis in polluted water/air treatment. In this study, TiO2 homogenously loaded quartz fiber felt was prepared by assembling of carboxyl-contained organic molecules functionalized TiO2 nanoparticles on the surface of amino group-modified quartz fiber by electrostatic adsorption between them and followed by an anneal process. The immobilization of TiO2 nanoparticles overcomes one main obstacle of the photocatalysts recycling in photocatalysis application. In addition, a plasma treatment endowed the hybrid photocatalyst a high hydrophilic property. Due to the homogeneous distribution of TiO2, charge carriers’ separation by carbon, and full contact between water and the photocatalyst derived from the high hydrophilia, the TiO2/quartz fiber felt shows excellent photocatalytic performance. Based on the stable loading and the capillarity effect of the contacted fibers photocatalyst, a demo capillarity-driven continuous-flow water treatment photocatalysis reactor was designed and built up. The TiO2 nanoparticle/quartz fiber hybrid photocatalyst can disposal organic contaminants in actual industrial waste water from a dyeing factory in the continuous-flow reactor. The chemical oxygen demand (COD) of the industrial waste water was decreased from 104 to 45 mg/L, overcoming the problem of deep water treatment which is difficult to solve by other methods. This study provides a new photocatalyst and reaction mode for the continuous-flow photocatalysis application.

Water and air pollutants have huge impacts on the entire living system. In addition, the newly emerging nanopollutants, increasing global warming, and consequent climate changes are posing major threats to the freshwater or fresh air availability. This has made it urgent to invent an appropriate water/air treatment technology that removes nanopollutants and also desalinates water to a significant extent. Carbon-based nanomaterials have generated marvelous interest in a wide range of research activities due to their high adsorption capacities. Carbon nanotubes, carbon nanotube bundles, and related materials have potential applications in gas/ion separation and water purification. Recently, gas/ion separation and water purification through carbon-based nanomaterials have received increasing attention. This review summarizes the properties of carbon nanotubes and carbon nanotube bundles related to gas separation, ion separation, and water purification using molecular dynamics simulations. Membranes-based carbon nanomaterials show promise of water purification and gas separation. These attractive properties of carbon nanotubes-based and carbon nanotube bundles-based nanomaterials make them proper candidates for gas separation, gas molecular-sieving processes, and desalination purposes in nanoscale dimensions.

Four experimental trials were carried out in order to evaluate the efficacy of different products (chemicals, resistance inducers and natural products) as well as heat air when applied to basil seeds naturally infested by Peronospora belbahrii, the causal agent of downy mildew of basil, a pathogen which is seed transmitted. Seed quality, as vigour index, was also evaluated. In general, seed treatment had a positive effect on the reduction of disease incidence and on plant biomass at the end of each trial, with very satisfactory results when disease incidence was lower than 10% and still satisfactory results with a higher disease incidence. Although many of the fungicides, resistance inducers and thyme oil treatments tested showed a significant disease reduction compared with the untreated control, the protection offered was only partial. Moreover, the effectiveness of the tested seed treatments varied considerably between the trials. The seeds treatment with heat air (65°C for 10 min) significantly reduced the number of infected plants per container. The interaction effect between the fungicides (at the lowest dosage tested, with the exception of acibenzolar-S-methyl, and dimethomorph), thyme oil and the heat air treatment was also significant. In terms of biomass, most treatments not significantly improved the fresh weight in comparison with the untreated control. The highest biomass was observed in the plots where seeds were dressed with mancozeb combined with heat air. Interestingly, thiram is also effective against other pathogens affecting basil and the thermal treatment and potassium phosphite are fully compatible with the rules of organic farming. Seed dressing represents the starting point of a full integrated approach for downy mildew management.

