Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

Catalytic oxidation of volatile organic compounds (VOCs) – A review

Adsorption of VOCs onto engineered carbon materials: A review

Formaldehyde is emitted from building and furnishing materials and consumer products, and is known to cause irritation of eyes and respiratory tract, headache, pneumonia, and even cancer. It is a dominant indoor air pollutant, especially in developing countries, and significant efforts have gone into indoor HCHO purification to meet environmental regulations and human health needs. Removal of HCHO by adsorbents has been investigated extensively using potassium permanganate, activated carbon, aluminum oxide, and some ceramic materials. Sorbent effectiveness is typically limited by low adsorption capacities. Catalytic oxidation is the most effective technology for volatile organic compound (VOC) abatement because VOCs can be oxidized to CO2 over certain catalysts at much lower temperatures than in thermal oxidation. Supported noble metal catalysts (Pt, Pd, Rh, Au, Ag) or metal oxide catalysts (Ni, Cu, Cr, Mn) have been used for the catalytic oxidation of VOCs. Complete oxidation of HCHO over catalysts occurs above 150 8C on clean and oxidized films of Ni, Pd, and Al and over silver–cerium composite oxide, above 100 8C over Ag/MnOx-CeO2 [18] and Au/CeO2, [19] and above 85 8C over Pd-Mn/Al2O3 [17] and Au/FeOx. As catalytic oxidation at even lower temperatures is desirable for indoor air purification, the development of a catalyst for total HCHOoxidation at room temperature is of great interest. In our recent study, 1% Pt/TiO2 catalyst was shown to be effective for HCHO oxidation at room temperature, achieving 100% conversion of d= 100 ppm HCHO to CO2 and H2O at a gas hourly space velocity (GHSV) of 50000 h . However, we also observed that this type catalyst is not as active as needed for practical applications, and deactivates with time-on-stream. Herein, we report a novel alkali-metal-promoted Pt/TiO2 catalyst for the ambient destruction of HCHO. We show that the addition of alkali-metal ions (such as Li, Na, and K) to Pt/TiO2 catalyst stabilized an atomically dispersed PtO(OH)x–alkali-metal species on the catalyst surface and also opened a new low-temperature reaction pathway, significantly promoting the activity for the HCHO oxidation by activating H2O and catalyzing the facile reaction between surface OH and formate species to total oxidation products. Figure 1a shows the HCHO conversion to CO2 as a function of temperature over the x% Na-1% Pt/TiO2 (x= 0, 1, and 2) samples at a GHSVof 120000 h 1 andHCHO inlet of d= 600 ppm. All gas streams were humidified to a RH of around 50%. Before each activity test, the samples were reduced in H2 at 300 8C for 30 min. The sodium-free catalyst had low activity for the HCHO oxidation reaction, with HCHO conversion being only about 19% at 15 8C. With 1% Na addition, the HCHO conversion reached 96% at 15 8C and 100% at 40 8C. With 2% Na addition, 100% HCHO conversion to CO2 and H2O was measured at 15 8C. The effect of Na addition on the surface reducibility was examined by H2 temperature-programmed reduction (TPR; Figure 1b). The amounts of H2 consumption were about the same over all the samples, but the addition of Na shifted the reduction peak to lower temperatures, that is, from 2 8C for 1% Pt/TiO2 to 6 8C for 1% Na-1% Pt/TiO2 and 11 8C for 2% Na-1% Pt/ TiO2. Thus, the sample reducibility correlates with the sample activity. The most active 2% Na-promoted sample had excellent stability as checked by long isothermal tests. For example, at a GHSV of 300000 h 1 and with the same other reaction conditions, approximately 80% HCHO conversion was maintained over a 72 h-long test (Figure 1a, inset). Li and K were equally effective promoters to Na and imparted the same high activity and stability to the Pt species (Supporting Information, Figure S1). Water vapor and oxygen effects on the activity of Na-Pt/TiO2 are important (Supporting Information, Figures S2,S3). Deionized-water washing of the samples was performed to check the alkali-metal and Pt interaction.While most of the Na was removed from the Nacontaining catalysts, a residual amount remained (Supporting Information, Table S1). Activity test results (Supporting Information, Figure S1) showed that the washed catalyst had identical activity for HCHO [*] C. Zhang, F. Liu, Y. Liu, Prof. H. He Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Shuangqing Road 18, Beijing, 100085 (China) E-mail: honghe@rcees.ac.cn

