Showing papers in "Environment Protection Engineering in 2008"

Effect of energy release and detailed surface mechanisms on multicomponent catalytic combustion

Abstract: The effect of combustion energy release and detailed surface mechanisms on multicomponent catalytic combustion process intensification is presented. It was found that in a recuperative converter the combustion of species of decreased reactivity (CH4) resulted in an increased heat recirculation and a higher temperature and consequently in higher CH4 conversion compared to more reactive C3H8. Further it was also found that catalytic combustion could be enhanced by the addition of other flammable gases even under isothermal conditions. The effect of H2 addition on combustibles conversion was more pronounced than that after CO addition because of the higher H2 adsorption rate that resulted in the consumption of O2 near and on the surface and consequently in an increased free sites availability for adsorption of other reactants.

The quality of sewage sludge stabilized for a long time in reed basins

Abstract: The aim of the work was to determine changes of long-term sewage sludge quality stabilized in reed basins from 7-15 years. The following parameters were evaluated: dry matter and organic matter concentration, nitrogen, phosphorus, and selected heavy metal (Cd, Ni, Pb, Cr, Cu, Zn) fractions. The material for the investigations was collected from 4 reed basin systems (utilisated sewage sludge) located in conventional WWTPs in Denmark (serving from 9 000 to 40 000 pe, producing from 232 to 870 t of d.m/a). Based on the obtained results, it was found that the sludge in reed basins was dewatered and stabilized. Furthermore, it was found that the concentration of nitrogen decreased while the concentration of phosphorus increased. The analyzed heavy metals were mostly bound with the residual fraction and their concentrations were below permissible values for agricultural usage as determined by Polish law. Thus an obtained product - stabilized sewage sludge can be potentially used as fertilizer.

Total gaseous mercury in the area of southern Baltic and in the coastal zone of the Gulf of Gdańsk during spring and autumn

Abstract: Total gaseous mercury (TGM) concentration was measured over the offshore waters of the Gdansk Deep during spring and autumn in the years 1999–2006. The results obtained were compared with TGM concentrations recorded at the same time in the air of the coastal zone of Gdynia and Sopot. Both offshore and in coastal zone, higher Hg(g) concentrations were measured in autumn than in spring. When analyzing mean Hg(g) concentrations in subsequent hours of the day, solar radiation effect on mercury level in the air was evident. Mercury levels in the air seemed to be controlled also by the presence of dissolved organic matter in the seawater, which is responsible for mercury complexation and for algae detoxification processes.

Activity of nitrifying biofilm in the process of water treatment in diatomite bed

Abstract: The study deals with the efficiency of removing ammonium nitrogen from water in biofiltration process. For the research purposes diatomite was used as packing of biological reactor. As a biofilter filler, diatomite was simultaneously the sorbent, the culture medium and the carrier of microorganisms. The biological activity of the bed was assessed taking account of the effectiveness of removing ammonia nitrogen in the process of nitrification and the time of biofilm formation. Diatomite stimulates the growth of biomass and the process of effective removal of ammonia nitrogen, reaching even 100%. SEM image proved that the surfaces of diatomite bed grains were overgrown with microorganisms. The biofilm structure was loose and porous, being characteristic of aerobic biofilm. The biofilm covered the entire grain surface.

Ion exchange-ultrafiltration integrated process as a useful method in removing natural organic matter from water

Abstract: The experiments conducted are focused on natural organic substances, removal from water in ion-exchange process, ultrafiltration process and ion exchange–ultrafiltration integrated process. The water from the Odra River and model solution were investigated. In treatment processes, various doses of 5 anion-exchange resins as well as polyethersulphone membranes with different cut-offs were used. The efficiency of process was determined by measuring a decrease both in the colour intensity and the UV 254 nm absorbance. The results show that separation efficiency in integrated process depends on resin dose added to water before ultrafiltration and on the membrane cut-off as well. Among the resins tested the most efficient was MIEX resin. The ion-exchange process carried out prior to the ultrafiltration increased, especially for high cut-off membranes, NOM retention and resulted in the decrease of membrane fouling intensity.

