The release of antimicrobial substances into surface waters is of growing concern due to direct toxic effects on all trophic levels and the promotion of antibiotic resistance through sub-inhibitory concentration levels. This study showcases (1) the variation of antibiotics in sanitary sewage depending on different timescales and (2) a method to assess the antibiotic resistance based on an inhibition test. The test is based on the measurement of the oxygen uptake rate (OUR) in wastewater samples with increasing concentrations of the selected antibiotic agents. The following antibiotics were analysed in the present study: clarithromycin (CLA) was selected due to its high toxicity to many microorganisms (low EC50), ciprofloxacin (CIP) which is used to generally fight all bacteria concerning interstitial infections and doxycyclin (DOX) having a broad spectrum efficacy. Results show that CLA inhibited the OUR by approximately 50% at a concentration of about 10 mg L−1, because Gram-negative bacteria such as Escherichia coli are resistant, whereas CIP inhibited about 90% of the OUR at a concentration equal to or greater than 10 mg L−1. In the case of DOX, a moderate inhibition of about 38% at a concentration of 10 mg L−1 was identified, indicating a significant antibiotic resistance. The results are consistent with the corresponding findings from the Clinical and Laboratory Standards Institute. Thus, the presented inhibition test provides a simple but robust alternative method to assess antibiotic resistance in biofilms instead of more complex clinical tests.
Assessment of contaminant impacts to federally identified endangered, threatened and candidate, and state-identified endangered species (collectively referred to as listed species) requires understanding of a species sensitivities to particular chemicals. The most direct approach would be to determine the sensitivity of a listed species to a particular contaminant or perturbation. An indirect approach for aquatic species would be application of toxicity data obtained from standard test procedures and species...
ABSTRACT
Two types of media, natural compost and a commercial engineered media, were evaluated in terms of sulfur toxicity and capacity for removal of hydrogen sulfide. A humidified gas stream of 50 ppmv H2S was passed through the media columns and effluent readings for H2S at the outlet were measured continuously. Sulfate was artificially added (40, 65, 100mg-S/g-compost) to the media to test its effect on removal efficiency and the biofilm and media. The overall baseline removal efficiencies of the natural...
Up to now, the recovery of precious metals used as catalysts in chemical processes has involved the use of incineration. Now, however, a British-Swedish joint venture has developed a process which uses supercritical water oxidation instead, which provides many economic and environmental advantages.
Precious metals are used extensively in catalysts in a wide range of industrial chemical processes. Sometimes they are used in a homogeneous form, but more often fixed to a solid support for ease of handling. In many...
The Kemwater Recycling Process – KREPRO for treatment of sewage sludge is based on a completely new separation technology, which uses existing knowledge in an innovative way. It reduces both the organic and inorganic content of the sludge. The organic content is re-duced by about 30% and the inorganic about 70% if digested sludge is treated. All metals and salts are dissolved; the remaining undissolved inorganics are mainly silicates like sand and grit.
In constast, most sludge treatment technologies used today...
Dairy wastewaters are rich in organic carbon and nutrients. When disposed without proper treatment they cause severe pollution of water and land. But if treated by anaerobic fermentation such wastewaters can yield useful clean energy in the form of methane. The systems commonly used for such fermentation throughout the world are Continuously Stirred Tank Reactors (CSTRs). We describe attempts to upgrade CSTR performance by incorporating biofilm support systems (BSSs) within the existing reactors. The focus of the...
1.1 Scope and Objectives
A small number of viable options are presently available for the bleaching of wood pulp (delignification and brightening) during the manufacture of pulp and paper. The use of chlorine dioxide (ClO2) in the bleaching process has largely superceded the earlier use of Cl2, or elemental chlorine, in the majority of North American pulp mills: It was discovered over a decade ago that the previous widespread use of Cl2 contributed to the production and subsequent release to the environment of...
Abstract
Waste represents an enormous loss of resources both in the form of materials and energy. Indeed, quantities of waste can be seen as an indicator of the material efficiency of society. Waste generation is increasing in the European Union, and amounted to about 3.5 tonnes of solid waste per person in 1995 (excluding agricultural waste) 1
Excessive quantities of waste result from:
inefficient production processes low durability of goods unsustainable consumption patterns. Solid waste is also increasingly...
