Study on the determination of PCDDs/Fs and HCB in exhaust gas

The subject of this study was to develop a method of simultaneous determination of PCDDs/PCDFs and HCB in exhaust gases from industrial installations. Sampling to determine PCDDs/PCDFs was conducted using the method described in PN-EN 1948-1: 2006, where the sorption material is polyurethane foam (PUF). In order to simultaneously collect PCDDs/PCDFs and HCB and to avoid sorbent bed breakthrough, it was necessary to apply an additional polyurethane sorption layer. Twenty-seven samples of exhaust gases from various cement plants and 40 samples of exhaust gases from hospital and industrial waste incineration plants collected in 2009/2010 in the entire territory of Poland were examined. The average content of PCDDs/Fs in samples from cement plants amounted to 0.076 ng I-TEQ N m(-3) (range of 0.002-0.62 ng I-TEQ N m(-3)), while the average content of HCB amounted to 10 ng N m(-3) (range of 0.98-60.5 ng N m(-3)). In the case of samples collected from waste incineration plants, the average concentration of PCDDs/Fs was 0.39 ng I-TEQN m(-3) (range of 0.002-5.68 ng I-TEQ N m(-3)). In the case of HCB, the average concentration was 238 ng N m(-3) (range of 3.21-2500 ng N m(-3)). Also, the interdependence of the concentration of PCDDs/PCDFs and HCB was determined in the analysed samples, with the ranges of low and high content of PCDDs/PCDFs being examined separately. In all cases, the determined values of the r correlation coefficient were within the range of 0.7-1.0, which indicates a good correlation between the concentrations of PCDDs/PCDFs and HCB.     

Comparison of different modifications on QuEChERS sample preparation method for PAHs determination in black, green, red and white tea

The aim of this work was the evaluation of QuEChERS extraction method for polycyclic aromatic hydrocarbon (PAH) determination in various types of tea. In the experiment, different kinds of extraction solvents, sorbents and a final method of sample preparation were compared. The final extracts were analysed by gas chromatography-selected ion monitoring-mass spectrometry. The results suggest that acetonitrile extraction, clean up with SAX and final liquid–liquid extraction was the best combination giving the most purified extracts and acceptable compound recoveries for different types of teas. In the study of real samples, compounds belonging to light PAHs were mostly detected, and heavy polycyclic aromatic hydrocarbons, including benzo[a]pyrene, were not identified in any of samples.     

Direct N2O emission from agricultural soils in Poland between 1960 and 2009

Nitrogen fertilization (N) is commonly known as a main source of direct nitrous oxide (N₂O) emission from agricultural soils. An area of 38 % of the total land surface of Poland was covered by agricultural soils in 2009. In this paper, we aimed at analyzing data regarding the land exploitation for 13 selected subareas of Poland between 1960 and 2009. Seven out of the 13 subareas studied are located in the West (area A), and six subareas are located in southeast of Poland (area B). The total area covered by large farms (>20 ha) differed largely, between area A (10.6 %) and area B (0.9 %) in 2009. Both areas varied in terms of the amount of fertilizers used annually, average crop yield and crop structure. Average direct emissions of N₂O from agricultural soils were 1.66 ± 0.09 kg N₂O–N ha^?1 a^?1 for area A, 1.39 ± 0.07 kg N₂O–N ha^?1 a^?1 for area B and 1.46 ± 0.07 kg N₂O–N ha^?1 a^?1 for the whole country between 1960 and 2009.     

Removal possibilities of colloidal chromium (III) oxide from water using polyacrylic acid

The lack of water is the most serious threat to humanity that leads to more efficient water and sewage treatment. Currently, many scientists are looking for new coagulants, flocculants and physicochemical methods allowing for sufficient removal of pollutants from water. The presence of various types of pigments, including chromium (III) oxide, poses the major problem. Even small amounts of these substances inhibit life processes in water. In this paper, the stability of Cr₂O₃ suspension in the absence and the presence of polyacrylic acid (PAA) was determined. To explain the changes in the system stability, the adsorption and electrokinetic measurements were performed. The chromium (III) oxide suspension not containing PAA is the most stable at pH?=?3. Under these conditions, each positively charged solid particle is surrounded by a negatively charged diffusion layer which protects from particle collision and aggregates formation (electrostatic stabilization). In turn, the Cr₂O₃ suspension containing the PAA is most unstable also at pH?=?3. In this case, the polymer causes destabilization of the colloidal suspension, which results from charge neutralization of solid particles by adsorbed PAA.     

