A fast ultrasound-assisted sequential extraction (UASE) procedure for the determination of cadmium, lead and nickel fractions in soil was developed and fully validated. The working parameters of an ultrasound probe were optimized by comparing the content of metals in soil extracts obtained by the UASE procedure with that obtained by the conventional (with the aid of a vertical rotor) modified Community Bureau of Reference (BCR) procedure. The content of metals in soil fractions was determined by electrothermal atomic absorption spectrometry. The total time of extraction of metals from soil was shorten from 48 h to 27 min (total sonication time). The trueness of the developed method was confirmed by analysis of the certified reference material BCR-701. In order to indicate critical points of the developed UASE method, uncertainties of fractionation results were calculated and compared with those calculated for conventional modified BCR procedure. The method usefulness was tested for the determination of metal fractions in different types of soil collected in the Podlasie Province (Poland). The proposed procedure could be used for fast screening of mobile fractions of several heavy metals in soil.

The carriers of nosocomial infections are the hands of medical personnel and inanimate surfaces. Both hands and surfaces may be contaminated as a result of contact with the patient, their body fluids, and touching contaminated surfaces in the patient’s surroundings. Visually clean inanimate surfaces are an important source of pathogens. Microorganisms have properties thanks to which they can survive in unfavorable conditions, from a few days to several months. Bacteria, viruses and fungi are able to transmit from inanimate surfaces to the skin of the patient and the medical staff. These pathogens include SARS-CoV-2, which can survive on various types of inanimate surfaces, being a potential source of infection. By following the recommendations related to washing and disinfecting hands and surfaces, and using appropriate washing and disinfecting agents with a broad biocidal spectrum, high material compatibility and the shortest duration of action, we contribute to breaking the chain of nosocomial infections.

A new fast method for determination of mobile zinc fractions in soil is proposed in this work. The three-stage modified BCR procedure used for fractionation of zinc in soil was accelerated by using ultrasounds. The working parameters of an ultrasound probe, a power and a time of sonication, were optimized in order to acquire the content of analyte in soil extracts obtained by ultrasound-assisted sequential extraction (USE) consistent with that obtained by conventional modified Community Bureau of Reference (BCR) procedure. The content of zinc in extracts was determined by flame atomic absorption spectrometry. The developed USE procedure allowed for shortening the total extraction time from 48 h to 27 min in comparison to conventional modified BCR procedure. The method was fully validated, and the uncertainty budget was evaluated. The trueness and reproducibility of the developed method was confirmed by analysis of certified reference material of lake sediment BCR-701. The applicability of the procedure for fast, low costs and reliable determination of mobile zinc fraction in soil, which may be useful for assessing of anthropogenic impacts on natural resources and environmental monitoring purposes, was proved by analysis of different types of soil collected from Podlaskie Province (Poland).Electronic supplementary materialThe online version of this article (doi:10.1007/s10661-015-5020-6) contains supplementary material, which is available to authorized users.

a b s t r a c tThe influence of pre-aeration in the equalization basin and the percentage (0, 5; 10; 15; 20; 30; 50 and 100%) of dairy sewage in the municipal waste stream on organic contaminants removal efficiency in SBR was tested. The organic compound fractions contribution in raw and purified sewage was also determined. The optimal non-pre-aerated dairy sewage contribution in municipal wastewater, providing high efficiency of treatment, was 30%. The S S was not stated in treated wastewater. The increase in the quantity of dairy sewage caused an increase in COD remaining fractions concentration. Depending on the amount of dairy sewage, proportions between different fractions underwent a change. The resulting mathematical models allow for explanation of about 85.0% of changes in (BOD 5 ), 91.3% (COD), 85.1% (X S ), and 85.4% (X I ).

The aim of the study was to demonstrate produced biogas dependence on batch composition as agricultural waste. Research was conducted in biogas power plant Biogas Adler, which was the first agricultural biogas plant built in Podlaskie province. The analysis showed in analyzed biogas production of biogas from waste from agricultural activity, is a good way of their utilization, while producing heat and electricity. Among the three analyzed substrates the highest efficiency of biogas production is characterized by corn silage and manure. Potato pulp significantly reduces the efficiency of biogas production. Independently of the composition and quality of substrates, to produce 1 MWh of the biogas plant consumes approx. 457 m 3 of biogas.