The water of the Wisła-Czarne reservoir is of very low hardness and alkalinity. In spite ofhigh SUVA values it is not susceptible to enhanced coagulation. In order to achieve the assumed results, coagulation with ALS (aluminium sulphate) should be conducted in two optional technological systems - in a conventional system and in "in-bed" coagulation dependently ofwater quality and its temperature. Effective treatment with ALS is possible, even at low temperature of the water, but at strict technological parameters. However, because of significant variations of water quality, especially after rainstorms, it is very difficult to meet such requirements. Application of pre-hydrolyzed Flokor 1,2A instead ofALS enables to eliminate reagents to the pH adjustment and to apply "in-bed" coagulation when water supplied to the WTP is of low turbidity. To assure stable technological system operation, in aspect of raw water quality changes, some activities were also undertaken, i.e. modernization of rapid filters, which involved a drainage system and exchange of sand bed for anthracite-sand bed. Treatment based on direct filtration results in decrease of reagents usage and, what is especially important, effective DBPs precursors removal.

This paper deals with the results of chemical pre-treatment of effluents from Chip Washing by coagulation. Three different, most frequently used coagulants i.e. calcium hydroxide, aluminium sulphate and ferric chloride were applied. Influence of single and simultaneous dosage of the reagents was investigated. Fully randomized block systems were applied in the factorial variance analysis and final approximation analytic-empiric mathematical equations with application of the central point method were formulated.

The objective of this study was to investigate the influence of aluminium coagulants basicity on the minimalisation of undesirable effects of coagulation such as decreasing pH and alkalinity, thereby water corrosivity. The experiments involved three types of surface water samples: from the Odra and Oława Rivers and a mountain stream, which differed in physico-chemical composition (especially in pH values and alkalinity). Alum (ALS) and polyaluminium chlorides (PACI) characterized by various basicity (r, %) were used as coagulants. The experimental results showed that decrease in water corrosivity depended on the basicity and dose of coagulant, pH and temperature of water prior to coagulation. With the increment of coagulation basic i ty the chemical stability of treated water improved and coagulants PAX-XL 3 and PAX-XL6 l were the best. Using of polyaluminium chlorides instead of alum decreased not only undesirable effects of coagulation but improved also the efficiency of water treatment.

This paper presents the results of tests performed on an installation with an aerated microelectrolytic bed (MEL-bed) and sludge sedimentation. The systems were designed in two versions, differing in the aeration method, i.e., a mechanically aerated coagulator (MAC) and an automatically aerated coagulator (AAC). The experiment demonstrated a high (approx. 84%) efficiency of phosphorus removal from a model solution for both versions. The corroding bed was the source of iron in the solution. In the initial phase aeration method affected the phosphorus removal rate, flocculation and sedimentation processes. Physical and chemical changes in the MEL-bed packing were observed.

The scope of work included the launch of the process of refining slag suspension in a gas oven using a variety of technological additives.

After the refining process (in the context of copper recovery), an assessment of the effect of selected reagents at the level of the slag

refining suspension (in terms of copper recovery). Method sieve separated from the slag waste fraction of metallic, iron - silicate and

powdery waste. Comparison of these photographs macroscopic allowed us to evaluate the most advantageous method of separating

metallic fraction from the slag. After applying the sample A (with KF2 + NaCl) we note that in some parts of the slag are still large

amounts of metallic fraction. The fraction of slag in a large majority of the elements has the same size of 1 mm, and a larger portion of the

slag, the size of which is from 2 to 6 mm. Definitely the best way is to remove the copper by means of the component B (with NaCl ) and

D (with KF2

). However, as a result of removing the copper by means of component C (with CaO) were also obtained a relatively large

number of tiny droplets of copper, which was problematic during segregation. In both cases we were able to separate the two fractions in a

fast and simple manner.

The suspension of the copper droplets in the post-processing slag taken directly from the KGHM-Polska Miedź S.A. Factory (from the

direct-to-blister technology as performed in the flash furnace) was subjected to the special treatment with the use of the one of the typical

industrial reagent and with the complex reagent newly patented by the authors. This treatment was performed in the BOLMET S.A.