Adsorption of 2,4-dichlorophenoxyacetic acid and 4-chloro-2-metylphenoxyacetic acid onto activated carbons derived from various lignocellulosic materials

Adsorption of 2,4-dichlorophenoxyacetic acid (2,4-D) and 4-chloro-2-metylphenoxyacetic acid (MCPA) from aqueous solution onto activated carbons derived from various lignocellulosic materials including willow, miscanthus, flax, and hemp shives was investigated. The adsorption kinetic data were analyzed using two kinetic models: the pseudo-first order and pseudo-second order equations. The adsorption kinetics of both herbicides was better represented by the pseudo-second order model. The adsorption isotherms of 2,4-D and MCPA on the activated carbons were analyzed using the Freundlich and Langmuir isotherm models. The equilibrium data followed the Langmuir isotherm. The effect of pH on the adsorption was also studied. The results showed that the activated carbons prepared from the lignocellulosic materials are efficient adsorbents for the removal of 2,4-D and MCPA from aqueous solutions.     

New insight into defining the lakes of the southern Baltic coastal zone

There exist many classification systems of hydrographic entities such as lakes found along the coastlines of seas and oceans. Each system has its advantages and can be used with some success in the area of protection and management. This paper aims to evaluate whether the studied lakes are only coastal lakes or rather bodies of water of a completely different hydrological and hydrochemical nature. The attempt to create a new classification system of Polish coastal lakes is related to the incompleteness of lake information in existing classifications. Thus far, the most frequently used are classifications based solely on lake basin morphogenesis or hydrochemical properties. The classifications in this paper are based not only on the magnitude of lake water salinity or hydrochemical analysis but also on isolation from the Baltic Sea and other sources of water. The key element of the new classification system for coastal bodies of water is a departure from the existing system used to classify lakes in Poland and the introduction of ion-“tracking” methods designed to identify anion and cation distributions in each body of water of interest. As a result of the work, a new classification of lakes of the southern Baltic Sea coastal zone was created. Featured objects such as permanently brackish lakes, brackish lakes that may turn into freshwater lakes from time to time, freshwater lakes that may turn into brackish lakes from time to time, freshwater lakes that experience low levels of salinity due to specific incidents, and permanently freshwater lakes. The authors have adopted 200 mg Cl^? dm^?3 as a maximum value of lake water salinity. There are many conditions that determine the membership of a lake to a particular group, but the most important is the isolation lakes from the Baltic Sea. Changing a condition may change the classification of a lake.     

Photocatalytic decomposition of methanol over La/TiO<Subscript>2</Subscript> materials

Lanthanum-modified TiO₂ photocatalysts (0.2–1.5 wt% La) were investigated in the methanol decomposition in an aqueous solution. The photocatalysts were prepared by the common sol-gel method followed by calcination. The structural (X-ray diffraction, Raman, X-ray photoelectron spectroscopy), textural (N₂ physisorption), and optical properties (diffuse reflectance spectroscopy, photoelectrochemical measurements) of all synthetized nanomaterials were correlated with photocatalytic activity. Both pure TiO₂ and La-doped TiO₂ photocatalysts proved higher yields of hydrogen in comparison to photolysis. The photocatalyst with optimal amount of lanthanum (0.2 wt% La) showed almost two times higher amount of hydrogen produced at the same time as in the presence of pure TiO₂. The photocatalytic activity increased with both increasing photocurrent response and decreasing amount of lattice and surface O species. It has been shown that both direct and indirect mechanisms of methanol photocatalytic oxidation participate in the production of hydrogen. Both direct and indirect mechanisms take part in the formation of hydrogen.     

锑矿区土壤重金属污染及优势植物对重金属的富集特征

通过野外调查采样,分析了冷水江锑矿区4个采样点土壤和优势植物中重金属含量,以及矿区生长的5种优势植物对Sb、As、Cd、Pb、Cu和Zn的的吸收与富集能力及其富集特性。结果表明,矿区土壤中6种重金属元素的平均含量均超出湖南省土壤背景值和全国土壤背景值,土壤受Sb污染最严重,其次是Cd、As的污染。5种优势植物淡竹叶、苎麻、芒草、狗尾草和白背叶体内Sb、As的含量都超过正常范围,具有修复矿区土壤Sb、As污染的潜力。其中苎麻对Sb的富集系数和转运系数均大于1,满足Sb超富集植物的基本特征,可作为生态恢复的先锋植物;芒草对Cd的富集系数和转运系数都大于1,对重金属有较强的耐性,作为重金属污染的修复植物具有较好的应用前景。     

Tannery waste as a renewable source of nitrogen for production of multicomponent fertilizers with biostimulating properties

Environmental Science and Pollution Research - The studies presented in this work show that solid tannery waste-like shavings can be used as high-protein materials for fertilizer production...