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EN
The article examined the influence of two additives, which are post-production waste from metallurgical processes, on the basic properties of cement mortars. Sludge and slag waste were used for testing. Both wastes were examined in terms of their chemical composition using a spectrometer, their specific density and grain composition were determined. As part of the tests, a series of standard mortars were made and the results obtained for modified mortars were compared to them. The produced cement composites used waste in amounts of 5, 10, 15 and 20% of the cement mass, used as a substitute for standard sand. After preparing the standard mortar and mortars containing additives for each series, consistency tests were performed using the flow table method. After an appropriate maturing time, flexural and compression tests were performed for all mortar series after 7 and 28 days of maturing, as well as water absorption tests. The research shows that the addition of these two wastes thickens the fresh cement mortar (from 0.62 to 15 %). The use of such waste also results in a decrease in flexural strength after 7 and 28 days (for sludge from 5 to 21% and for slag from 2 to 11%). However, the compressive strength of mortars decreased by 11% in the case of the addition of 20% of sludge and was almost the same as that of the standard mortar after the addition of 20% of slag.
PL
Poferment z fermentacji biomasy (DR) i popiół lotny (FA) zmieszano z biowęglem z osadów ściekowych (SSC) w stosunku 10:10:80 i spiekano w temp. 1050°C. Produkt został zgranulowany z przeznaczeniem na materiały budowlane i przetestowany zgodnie z chińskimi normami krajowymi. Wszystkie wskaźniki jakości granulatu spełniły wymagania chińskich norm krajowych dla granulatu budowlanego. Wskaźnik potencjalnego ryzyka ekologicznego związanego z obecnością metali ciężkich był niski, a produkt był bezpieczny.
EN
Biomass fermentation digestate and fly ash were mixed with sludge biochar in the ratio of 10:10:80 and sintered at 1050°C. The product was pelletized to building materials and tested according to China national stds. All the qual. indicators of the pellets met the requirements of the China national stds. for construction pellets. The potential ecol. risk index of heavy metals was low, and the product was safe.
EN
The aim of the present study was to determine: the impact of electric current density on the quantity and quality of sewage sludge produced in anaerobic sequencing bio-electrochemical reactor (AnSBBER) with an iron electrode during the treatment of drainage from soilless cultivation of tomatoes. Direct electric current (DC) effect was determined at its following densities (J): 0.63 A/m2 (R1), 1.25 A/m2 (R2), 2.5 A/m2 (R3), and 5 A/m2 (R4). Sodium acetate in (C:N) ratio of 1.0 was supplied to the reactors to ensure the proper biofilm development. Contents of elements (K, P, S, Na, Al, Cu, Fe, Mn, Mo, Zn, Mg, C, N and Ca) in the biofilm were determined. Additionally, the content of total suspended solids and the percentage share of volatile suspensions (VSS) in the sludge were determined. The study showed that the organic matter content in the sludge corresponded to the values typical of the stabilized sludge (up to 28.8% d.m. in R2).The increase in electric current density caused an increase in the concentration of phosphorus in the formed sludge (from 6.34 to 8.00% d.m. in 0.63 and 5.00 A/m2, respectively). The analyzed sludge, compared to municipal sludge from wastewater treatment plants with biological reactors and activated sludge chambers, is richer in such elements as phosphorus, nitrogen, calcium, magnesium, potassium, sodium, and iron.
EN
The article examinee the characteristics of sewage sludge and its impact on the environment. The description of technical installations, sludge sites in the municipal wastewater treatment systems, which are sources of unfavorable sanitary and epidemiological condition of the studied territory, was presented. A detailed analysis of the structure, composition and morphology of sludge sediment was given. It was found that the sludge presents a loose, rough heterogeneous porous structure represented by the presence of a fibrous substrate with amorphous scaly-crystalline inclusions. During laboratory analyses of the composition of the dry residue, the presence of such types of heavy metals as chromium, manganese, nickel, copper, zinc, lead, cobalt, molybdenum, cadmium was revealed. The excess of permissible concentrations of various elements was observed: chromium more than 7.1 at MPC – 6.0 by 1.18 times; copper more than 3.3 at MPC – 3.0 by 1.1 times; zinc more than 27.3 at MPC – 23.0 by 1.18 times; lead more than 34.3 at MPC – 32.0 by 1.07 times; cobalt more than 6.4 at MPC – 5.0 by 1.28 times; molybdenum more than 6.9 at MPC – 5.0 by 1.3 times. Soil analysis revealed a pH of 7.1, which is neutral, may be optimal for plants; the concentration of calcium, iron and chromium does not exceed the established maximum permissible values. When analyzing the air environment of the territory of the treatment facilities, the presence of gaseous pollutants, such as methane, ammonia, nitrogen dioxide, hydrogen sulfide, carbon monoxide, was established. It has been established that anthropogenic sludge landfills are the sources that create a technogenic load on the atmospheric air, polluting it with methane, since the concentration of methane exceeds the MPC by more than 3 times.