`The oceans are in trouble and so are we,` oceanographer Sylvia Earle, National Geographic explorer in residence and researcher for the Smithsonian, was quoted as saying in an article on the web by Seth Borenstein writing for the Philadelphia Inquirer and San Jose Mercury News Washington Bureaus. Citing a study by the Harvard Medical School`s Center for Health and the Global Environment covering 1976 to 1996, Borenstein reports a greater than fourfold increase in harmful algal blooms (74 to 329). `stranding of...
Sites where halogenated VOCs may be found include burn pits, chemical manufacturing plants or disposal areas, contaminated marine sediments, disposal wells and leach fields, electroplating/metal finishing shops, firefighting training areas, hangars/aircraft maintenance areas, landfills and burial pits, leaking collection and system sanitary lines, leaking storage tanks, radioactive/mixed waste disposal areas, oxidation ponds/lagoons, paint stripping and spray booth areas, pesticide/herbicide mixing areas, solvent...
Issue: In Europe some uses of biotechnology are meeting vocal opposition from certain quarters. Nevertheless, the vast amount of knowledge acquired recently in biology can be used to develop and apply biotechnology for an environmentally safe agriculture. Public acceptance and a new policy impetus can serve to promote the introduction of safe and competitive agricultural technologies that have a minimum environmental impact. Relevance: Increasing long-term health and environmental concerns regarding the use of...
Abstract
Different parameters were investigated to evaluate their effect on the process removal efficiency of COD and color, including H2O2 concentration, UV power, multi-step addition of H2O2, and air bubbling. As a result, the color can be removed completely within 20 minutes, and the COD removal of approximately 90% can be achieved within 40 minutes of UV illumination. This process favors the H2O2 addition in one step rather than in four steps. Supply of oxygen does not enhance the process removal efficiency....
Carlton United Brewery installed a Trade Waste Monitoring System to analyse the temperature, flows, pH and chemical compounds in their trade wastewater. This cleaner production initiative was a licensing condition of the Northern Territory`s Power and Water Authority (PAWA). As a result of the pretreatment, CUB is able to discharge their brewery wastewater to sewer.
Background
Carlton and United Breweries purchased the Darwin Brewery in October 1996 and commenced operations in November 1996. The Brewery is...
Site soil conditions frequently limit the selection of a treatment process. Process-limiting characteristics such as pH or moisture content may sometimes be adjusted. In other cases, a treatment technology may be eliminated based upon the soil classification (e.g., particle-size distribution) or other soil characteristics.
Soils are inherently variable in their physical and chemical characteristics. Usually the variability is much greater vertically than horizontally, resulting from the variability in the...
It may be necessary to know other subsurface information to remediate inorganics in ground water, surface water, and leachate. Treatability studies are usually necessary to ensure that the contaminated ground water can be treated effectively at the design flow. A subsurface geologic characterization would be particularly important to characterize the effects of adsorption and other processes of attenuation. Ground water models are also often needed to predict flow characteristics, changes in contaminant mixes and...
Pressures on the environment may occur through chemical, physical and biological agents. The subject of this study is physical agents, where physical fields are examined.
Physical fields are part of the natural environment. Depending upon their properties and the surrounding conditions, physical fields are transmitted through the spaces in which we live, potentially affecting human health and nature. Human activity can add to, modify, and enhance and reduce the intensity of these fields. Furthermore, changes in...
Air sparging involves injecting a gas (usually air/oxygen) under pressure into the saturated zone to volatilize groundwater contaminants and to promote biodegradation in saturated and unsaturated soils by increasing subsurface oxygen concentrations. Vola tilized vapors migrate into the vadose zone where they are extracted via vacuum, generally by a soil vapor extraction system. The term biosparging is sometimes used interchangeably with air sparging to highlight the bioremediation aspect of the treatment process...
Customer comments
No comments were found for Assessing antibiotic resistance of microorganisms in sanitary sewage. Be the first to comment!
