Simplification of the Procedure of Preparing Samples for PAHs and PCBs Determination / Uproszczenie Procedury Przygotowania Próbek Do Oznaczania Wwa I Pcb

Abstract

Abstract:The work presents examination results of the common determination of PAHs and PCBs in industrial sludge and supernatants. Sewage sludge was taken from the wastewater treatment plant, and supernatants were obtained by their centrifuging. The prepared samples of sewage sludge and supernatants were subjected to extraction with applying the mixture of organic solvents. Cyclohexane and dichloromethane were used for constant samples, and methanol, cyclohexane and dichloromethane -for liquid. Extracts, after separation from samples of sewage sludge and supernatants, were cleared on the silica gel in vacuum conditions and concentrated in the stream of nitrogen. In such prepared extracts there was conducted the qualitative-quantitative analysis of 16 PAHs using the GC-MS system. Next, the samples were evaporated and poured with water and methanol until the clear solution was obtained. Extracts were cleared on octadecyl C18 columns, and then concentrated in the nitrogen stream. In these extracts PCBs was also determined with the application of the gas chromatograph with mass spectrometer. The range of concentrations 16 PAHs in sewage sludge equalled 10-16 mg/kg d.w. . Summary average concentration 16 PAHs in supernatants was reached 17 μg/L. Average recovery of PAHs introduced to sewage sludge in the form of reference mixture was 78% (with consideration of naphthalene). In the case of supernatants, the average value of recovery reached 60%. Average PCBs concentration in supernatants equalled 10 ng/L. For sewage sludge the sum of marked PCBs was an average 1.23 μg/kg d.w. . In the case of particular PCBs the percentage recovery of the reference mixture for supernatants was 86%, while for sewage sludge it was 55%.

Biochemical Neutralization of Coke Excess Sewage Sludge During Anaerobic Digestion Process

“…where: t z -external air temperature, K (temperature of external air in winter t z = -20 °C) k -coefficient of heat loss as a result of heat of walls of fermentation chambers MJ m -2 h -1 K -1 , (0.004 MJ m -2 h -1 K -1 ) F -surface of walls of fermentation chambers, m 2 . The amount of thermal energy Q E (MJ d -1 ) using equation (16) was determined:…”

“…The wastewater in the coking plant is treated using biological processes. The sewage sludge formed during treatment process is polluted with the following contaminants: phenols, tar and oily substances, aliphatic and aromatic hydrocarbons, organic and inorganic halogenated compounds, ammonia, cyanides, hydrogen sulphide, thiosulfates, sulphates and chlorides [1][2][3][4] . Thus, the effectiveness of decomposition of these pollutants is required.…”

Archives of Environmental Protection

“…On the other hand, the large quantity plant use and unconscious release of POPs led to their wide distribution around the world, which brought pollution to our environment. Soil environment can continuously accept any potential released PCBs (Hutzinger 1974, Macherzyński et al 2012, Sawhney 1988. Although the use of PCBs is banned worldwide under the Stockholm Convention, these chemicals are still commonly found in soil due to their long persistence and can still pose long term ecological risk (Szymański et al 2016).…”