Influence of Intensive Animal Breeding to the Appearance of Infectious Diseases (Zoonoses)

Intensive animal breeding and production is based on farm breeding of animals which represents a major source of raw material for food production. Preserving health of animals requires a good practice during breeding, appropriate feeding and watering, adequate control of pests and wild animals. Animal breeding and production of food of animal origin requires significant engagement of veterinary services within the frame of epizootiological, epidemiological, veterinary and sanitary surveillance. Farm manner of cattle breeding can represent a danger of air, water and ground contamination. In the farms situated in a small space, overcrowded with animals there are ideal conditions for the appearance and spreading of causative agent of infectious diseases (prions, viruses, rickettsiae, chlamydia, bacteria, parasites and fungi), which can be transmitted also to humans and wild animals. From the aspect of public health, special attention should be given to the farms with large number of animals and farms with intensive breeding conditions. This is especially important in pig and poultry breeding, where moderate or high prevalence of infections such as salmonellosis and campylobacteriosis are often present, regardless of the fact that the level of clinical illness caused by these infections is relatively low. Intensive production in animal husbandry leads to increased animal waste, and the richest source of infectious agents represents animal feces

Role of active layer in the performance of aromatic and semi-aromatic nanofiltration membranes for water purification

Nanofiltration (NF) membranes that differ in molecular weight cut off (MWCO), active layer chemistry, porosity and pore size distribution are available for different applications. These membranes are typically made of three layers: the active layer, polysulfone support layer and a fabric for mechanical strength. It has been proven that the performance of an NF membrane is almost entirely dependent on the active layer, which can be made of polyamide, polypiperazine amide, cellulose acetate or polyethersulfone. Polyamide, which is considered fully aromatic (FA) and polypiperazine, which is considered semi-aromatic (SA), are the most commonly used active layers in NF membranes for water treatment. Several studies evaluated commercially available NF membranes for ion rejection, effect of pH, temperature, pressure but very few have attempted to explain their performance based on the membrane active layer chemistry. This study is focused on understanding the difference in performance between fully aromatic (FA) and semi-aromatic (SA) membranes for the removal of typical ions of concern in water purification. Four commercially available membranes, two each of FA and SA types were selected for this study. Fourier Transform Infrared (FTIR) spectroscopy was used to substantiate that the selected membranes are truly representative of FA and SA membrane type without any coating or other surface modifications. Membrane performance was analyzed in terms of ion rejection and permeate flux. Membrane volume charge densities as a function of electrolyte concentration were analyzed by measuring their zeta potential as function of pH and electrolyte composition and concentration. The membrane mean pore size was determined using the membrane potential technique [1]. Membrane potential data were analyzed using the steric, electric and dielectric exclusion (SEDE) model [2]. Also, SEDE model was used to calculate the dielectric constants for different electrolyte composition and compare them for FA and SA membranes. The ion rejection and permeate flux for all four membranes was studied for different feed composition using a SEPA cross flow NF cell at a fixed transmembrane pressure and temperature. The feed composition was selected such that it is representative of the acid mine drainage (AMD) typically found in Pennsylvania, which is characterized by high sulfate concentration and low pH. The resulting ion rejection and permeate flux were compared for the four membranes with goal of understanding the difference in the performance of FA and SA membranes as a function of the active layer chemistry. The experimental results indicate that the rejection of sulfate was in all cases above 98% but the rejection of the counterions was significantly better for the fully aromatic membranes. Major disparity was observed in the rejection of sodium and chloride ions between FA and SA membranes even when they had the same MWCO’s. This disparity was studied in terms of the electronegativity of the four membranes and the results will be presented at the conference. 1. Escoda, A., et al., Determining the Dielectric Constant inside Pores of Nanofiltration Membranes from Membrane Potential Measurements. Langmuir, 2010. 26(18): p. 14628-14635. 2. Szymczyk, A. and P. Fievet, Investigating transport properties of nanofiltration membranes by means of a steric, electric and dielectric exclusion model. Journal of Membrane Science, 2005. 252(1–2): p. 77-88

COMBINED THEORETICAL AND EXPERIMENTAL INVESTIGATION OF MECHANISMS AND KINETICS OF VAPOR-PHASE MERCURY UPTAKE BY CARBONACOUES SURFACES

