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1
Content available The content and composition of organic matter in bottom sediments of the Rybnik reservoir - preliminary studies
Baran A., Mierzwa-Hersztek M., Gondek K., Szara M., Tarnawski M.
Geology, Geophysics and Environment
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2018
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Vol. 44, no. 3
309--317
EN
Organic matter has important influences on the fate of environmental pollution in water dam reservoirs. The aim of the studies was to assess content of organic matter fractions in Rybnik reservoir bottom sediments, and to determine their influence on the content of heavy metals and PAHs. In three sediment samples, the content of C organic (Corg), C extracted (Cex), C humic acid (Cha), C fulvic acid (Cfa) and C non-hydrolyzed (Cnh), buffer capacity, and content of heavy metals and PAHs was analyzed. We found the highest content of Corg, Cex, Cha, Cfa and Cnh in sample 3 (the outlet, near the dam), while the lowest content was found in sample 2 (middle). The fraction of Cnh was dominant in sediment sample 3 (outlet, near dam) and 1 (inlet), whereas the fraction of Cha dominated in sample 2 (middle). Rybnik bottom sediments are characterized by their high buffer capacities (samples 3, 1) shaped among others by the high content of organic matter. The high organic matter content in samples 3 (outlet) and 1 (inlet) and also high total contents of heavy metals and PAHS in these sediments demonstrate that these pollutants have a strong affinity for organic matter in the sediments. Moreover, the highest mobility of metals, from sample 2 (middle), is connected with the low content of organic matter substances and the low buffer capacities of sediments.
2
Content available Potential effect of pH on the leaching of heavy metals from sediments of the Carpathian dam reservoirs
Szarek-Gwiazda E.
Geology, Geophysics and Environment
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2014
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Vol. 40, no. 4
349--358
EN
Eutrophication processes occurring in the Carpathian dam reservoirs (southern Poland) have resulted in a drastic increase of incidences of decrease of pH and oxygen content in near-bottom water, which may affect metal remobilization from the sediment. The study is aimed to determine the buffer capacity and effects of decreasing pH on the remobilization of heavy metals (Cd, Pb, Cu, Zn, Mn and Fe) from sediments of the Dobczycki Reservoir (DR), the Czorsztyński Reservoir (CR), and the Rożnowski Reservoir (RR), the right side tributary of the Vistula River. Buffering capacity and the leaching of heavy metals from sediments accompanied with an increase in acidity were analyzed in 0.00-0.24 M HNO3 solutions. Studied sediments had a high buffer capacity. Buffer capacity of sediments at studied sites of the DR and CR was different due to differences in the composition of sediments. The reservoir sediments had a variable ability to release heavy metals with increasing acidity. At pH ~5 and pH ~3, a considerable leaching of Mn (up to 60% and 85% of the total amount, respectively), Cd (up to 35% and 56% respectively), Pb (up to 25% and 39%), the lower leaching of Cu (up to 18% and 30%) and Zn (up to 14% and 20%), and the lowest leaching of Fe (below 5%) were found. The decrease of pH of the water-sediment system caused by eutrophication processes may affect the mobilization of certain heavy metals (mainly Mn, Cd and Pb) from sediment into the water column of the studied Carpathian reservoirs.
3
Content available remote Characteristic of post-consumer wood chips and particles used in particleboard production. Part II.
Janiszewska D., Frąckowiak I., Andrzejak C.
Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology
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2014
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No. 87
75--78
EN
Characteristic of post-consumer wood chips and particles used in particleboard production. Part II. The article presents the results of further research aiming at characteristic of post-consumer raw material obtained in industrial conditions, as described in Part I. This part presents the properties of post-consumer wood chips and obtained particles, such as formaldehyde content, pH and buffer capacity of particles. The sand content in tested chips was determined as well. The studies were carried out in comparison to pine wood.
4
Content available Buffer Properties of Forest Soils in Selected Protected Areas
Raczuk J., Deska J.
Ecological Chemistry and Engineering. A
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2012
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Vol. 19, nr 3
231-237
EN
The paper presents the results of research on forest soil buffer capacity in selected protected areas. The soil buffer capacity was determined for each soil horizon using modified Arrhenius method. Buffer curves were sketched and soil buffer areas were measured with computer techniques. The date obtained were compared with some soil physical and chemical properties using statistical method. Organic (O) and humus (A) horizons of forest soils demonstrate a greater abilities of buffering alkalines than acids whereas buffer capacity of deeper-lying horizons changes as their physical and chemical properties change. Of the examined types of forest soils, the greatest buffer capacity was found for river alluvial soils. The results of the study indicate that the buffer areas are significantly correlated with pH, hydrolytic acidity, content of organic C, clay fractions, sum of exchangeable bases and cation exchangeable capacity.
PL
W pracy przedstawiono wyniki badań nad zdolnościami buforowymi gleb wybranych obszarów chronionych. Analizie poddano 7 profili gleb leśnych reprezentujących następujące podtypy gleb: mady rzeczne brunatne, mady rzeczne próchnicze, gleby płowe zaciekowe, gleby rdzawe brunatne, gleby rdzawe właściwe oraz gleby bielicowe właściwe. Wykreślono dla nich krzywe buforowe zmodyfikowaną metodą Arrheniusa i zmierzono techniką komputerową powierzchnie buforowe gleb. Uzyskane dane porównano statystycznie z niektórymi właściwościami fizyczno-chemicznymi gleb. Poziomy organiczne (O) i próchniczne (A) gleb leśnych wykazują większe zdolności buforowania zasad niż kwasów, natomiast zdolności buforowe poziomów głębiej zalegających zmieniają się wraz z ich właściwościami fizyczno-chemicznymi. Wśród badanych typów gleb leśnych największe zdolności buforowe wykazują mady rzeczne. Wyniki badań wskazują, że powierzchnie buforowe badanych gleb są istotnie skorelowane z pH, kwasowością hydrolityczną, zawartością węgla związków organicznych, frakcja iłu, sumą zasad wymiennych oraz z kationową pojemnością sorpcyjną.