The effect of postharvest heat treatment (37 °C, 3 days) on ascorbic acid (AsA) metabolism related to chilling resistance in peach fruit stored at 5 °C has been studied. Chilling injury (CI) index and hydrogen peroxide (H2O2) levels as well as gene expression levels of mitochondrial L-galactono-1, 4-lactone-dehydrogenase (GalLDH) related to AsA synthetic metabolism, cytosolic ascorbate peroxidase (APX), chloroplastic APX, peroxisomal APX1-3, cytosolic monodehydroascorbate reductase (MDAR), chloroplastic MDAR, chloroplastic dehydroascorbate reductase (DHAR), and chloroplastic glutathione reductase (GR) related to AsA regeneration cycle metabolism were measured. Treated fruit maintained its initial H2O2 levels after heat conditioning, showing significantly higher levels when compared with non-heated fruit. However, during cold storage, heat-treated fruit exhibited lower H2O2 levels than control fruit; heated fruit had the lowest CI index at the end of storage. The transcription levels of all of genes (GalLDH, APX, MDAR, and DHAR), except for GR, sharply increased, and were higher than those of control fruit, immediately after heat treatment. Then, transcription levels sharply declined to levels lower than control fruit at 7–14 days. Little difference of gene expression was observed in the end of storage. These results suggest that AsA metabolism gene expression was temporarily and sharply induced by higher H2O2 levels after heat treatment, which might inhibit the elevation of H2O2 level at the initial period of cold storage, and followed by lower genes expression of AsA metabolism accompanied by lower H2O2 levels following transfer to cold storage.

Controlled atmosphere (CA) has been widely used to help extend the shelf life and maintain the quality of horticultural products. In the present study, broccoli (Brassica oleracea L. cv. Youxiu) florets were stored under CA with high levels of O2/CO2 at 15 °C, including 100 % O2, 80 % O2 + 20 % CO2, 60 % O2 + 40 % CO2, 40 % O2 + 60 % CO2, and air (control), to determine the effects of CA on storage period and on some physiological properties during storage. The results showed that compared with the control, the treatments combining O2 and CO2 effectively extended the storage period and inhibited respiration rate, ethylene production, and reductions in weight loss, chlorophyll, and ascorbic acid levels. Moreover, the CA treatments inhibited the increases in both superoxide radicals (O 2 −· ) production rate and hydrogen peroxide (H2O2) level and reduced malondialdehyde accumulation, which could be beneficial in delay of senescence by alleviation of oxidative damage. In addition, broccoli florets exposed to CA conditions maintained lower activities of superoxide dismutase and peroxidase that are responsible for scavenging of O 2 −· and H2O2 and alleviating lipid peroxidation. Among the treatments, the maximum efficacy was observed with a CA of 40 % O2 + 60 % CO2, which prolonged the storage period of broccoli heads to 17 days (d) compared with 4 d under air treatment. Conversely, 100 % O2 treatment accelerated senescence and deterioration in the quality of broccoli, resulting in a shorter storage period. These results suggest that the establishment of an appropriate CA condition with high levels of O2/CO2 may be an ideal strategy for maintaining the quality of broccoli florets during storage.

Mesoporous titania as powders and thin films on ITO were prepared using gelatin as an available and non-expensive pore-forming agent. The mesoporous TiO2 manifested a much higher photocatalytic activity in the gas-phase air oxidation of ethanol and acetaldehyde than the commercial nanocrystalline TiO2 P25 (Degussa Corp.). The mesoporous ITO/TiO2 films exhibited 12-14% efficiency of photocurrent generation in aqueous Na2S electrolyte when illuminated by UV light. Deposition of CdS and PbS nanoparticles onto the surface of ITO/TiO2 further increases the photocurrent yields and expands the light sensitivity range of the films to 500-520 nm (CdS) and to 650-700 nm (PbS).

