Processing of whey from dairy industry waste

An investigation carried out in 11 dairies in Serbia has shows that 78.75 % of whey, a by-product of cheese industry, is emitted into river systems, thus contributing to the organic pollution of the environment. This pollution can be avoided by processing of whey into food and pharmaceuticals. It is shown that low-temperature regime of whey concentration and fractionation, based on vacuum concentration and diafiltration, preserves whey proteins undenaturated, as proved by differential scanning calorimetry method. Functional native whey proteins based food products, with potentially high immunomodulatory activity, are obtained.     

Fe-exchanged zeolite as the effective heterogeneous Fenton-type catalyst for the organic pollutant minimization: UV irradiation assistance

The issue of investigations in this study was an application of heterogeneous Fenton-type catalyst, Fe-exchanged zeolite FeZSM5, for the minimization of phenol and overall organic content in the model wastewater. Applied treatment systems included variation of heterogeneous and homogeneous Fenton-type catalyst with and without the assistance of UV irradiation, FeZSM5/H2O2, Fe2+/H2O2/NH4ZSM5, Fe3+/H2O2/NH4ZSM5, UV/FeZSM5/H2O2, UV/Fe2+/H2O2/NH4ZSM5 and UV/Fe3+/H2O2/NH4ZSM5. Processes efficiency was evaluated on the basis of phenol removal, mineralization extent, H2O2 consumption and concentration of iron ions in the bulk after the treatment. By all applied systems, complete phenol removal was achieved in less than 30 min of treatment time. Systems including heterogeneous Fenton-type catalyst showed somewhat lower mineralization efficiency in comparison to the corresponding systems applying homogeneous Fenton-type catalysts and the addition of synthetic zeolite NH4ZSM5. Significantly lower concentration of iron ions in the bulk after the treatment could give these systems, particularly UV/FeZSM5/H2O2, a great advantage over the homogeneous Fenton-type systems.     

Implication of zinc excess on soil health

This study was undertaken to evaluate zinc's influence on the resistance of organotrophic bacteria, actinomyces, fungi, dehydrogenases, catalase and urease. The experiment was conducted in a greenhouse of the University of Warmia and Mazury (UWM) in Olsztyn, Poland. Plastic pots were filled with 3 kg of sandy loam with pH_KCl – 7.0 each. The experimental variables were: zinc applied to soil at six doses: 100, 300, 600, 1,200, 2,400 and 4,800 mg of Zn²⁺ kg^?1 in the form of ZnCl₂ (zinc chloride), and species of plant: oat (Avena sativa L.) cv. Chwat and white mustard (Sinapis alba) cv. Rota. Soil without the addition of zinc served as the control. During the growing season, soil samples were subjected to microbiological analyses on experimental days 25 and 50 to determine the abundance of organotrophic bacteria, actinomyces and fungi, and the activity of dehydrogenases, catalase and urease, which provided a basis for determining the soil resistance index (RS). The physicochemical properties of soil were determined after harvest. The results of this study indicate that excessive concentrations of zinc have an adverse impact on microbial growth and the activity of soil enzymes. The resistance of organotrophic bacteria, actinomyces, fungi, dehydrogenases, catalase and urease decreased with an increase in the degree of soil contamination with zinc. Dehydrogenases were most sensitive and urease was least sensitive to soil contamination with zinc. Zinc also exerted an adverse influence on the physicochemical properties of soil and plant development. The growth of oat and white mustard plants was almost completely inhibited in response to the highest zinc doses of 2,400 and 4,800 mg Zn²⁺ kg^?1.     

The biochemical activity of soil contaminated with fungicides

Excess fungicides can pose a serious threat to the soil environment. Fungicides can lower the microbiological and biochemical activity of soil and lead to yield declines. Soils contaminated with fungicides have to be remediated to maintain the optimal function of soil ecosystems. This study evaluates the effect of neutralizing substances on soil enzymatic activity and the yield of Triticum aestivum L. in soil contaminated with fungicides. Sandy loam (Eutric Cambisols) with pH_KCl 7.0 was contaminated with an aqueous solution of Amistar 250 SC and Falcon 460 EC in the following doses: 0 (soil without fungicide – treated as a control), RD (dose recommended by the manufacturer) and 300?×?RD (dose 300-fold higher than the recommended dose). Soil was supplemented with bentonite and basalt meal at a dose of 10?g kg^?1 DM of soil (dry mass of soil). The fungicide dose recommended by the manufacturer did not induce changes in soil enzymatic activity or the yield of T. aestivum L. Our findings indicate that the tested fungicides can be safely applied to protect crops against fungal pathogens. However, when applied at the dose of 300?×?RD, the tested fungicides strongly inhibited soil enzymatic activity and disrupted the growth and development of spring wheat. Soil supplementation with bentonite and basalt meal improved the yield of T. aestivum L., and bentonite was more effective in reducing fungicide stress. The analyzed substances were not highly effective in restoring biochemical homeostasis in soil.     