EN
This study was aimed to investigate the development of a technology for the extraction of niobium pentaoxide and ammonium sulfate from titanium-magnesium production waste, specifically, the sublimates of dust chamber into concentrate in the form of niobium pentoxide. Optimal conditions for washing the niobium hydroxide precipitate by repulpation with hot (60–70°C) distilled water, drying at 200°C for 6 hours were determined. The influence of temperature and duration of the process was studied. Optimal conditions for the dynamic desorption of niobium from saturated ionite (Purolite A100) was determined. The results further indicated that the optimum quantity of the solution of desorption with sulfuric acid was equal to 5.5% and ammonium oxalate was equal to 4%, while temperature and the flow rate of the desorbing solution was 22–27°C and 6 rpm, respectively. The study of the precipitation of niobium from sulfuric acid desorbates showed that the interaction of niobium ions with ammonia takes place at a low rate. The degree of precipitation of niobium hydroxide equal to 99.6% was achieved in 7 hours of agitation of the suspension at a temperature of 22–25°C.
EN
In the present study, paperboard mill sludge derived nanocellulose as biosorbent for removal of hexavalent chromium from simulated aqueous solution prepared from potassium dichromate. The adsorbents namely, CA-NC and FA-NC were prepared through citric and formic acid hydrolyses of the nanocellulose. The prepared sorbents were utilized for the adsorption of Cr(VI), with parameters such as pH, adsorbent dosage, solute concentration and contact time played pivotal role in the study. The ideal circumstances of these parameters to perform well were notably pH of 2, with adsorbent dose of 1.5 g, solute concentration of 100 mg•L-1, with a contact duration of 60 minutes. The adsorption followed pseudo second order reaction and fitted the Langmuir isotherm model indicating chemisorption coupled with monolayer adsorption of adsorbate onto the adsorbent.
PL
Technologia membranowa w oczyszczaniu ścieków jest uważana za najlepszą dostępną metodę. Jednak wysoka wydajność oczyszczania ścieków powoduje wzrost zanieczyszczeń w osadach ściekowych, będących produktem ubocznym procesów oczyszczania ścieków. Osady ściekowe mają właściwości glebotwórcze i nawozowe. Najlepszą metodą zagospodarowania osadów ściekowych jest wykorzystanie ich jako nawozu. Jednak głównym kryterium możliwości ich wykorzystania jako nawozów jest zawartość metali ciężkich i jaj pasożytów. W niniejszym badaniu porównano zawartość metali ciężkich w osadach ściekowych z trzech różnych oczyszczalni ścieków przed i po modernizacji do technologii MBR. Przeprowadzono analizę specjacyjną metali i obliczono wskaźniki ryzyka, w celu oszacowania rzeczywistego ryzyka zanieczyszczenia, związanego z wykorzystaniem osadów ściekowych jako nawozów. Głównym problemem badawczym artykułu jest odpowiedź na pytanie: czy podwyższona zawartość metali ciężkich w osadach ściekowych z oczyszczalni MBR może rzeczywiście powodować ryzyko skażenia środowiska?
EN
Membrane technology in wastewater treatment is considered the best method available. However, the high efficiency of wastewater treatment results in increased contaminants in sewage sludge, a byproduct of wastewater treatment processes. Sewage sludge with have soil-forming and fertilizing properties. The best method of managing sludge is to use it as fertilizer. However, the main criterion for the possibility of using them as fertilizers is determined by the content of heavy metals and parasite eggs. This study compared the heavy metal content of sludge from three different wastewater treatment plants before and after upgrading to MBR technology. A speciation analysis of the metals was performed, and risk indicators were calculated to estimate the actual risk of contamination from the use of sewage sludge as fertilizers. The main research problem of the paper is to answer the question: whether the elevated heavy metal content of sludge from MBR treatment plants can indeed cause a risk of environmental contamination.
PL
SNIT to kluczowa technologia na drodze do neutralnego klimatycznie oczyszczania ścieków. Oprócz poprawy skuteczności usuwania azotu zapewni również znaczne oszczędności eksploatacyjne dzięki niższemu zapotrzebowaniu na tlen i wyższej produkcji gazu fermentacyjnego.