5
Content available remote Production flow synchronisation versus buffer capacities in assembly systems
Dobrzańska-Danikiewicz A., Krenczyk D.
Journal of Achievements in Materials and Manufacturing Engineering
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2008
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Vol. 29, nr 1
91-98
EN
Purpose: The goal of the considerations carried-out in that paper is the determination of the system synchronisation conditions. Those conditions concern capacities of system buffers. The fulfilment of the developed conditions should guarantee the production flow synchronisation into the expected steady state determined by the system bottleneck. In analysed assembly system rhythmic concurrent production with wide assortment is realised. Design/methodology/approach: The considerations presented in that paper are rooted in the authority method called Requirements and Possibilities Balance Method (RPBM). The experiments in the computer simulations programmes have been carried-out within the confines of the researches. The computer simulation models of the assembly systems using Taylor II for Windows and Enterprise Dynamics have been built. Findings: There are two kinds of system buffers: the entrance buffers and the inter-resources buffers in the assembly systems. The interdependences informing about the required number of elements allocated into the system buffers in order to the production realisation during the first cycle of the system steady state has been formulated. Moreover, the minimal buffer capacities have been determined. Research limitations/implications: The developed interdependences constitute the first step towards formulation of the automatic method designed for the automatic construction of rules controlling the system work during system transition state. That method should enable the automation of the system buffers filling-up. Practical implications: The presented system synchronisation conditions can become an integrated part of existing authority computer system. It aids the decision-making process connected with production planning and control. Originality/value: To develop the interdependences is the main achievement of the given paper. The presented approach permits to solve the problem concerning the production flow synchronisation into the expected steady state determined by the system bottleneck.
6
Content available remote Required buffer capacities in assembly systems
Krenczyk D., Dobrzańska-Danikiewicz A.
Journal of Achievements in Materials and Manufacturing Engineering
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2007
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Vol. 23, nr 1
95-98
EN
Purpose: The aim of the realised analysis is the determination of the set of conditions. The fulfilment of those conditions enables the synchronisation of the assembly system work into the steady state. It is necessary to specify the rules controlling the assembly system work. Rhythmic concurrent production with wide assortment in the considered assembly system is realised. Design/methodology/approach: The theoretical roots of the considerations presented in that paper include theory of constraints. The presented approach is consistent with the authority method called Requirements and Possibilities Balance Method (RPBM). Findings: Two kinds of system buffers: the entrance buffers and the inter-resources buffers are considered in that paper. The number of buffers elements needed for production during first steady state of the given system has been determined. Mathematical formulas specifying the minimal capacity of the buffers allocated in the assembly system have been outworked. Research limitations/implications: The formulas specifying the minimal buffer capacity constitute the first step towards formulation of the automatic method. That method is designed for the automatic construction of rules controlling the system work during transient phases between two different steady states. The process enables automation of the introduction filling of the system buffers. Practical implications: The presented formulas can become an integrated part of existing authority software. The developed computer system aids the decision-making process connected with production planning and ensures effective utilisation of production resources. Moreover, the formulas correctness during computer simulations has been verified. Originality/value: To develop the formulas specifying the minimal capacity of the system buffers is the main achievement of the given paper. The presented approach permits to solve the problem concerning the synchronisation of the assembly system work into the steady state.
7
Content available remote Wpływ zmian zachodzących podczas składowania trocin sosnowych na właściwości płyt wytwarzanych z ich zastosowaniem
Frąckowiak I.
Drewno : prace naukowe, doniesienia, komunikaty
|
2005
|
vol. 48, nr 173
81-94
PL
W artykule przedstawiono skład frakcyjny i pojemność buforową sosnowych trocin tartacznych świeżych (przed składowaniem) oraz składowanych przez pół roku w warunkach przemysłowych. Omówiono wpływ czasu i położenia trocin w hałdach na te właściwości. Wytwarzano trzywarstwowe płyty z trocin składowanych w różnym czasie. Parametry i warunki wytwarzania płyt oraz surowce chemiczne, zgodne z aktualnie stosowanymi w produkcji płyt wiórowych, były czynnikami stałymi. Zbadano wytrzymałość płyt na zginanie statyczne i rozciąganie prostopadłe do płaszczyzn, spęcznienie płyt po moczeniu w wodzie oraz zawartość formaldehydu. Wyniki badań wykazały, że powyższe właściwości płyt są zdeterminowane kwasową pojemnością buforową trocin, której wartość jest ściśle związana z warunkami ich składowania. Od warunków tego procesu zależy, w dużej mierze poziom i stabilność właściwości płyt oraz pośrednio efektywność produkcji.
EN
The process of storing sawdust in the industrial scale was examined in experimental heaps of the following size: height 15 m, width 25 m, and length 45 m. The method of forming the heaps and placing in them study samples stored for different periods of time were described. Throughout the whole storage period,, temperature in the heaps was controlled by means of probes inserted in the heaps when they were formed. Fraction composition and buffer capacity of fresh sawdust (prior to the storage period and when stored already for 4 and 6 month) were examined throughout the whole width of the heaps at different distances from the ground. Fraction composition and buffer capacity of sawdust were determined.
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