Alkali‐Metal‐Promoted Pt/TiO2 Opens a More Efficient Pathway to Formaldehyde Oxidation at Ambient Temperatures

WHO Guidelines for Indoor Air Quality: Selected pollutants.

A review of the emission of VOCs from polymeric materials used in buildings

BRE has conducted a national representative survey of air pollutants in 876 homes in England, designed to increase knowledge of baseline pollutant levels and factors associated with high concentrations. Homes were monitored for carbon monoxide (CO), nitrogen dioxide (NO(2)), formaldehyde and volatile organic compounds (VOCs). In the majority of the homes, concentrations of the measured pollutants were low. However, some homes have concentrations that would suggest a need for precautionary mitigation. Those factors that are most likely to lead to exposures of concern in homes are identified as gas cooking (for CO and NO(2)), the use of unflued appliances for heating (for CO and NO(2)), emissions from materials in new homes (for total VOC (TVOC) and formaldehyde), and painting and decorating, with a significant increase in risk suspected to exist where there is not a place to store materials away from the living space (for TVOC). It is noteworthy that seasonal effects on CO and NO(2) were largely due to indoor sources. This would need to be considered when interpreting time series studies of the effect of outdoor air pollution on health. It is also of some significance that the critical factors are related much more to sources than to ventilation: source control is therefore, as would be expected, the most appropriate approach to reducing the risk of hazardous exposure to air pollutants in homes.

Exposure to air pollutants in English homes.

The UK government has committed to an 80% reduction in carbon emissions by 2050, with housing accounting for 27% of total current emissions There are several drivers both to reduce emissions from homes and to reduce fuel poverty, promoting a range of building and behavioural measures in homes The health benefits of warmer homes in winter have been described, but there has been less consideration of the potential negative impacts of some of these measures We examine the changes in UK homes, and the possible consequences for health The main concerns for health surround the potential for poor indoor air quality if ventilation is insufficient and the possible risks of overheating in heatwave conditions This paper notes a limited evidence base and the need for further research on the health effects of energy-efficient homes, particularly with regard to ventilation

/pdf/will-drivers-for-home-energy-efficiency-harm-occupant-health-3oicfcr7dp.pdf

Will drivers for home energy efficiency harm occupant health

Relationships between socioeconomic and lifestyle factors and indoor air quality in French dwellings.

An array of three long period gratings (LPGs) fabricated in a single optical fibre and multiplexed in the wavelength domain was used to measure simultaneously temperature, relative humidity (RH) and volatile organic compounds (VOCs). Each LPG sensor was designed to optimize its response to a desired measurand. The LPGs were fabricated with periods such that they operated at or near the phase matching turning point. The sensors were calibrated in the laboratory and the simultaneous measurement of the key indoor air quality parameters was undertaken in laboratory and office environments. It was demonstrated successfully that the data produced by the LPG sensor array under real conditions was in a good agreement with that produced by commercially available sensors. Further, the potential application of fibre optic sensors for VOCs detection at high levels has been demonstrated.

/pdf/multi-parameter-measurements-using-optical-fibre-long-period-2iayt6wvvr.pdf

Derrick Crump

Papers

A review of the emission of VOCs from polymeric materials used in buildings

Exposure to air pollutants in English homes.

Will drivers for home energy efficiency harm occupant health

Relationships between socioeconomic and lifestyle factors and indoor air quality in French dwellings.

Multi-parameter measurements using optical fibre long period gratings for indoor air quality monitoring