The effect of preparation of biogenic sorbent on zinc sorption

The aim of this study is to prepare biogenic sulphides by using bacteria for the removal of zinc cations from their solutions. Theproduction was realized in a bioreactor under anaerobic conditions at 30 °C. Sorbents were prepared by sulphate-reducing bacteria indifferent nutrient medium modifications, under two modes of bacteria cultivation. Created precipitates of iron sulphides were removedfrom the liquid phase of the cultivation medium by filtration, dried and used for the sorption experiments

The Reclamation of Industrial Wastes Inclusive Sulphates by Sulphate-Reducing Bacteria

The objective of our study was to verify experimentally the possibility of using coal mine drainage and gypsum from the stabilizate (the final product from the combustion desulphurisation) as the source of sulphate for the cultivation of SRB with the prospect of: purging of mine waste waters inclusive sulphates, recycling of desulphurisation agent (limestone) and production of elemental sulphur from hydrogen sulphide. The results confirmed the theoretical assumptions on the use of gypsum, which forms the substantial component of stabilizate, as the source of sulphate for sulphate-reducing bacteria, which produce hydrogen sulphide in the process of bacterial reduction of sulphates. They also showed the possibility of recycling the desulphurisation agent limestone, as well as the realistic alternative of using stabilizate in the production of elemental sulphur which still represents an important raw material needed in chemical, paper or other industries

Neka svojstva prašine smrekovine dobivene procesom brušenja

This paper presents the research of selected properties of spruce dust generated from experimental sanding by a hand belt sander with two sanding models - along the wood fibres and perpendicular to the wood fibres in the radial direction. The experiment was carried out for the purpose of obtaining the basic characteristics of wood sanding dust – granularity, size and shape of individually formed particles, and bulk properties (bulk density, bulk angle, and tilt angle) that are important for suction, which is connected with the quality of living and working environments. The particles smaller than 100 micrometers are unsuitable for both environments, since they do not sediment in space at all or only partly, and they are characterized as airborne dust. The most harmful particles for humans are those smaller than 2.5 μm as they reach the lung alveoli. When sanding wood the finest particles are formed and therefore it is important to know the basic characteristics of sanding dust in order to deal with these problems effectively. On the basis of the mesh sieve analysis, we can state that in sanding perpendicular to the wood fibres the share of particles smaller than 100 μm is 76.94 % on average and along the wood fibres it is only 56.01 %. The structure, shape and size of particles were investigated by microscope. When using the longitudinal model of sanding, the fibrous elements were formed for the most part. When using the perpendicular model, isometric particles were predominantly formed in smaller fractions and particles of fibrous shape in larger fractions. The smallest particles were found in the following samples. When the perpendicular model of sanding was used, we have found the smallest particle in the investigated samples with the diameter of 1.68 μm, and when the longitudinal model of sanding was used, the particle with the diameter of 1.75 μm. Bulk density of spruce dust from the longitudinal model of sanding is 77.77 kg · m-3, while dust from the perpendicular model of sanding is 116.68 kg · m-3. Tilt angle of spruce dust in a longitudinal direction of sanding is 33.4°, and in a perpendicular direction it is 37.4°. Bulk angle for the perpendicular model of sanding is 48.7°, and for longitudinal model of sanding it is 48.3°. The obtained results have confirmed that the model of sanding at which wood dust was formed is a significant factor affecting properties of wood bulk material.U radu su istraživana neka svojstva prašine smrekovine dobivene ručnim eksperimentalnim brušenjem u dva smjera – u smjeru vlakanaca i okomito na njih, i to u radijalnom smjeru. Cilj istraživanja bio je odrediti osnovna obilježja čestica bruševine – granulaciju, veličinu čestica i oblike individualnih čestica, nasipna svojstva (nasipnu gustoću, nasipni kut i kut klizanja s kosine), koje su važne pri njihovu odsisavanju i za njihov utjecaj na kvalitetu općega i radnog okoliša. Za obje vrste okoliša štetno je postojanje čestica manjih od 100 μm, a s obzirom na to da se one teško talože ili se uopće ne talože, smatraju se lebdećim česticama. Najštetnije čestice za ljudski organizam jesu one manje od 2,5 μm jer dospijevaju do plućnih alveola. Uspješno rješavanje problema nastajanja najfinijih čestica bruševine moguće je uz poznavanje njihovih osnovnih obilježja. Granulometrijskom analizom bruševine nastale brušenjem okomito na drvna vlakanca izmjeren je udio od 76,94 % čestica manjih od 100 μm, a brušenjem u smjeru vlakanaca samo 56,01 %. Struktura, oblik i veličina čestica istražena je uz pomoć mikroskopa. Pri brušenju duž vlakanaca formirani su pretežno vlaknasti elementi. Pri brušenju okomito na vlakanca uglavnom su nastajale izometrične čestice u sitnijim frakcijama te čestice vlaknastog oblika u krupnijim frakcijama. Među česticama nastalim pri brušenju okomito na vlakanca izmjeren je najmanji promjer čestice od 1,68 μm, a pri brušenju uzdužno s vlakancima promjer 1,75 μm. Nasipna gustoća smrekove bruševine pri uzdužnom brušenju iznosi 77,77 kg/m³, odnosno 116,68 kg/m³ pri brušenju okomito na vlakanca. Kut klizanja s kosine bruševine nastale brušenjem u smjeru vlakanaca iznosi 33,4°, a kut klizanja bruševine nastale brušenjem okomito na vlakanca 37,4°. Nasipni kut za bruševinu nastalu brušenjem okomito na vlakanca iznosi 48,7°, a za bruševinu nastalu brušenjem uzdužno na vlakanca 48,3°. Dobiveni rezultati potvrdili su da smjer brušenja s obzirom na smjer vlakanaca ima značajan utjecaj na veličinu i svojstva usitnjenoga drvnog materijala