Company in the semi-industrial conditions. The result of the CaCO3, and Na2CO3 chemicals influence on the coagulation and subsequent

sedimentation of copper droplets on the crucible bottom were subjected to comparison with the sedimentation forced by the mentioned

complex reagent. The industrial chemicals promoted the agglomeration of copper droplets but the coagulation was arrested / blocked by

the formation of the lead envelope. Therefore, buoyancy force forced the motion of the partially coagulated copper droplets towards the

liquid slag surface rather than sedimentation on the crucible bottom. On the other hand, the complex reagent was able to influence the

mechanical equilibrium between copper droplets and some particles of the liquid slag as well as improve the slag viscosity. Finally, the

copper droplets coagulated successfully and generally, were subjected to a settlement on the crucible bottom as desired / requested.

During the process of ,,enhanced coagulation" except for colloids and suspensions removal, the removal of associated organic compounds including DPD (Disinfection By-Products) precursors is crucial. It is often necessary to decrease color and turbidity of treated water to values which arc significantly lower than accepted for drinking water. On the basis of presented results of the research it was found out that under strict technological conditions coagulation of low mineralization waters ensures effective treatment, including significant THMs precursors removal, even when water is of low temperature. However, it is necessary to apply two different methods of coagulation (volumetric coagulation and direct filtration) dependently of water temperature with the usage of the same equipment (a flocculation chamber, a vertical sedimentation tank and a pressure rapid filter) including the same point of a coagulant dosing. During the periods of ,,high temperature" the treatment should be based on volumetric coagulation and during the periods of ,,low temperature" of water direct filtration should be applied.

Lcachates from municipal solid waste landfills should be included in the group of strongly contaminated industrial wastewaters. This results form the presence of highly concentrated various organic and inorganic compounds, which frequently have toxic properties. Therefore, the proper purification of the leachates prior to their discharging to the environment is of great importance. One of the chemical methods that can be used for the purification of leachates is coagulation. The main objective of the experiments presented in the current study was to determine the effect of coagulation, combined with sedimentation, on the physicchemical and toxicological characteristics of leachates from one of a municipal solid waste landfill in Poland. Standard .jar-test" experiments were employed for coagulation. Polyaluminum chloride and ferric chloride were used as coagulants. Raw leachates as well as those after coagulation were tested for toxicity using a battery of tests embracing algal growth inhibition test, microbiotests and IQ Toxicity Tests with crustaceans and bacterial luminescence inhibition test (LUM!Stox). The studies carried out demonstrated that ferric chloride (0.92 g Fc3·/CODc, removed) is more effective technologically in the removal of organic compounds from lcachates than polyaluminum chloride (1.22 g AP'/CODc, removed). For optimal doses of coagulants the most advantageous coagulation effects were achieved at pH 6.5-6.6, adjusted with the use of NaOH. Coagulation conducted under optimal conditions allows for reducing the content of organic compounds, as expressed by CODc, values, from 40 to 84%. This effect of organic compound removal from leachatcs in the process of coagulation did not result in significant decrease of their toxicity, For the above reasons the coagulation process can be useful only as one of the clements· of a technological setup for the purification of leachates from municipal solid waste landfills. The battery of tests used in the studies proved usefulness for the evaluation of the toxicity of leachatcs with varied degree of contamination as well as at various stages of their purification.

Acoustic radiation sources are successfully applied to cleaning rooms from dust of fairly large particle sizes (ten micrometers and larger). The sedimentation of fine aerosols (particle diameter of 1-10 microns) is a more complicated challenge. The paper is devoted to the substantiation of the acoustic sedimentation method for such aerosols. On the basis of the mathematical model analysis for aerosol sedimentation by the acoustic field the mechanisms of this process have been determined and include the particle coagulation acceleration and radiation pressure effect. The experimental results of the acoustic sedimentation of a model aerosol (NaCl) are shown. The calculation results according to the mathematical model for coagulation and sedimentation, on the basis of the Smolukhovsky’s equation taking into account various mechanisms of aerosol sedimentation by sound depending on the particle sizes and sound intensity, are given. The necessity to use intensive sources of high-frequency sound has been confirmed, suggesting that these sources must be located above dust clouds.