PL
W styczniu 2022 roku, w Dzienniku Ustaw (Dz.U. 2022 poz. 89) zostało opublikowane Rozporządzenie Ministra Klimatu i Środowiska z dnia 31 grudnia 2021 r., zmieniające rozporządzenie w sprawie komunalnych osadów ściekowych. Jest to kolejna zmiana przepisów wykonawczych w tym zakresie.
PL
Istotny wpływ na działanie osadników wtórnych mają nie tylko przyjęte parametry i wskaźniki technologiczne charakteryzujące pracę tych urządzeń, jak przepływ ścieków czy obciążenie powierzchni zbiornika osadem czynnymi. Często główną przyczyną złego funkcjonowania mogą by( zakłócenia pracy samych reaktorów biologicznych. Tylko optymalizacja pracy układu reaktor biologiczny - osadnika wtórny może zagwarantować uzyskiwanie wysokiej efektywności redukcji zanieczyszczeń w ściekach, które po oczyszczeniu odprowadzane do środowiska.
EN
In this case study we compared the fertiliser properties of an industrial wastewater treatment sludge and a sludge ash to the requirements of the Finnish Fertiliser Product Decree. The sludge was obtained from the activated sludge wastewater treatment plant of a Finnish non-integrated pulp mill. The sludge was furthermore incinerated at a laboratory in a muffle furnace (850 °C) to obtain sludge ash. The total Cd (4.9 mg/kg d.m.) concentration in the pulp sludge exceeded the Finnish limit value (1.5 mg/kg d.m.) for fertiliser products used in agriculture. In the sludge ash, the total concentration of Cd (39 mg/kg; d.m.) exceeded the Finnish limit value (25 mg/kg d.m.) for ash fertilisers used in forestry. These results restrict the potential reuse options of these residues. However, from the utilisation point of view, the enrichment of essential plant macro-nutrients was most notable, resulting to the following total concentrations of these elements in the sludge ash: P (26,000 mg/kg d.m.), S (40,000 mg/kg d.m.), K (11,000 mg/kg d.m.), Ca (83,000 mg/kg d.m.) and Mg (10,000 mg/kg d.m.). Therefore, we conclude that, the converting of sludge into ash may promote the reuse of this wastewater treatment residue to a more value-adding fertiliser by-product to be used as a soil improver and growing medium in landscaping or landfills sites or other closed industrial areas, where heavy metal limit values for fertilisers are not applied in Finland.
PL
W pierwszej części artykułu przedstawiono schemat technologiczny oraz wyniki badań flotacji szlamów z elektrolizy na nowej linii pilotażowej w ZGH Bolesław S.A., prowadzonych początkowo w kierunku określenia optymalnego uziarnienia nadawy do procesu klasyfikacji, optymalnych parametrów pracy hydrocyklonu oraz wyznaczenia optymalnych warunków flotacji głównych, kontrolnych i czyszczących, w aspekcie określenia optymalnego zestawu odczynników do flotacji. Określono optymalny skład ziarnowy nadawy do procesu klasyfikacji, wyrażony wielkością jednostkowego obciążenia młyna rozmielającego szlamy, wyznaczono optymalne parametry klasyfikacji szlamów w hydrocyklonie, wyrażone wielkością wychodu jego produktu przelewowego, oraz określono optymalne warunki flotacji, dotyczące ilości i rodzaju stosowanych odczynników flotacyjnych. W dalszej części przedstawiono wpływ pozostałych parametrów flotacji na zawartość srebra i jego uzysk w produkowanym koncentracie, takich jak: zagęszczenie nadawy do flotacji, prędkość obwodowa wirników, wielkość dawki głównego zbieracza Selkol w procesach flotacji głównych oraz wielkość pH zawiesiny.
EN
The first part of the paper presents the technological diagram and the results of the flotation process of sludge from electrolysis on a new pilot line at ZGH Boleslaw S.A. initially aimed at determining the optimal grain size distribution of the feed for the classification process, optimal parameters of the hydrocyclone operation and determination of the optimal conditions for main, control and cleaning flotation in terms of determining the optimal set of reagents for flotation. The optimal grain composition of the feed for the classification process was determined, expressed by the unit load of the sludge milling mill, the optimal parameters for sludge classification in the hydrocyclone expressed by the size of its overflow product output were determined, and the optimal flotation conditions for the amount and type of flotation reagents used were determined. The following section presents the effect of other flotation parameters on the content of silver content and its recovery in the concentrate produced, such as: flotation feed compaction, rotor peripheral speed, the size of the main Selkol collector dose in the main flotation processes and the pH of the suspension.