Exploitation of bioremediation in the environment protection

Soils and waters contaminated with toxic metals pose a major environmental problem that needs an effective and affordable technological solution. Many areas remain contaminated with no remediation in sight because it is too expensive to clean them up with available technologies. Bioremediation may provide an economically viable solution for remediation of some of these sites. The bioremediation is an application of the biological treatment to the cleanup of hazardous chemicals and is an example of the environmental biotechnology. The aim of this paper is to give a theoretical and practical view concerning the possibility of the bioremediation exploitation in the environment protection. This paper includes some results of the bioremediation of the acid mine drainage by sulphate-reducing bacteria

Analisi del trend di mortalità durante la venuta e la causa di contagio di pollame in allevamento sull‘azienda agricola Lieskovec (Repubblica Slovacca) dal 2006 al 2010

The influence of transport distance and temperature on the dead on arrival and condemnation causes of broiler chickens from a small farm Lieskovec (Slovak Republic) in the period 2006-2010 was evaluated. The results showed significant increase in dead on arrival and condemnation percentage in relation to the transport distance and season. The average percentage of the dead on arrival throughout the whole period was 0.209% (0.031 to 0.702%) and the average percentage of condemnation was 0.524% (0.041 to 1.422). The most common causes of condemnation were cyanosis, birds slaughtered in agony, breaking of the legs and wings and cachexy.Sažetak Istraživan je utjecaj trajanja transporta i temperature u transportu na uzroke uginuća i procjenu bolesnih stanja tovnih pilića s male farme Lieskovec (Republika Slovačka) u razdoblju od 2006. do 2010. godine. Rezultati su pokazali značajan porast uginuća i postotak bolesti ovisno o vremenu transporta i godišnjem dobu. Prosječan postotak uginulih pilića pri istovaru u klaoničkom objektu tijekom istraživanog perioda je iznosio 0,209% (0,031 do 0,702%) a znakovi bolesnih stanja uočeni su u 0,524% slučajeva (0,041 do 1,422). Uzroci su bili cijanoza, lom nogu i krila, kaheksija, te je zamijećeno iskrvarenje pilića u agoniji.Zusammenfassung Es wurde der Einfluss von Transportentfernung und Temperatur auf die Kadaver beim Ankommen und Verseuchungsursache von Masthühnern auf der kleinen Farm Lieskovac (Republik Slowakei) in der Zeitspanne vom 2006 – 2010 untersucht. Die Resultate zeig- ten einen bedeutenden Aufstieg des Verendens beim Ankommen und Erhöhung des Verseuchungsprozentes in Bezug auf die Trans- portentfernung und Jahreszeit. Der durchschnittliche Prozent des Verendens beim Akommen betrug während der ganzen Periode 0.209 % (0.031 bis 0.702 %) und der durchschnittliche Verseuchungsprozent betrug 0.524 % (0.041 bis 1.422). Die häufigsten Ursachen dafür waren: Zyanose, Hühner geschlachtet in Agonie, Bruch der Beine und der Flügel, allgemeine Schwäche.Sommario In quest‘articolo è stato ricercato l‘influsso della distanza di trasporto e della temperatura agli addomi nel momento di venuta, e la causa di contagio di pollame in allevamento dalla piccola azienda d‘allevamento Lieskovec (nella Repubblica Slovacca) tra gli anni 2006 e 2010. I risultati hanno dimostrato una notevole crescita di mortalità fino al momento di venuta e la crescita della percentuale di contagio rispetto alla distanza del trasporto e della stagione. La percentuale in media di polli morti fino all‘arrivo durante tutto il periodo faceva lo 0.209% (dallo 0.031 allo 0.702%) e la percentuale in media di contagio faceva lo 0.524% (dallo 0.041 allo 1.422). I motivi che più spesso si ripetevano erano: la cianosi, i polli macellati nell’agonia, le fratture delle gambe e delle ali di polli e la loro debolezza in generale