Anoxic brain injury resulting from cardiac arrest is responsible for approximately two-thirds of deaths. Recent evidence suggests that increased oxygen delivered to the brain after cardiac arrest may be an important factor in preventing neuronal damage, resulting in an interest in hyperbaric oxygen (HBO) therapy. Interestingly, increased oxygen supply may be also reached by application of normobaric oxygen (NBO) or hyperbaric air (HBA). However, previous research also showed that the beneficial effect of hyperbaric treatment may not directly result from increased oxygen supply, leading to the conclusion that the mechanism of hyperbaric prevention of brain damage is not well understood. The aim of our study was to compare the effects of HBO, HBA and NBO treatment on gerbil brain condition after transient forebrain ischemia, serving as a model of cardiac arrest. Thereby, we investigated the effects of repetitive HBO, HBA and NBO treatment on hippocampal CA1 neuronal survival, brain temperature and gerbils behavior (the nest building), depending on the time of initiation of the therapy (1, 3 and 6 h after ischemia). HBO and HBA applied 1, 3 and 6 h after ischemia significantly increased neuronal survival and behavioral performance and abolished the ischemia-evoked brain temperature increase. NBO treatment was most effective when applied 1 h after ischemia; later application had a weak or no protective effect. The results show that HBO and HBA applied between 1 and 6 h after ischemia prevent ischemia-evoked neuronal damage, which may be due to the inhibition of brain temperature increase, as a result of the applied rise in ambient pressure, and just not due to the oxygen per se. This perspective is supported by the finding that NBO treatment was less effective than HBO or HBA therapy. The results presented in this paper may pave the way for future experimental studies dealing with pressure and temperature regulation.

The application of electrochemically enhanced photocatalysis in air treatment using a Nafion-based photoelectrochemical cell and TiO2/WO3 photoanodes for organic vapor photooxidation under both UV and visible light irradiation is briefly presented. In that direction, the obtained results regarding the preparation and characterization of the TiO2/WO3 photoanodes with enhanced photocatalytic activity are reviewed. Particular emphasis is given in the comparison of the photocatalytic behavior of bilayer TiO2/WO3 coatings, electrosynthesized on stainless steel mesh and powder C + mixed (WO3 + TiO2) photoanodes. The advantages of using a high surface area C + mixed (WO3 + TiO2) powder catalysts as photoanodes against their plain TiO2 + C and WO3 + C analogues are discussed.

Experimental data are provided on perfluorocarbon accumulation from atmospheric air in an industrial facility in Ukraine in the process of air treatment in a modern air-fractionating plant with production of krypton–xenon mixture. Comparison of the obtained data with the calculated values supports the proposition put forward by these authors regarding the crucial contribution of adsorption processes to the final outcome of perfluorocarbon accumulation in the end product. One can monitor the process of rise in perfluorocarbon content in the atmospheric air at the site of an industrial facility by determining the variation in perfluorocarbon accumulation in the end product (krypton–xenon mixture).

In modern societies, people spend about 90 percent of their time inside buildings. The challenge of building physics is to ensure that buildings are planned, constructed and built to provide a comfortable and healthy working and living environment. As construction style has changed during recent years, the planning phase has to be much more precise and the need of simulation programs that respond to every little change arises. An increasing problem in Austria is the indoor humidity. In the field of renovated buildings with airtight new building envelopes, mould growth due to high indoor relative humidity (RH) is a persistent problem. On the other hand, in recently realized Austrian passive houses with an air treatment system, the low humidity level of the indoor air is a problem with which scientists have been struggling for some time. It has been observed in numerous measurements and it is also easily computationally detectable that in winter period the indoor relative humidity level often drops below 30% RH. Low and high relative humidity levels have negative effects on the comfort feeling and health of the occupants of the dwelling and should therefore be avoided. However, it is expensive to increase or decrease the humidity in houses mechanically. Therefore, the existing room moisture should be used sensibly in buildings with a ventilation system. In buildings with a high indoor humidity it is necessary to adjust the ventilation depended on moisture production. This paper focuses on low indoor humidity and presents some different methods by which the indoor relative humidity can be regulated. The effects of adapting parameters such as ventilation rate and buffering material in the dwelling were clearly reflected in the measured temperature and relative humidity. “BuildOpt_VIE” software developed at the Vienna University of Technology was used for the dynamic building simulation in this study.