13
Content available Processing of Titanium-Magnesium Production Waste
EN
The article presents the results of research on the processing of such wastes of titanium-magnesium production as sludge from sludge dumps and fine dump dusts from the electric smelting of ilmenite concentrates. The results of nitric acid leaching of sludge with the transfer of calcium into solution and the production of calcium nitrate are given. Titanium-containing cake after nitric acid leaching of sludge and electric smelting dust cannot be returned to the technological process due to its high silica content, so the silicon impurity was removed from their composition. Silicon removal was performed by fluoroammonium processing with sublimation of hexafluorosilicate compounds. An amorphous silicon dioxide product was obtained, after ammonia hydrolysis of silicon-containing sublimations and appropriate treatment of the sediment. The residue from the sublimation of silicon fluorides consists mainly of titanium-containing phases and can be suitable for return for electrofusion after ammonia treatment.
EN
Since anaerobic digestion (AD) is the preferred procedure for sludge treatment and disposal, it is constrained by the hydrolysis and acidogenesis stages. Nanomaterials have an impact on the AD process due to their unique properties (large specific surface areas, solubility, adsorption reduction of heavy metals, degradation of organic matter, reduction of hydrogen supplied and catalytic nature) which make them advantageous in many applications due to their effectiveness in improving the AD efficiency. Magnetic Nanoparticles (MNPs) were used in the present study to improve the biogas production. The experiments were divided into two stages to evaluate the effect of adding MNPs to two types of sewage sludge (SS): attached growth process (AG) and activated sludge (AS). The first stage consists of 15 tests divided into three experiments (A, B, and C). Doses of MNPs (20, 50, 100, 200) mg/l were added to all digesters in the same experiment except for one digester (the control). Experiments A, B and C achieved the highest biogas production when 100 mg/l of MNPs was added. They were 1.9, 1.93 and 2.07 times higher than the control for A, B and C respectively. The second stage consists of 12 tests with a pretreatment for some of SS. It was divided into two experiments (D, E), where the chemical pretreatment was applied to experiment D and the thermal pretreatment was applied to experiment E except for the control. For digester D4, which had 100 mg/l of MNPs after a chemical pretreatment at pH = 12, the biogas production increased by 2.2 times higher than the control (D0) and 1.5 times higher than the untreated sludge with the addition of 100 mg/l MNPs (DN). Thermal pretreatment at 100 °C with addition of 100 mg/l MNPs (E4) achieved a biogas yield 2 times higher than the control (E0), and 1.39 times higher than untreated sludge with 100 mg/l MNPs (EN). The previous results indicate that the integration of magnetite can serve as the conductive materials, promoting inherent indirect electron transfer (IET) and direct interspecies electron transfer (DIET) between methanogens and fermentative bacteria which lead to a more energy-efficient route for interspecies electron transfer and methane productivity. This study demonstrated the positive effect of magnetite on organic biodegradation, process stability and methane productivity.
EN
One of the greatest environmental problems of modern countries is the pollution of territories with waste. Of particular concern are the wastes generated during the treatment of municipal wastewater, i.e. sewage sludge. They are the inevitable price of urbanization and improved quality of life. As a result of the research conducted, a comprehensive analysis of the composition of municipal sewage sludge was conducted using the example of four small settlements in East Kazakhstan. The results of laboratory studies established the composition of the organic part, biogenic elements, as well as microbiological and parasitological indicators. It was revealed that cadmium, copper, zinc and arsenic are main sources of problems in wastewater treatment plant sludge. For copper and zinc, the standards set by the European Directive 86/278/EEC were exceeded by up to 3.2 and 1.5 times, respectively. At the same time, there is an increased content of nutrients. Organic matter in all studied samples exceeds the minimum established values by 3.5–3.7 times; the potassium content in all studied samples is 5.1–5.6 times higher than the minimum established value for organomineral fertilizers in the Republic of Kazakhstan. The concentration of hydrogen ions (pH) corresponds to neutral. Tests for the determination of microbiological and parasitological parameters indicate that the studied sludge does not contain various pathogenic bacteria and microorganisms.