The article presents the results of research aimed at increase of the efficiency of gas cleaning equipment based on the Venturi tube using high-intensity ultrasound. The model based on known laws of hydrodynamics of multiphase mediums of dust-extraction in Venturi scrubbers was proposed. Modification of this model taking into account ultrasonic field allows evaluating optimum modes (sound pressure level) and conditions (direction of ultrasonic field, square and number of ultrasonic sources) of ultrasonic influence. It is evaluated that optimum for efficient gas cleaning is the mode of ultrasonic action at the frequency of 22 kHz with sound pressure level of 145. . . 155 dB at the installation of two radiators with area of 0.14 m2, four radiators with area of 0.11 m2 or six radiators with area of 0.08 m2 at the angle of 45 degrees to the axis of Venturi tube. Numerical calculations showed that realization of ultrasonic action is the most efficient for the reduction (up to 15 times) of the content of fine-dispersed fraction (2 μm and less), which is impossible to extract without ultrasonic action. The received theoretical results were confirmed by industrial testing by typical dust-extraction plant and used as foundations of development of apparatuses with the radiators of various sizes.

This investigation was undertaken to determine the optimum conditions for physical-chemical treatment of waste water contaminated with heavy metals in the industry of metallic coatings. The industry uses substances such as: inorganic acids, alkalis, acidic and alkaline metal salts, that has a high water demand in the processes of flushing and cleaning the parts to be coated. According to the preliminary characterization of samples and reported in the literature theory, physico-chemical process was implemented for the removal of contaminants that consisted in chemical oxidation of CN-ions, followed by chemical precipitation made next to a coagulation/flocculation and subsequent adsorption on activated coal. Laboratory scale tests showed the optimal conditions of treatment including chemical oxidation by the addition of 4.15 cm3 of H2O2(30%) per gram of CN, chemical precipitation with NaOH to a pH of 12, followed by coagulation/flocculation with Fe2(SO4)3 at a speed of 135 rpm for 3 min and 20 rpm for 20 min and finally the addition of 1.0 g of adsorbent previously activated at 700°C. From this study, it is clear that the adsorption on activated carbon is highly efficient in the removal ofheavy metals from industrial waste water from electroplating. However, it is also clear that the parallel application of the treatments, shown here, is more effective to completely remove contaminants such as lead, nickel, silver, and copper at la-boratory scale, so it is recommended the simultaneous use of these physico-chemical processes.

The removal of nitrates from aqueous solutions is cumbersome because of their high solubility in water. The use of zero-valent iron (ZVI) for the reduction of nitrates is the chemical process and it is an alternative method to the biological ones. The aim of the present study was to evaluate the eff ectiveness of nitrates removal from water solution by using the ZVI process. The process was coupled with the removal of COD, phosphates and turbidity by using by-products of nitrates reduction. Batch tests were performed to evaluate the eff ectiveness of ZVI in the removal of nitrates from aqueous solutions. The eff ectiveness of nitrates removal was analyzed after 5, 10, 20, 30 and 60 min. and compared to the initial concentration of pollutants. Simultaneously analysis of ammonium nitrogen and nitrites was controlled to identify products of nitrates reduction under various pH. The removal of COD, phosphates and turbidity was also performed in batch tests. The eff ectiveness of the emoval by using three types of chemicals was compared – PIX, FeSO4, and waste Fe2+/Fe3+ from the ZVI process. The results obtained in the study indicate that ZVI can be eff ectively used in the treatment of water polluted with nitrates and the by-products of the process could be further applied in the removal of COD, phosphates and turbidity. Based on the results the method should be advised as a promising alternative to the technologies used nowadays under technical scale as a technology that fits with a circular economy.

In this article a three-dimensional mathematical model of radiofrequency ablation during open-heart surgery is presented. It was developed to study temperature field distribution into myocardial tissue. This model uses an anatomically correct 3D model for the left atrium, obtained by magnetic resonance imaging (MRI) processing of a patient; takes into account thermoelectric characteristic differences depending on the area of electric current application; considers cooling by the air flow. An ex-vivo experiment on the pig’s heart was performed where the depth of myocardium tissue damage was measured for the model validation. It was shown that the deviation of the model data from the experiment is within the limits of instrumental measurement error. The developed model is proposed to be used for heart ablation procedures planning, or new equipment development.