Raw moso bamboo (Phyllostachys pubescens) was examined to optimize the carbonization and the consecutive air activation procedure. Influence of sample size, nitrogen flow rate, heating rate and final temperature on the carbon yield and the pore structure was investigated for the raw bamboo. The short length cutting along bamboo trunk and the increase in heating rate to 40°C/min and nitrogen flow rate up to 500 ml/min was found to be advantageous for the carbonization of raw bamboo at 500°C, resulting in a surface area of 230 m2/g with a bamboo char yield of 25% on dry base. In the next step, effects of air treatment temperature, ash content and its composition on the pore development were studied for the prepared bamboo char in comparison with coconut shell char. Additional increase in surface area by 200 m2/g with 97% yield could be achieved conducting the 2-hour air treatment at 280°C for the bamboo char, whereas only a 100 m2/g rise in surface area was attained for the coconut shell char, partly due to the difference in K2CO3 content in the char.

Herrmann, Jean Marie; Photocatalysis is based on the double aptitude of the photocatalyst (essentially titania) to simultaneously adsorb reactants and absorb efficient photons. Heterogeneous photocatalysis is able to be efficient in Fine, "Green" and Environmental Chemistry. Photocatalysis induces mild oxidations in the absence of water by generating active neutral atomic O* species. For instance, the oxidation of 4-tert-butyl-toluene is 100% selective in 4-tert-butyl-benzaldehyde. In water treatment, many toxic inorganic ions are oxidized in their harmless upper oxidized state. The elimination of organic pollutants is the main field of water photocatalytic decontamination. Most of aliphatic and aromatic pollutants are totally mineralized into CO2 and innocuous inorganic anions. More complex molecules, such as pesticides (herbicides, insecticides, fungicides, etc.) or dyes, are totally destroyed. Another example of green chemistry is the total degradation of dyes in water, in particular for the azo-dyes, with 100% selective degradation of -N=N- azo-groups into di-nitrogen. Photocatalysis is also active in the "bio-world" by killing bacteria (E. Coli, streptococcus, etc.) in water without re-growth. Air pollutants can also be destroyed, especially all the VOC's (volatile organic compounds), providing certain air humidity enabling titania to produce cracking OH center dot radicals. For chemical engineering reasons, the photocatalyst has to be fixed on a photo-inert support. In these conditions, UV-irradiated titania-based photocatalysis could be applied to the elimination of air pollutants, VOC's, solvents, odors, chemicals, etc. Air treatment has to be associated with water and solid waste treatment because of odors. This is conducted by covering water treatment ponds or lagunas by rafts on which large sheets of Ahlstrom paper are deposited, supporting titania associated with activated carbon. Eventually, virus AH5N2, a model virus close to H5N1, responsible for the avian flu could be totally inactivated. Photocatalysis is directly connected with all 12 principles of Green Chemistry defined by Anastas (1998) and possesses open perspectives for China.

Anatase Ti0.94Nb0.06O2 (TNO) films were fabricated on glass substrates by sol–gel method using a dip-coating technique. The annealing treatment was separated into two steps, first in air at 350–550 °C for 1 h and then in vacuum of 4.0 × 10−4 Pa at 550 °C for 1 h. The influence of vacuum annealing treatment to the electrical and optical properties was discussed. Especially, the role of air annealing treatment from 350 to 550 °C on the crystallization and the structure of the films was analyzed. It is proved that the films annealed at 550 °C in air and then 550 °C in vacuum exhibited the minimum resistivity of 19.3 Ω·cm and the average optical transmittance of about 75% in the visible range, indicating that the sol–gel method is a feasible and promising method to fabricate TNO films.

