Physicochemical and geotechnical properties of an ash-slag mixture deposited on a landfill in terms of its use in engineering

Coal combustion ash-slag mixtures have been deposited in landfills in Poland for decades. At the same time, there is a shortfall in the amount of available materials related to the construction and modernisation of transportation infrastructure. Thus, a typical landfill of a power station was chosen and the aim of the study was to assess the suitability of an ash-slag landfill mixture for construction engineering purposes. The following physicochemical analyses were conducted: pH, specific electrical conductivity and determination of the leachability of basic (Ca, Na, K and Mg) and trace elements (Cd, Pb, Cr, Zn and Cu). The content of selected basic and trace elements were determined in the eluates by FAAS and standard methods were applied for geotechnical analyses. The most likely conditions were assumed to the model. The mixture will not jeopardize surface water quality in terms of the concentrations of basic, hazardous or priority elements. The content of these elements also does not exceed permissible concentrations for groundwater. The conductance and pH of the eluates are in compliance with current laws. The solid mixture has favourable geotechnical parameters which are significantly dependent on moisture content. The slope stability calculations for embankments created from the mixture at optimum moisture content and high compaction (Is≥ 0.95) indicate that they will be stable even in the case of high gradients (1:1.5). The slopes will be unstable in conditions of submersion, which should not occur if we assume the embankment will be used for passive flood protection. The mixture is particularly suitable for the purposes of earth structures, provided that they are isolated from water

The impact of the combustion waste landfill of the Skawina Power Plant on selected elements of the agricultural production area

Field observations and interviews with residents of Kopanka, Ochodza and Borek Szlachecki villages indicate that the agricultural production area located near the combustion waste landfill is negatively affected. Two distinct phenomena are observed: increased dust concentration in the air and excessive soil moisture or even flooding. The aim of the study was to assess whether and to what degree the landfill affects the content of the trace elements Cd(II), Pb(II), Zn(II) and Cu in the soil and plants of the adjoining agricultural production areas. The content of Cd(II), Pb(II), Zn(II) and Cu in the soil of the studied area was within the acceptable norms specified in the regulation of the Ministry of the Environment (Dz. U. 2002 nr 165, poz. 1359). In the herbaceous vegetation growing at sampling points W150, E150, E100 and N100, the acceptable level of Cd(II) specified in the regulation of the Ministry of Agriculture and Rural Development exceeded the norms (Dz. U. 2012 poz. 203). In turn, all the plant samples Pb(II) showed acceptable levels. The content of Zn(II) and Cu in the plant material meets the criteria for fodder proposed by IUNG (Kabata-Pendias et al. 1993). The high phytoaccumulation indices for Cd(II) and Zn(II) in the plant material may be due to dust fall containing metals. However, without precise quantitative and qualitative measurements of dust fall, it is difficult to ascertain to what extent this is caused by migration from the landfill and to what extent it is a result of deposits of pollutants from other sources

Lead and iron contents in parsley being cultivated in the area of Chrzanów geochemical anomaly

Selected research polygon is both a geochemical anomaly and suburban area (Krakow City & Upper Silesia agglomeration). The inhabitants here have detached houses with gardens of one or two acres size, where “home-made”, fresh, low-processed food could be produced. The anomaly is reflected in high values of heavy metals contents, especially cadmium, lead and zinc, in the soils of the region. This is the result of both natural and anthropogenic factors. The purpose of the paper was to evaluate lead and iron contents in roots and leaves of parsley being cultivated in Trzebinia Commune, which is located in the area. Considering , there is a positive geochemical anomaly, the lead contents in soil were low – the average value was 88.67 mg*kg-1 d.m. and only two contents – 218.98 and 119.35 exceeded 100 mg*kg-1d.m. From the other hand the lead contents in parsley roots were high, many times higher than the allowable values. The lead contents in parsley leaves were also high. Phytoaccumulation indices were low, only one had the average value, but at their minimal range (1.02 and 10.3 adequately for leaves and roots). Translocation index of lead was close to one. The iron contents in soils were not high and they fell within the scope of low and average ranges that occur in Polish soils. The iron contents in leaves were high, attractive from nutrition point of view