Analiza signala dobivenih s površina koje su nastale abrazivnim vodenim mlazom pomoću spektra amplituda-frekvencija i funkcije autokorelacije

The paper deals with the description of contemporary methodology of topography evaluation of surfaces created by the abrasive water jet by using the existing standard and non-standard parameters in combination with an autocorrelation function. The grid projection method was used for measurement of samples prepared from stainless steel AISI 309 by abrasive water jet. The optical signals obtained by means of grid projection method of these surfaces were processed by Fourier transform and the norm autocorrelation function in order to get information about height and longitudinal fluctuations. The obtained results are analysed and interpreted.U ovom radu je opisana suvremena metodologija topografske evaluacije površina, koje su nastale abrazivnim vodenim mlazom, korištenjem standardnih i ne-standardnih parametara u kombinaciji s funkcijom autokorelacije. Metoda projekcije mreže je korištena za mjerenje uzoraka pripremljenih od nehrđajućeg čelika AISI 309 pomoću abrazivnog vodenog mlaza. Optički signali dobiveni pomoću metode projekcije mreže ovih površina su obrađeni pomoću Fourier pretvorbe i funkcije autokorelacije norme kako bi se dobile informacije o fluktuacijama visine i duljine. Dobiveni rezultati su analizirani i objašnjeni

The Application of Sulphate-Reducing Bacteria for the Heavy Metals Elimination from Acid Mine Drainage

One of the most important problems affecting mining companies around the world is the treatment of acid mine drainage (AMD). AMD is characterised by its high acidity, high concentration of metals (Cu, Zn, Cd,) and high concentration of dissolved sulphates. The techniques traditionally used for the treatment of AMD have been based on chemical methods of neutralization and precipitation. A possible alternative to the chemical treatment of AMD is bioremediation using anaerobic sulphate-reducing bacteria (SRB). The treatment of AMD by SRB is based on the ability of SRB to reduce sulphates to hydrogen sulphide, which binds readily with metals to form sparingly soluble precipitates. In this study we have attempted to investigate the feasibility of anaerobic biotreatment of the copper contaminated model solution and a real effluent AMD from the shaft Pech (the locality Smolnik) using SRB. This method involves three stages: The H2S production by sulphate-reducing bacteria, the metals precipitation by the biologically produced H2S and the metal sulphides filtration. The studies confirm that copper was effectively recovered from the solution using bacterial produced H2S. An initial copper concentration 10 mg.l-1 was decreased to less than 0.05 mg.l-1 after 3 hours. The most adequate pH value for cooper precipitation was 2.5. Results of the copper precipitation from the areal effluent indicates that the optimal pH value for the copper precipitation is 3.5, but the created precipitates contain a mixture of copper and iron sulphides