The microstructure of self-supported 1.5–10-μm thick Pd/23 wt%Ag membranes grown by magnetron sputtering have been studied after heat treatment and hydrogen permeation tests using electron microscopy and synchrotron X-ray diffraction. After hydrogen flux stabilization and permeance measurements at 300 °C, the membranes were annealed in air at 300 °C or in N2/Ar at 300/400/450 °C for 4 days and then tested for hydrogen permeation. The permeation results show that changes in permeability depend on the treatment atmosphere and temperature, as well as membrane thickness. Air treatment at ~300 °C generally induced a positive effect on permeation in the thickness range of 1.5–10 μm. Significant microstructural changes, including grain growth, strain relief, void formation, and growth of nodules occurred in the membranes. The changes in microstructure are more severe for the thinner membranes, and may be attributed mainly to the oxidation processes at or near the surface. For samples annealed in N2/Ar, enhanced permeation was only obtained with treatment at ~450 °C for 5 and 10 μm. The changes in the microstructure generally increased with heat-treatment temperature, and decreased with membrane's thickness. The membrane with enhanced permeation was accompanied by significant grain growth, strain relief, and surface roughening. For all the membranes, the relative changes in the microstructure were substantially more prominent on the permeate surface than on the feed surface. Details of the analysis are presented and discussed.

Stable TiO2 sols were prepared using two non-aqueous sol–gel processes with titanium n-butoxide and titanium isopropoxide, respectively. Crystallization and phase transitions of powders and thin films were studied by ex situ and in situ X-ray diffraction. For both methods, TiO2 began to crystallize around 320 °C in air. Using helium instead of air during heat treatment slowed down the crystallization and substoichiometric powders were formed. TiO2 thin films were obtained by spin coating. The morphology of the films was evaluated using scanning electron microscopy. The films were homogeneous and transparent in the visible range. The effect of the heating atmosphere and the type of substrate was investigated.

Indian citrus ringspot virus (ICRSV) is known to cause serious disease problem in Kinnow (Citrus nobilis Lour × C. deliciosa Tenora) plants. This work reports the elimination of ICRSV by using thermotherapy coupled with shoot tip grafting in vitro. Nodal segments from infected mother plants (indexed by indirect ELISA and RT-PCR) were treated both in water bath and moist hot air at different temperatures viz. 40, 45 and 50°C for 30, 60 and 120 min and cultured on MS medium containing 2-iP (1 mg/l) and malt extract (800 mg/l). Shoot tips were excised from the nodal sprouts and grafted on to rough lemon (C. jambhiri) rootstock under aseptic conditions. Water bath treatment was found to be more effective as compared to moist hot air treatment as maximum number of ICRSV free plants (36.84%) were obtained by grafting the tips (0.7 mm) taken from the nodal segments treated at 50°C in water bath for 2 h. In an alternate treatment regime, 1-year-old infected plants were kept at various temperatures viz.36, 38 and 40°C in a thermotherapy chamber. Maximum of 60% ICRSV free plants were obtained by grafting the tips (0.7 mm) from the plants placed at 40°C followed by the plants placed at 38°C (59.09%) and the least was observed in case of the plants placed at 36°C (40.74%). Only those plants/plantlets were considered virus free, which showed negative reaction both in Indirect ELISA and RT-PCR.

Ethylene decreases the content of endogenous abscisic acid (ABA) and increases the level of bioactive gibberellin A1 (GA1) in the submerged internodes of deepwater rice. During partial submergence, internodes of deepwater rice undergo rapid elongation as a result of ethylene accumulation in the internodal lacunae. In anin vitro experiment using stem sections from deepwater rice, treatment with 5 μL L-1 ethylene promoted stem growth by up to 3.2-foId times over air treatment. Expression patterns were analyzed for genes that encode GA- and ABA-biosynthesis enzymes to determine any possible molecular basis for the changes observed in GA1 and ABA contents as a result of ethylene action. Expression of theOsGA20ox2 andOsGA20ox4 genes, which encode GA 20-oxidase, and of theOsGA3ox2 gene, which encodes the enzyme that converts GA20 to CA1, was up-regulated, whereas that of three ABA-biosynthetic genes —OsNCED1, OsNCED2, andOsNCEDS-was down-regulated in the presence of ethylene. These results indicate that GA and ABA contribute equally to the submergence-or ethylene-induced stem elongation of deepwater rice via the coordinated and opposite regulation of biosynthesis.