High-resolution cryo-EM structures of plant cytochrome b6fb_{6}f at work

Plants use solar energy to power cellular metabolism. The oxidation of plastoquinol and reduction of plastocyanin by cytochrome $b_{6}f$ (Cyt $b_{6}f$) is known as one of the key steps of photosynthesis, but the catalytic mechanism in the plastoquinone oxidation site ($Q_{p}$) remains elusive. Here, we describe two high-resolution cryo-EM structures of the spinach Cyt $b_{6}f$ homodimer with endogenous plastoquinones and in complex with plastocyanin. Three plastoquinones are visible and line up one after another head to tail near $Q_{p}$ in both monomers, indicating the existence of a channel in each monomer. Therefore, quinones appear to flow through Cyt $b_{6}f$ in one direction, transiently exposing the redox-active ring of quinone during catalysis. Our work proposes an unprecedented one-way traffic model that explains efficient quinol oxidation during photosynthesis and respiration. Structures of cytochrome $b_{6}f$ with and without plastocyanin imply a one-way traffic of quinones for efficient photosynthesis

TRACE ELEMENT CONTENTS IN TOPSOIL LOCATED NEAR STEEL PLANT IN KRAKOW-NOWA HUTA

The paper presents the results of cadmium, lead and zinc contents in topsoils of arable land located in vicinity Steel Plant in Krakow-Nowa Huta. Soil samples were collected in autumn 2007 from the 0-20 cm layer placed in a west-east trnsect of 7,5 km length. It started approximately 5km east form the border of the steel plant. .Sampled area is characterized by high level of agriculture, where the dominant crops have been vegetables, mainly cabbage and cauliflower. It was found, the soil was not contaminated with heavy metals. All samples met the requirements of the Polish Minister of the Environment. Also the assessment according to Institute of Soil Science and Plant Cultivation method showed only incerased content 60% in case of zinc and only 13% for Cd. Any levels of pollution were not observed. There also decreasing trend of accumulation were stated as a function of growing distance from the steel plant

Suitability of Selected Plant Species for Phytoremediation: A Case Study of a Coal Combustion Ash Landfill

Coal bottom and fly ash waste continue to be generated as a result of energy production from coal in the amount of about 750 million tonnes a year globally. Coal is the main source of energy in Poland, and about 338 million tonnes of combustion waste has already been landfilled. The aim of the research was to identify factors determining the Cd, Pb, Zn and Cu phytostabilisation by vegetation growing on a coal combustion waste landfill. Soil and shoots of the following plants were analysed: wood small-reed, European goldenrod, common reed; silver birch, black locust, European aspen and common oak. The influence of the location where the plants grew and the influence of the interaction between the two factors (species and location) were significant. The tree species were more effective at accumulating heavy metals than the herbaceous plants. European aspen had the highest Bioaccumulation Factor (BCF) for cadmium and zinc. A high capacity to accumulate these elements was also demonstrated by silver birch, and in the case of cadmium, by common oak. Accumulation of both lead and copper was low in all plants. The Translocation Factors (TF) indicated that the heavy metals were accumulated mainly in the roots. European aspen, silver birch and European goldenrod were shown to be most suitable for stabilization of the metals analysed in the research

Ocena właściwości chemicznych i geotechnicznych mieszaniny popiołowo-żużlowej z elektrowni Skawina S.A. w modelowym badaniu zapory ziemnej