The effect of changes to the method of estimating the pollen count from aerobiological samples

Pollen data have been recorded at Novi Sad in Serbia since 2000. The adopted method of producing pollen counts has been the use of five longitudinal transects that examine 19.64% of total sample surface. However, counting five transects is time consuming and so the main objective of this study is to investigate whether reducing the number to three or even two transects would have a significant effect on daily average and bi-hourly pollen concentrations, as well as the main characteristics of the pollen season and long-term trends. This study has shown that there is a loss of accuracy in daily average and bi-hourly pollen concentrations (an increase in % ERROR) as the sub-sampling area is reduced from five to three or two longitudinal transects. However, this loss of accuracy does not impact on the main characteristics of the season or long-term trends. As a result, this study can be used to justify changing the sub-sampling method used at Novi Sad from five to three longitudinal transects. The use of two longitudinal transects has been ruled out because, although quicker, the counts produced: (a) had the greatest amount of % ERROR, (b) altered the amount of influence of the independent variable on the dependent variable (the slope in regression analysis) and (c) the total sampled surface (7.86%) was less than the minimum requirement recommended by the European Aerobiology Society working group on Quality Control (at least 10% of total slide area).     

Radon versus other lung cancer risk factors: How accurate are the attribution estimates?

This notebook paper provides a brief overview of attribution estimates for some key lung cancer risk factors, focusing on indoor radon gas exposure in the U.S., UK, and Canada. Tobacco smoking represents the primary cause of lung cancer worldwide. Radon is regarded as the second leading lung cancer risk factor in the U.S. and Canada. It can be observed, however, that the reported estimates appear not to add up to the maximum cumulative attribution of 100%.

Implications: Limitations and uncertainties associated with published epidemiological studies and the observed lack of consistency in lung cancer attribution estimates for radon and other non-smoking lung cancer risk factors should be taken into consideration by policy makers in setting population health protection priorities.     

Occurrence of aflatoxin M1 in human milk samples in Vojvodina,Serbia: Estimation of average daily intake by babies

The objectives of the study were to determine the aflatoxin M1 content in human milk samples in Vojvodina, Serbia, and to assess the risk of infants' exposure to aflatoxins food contamination. The growth of Aspergillus flavus and production of aflatoxin B1 in corn samples resulted in higher concentrations of AFM1 in milk and dairy products in 2013, indicating higher concentrations of AFM1 in human milk samples in 2013 and 2014 in Serbia. A total number of 60 samples of human milk (colostrum and breast milk collected 4–8 months after delivery) were analyzed for the presence of AFM1 using the Enzyme Linked Immunosorbent Assay method. The estimated daily intake of AFM1 through breastfeeding was calculated for the colostrum samples using an average intake of 60 mL/kg body weight (b.w.)/day on the third day of lactation. All breast milk collected 4–8 months after delivery and 36.4% of colostrum samples were contaminated with AFM1. The greatest percentage of contaminated colostrum (85%) and all samples of breast milk collected 4–8 months after delivery had AFM1 concentration above maximum allowable concentration according to the Regulation on health safety of dietetic products. The mean daily intake of AFM1 in colostrum was 2.65 ng/kg bw/day. Results of our study indicate the high risk of infants' exposure, who are at the early stage of development and vulnerable to toxic contaminants.     

Determination of the specific alpha activity of thick sources with a large area ZnS(Ag) scintillation detector

A method for determining the specific alpha activity of thick sources using a large area ZnS(Ag) scintillation detector is presented. In this method a quadratic relationship between the detector response and window thickness is assumed. This method provides a quick estimation of alpha activity in the sample, so it is an indicative method. The aim of this experimental work is to approve theoretical assumption and to develop a standard routine method for absolute alpha measurements of thick contaminated environmental sources. For this purpose reference material U(3)O(8) and spiked standards of soil were used. Measurements of contaminated soil samples from south Serbia showed the practical application of this method.