The production of biogas in landfills, its composition and the problems resulting from its generation are all reviewed. Biofiltration is a promising option for the control of emissions to atmosphere of the methane contained in biogas issued from the smaller and/or older landfills. A detailed review of the methane biofiltration literature is presented. The microorganisms, mainly the methanotrophs, involved in the methane biodegradation process, and their needs in terms of oxygen and carbon dioxide utilization, are described. Moreover, the influence of nutrients such as copper, nitrogen and phosphorus, and the process operating conditions such as temperature, pH and moisture content of the biofilter bed, are also presented. Finally, the performance of various filter beds, in terms of their elimination capacities, is presented for laboratory scale biofilters and landfill covers.

Volatile organic compounds (VOCs) are major contaminants of indoor air, with concentrations often several times higher than outdoors. They are recognized as causative agents of "building-related illness" or "sick-building syndrome". Our previous laboratory test-chamber studies have shown that the potted-plant/root-zone microorganism microcosm can eliminate high concentrations of air-borne VOCs within 24 hours, once the removal response has been induced by an initial dose. However, the effectiveness of the potted-plant microcosm in 'real-world' indoor spaces has never previously been tested experimentally. This paper reports the results of a field-study on the effects of potted-plant presence on total VOC (TVOC) levels, measured in 60 offices (12 per treatment), over two 5-9 week periods, using three planting regimes, with two 'international indoor-plant' species. Fourteen VOCs were identified in the office air. When TVOC loads in reference offices rose above 100 ppb, large reductions, of from 50 to 75% (to

Volatile organic compounds containing reduced sulphur such as thiols and thioethers are released mostly from biological activities and a number of manufacturing processes, such as papermaking and petroleum refining. Environmentally benign and cost-effective air pollution control technology for reduced sulphur compounds is still a topic of research, e.g., in pulp and paper industry. Due to its advantages, photocatalytic oxidation over titanium dioxide presents a potential alternative for the air treatment strategies. The temperature influence on the reaction pathway and kinetics of gas-phase photocatalytic oxidation and thermal catalytic decomposition of ethanethiol over Degussa P25 TiO2 was established by a continuous flow method in a simple tubular reactor at temperatures from 373 to 453 K. Kinetic parameters for ethanethiol were: adsorption enthalpy −45 kJ mol−1 and activation energy 42 kJ mol−1. Sulphur dioxide, carbon monoxide, carbon dioxide, acetic acid and water were identified as by-products.

The phenomenon of chlorinated byproduct formation and their possible emission from odor control systems employing chlorine scrubbing solutions was evaluated. Experiments with hypochlorite scrubbing solution were performed with a bench-scale, single-stage, packed-bed odor scrubber to explore the potential for generating toxic air contaminants (TACs) such as chloroform in full-scale operating units. Known concentrations of a mixture of volatile organic compounds (VOCs) commonly found in wastewater were introduced at realistic field concentrations in an airstream to the inlet of a counter-current packed-tower operated with different scrubbing solutions. Formation of TACs was observed in the scrubbing solution under low-, neutral- and high-pH conditions. The addition of a mixture of VOCs: acetone, methylethylketone, formaldehyde and acetaldehyde, produced chloroform under neutral to high pH conditions. Under low-to neutral-pH conditions, toluene and chlorophenol produced chlorotoluenes and chlorophenols as reaction byproducts. Under the bench-scale unit’s operating conditions, trace levels of the reaction byproducts formed were stripped from the re-circulated scrubber solution into the outlet gas. Based on the bench-scale observations and a quasi-steady-state, first-order reaction model applied to the scrubber reservoir and packed tower system, scrubber solution residence time in the liquid reservoir is hypothesized to be an important operating parameter affecting TAC formation in full-scale hypochlorite-based, packed-tower, odor control units.