W modelu zapory ziemnej zbudowanej w korycie hydraulicznym badano podstawowe właściwości chemiczne i geotechniczne mieszaniny popiołowo-żużlowej, pozyskanej z Elektrowni Skawina SA. Dysponując piezometrami pozwalającymi ująć wody: górną, dolną oraz filtrującą przez nasyp, badano ich jakość po dobowej i dwudziestopięciodobowej ekspozycji. Wykorzystano wodę wodociągową – ze względu na lokalizację jednostki była to woda z Wodociągów Krakowskich. Z właściwości fizycznych badano skład granulometryczny gruntu, wskaźnik różnoziarnistości, wilgotność naturalną, gęstość objętościową, gęstość objętościową szkieletu, wilgotność optymalną, maksymalną gęstość objętościową szkieletu, współczynnik filtracji. Sklasyfikowano grunt według norm PN-B-02481:1998 i PKN-CEN ISO/TS 17892-4:2009. Wykreślono krzywą filtracji. Materiał nasypu – z uwagi na jego parametry geotechniczne – bardzo łatwo poddawał się zjawisku sufozji. Pomierzone objętościowe natężenie przepływu było w przedziale 1700–2500 cm3 · godz.–1. Z właściwości chemicznych badano stężenia ośmiu metali, konduktancję i pH wód dolnej, górnej i z korpusu zapory przy ekspozycjach po jednej i dwudziestu pięciu dobach. Warunki ługowalności badanych składników były odmienne od założonych w normie [Rozporządzenie… 1999], jednak znacznie bardziej zbliżone do warunków na pograniczu budowla wodna – ekosystem. Analizując zawartości metali, wartości pH oraz kondunktancji w odciekach uzyskiwanych z piezometrów rozmieszczonych w modelu zapory, należy stwierdzić, iż badany materiał wpływa na zmianę chemizmu wód mających z nim bezpośredni kontakt, szczególnie w odniesieniu do zawartości Na, K, Ca i Mg, przekraczając dopuszczalne dla wód powierzchniowych i podziemnych normy [Rozporządzenie… 2008, Rozporządzenie... 2011]. Ołów, kadm oraz chrom występują w stosunkowo wyrównanych zakresach w obu okresach ekspozycji, spełniając równocześnie dopuszczalne normy dla wód powierzchownych i podziemnych oraz normy w przypadku wprowadzaniu ścieków do wód lub ziemi [Rozporządzenie…2006, Rozporządzenie…2008, Rozporządzenie... 2011]

TRACE ELEMENT CONTENTS IN TOPSOIL LOCATED NEAR STEEL PLANT IN KRAKOW-NOWA HUTA

The paper presents the results of cadmium, lead and zinc contents in topsoils of arable land located in vicinity Steel Plant in Krakow-Nowa Huta. Soil samples were collected in autumn 2007 from the 0-20 cm layer placed in a west-east trnsect of 7,5 km length. It started approximately 5km east form the border of the steel plant. .Sampled area is characterized by high level of agriculture, where the dominant crops have been vegetables, mainly cabbage and cauliflower. It was found, the soil was not contaminated with heavy metals. All samples met the requirements of the Polish Minister of the Environment. Also the assessment according to Institute of Soil Science and Plant Cultivation method showed only incerased content 60% in case of zinc and only 13% for Cd. Any levels of pollution were not observed. There also decreasing trend of accumulation were stated as a function of growing distance from the steel plant

Zróżnicowanie zawartości Cd, Pb, Zn i Cu w liściach tytoniu szlachetnego(Nicotiana tabacum l.) uprawianegow rejonie Proszowic

Celem pracy była ocena zróżnicowania zawartość Cd, Pb, Zn i Cu w tytoniu typu Virginia uprawianym w rejonie Proszowic. Próby roślin i gleb pobierano z pól uprawnych położonych w sołectwach Bobin, Wolwanowice, Kościelec, Mysławczyce oraz Kuchary. Zawartości kadmu, ołowiu, cynku i miedzi oznaczono metodą FAAS na aparacie Solaar M6 firmy Unicam. Badane liście tytoniu cechowały się słabym stopniem kumulacji ołowiu, cynku i miedzi oraz intensywnym stopniem kumulacji kadmu. Stwierdzono dodatnie korelacje pomiędzy zawartościami kadmu i miedzi w glebie a stężeniami tych pierwiastków w liściach tytoniu. Zależność ta jest odwrotna (korelacja ujemna) w przypadku cynku. Nie stwierdzono statystycznie istotnej korelacji w odniesieniu do zawartości ołowiu. Analiza wariancji wykazała zróżnicowanie zawartości badanych metali zarówno w liściach, jak i glebach