Functional Relationships with N Deposition Differ According to Stand Maturity in Calluna-Dominated Heathland

Plant and soil bio(chemical) indicators are increasingly used to provide information on N deposition inputs and effects in a wide range of ecosystem types. However, many factors, including climate and site management history, have the potential to influence bioindicator relationships with N due to nutrient export and changing vegetation nutrient demands. We surveyed 33 heathlands in England, along a gradient of background N deposition (7.2–24.5 kg ha⁻¹ year⁻¹), using Calluna vulgaris growth phase as a proxy for time since last management. Our survey confirmed soil nutrient accumulation with increasing time since management. Foliar N and phosphorus (P) concentrations in pioneer- and mature-phase vegetation significantly increased with N deposition. Significant interactions between climate and N deposition were also evident with, for example, higher foliar P concentrations in pioneer-phase vegetation at sites with higher temperatures and N deposition rates. Although oxidized N appeared more significant than reduced N, overall there were more, stronger relationships with total N deposition; suggesting efforts to control all emissions of N (i.e., both oxidized and reduced forms) will have ecological benefits.

Electronic supplementary material

The online version of this article (doi:10.1007/s13280-014-0529-4) contains supplementary material, which is available to authorized users.     

Performance and Problems of Claus Plant Operation on Coke Oven Acid Gases

The application of Claus Plant sulfur recovery units to the coke oven gas (COG) acid gases at three Bethlehem Steel Corporation plants is discussed. While many of the problems encountered are not unique to coke oven gas-derived acid gases, it was found that special consideration must be given to the effect of components not normally encountered in the typical Claus plant application to petroleum derived gases. It is perhaps fortunate that the feed composition to the three units was sufficiently different to expedite recognition of the source of some of these difficulties. One substance of concern is the hydrogen cyanide normally found in COG acid gases. In the absence of some means of removing or decomposing this material before it enters the Claus Plant extensive corrosion within the unit is observed after a short period of time. This is due to the fact that, contrary to expectation, a substantial quantity of this material survives the burner flame. The various alternatives in its elimination are discussed. A second major contaminant in COG acid gases is particulate iron sulfide and iron cyanide. While the exact source of these materials is in doubt, there is little doubt that in the absence of their removal, inorganic blockages within the Claus Plant will occur. By properly accounting for the special properties of coke oven gas-derived acid gas we have recently achieved short term sulfur recovery efficiencies of 95% and higher.     

Control of Odors and Aerosols from Spent Grain Dryers

The information contained in this paper is directed to research workers concerned with odor identification and the development of methods for removal of odorous components from hot, moist stack gases and to application engineers faced with the practical problem of selecting effective, yet economical, odor control equipment for industrial operations. The new techniques described here demonstrate the beneficial uses of gas phase reactions as a conditioning step preceding absorption in a chemically reactive solution. Cost comparisons show markedly lower costs for full-scale reactor-absorbers than for gas incinerators for equal contaminant removal. Other methods of removing odors at the source, e.g., injection of ozone, use of nonvolatile oxidizing agents in solution, and adsorption on activated charcoal, were found to be impractical, ineffective, or both. The application of reactor-absorbers to spent grain drying is discussed in detail and reference is made to the use of this technique for other food industry waste treatment processes including rendering and fish and poultry meal production.     

Technician Training in Environmental Health Science

In colleges and universities across the country, courses in ecology and environmental science are among the newest additions to the catalog. The goal of such courses is to make students aware of the environmental dilemma, a just and necessary goal. However, there is a need to do more than this. Jobs dealing with environmental protection are becoming more and more complex due to the recent passage of State and Federal legislation, which includes the Clean Air Act, the Amendments to the Water Pollution Control Act and the Occupational Safety and Health Act, just to name a few. Trained personnel are needed by industry and government. For this reason, in 1971, Middlesex County College initiated an Environmental Health Science Technology Program.     

Survey on the Use of Pulse-Jet Fabric Filters

Pulse-jet fabric filters rely on the filtration of dirty flue gas by the outside surface of the bags, which are then cleaned by a shock wave generated by an air pulse entering each bag from the top. As it travels down the length of the bag, the shock wave flexes the fabric and dislodges the dust cake. Enhancement of the pulse may be achieved by using a venturi, and cleaning may be on-line or off-line. This paper summarizes the results of an exhaustive study conducted for the Electric Power Research Institute to provide a convenient and versatile information base about the use of pulse-jet fabric filters on coal-fired boilers. Predominant features of the many pulse-jet installations identified by vendor survey and literature survey are shown in graphical and tabular form.     

Optimal Loading Rates and Economic Analyses for Anaerobic Digestion of Poultry Waste

ABSTRACT

Four combinations of litter and carcasses from broiler chickens were examined utilizing a thermophilic, stirred-tank digester of demonstration size of approximately 10,000 gal. Under computed optimal loading rates, litter with paper bedding had the highest daily production of methane over an 8-day retention period. The greatest methane production per lb of volatile solids was achieved over 10 days with litter and paper bedding combined with carcasses. This research found that sufficient poultry litter is generated within 20 mi (32 km) of Moorefield, WV, to support a commercial-sized digester operation. However, anaerobic digestion of poultry waste cannot be financially supported by methane production alone. To be financially viable, anaerobic digestion requires a disposal fee for poultry waste and/or the sale of the digested solid effluent as an organic fertilizer to retail markets.     

Road Dust Resuspension in the Vicinity of Limestone Quarries in Jordan

Abstract

Many areas in Jordan suffer from elevated levels of coarse particulate matter (PM₁₀). One potentially significant source of the observed PM is the resuspension of road dust in the vicinity of limestone quarries. To obtain data to assess the impact from this source, PM₁₀ road dust resus-pension factors near Abusiiah, a town to the north east of Amman surrounded by many quarries and brick factories, were measured. Measurements included PM₁₀ mass, particle size distributions, wind speed, and wind direction.The results showed that PM₁₀ concentrations could be as high as 600 µg/m³, and most of the airborne PM is in the coarse fraction. Loading trucks play a major role in resus-pending road dust, with an observed PM₁₀ emission rate of >6000 mg/km.     

Air Quality Measurements for the Aerosol Research and Inhalation Epidemiology Study

Abstract

Measurements of pollutant gases, airborne particulate matter mass and composition, and meteorology have been made at a core site near downtown Atlanta, GA, since August 1998 in support of the Aerosol Research and Inhalation Epidemiology Study (ARIES). This site is one of eight in the Southeastern Aerosol Research and Characterization network. The measurement objective is to provide a long-term, multivariate dataset suitable for investigating statistical associations of respiratory and cardiovascular disease with airborne particulate matter composition, meteorology, and copollutant gases through epidemiologic modeling. Measurements are expected to continue through 2010. Ancillary multiyear measurements at additional sites in the Atlanta metropolitan area and in short-term exposure assessments have been used to estimate the exposure/measurement error associated with using data from a central site to approximate human exposures for the entire area. To date, 13-, 25-, and 53-month air quality datasets have been used in epidemiologic analyses.