The types of biofilter modeling may be primarily classified in accordance with whether a biofilm is differ- entiated from other phases in each model. It may be a secondary classification with regard to biofilter-modeling whether sorption volume and/or adsorption are adopted as reservoirs or not. Thirdly, biofilter models are classified as to whether adsorption is assumed to exist through gas phase and/or a biofilm. Among all the biofilter-models of previous inves- tigators all model-components including gas phase, a biofilm, sorption volume and adsorption surface are considered only in the model of Lim. Since his model does not require a numerical solution but an algebraic solution to describe the concentration of organic pollutants in waste-air-streams along the height of a biofilter even under unsteady-state conditions, it satisfies the condition of simplicity that is one of the important model requirements. In spite of its simplicity, Lim's model predictions are fairly good to fit Hodge and Devinny's experimental data.

Pollutant degradation in biotrickling filters for waste air treatment is generally thought to occur only in the biofilm. In two experiments with toluene degrading biotrickling filters, we show that suspended microorganisms in the recycle liquid may substantially contribute to the overall pollutant removal. Two days after reactor start up, the overall toluene elimination capacity reached a maximum of 125 g m(-3) h(-1), which was twice that found during prolonged operation. High biodegradation activity in the recycle liquid fully accounted for this short-term peak of pollutant elimination. During steady-state operation, the toluene degradation in the recycle liquid was 21% of the overall elimination capacity, although the amount of suspended biomass was only 1% of the amount of immobilized biomass. The results suggest that biotrickling filter performance may be improved by selecting operating conditions allowing for the development of an actively growing suspended culture.

In order to elucidate the role of acidity in reaction of selective NO reduction by hydrocarbons in oxygen-rich circumstances, a commercial γ-alumina was treated under atmosphere at moderate temperature range and the acidic sites of treated alumina were determined by differential NH3 adsorption heat at 473 K. The alumina has little impurity of Na, Fe, Si. The BET surface area and average pore width are 350 m2/g and 4 nm respectively. Air treatment at moderate temperature has no serious effect on the total amount of acidic sites above 70 kJ/mol, but influences the acidic site distribution at the initial and the tail energy sides. Treatment at higher temperature gives rise to a higher initial adsorption heat due to activation of alumina surface. Disappearance of carbon-contained species and appearance of distinct surface hydroxyl groups under air treatment above 673 K are plausibly observed by FT-IR. Degree of dehydration has a tremendous effect on development of Bronsted acidic sites. The relationship of changes in acidic site distribution at moderate temperature and De-NOx activity at the same temperature was discussed.

A great deal of research has been directed towards the problem of reduction and control of volatile organic compounds (VOCs). The aim of this research is to find a process that is both efficient and inexpensive in comparison with traditional air treatment technologies. Our biofilter (one stage system, 2 m in height) is an aerobic system for waste gases containing VOCs using the degradation properties of microbial flora (assorted cultures of Bacillus, Micrococcus, Acinetobacter and yeast). In this process, polluted gas diffuses across a filter bed into which a microbial culture has previously been introduced. Peat is the medium of choice for inoculation with microorganisms because of its adsorption and absorption properties, ability to retain moisture, and buffering capacity. Furthermore, the peat utilized is spherical in shape; thus, it is possible to avoid problems related to compacting. The objective of this study was to eliminate VOCs emitted from a rotogravure process. We were able to achieve promising results from biofiltration of two types of VOCs (a mixed solvent containing isopropyl acetate and 1-nitropropane, and the solvent: 1-nitropropane). The results obtained indicate that the elimination of nitropropane and the mixed solvent in the biofilter are considered to follow zero-order kinetics with reaction rate limitation and diffusion rate limitation, respectively.