The first part of this study evaluated the application of a versatile optical technique to study the adsorption and desorption of model adsorbates representative of volatile polar (acetone) and non-polar (propane) organic compounds on a model carbonaceous surface under ultra high vacuum (UHV) conditions. The results showed the strong correlation between optical differential reflectance (ODR) and adsorbate coverage determined by temperature programmed desorption (TPD). ODR technique was proved to be a powerful tool to investigate surface adsorption and desorption from UHV to high pressure conditions. The effects of chemical functionality and surface morphology on the adsorption/desorption behavior of acetone, propane and mercury were investigated for two model carbonaceous surfaces, namely air-cleaved highly oriented pyrolytic graphite (HOPG) and plasma-oxidized HOPG. They can be removed by thermal treatment (> 500 K). The presence of these groups almost completely suppresses propane adsorption at 90K and removal of these groups leads to dramatic increase in adsorption capacity. The amount of acetone adsorbed is independent of surface heat treatment and depends only on total exposure. The effects of morphological heterogeneity is evident for plasma-oxidized HOPG as this substrate provides greater surface area, as well as higher energy binding sites. Mercury adsorption at 100 K on HOPG surfaces with and without chemical functionalities and topological heterogeneity created by plasma oxidation occurs through physisorption. The removal of chemical functionalities from HOPG surface enhances mercury physisorption. Plasma oxidation of HOPG provides additional surface area for mercury adsorption. Mercury adsorption by activated carbon at atmospheric pressure occurs through two distinct mechanisms, physisorption below 348 K and chemisorption above 348 K. No significant impact of oxygen functionalities was observed in the chemisorption region. The key findings of this study open the possibility to apply scientific information obtained from the studies with simple surfaces like HOPG under ideal conditions (UHV) to industrial sorbents under realistic process conditions. HOPG surface can be modified chemically and topologically by plasma oxidation to simulate key features of activated carbon adsorbents

Development of Novel Activated Carbon-Based Adsorbents for Control of Mercury Emission From Coal-Fired Power Plants

The overall objective of this study is to evaluate pertinent design and operational parameters that would enable successful application of activated carbon adsorption for the reduction of mercury emissions from coal-fired power plants. The study will evaluate the most suitable impregnate such as sulfur, chloride and other chelating agents for its ability to enhance the adsorptive capacity of activated carbon for mercury vapor under various process conditions. The main process variables to be evaluated include temperature, mercury concentration and speciation, relative humidity, oxygen content, and presence of SO2 and NOx in the flue gas. The optimal amount of impregnate for each of these carbons will be determined based on the exhibited performance. Another important parameter which governs the applicability of adsorption technology for the flue gas clean up is the rate at which vapor phase mercury is being removed from the flue gas by activated carbon. Therefore, the second part of this study will evaluate the adsorption kinetics using the impregnated activated carbons listed above. The rate of mercury uptake will also be evaluated under the process conditions that are representative of coal-fired power plants. Concerned with the ability of the adsorbed mercury to migrate back into the environment once saturated adsorbent is removed from the system, the study will also focus on the mercury desorption rate as a function of the type of impregnate, loading conditions, and the time of contact prior to disposal

Fouling in direct contact membrane distillation during treatment of produced water from unconventional (shale) gas production

Hydraulic fracturing used for natural gas extraction from unconventional onshore resources (i.e., shale plays) generates large quantities of produced water. This water needs to be managed efficiently and economically to ensure further development of this industry. The most common solution for produced water management is disposal by deep well injection. This approach is being scrutinized by public and regulatory agencies due to increasing number of seismic events associated with this practice. The industry is now striving to reuse the produced water for hydraulic fracturing, which is feasible only as long as there are sufficient number of new gas wells being developed. The total dissolved solids (TDS) content of produced water can be in excess of 300,000 mg/l with sodium and chloride being the primary ions, followed by calcium, barium, strontium and magnesium. This water also contains some organics and heavy metals at low concentrations. Most membrane-based technologies employed today for seawater desalination are not feasible in this industry due to extremely high TDS of produced water. Membrane distillation (MD) can achieve complete rejection of ions and non-volatile organics as long as the membrane pores are not wetted. MD may be a cost effective method to treat produced water due to its reasonably high permeate flux and ability to operate using low-quality heat (i.e., it operates at temperatures well below the boiling point of water). This study focuses on the potential for membrane wetting and/or fouling by inorganic salts present in produced water in the case of direct contact membrane distillation (DCMD) treatment of actual produced water from unconventional gas wells in Pennsylvania. The produced water was concentrated to near halite saturation limit to evaluate potential scaling and its impact on DCMD performance. Initial experiments showed that no membrane wetting occurred as evidenced by extremely low conductivity of the permeate stream. Iron-based scale accumulated on the membrane surface along with embedded islands of barium chloride and sodium chloride. The inorganic scale that formed on PTFE membranes during several hours of operation had negligible effect on MD performance in terms of permeate flux and thermal efficiency. Inspection of these inorganic scales suggests that they are typically very thin (i.e., several microns) and highly porous, which may explain the lack of observable impact on the transport of water vapor in DCMD module. Initial results suggest that DCMD has great potential for desalination of highly concentrated wastewaters generated by the unconventional gas industry. However, inorganic scale that may form on the feed side could potentially impact the performance of this technology. Further insights into the composition and morphology of inorganic scales that may form under realistic operating conditions will be presented at the conference together with pretreatment options and scale mitigation approaches to minimize the effect of scaling on DCMD performance when treating produced water from the most productive shale plays in the U.S

