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A new selective and sensitive method for the determination of insoluble fatty acid salts (soap) in sewage sludge samples is proposed. The method involves a clean up of sample with petroleum ether, the conversion of calcium and magnesium insoluble salts into soluble potassium salts, potassium salts extraction with methanol, and a derivatization procedure previous to the liquid chromatography with fluorescence detection (LC-FLD) analysis. Three different extraction techniques (Soxhlet, microwave-assisted extraction and ultrasounds) were compared and microwave-assisted extraction (MAE) was selected as appropriate for our purpose. This allowed to reduce the extraction time and solvent waste (50 mL of methanol in contrast with 250 mL for Soxhlet procedure). The absence of matrix effect was demonstrated with two standards (C(13:0) and C(17:0)) that are not commercials and neither of them has been detected in sewage sludge samples. Therefore, it was possible to evaluate the matrix effect since both standards have similar environmental behaviour (adsorption and precipitation) to commercial soaps (C(10:0)-C(18:0)). The method was successfully applied to samples from different sources and consequently, with different composition.
This article was published in the following journal.
The objective of this study was to ascertain the cytotoxic, genotoxic and mutagenic potential of sewage sludge using Allium cepa bioassay. Solubilized and crude sludge from two sewage treatment statio...
Bacteria are assumed to efficiently remove organic pollutants from sewage in sewage treatment plants, where antibiotic-resistance genes can move between species via mobile genetic elements known as in...
Sewage sludge and biosolids production and management are a central component of water and sanitation engineering. The culmination of previous incremental technologies and regulations aimed at solving...
Sewage sludge is a considerable source of greenhouse gas (GHG) emission in the field of organic solid waste treatment and disposal. In this case study, total GHG emissions from sludge anaerobic digest...
The purpose of this research is to investigate the feasibility to utilize the slag collected after gasification of organic fuel combined with sewage sludge. The residue left after gasification process...
The aim of the study is to evaluate the effectiveness in removing chemical exposure on hand, we compare removal efficiency of Di-(2-ethylhexyl)phthalate (DEHP) on hands by hand washing wit...
Introduction. Lymphatic filariasis is a devastating mosquito-transmitted parasitic disease that causes lymphedema or elephantiasis of the leg in 15 million persons, the majority of whom a...
The purpose of this study is to assess the role of dietary fibre in Irritable Bowel Syndrome (IBS) treatment, in particular the role of increasing the content of soluble or insoluble fibre...
Surgical site infections (SSI) constitute a significant health-economic and clinical challenge. The investigators conducted a cluster-randomized, cross-over study to compare the efficacy o...
Primary Objective: To evaluate the potential of hydratation and renewal of the mucosa, through corneometry measurement and individual questionnaire perception. Secondary Objective:...
A genus of gram positive, acetogenic, thermophilic bacteria in the family Thermoanaerobacteraceae. Known habitats include HOT SPRINGS, horse manure, emu droppings, and sewage SLUDGE.
The sole genus in the family Methanospirillaceae whose organisms are progressively motile by means of polar, tufted flagella. They have been isolated from sewage-sludge and pear waste digesters as well as marine and non-marine habitats.
The absence of a useful purpose or useful result in a diagnostic procedure or therapeutic intervention. The situation of a patient whose condition will not be improved by treatment or instances in which treatment preserves permanent unconsciousness or cannot end dependence on intensive medical care. (From Ann Intern Med 1990 Jun 15;112(12):949)
The analysis of a chemical substance by inserting a sample into a carrier stream of reagent using a sample injection valve that propels the sample downstream where mixing occurs in a coiled tube, then passes into a flow-through detector and a recorder or other data handling device.
A type of scanning probe microscopy in which a very sharp conducting needle is swept just a few angstroms above the surface of a sample. The tiny tunneling current that flows between the sample and the needle tip is measured, and from this are produced three-dimensional topographs. Due to the poor electron conductivity of most biological samples, thin metal coatings are deposited on the sample.
Within medicine, nutrition (the study of food and the effect of its components on the body) has many different roles. Appropriate nutrition can help prevent certain diseases, or treat others. In critically ill patients, artificial feeding by tubes need t...