The effects of the nutrient solution oxygenation on the growth of tomato plants and colonization of plant roots by Pythium F707, an isolate with filamentous non-inflated sporangia, were investigated under hydroponic conditions. Lipoperoxidation was also estimated determining lipoxygenase activity and conjugated dienes. Tomato plants were grown under either a high (11-14%; Air treatment), a moderate (5.8-7%; Control) or a low (0.8-1.5%; Nitrogen treatment) oxygen concentration and inoculated or not with the pathogen. The high oxygen treatment resulted in a marked increase in plant growth, as measured by shoot and root weights. Root and top weights were about the same in the nitrogen-treated plants and the controls. In these treatments, plants started showing typical symptoms of root decay and infection within 6 days after inoculation with Pythium F, while highly oxygenated plants remained healthy throughout the experiment and showed a significant decrease in root colonization by the pathogen, as estimated by the immunoenzymatic staining procedure and isolation of thalles on selective medium. Nitrogen-treated plants and controls produced higher amounts of conjugated dienes and revealed increased lipoxygenase activities in comparison with highly oxygenated plants. These differences were more pronounced after inoculation with the pathogen. Our data suggest that increases in lipoxygenase activity detected in the present study in tomato roots grown under oxygen stress and inoculated with Pythium F may lead to degradation and disorganization of membrane lipids. That disorganization may facilitate root colonization by the pathogen and appearance of decay.

Octahedral magnetite (Fe3O4) nanoparticles (NPs) with dimensions ranging from 20 to 110 nm are prepared via the decomposition of iron oleate complex in the presence of cetyltrimethylammonium bromide (CTAB) and various organic solvents. It is shown that the addition of an optimal amount of CTAB prompts the growth of equi-dimensional octahedral NPs with dominant {111} facets. Moreover, it is shown that the size of the octahedral NPs can be controlled by adjusting the relative amounts of oleic acid and CTAB and choosing an appropriate high-boiling point organic solvent. The X-ray diffraction analysis results reveal that the compositions of the as-synthesized NPs are solvent-dependent and contain different amounts of iron metal, wustite and magnetite phases. The as-synthesized NPs are oxidized to pure magnetite via an air treatment and the room-temperature magnetic properties of the resulting products are then characterized by means of a superconducting quantum interference device. The results indicate that the superparamagnetic limit for the current magnetite NPs is equal to approximately 33.3 nm at a temperature of 300 K.

Die Absauganlagen sind durch einen grosen Energieverbrauch charakterisiert. Eine der Moglichkeiten zur Senkung des Energieverbrauchs ist der Einsatz von Absaugsystemen mit veranderlichem Luftverbrauch. Es wird ein mathematisches Modell vorgestellt, das zur Beschreibung und Erklarung der Systemwirkung bei unterschiedlicher Anzahl von geoffneten Absaugleitungen geeignet ist. Das Verfhren kann rechnergestutzt realisiert werden.

The performance of an air dehumidifier composed of a tube bank sprinkled with a LiCl/H2O hygroscopic solution and cooled inside by water is studied under steady state conditions. An one-dimensional model simulating also the case of solution recirculation is presented together with the experimental procedure for the evaluation of the mass transfer coefficient for the apparatus. A series of tests on an experimental absorber validates the model. The behaviour of the apparatus together with a simplified parametric study are then presented for a full scale absorber with air and solution flowing both in countercurrent and in cocurrent. The external parameters controlling the apparatus performance are also defined.

A study has been made of the effects of O2, N2, CO2, and air treatment during steeping of two varieties of barley, Nordal from Denmark and Tokak from Turkey. Steeping time was varied from 1 to 3 days and the seeds subsequently germinated on sand for 7 days. Water uptake, endosperm modification (measured as cell wall breakdown), and embryo growth (measured as root and shoot growth) were monitored throughout germination.