Changes in carbon electrode morphology affect microbial fuel cell performance with Shewanella oneidensis MR-1

The formation of biofilm-electrodes is crucial for microbial fuel cell current production because optimal performance is often associated with thick biofilms. However, the influence of the electrode structure and morphology on biofilm formation is only beginning to be investigated. This study provides insight on how changing the electrode morphology affects current production of a pure culture of anode-respiring bacteria. Specifically, an analysis of the effects of carbon fiber electrodes with drastically different morphologies on biofilm formation and anode respiration by a pure culture (Shewanella oneidensis MR-1) were examined. Results showed that carbon nanofiber mats had -10 fold higher current than plain carbon microfiber paper and that the increase was not due to an increase in electrode surface area, conductivity, or the size of the constituent material. Cyclic voltammograms reveal that electron transfer from the carbon nanofiber mats was biofilm-based suggesting that decreasing the diameter of the constituent carbon material from a few microns to a few hundred nanometers is beneficial for electricity production solely because the electrode surface creates a more relevant mesh for biofilm formation by Shewanella oneidensis MR-1

Sulfurization of a carbon surface for vapor phase mercury removal -II: Sulfur forms and mercury uptake

Abstract Sulfur forms deposited on carbonaceous surfaces after exposure to hydrogen sulfide were analyzed using XPS and XANES. Higher temperatures promote the formation of organic sulfur and the presence of H 2 S during the cooling process increased elemental sulfur content. Temperatures between 400-600°C were found to be optimal for producing effective mercury uptake sorbents. The increased amount of sulfur deposited during the cooling process in the presence of H 2 S was very effective towards Hg uptake in nitrogen. Correlation of mercury uptake capacity and the content of each sulfur form indicated that elemental sulfur, thiophene, and sulfate are likely responsible for mercury uptake, with elemental sulfur species being the most effective

Sulfurization of carbon surface for vapor phase mercury removal -I: Effect of temperature and sulfurization protocol

Abstract The uptake of hydrogen sulfide by carbon materials (ACFs and BPL) under dry and anoxic conditions was tested using a fixed bed reactor system to determine the effects of sorbent properties, temperature (200-800°C) and sulfurization protocols on the sulfur content, sulfur stability, sulfur distribution, and to elucidate possible reaction mechanisms for the formation of sulfur species. Sorbents with higher surface areas showed higher uptake capacity, indicating that active sites for sulfur bonding are formed during the formation of the pore structure. The sulfur content and stability generally increased with the increase in temperature due to a shift in the reaction mechanism. The sulfurization process is associated with the decomposition of surface functionalities, which creates active sites for sulfur bonding. The presence of H 2 S during the cooling process increased the sulfur content by increasing the presence of less stable sulfur forms. Sulfurized sorbents produced at high temperatures have pore structure similar to that of the virgin carbons

Development of novel activated carbon-based adsorbents for control of Mercury emissions from coal-fired power plants

The overall objective of this study is to evaluate pertinent design and operational parameters that would enable successful application of adsorption-based technologies for the reduction of mercury emissions from coal-fired power plants. The first part of the study will evaluate the most suitable impregnate for its ability to enhance the adsorptive capacity of activated carbon for mercury vapor under various process conditions. The second part of the study will evaluate the rate of mercury uptake (adsorption kinetics) by several impregnated activated carbons. Concerned with the ability of the adsorbed mercury to migrate back into the environment once saturated adsorbent is removed from the system, the study will also determine the fate of mercury adsorbed on these impregnated carbons

BLOOD FLOW RESTRICTION DOES NOT AFFECT ACUTE MEASURES OF POWER AND FATIGUE DURING MAXIMAL CYCLING AMONG WOMEN

While it is known that blood flow restriction (BFR) can positively affect training and rehabilitation progression timelines, the physiological basis of this intervention is not fully understood. The purpose of this study was to determine the short-term impact of BFR upon power and fatigue performance measures during maximal cycling. In this study, maximal cycling was assessed using the Wingate Anaerobic Test (WAnT). Using a counterbalanced design, fourteen female participants completed standardized BFR and non-BFR protocols while completing the WAnT. No statistically-significant differences (p ≤ 0.05) were found between conditions for measures of peak power (PP), low power (LP) or fatigue index (FI). These findings suggest that BFR had no statistically-significant acute effect on these performance measures commonly assessed during the WAnT