Removal of sulphates from waste waters by sulphate-reducing bacteria

are present in almost all types of water, usually as a simple anion SO42-. The sulphates together with hydrogencarbonates and chlorides are principal anions in natural waters. In typical underground and surface waters, the concentration of sulphates is in the range from ten to hundreds milligrams per litre.Nowadays, the importance of the control of sulphate concentration in waste waters increases. According to the Slovak legislation the limit concentration of sulphates in surface and drinking waters is 250 mg.l-1 . In rivers the contents of sulphates increases mainly by the discharge of waste waters, which are coming mainly from chemical, textile, metallurgical, pharmaceutical, paper and mining industry. The concentration of sulphates in these waters is in the order of grams per litre.Many technologies for the sulphates removal from waste waters exist, including biologico-chemical processes. The principle of one of these methods is the reduction of sulphates by sulphate-reducing bacteria to hydrogen-sulphide.The objective of this work was to study the effect of initial sulphates concentration on the activity of anaerobic sulphate reducers as well as the kinetics of the anaerobic sulphate reduction. The batch reactor was used at temperature of 30°C and pH 7,5. Lactate was used as the carbon source

Removal heavy metals and sulphate from waste waters by sulphate-reducing bacteria

This article is devoted to the process of bacterial sulphate reduction, which is used to removal of heavy metals and sulphate ions from waste waters.The life of animals and plants depends on the existence of microscopic organisms microorganisms (MO), which play an important role in cycle changes of biogenic elements on the earth. The sulphur cycle in the nature is considered as one of the oldest and most significant biological systems (Fig. 1). The sulphate-reducing bacteria (SRB) miss the assimilatory part of the cycle and produce sulphides. The microbial population of this dissimilatory part is called sulfuretum. The SRB can be found in anaerobic mud and sediments of freshwater, thermal or non-thermal sulphur springs, mining waters from sulphide deposits, oil deposits, sea and ocean beds, and in the gastrointestinal tract of man and animals. The SRB represent a group of chemoorganotrophic, strictly anaerobic and gramnegative bacteria, which exhibit a great morphological and physiological diversity. Despite of their considerable morphological variety, they have one property in common, which is the ability to utilise preferentially sulphates (occasionally sulphites, thiosulphates, tetrathionates) as electron acceptors, which are reduced to sulphides, during anaerobic respiration. The electron donors in these processes are simple organic compounds as lactate, malate, etc.,(heterotrophically reduction) or gaseous hydrogen (autotrophically reduction). SRB can produce a considerable amount of hydrogen sulphide, which reacts easily in aqueous solution with the cations of heavy metals, forming metal sulphides that have low solubility. The bacterial sulphate reduction can be used for the treatment of acid mine drainage waters, which is considered to be the major problem associated with mining activities.In order to remove heavy metals from waste waters, e.g., from galvanizing plants, mine waters (Smolnik, obov locality) and metallurgic plants (works Krompachy) by use of the activity of SRB, mixed strains were isolated, cultivated, and their production of hydrogen sulphide was assessed. The cultures were then tested for the ability to precipitate copper and sulphates from a model solution.The bacteria were isolated from water samples from two localities: Východoslovenské eleziarne (works) VS and spring Gajdovka Gj. Isolation, cultivation and eliminating Cu2+ and SO42- was carried out under following conditions: statically, temperature 30 oC, pH 7,5, nutrient medium by J. Postgate (medium B, C and D) and anaerobic conditions. Residual copper in the solution was measured by atomic absorption photometry. The concentracion of sulphates in the solution was measured by the nefelometric method.Our findings from the isolation of SRB from two Slovak water samples and testing the cultures for their ability to remove copper permit the following conclusions: SRB occur in sufficient numbers in sulphur mineral water from natural sources and in industrial waste waters reservoirs, the sulphate-reducing activity can be harnessed for the purification of some industrial waste waters.The nature possesses a great biological potential that can be exploited under certain conditions in the cleanup of environmental pollution resulting from the industrial activity in the past and present

The Metal And Sulphate Removal From Mine Drainage Waters By Biological-Chemical Ways

Mine drainage waters are often characterized by high concentrations of sulphates and metals as a consequence of the mining industry of sulphide minerals. The aims of this work are to prove some biological-chemical processes utilization for the mine drainage water treatment. The studied principles of contamination elimination from these waters include sulphate reduction and metal bioprecipitation by the application of sulphate-reducing bacteria (SRB). Other studied process was metal sorption by prepared biogenic sorbent. Mine drainage waters from Slovak localities Banská Štiavnica and Smolník were used to the pollution removal examination. In Banská Štiavnica water, sulphates decreased below the legislative limit. The elimination of zinc by sorption experiments achieved 84 % and 65 %, respectively