The availability of drinking water is one of the several problems humans face, considering that its availability is reduced to 0.80% of the existing fresh water. Then, coagulation-flocculation is a stage of this treatment. It is a process that agglomerates the suspended particles in a larger (floc) that could be separated by sedimentation and filtration processes to make the water drinkable. So, this work aimed to evaluate the effect of the dose of coagulant of yam starch ( Dioscorea rotundata) and the speed of agitation in the turbid water treatment process. For which the yam starch was extracted by implementing two methods which were NaOH and H2O, using centrifugation at 1500 rpm for 10 min, and adjusting the pH with HCl and NaOH 0.20 M, for later determining the effect of agitation speed (rpm) and coagulant concentration (ppm) on the percentage of turbidity removal, pH, and colour, to be compared with a synthetic coagulant. A yield of 42.60% was found in the wet base. The natural coagulants extracted with NaOH presented better turbidity removal, with a percentage of 92.48% at an agitation speed of 40 rpm and a concentration of 250 ppm. It can be concluded that natural yam coagulant can be recommended for use in the coagulation stage in the raw water treatment process for subsequent conversion to drinking water.

This study is the evaluation of the coagulation efficiency of the aluminum sulfate on the removal of catechol and pyrogallol. The study has focused on the impact of inorganic components of hardness Algerian waters. Jar-test trials were conducted on the two phenolic compounds dissolved in distilled water only, which was later enriched with minerals. Several reaction parameters varied, including the effect of pH and the influence of the salt content, and this approach yielded a better understanding of interaction between phenolic compounds and calcium/magnesium salts. The results indicate that the process efficiency depends on the number and position of OH in molecules. The main mechanisms would be either a physical adsorption, an exchange of ligand, or complexation on the floc surface of aluminum hydroxide. Moreover, the addition of inorganic salts appears to improve removal efficiency of tested phenolic compounds and have an effect on the optimal pH range for coagulation.

Humic substances (HS) are hydrophobic parts of dissolved organic matter, which are hard to degrade using biological processes. When exposed to disinfection processes, the HS present in wastewater could lead to the formation of disinfection by-products (DBPs), which are harmful and dangerous to health. Thus, a chemical coagulation process is commonly used for HS removal. This work used a cylindrical galvanic cell (CGC) with an iron anode and a copper cathode, where the dissolution of the anode served as an alternative source of metal ions for HS coagulation. The galvanic cell current for CGC stabilized at around 0.6 mA, and the voltage fluctuated, ca. 0.5 V for all solutions. The peaks observed on cyclic voltammograms could be associated only with oxidation and dissolution of iron; no other process was identified. After the process, the structures and molecular composition of the anode surface suggest the loss of Fe mass and the formation of iron oxides due to corrosion. The initial pH of the tested solution influenced the total Fe concentration in the solution as well as colour and turbidity. The quantitative removal of HS by electrolysis and membrane filtration processes at initial pHi = 6.0 yielded 72% and 90%, respectively, after 6 and 10 min. The mechanism of sorption on the flocs of hydroxides as a primary factor in HA removal was suggested.

The purpose of the presented research is to analyse possible methods of thickening of the Microcystis aeruginosa (Kützing) Kützing cyanobacteria using the obtained concentrate as a biomass for the production of energy carriers and bio-logically valuable substances. Method of cyanobacteria thickening under the action of electric current and in the electric field, as well as the method of coagulation–flocculation and gravity thickening, was experimentally investigated in lab-scale conditions. Electrical methods didn't show positive results for the Microcystis aeruginosa thickening, despite the re-ports of their potential efficiency in a number of previous studies. The high efficiency of the method of coagulation–flocculation and gravity thickening of Microcystis aeruginosa suspensions was obtained. The optimum concentrations of industrial polymeric coagulants and flocculants for the thickening of Microcystis aeruginosa suspensions were defined in the range of about 10 ppm for the coagulants and about 1 ppm for the flocculants. Negative effect of the previous cavitational treatment of the diluted suspensions of Microcystis aeruginosa on the effectiveness of the coagulation–flocculation and gravitational thickening was confirmed experimentally. Hydrodynamic cavitation should be recommended to use after the thickening as the next step of processing of concentrated suspensions of Microcystis aeruginosa to achieve maximum extraction of energy carriers and biologically valuable substances.