Historical changes in air pollution in the tri-border region of poland, czech republic and germany

Abstract: In this study, we show the trends in the concentration of SO2 and particulate matter (PM) in two health resorts, located in the tri-border region of Poland, Germany and Czech Republic. We analyze the annual time series and the seasonal variability of PM concentration for the months of July and February over the period of 1996–2007. Additionally, in July 2006, we measured the mean 24-hour concentration of PM and the content of heavy metals (by EDXRF analysis). We prove that nowadays air pollution in this region has diminished to a large extent as compared to the 90s of the last century. In Cieplice, the local influence is still evident; while Czerniawa is exposed to a periodical advection of polluted air from regional sources.

Free proline synthesis in leaves of three clones of basket willow (Salix viminalis) as a response to substrate salinity

Abstract: A two-factor hydroponic experiment was conducted on nutrient medium whose concentrations were as follows: 0.068, 0.136 and 0.170 mol·dm. During the experiment, the proline content was determined 12, 48 and 168 hours after applying the stress agent in the leaves of three basket willow clones using the method of BATES at al. [1]. The study aimed at determining the effect of different NaCl concentrations in substrate as well as the influence of stress time on the proline content in the leaves of basket willow clones (“Bjor”, “Jorr” and “Tora”). The “Bjor” clone was found to be characterised by the highest proline content, whose concentration rose together with an increase in the salinity of nutrient medium and the time of osmotic stress applied. The “Jorr” clone was characterised by the lowest proline content in leaf fresh mass, with its maximum value being found after 48 hours of stress duration.

Isolation and kinetic characteristics of methyl isobutyl ketone (MIBK) degrading microorganisms

Abstract: From a biofilter bed used for cleaning the MIBK-doped air, nine bacteria strains decomposing this substance, being used as the only source of carbon and energy, were isolated. The most active strains were identified as Rhodococcus globerulus, Gordonia terrae, Gordonia bronchialis and Bacillus subtilis. The rate of MIBK decomposition by these microorganisms was tested within its concentration ranging from approx. 0.1 to 3 g m. They degraded MIBK at a maximum rate ranging from approx. 15 to approx. 50 g m·h. The highest biodegradation rate in suspension (EC), i.e. 163 g m·h, was observed in Gordonia terrae. The number of micoorganisms reached the value of 10 cfu in 1 cm of liquid culture.

Hydraulic analysis of EcoINFRA2 storage reservoir functioning

Abstract: The paper presents hydraulic analysis of functioning of new generation storage reservoir EcoINFRA2 which serves the reduction of hydraulic load of sewage system and its objects. Usable profits of hydraulic scheme of this reservoir enables its specific usage in urban areas and under special ground-water conditions as well as when it is necessary to reduce sewage system network depth. Formulated hydraulic model embraces the characteristic phases of reservoir functioning, which are defined as boundary hydraulic conditions in the limits of permissible filling level of every chamber of reservoir. The developed hydraulic basis of EcoINFRA2 reservoir functioning makes the foundation for the creation of mathematical model and formulation of software instruments for designing such type of objects functioning in gravitational sewage systems.

Removal and recovery of volatile organic compounds (VOCs) from waste air streams in thermal swing adsorption (TSA) system with closed-loop regeneration of adsorbent

Abstract: The cyclic thermal swing adsorption (TSA) process for volatile organic compounds recovery from the waste air is studied theoretically and experimentally. The TSA cycle is operated in three steps: an adsorption step with cold feed, a desorption step with hot inert gas and a cooling step with cold inert gas. The desorption and cooling are affected by a nitrogen circulating through a heater, an adsorber and a condenser. Toluene and isopropanol are chosen as the volatile organic compounds. Activated carbon Sorbonorit 4 is used as an adsorbent.

Oxidation of carbon oxide over monolithic platinum catalysts doped with metal oxides

Abstract: The deposition of NiO, MnO, CeO2, Co3O4 or Fe3O4 onto the surface of an Al2O3-based washcoat enhances the activity of the 015% Pt/Al2O3 catalyst in CO oxidation The highest activities were found to be those of the 015% Pt/01% Mn/Al2O3 and 015% Pt/01% Ce/Al2O3 catalysts, over which a 100% conversion of CO was achieved at 204 °C and 209 °C, respectively The activity of 015% Pt/Al2O3, as well as that of the oxide-doped 015% Pt/MOx /Al2O3 (M = Ni, Mn, Ce, Co, Fe) catalysts, can be notably increased by using Pt(NO3)4 as a Pt precursor instead of H2PtCl6