The suspension of copper droplets in the slag is considered. The copper/slug suspension is delivered as the product from the direct-toblister

process which is applied in the KGHM – Polska Miedź (Polish Copper) S.A. factory. The droplets / slag suspension was treated by

a special set of reagents (patented by the authors) to improve the coagulation process. On the other hand, the observations are made to

estimate if the melting / reduction process in the furnace is sufficiently effective to avoid a remaining of carbon in the copper droplets.

The coagulation process was carried out in the crucible (laboratory scale). However, conditions imposed to the coagulation / solidification

process in the laboratory scale were to some extent similar to those applied usually in the industry when the suspension is subjected to the

analogous treatment in the electric arc-furnace. Some suggestions are formulated how to improve the industrial direct-to-blister process.

Coagulation and solidification of the copper droplets suspend in the liquid slag are usually accompanied by the appearance of the Cu-Cu2O eutectic. Locally, this eutectic is created in the stationary state. Therefore, frequently it has a directional morphology. Since the E = (Zn) + Zn16Ti – eutectic is similar in the asymmetry of the phase diagram to the Cu-Cu2O – eutectic, the (Zn) single crystal strengthened by the E = (Zn) + Zn16Ti precipitate is subjected to directional growth by the Bridgman’s system and current analysis. Experimentally, the strengthening layers (stripes) are generated periodically in the (Zn) – single crystal as a result of the cyclical course of precipitation which accompanies the directional solidification. These layers evince diversified eutectic morphologies like irregular rods, regular lamellae, and regular rods. The L – shape rods of the Zn16Ti – intermetallic compound appear within the first range of the growth rates when the irregular eutectic structure is formed. Next, the branched rods transform into regular rods and subsequently the regular rods into regular lamellae transitions can be recorded. The regular lamellae exist only within a certain range of growth rates. Finally, the regular rods re-appear at some elevated growth rates. The entropy production per unit time and unit volume is calculated for the regular eutectic growth. It will allow to formulate the entropy production per unit time for both eutectic structure: rod-like and lamellar one.

Ultrasonic processing in the cavitation mode is used to produce the composite materials based on the metal matrix and reinforcing particles of micro- and nano-sizes. In such a case, the deagglomeration of aggregates and the uniform distribution of particles are the expected effects. Although the particles can not only fragment in the acoustic field, they also can coagulate, coarsen and precipitate. In this paper, a theoretical study of processes of deagglomeration and coagulation of particles in the liquid metal under ultrasonic treatment is made. The influence of various parameters of ultrasound and dispersion medium on the dynamics of particles in the acoustic field is considered on the basis of the proposed mathematical model. The criterion of leading process (coagulation or deagglomeration) has been proposed. The calculated results are compared with the experimental ones known from the scientific literature.

The presence of natural organic matter (NOM) in water has a significant influence on water treatment processes. Water industries around the world consider coagulation/flocculation to be one of the main water treatment methods. The chief objective of conventional coagulation-based processes is to reduce the turbidity of the water and to remove natural organic matter (NOM) present in solutions. The aim of this paper is to present some developments in terms of improved coagulation for the drinking water of Sidi Yacoub treatment plant located in the Northwest of Algeria.
The experiments involved studying the effects of the application of two coagulants (ferric chloride and aluminium sulphate) on the removal of turbidity and natural organic matter from water by measuring the chemical oxygen demand ( COD) and the UV absorbance at 254 nm. The results showed that the rate of turbidity removal increased from 81.3% to 88% when ferric chloride was applied and from 89.91% to 94% when aluminium sulphate was applied. For NOM removal, the maximum removal rates of COD and UV254 were 48% and 52%, respectively, in the case of ferric chloride. These rates increased to 59% and 65% after optimised coagulation. When aluminium sulphate was used, the rate of removal in water increased from 43% to 55% for COD and from 47% to 59% for UV254 after optimised coagulation. The combination of the two coagulants at equal dosage shows a slight improvement in the values obtained after optimisation, both in terms of turbidity and the NOM.