EN
In this study, the effect of thermal pre-treatment (TP) on the physical characteristics and co-digestion of a mixture of food waste and sludge was investigated. The food waste (FW) to sewage sludge (SS) ratio used in this research is 1:2 (VS-based) to form a final concentration of 11.20%. The inoculum to substrate ratio was set at 1:1 (volumebased). Undoubtedly, the results show that TP has changed the physical characteristics of the food waste to sewage sludge mixture. The results show that the pretreatment increased the biogas production from 4385 ml for the untreated reactor to 5685 for the reactor R2(140) at 140 °C and the improvement in biogas production reaches 29.65% in the reactor R2(140) and the removal of volatile solids was 58.90%. Therefore, after the biomethane potential test, the temperature of 140 °C was found to be optimal in the production of biogas. The optimal condition is to use a mixture of pre-treated SS at the temperature of 140 °C and untreated FW, so TP is recommended to be used in anaerobic digestion of the mixture of food waste and sewage sludge.
EN
Sources of formation of environmental hazards in the Technosphere are industrial facilities and other objects of economic activity. The danger lies in the transformation of elements of the natural subsystem, and in the impact on humans. Man-made impact contributes to the emergence and accumulation of environmental hazards in the environment. The type of technological process, the frequency of its action and the intensity of man-made factors contribute to the appearance of manifestations of environmental danger, which puts before society the need to study the state of this danger and ways to eliminate it. Determining the real state of human environmental safety and the natural environment under the influence of factors of contamination of soil and hydrosphere waste from electroplating production with harmful and dangerous substances is a problem today. The economic complex of the electronic and radio engineering industry plays an essential role in the formation of the city’s environmental hazard. These enterprises are the main sources of environmental hazards, the priority among which is the type of hazard caused by chemical factors affecting the environment. Liquid and solid waste in their storage areas on the territory of enterprises creates an environmental hazard, since harmful substances contained in them pollute soils, open reservoirs, and underground aquifers. Heavy metal ions found in sludge and taken to landfills can form water-soluble complex compounds and create an environmental hazard, which manifests itself in contamination of soils and underground aquifers. All of the above causes a problem that needs to be solved in order to significantly limit the formation of sludge during the production of printed circuit boards and the use of electroplating processes, which will make it possible to reduce environmental hazards. One of the serious, unresolved and constantly increasing problems is the problem of solid waste: its quantity is constantly growing, the composition is becoming more diverse, there are not enough territories for their placement, and the cost of their disposal is increasing. It should be noted that the problem of solid waste has long turned from a purely ecological one into a socio-ecological one: solid waste is not only a significant factor in pollution of the air Environment, Water Resources, soil and other natural components, but also the cause of a decrease in the quality of life, which is manifested in an increase in the incidence of diseases of the population, a decrease in income, deterioration of working and Recreation conditions. Solid waste management within the framework of socio-economic policy directly affects the development of the region. A special feature of Solid Waste Management is that this process is initiated simultaneously at different levels of management: from state to local (level of an economic entity).
18
Content available remote Types and valorization of sludge generated in water treatment processes
EN
This paper is a study on the problem of sludge formation in water treatment processes. Various physical and chemical processes used in technological systems of water treatment were described and those which are the source of sludge were indicated. The chemical composition of the sludge was presented, with particular emphasis on hazardous organic and inorganic pollutants. An essential part of the work was to consider the possibilities and ways of valorizing sludge. It was deter- mined that the type of generated sludge depends on the applied process and its pollution degree depends on the type and quality of the water taken. Most of the sludge is formed during the coagulation process of surface waters, which may be contaminated with various heavy metals. Among the possibilities and methods of sludge valorization, an interesting way to use it is in construction, as an admixture to various building materials. It is also possible to use sludge as an unconventional adsorbent or reaction catalyst in the oxidation of organic pollutants present in wastewater.
PL
Ścieki surowe z produkcji wodorozcieńczalnych farb dekoracyjnych oczyszczano w dwustopniowej chemiczno-biologicznej instalacji. Na chemicznym stopniu stosowano koagulację jednoetapową reagentami zawierającymi sole Al lub Fe albo dwuetapową z mlekiem wapiennym i reagentami z solami żelaza, z końcową flokulacją. Zawartość ługowanych metodą TCLP jonów Ba, Co, Cr, Cu, Mo, Ni, Sb, Pb, Ti i Zn z osadu nadmiernego i osadów mieszanych była zróżnicowana ilościowo. Zawartość ta była śladowa (poniżej 2,1 mg/kg s.m.) w szlamach po dwuetapowej koagulacji z chemicznego stopnia oczyszczania.
EN
Crude wastewater from the prodn. of water-based decorative paints was one- or two-step treated with Al or Fe salts, or lime milk and Fe salts and flocculated to remove the solid pptr. The leaching by TCLP method of Ba, Co, Cr, Cu, Mo, Ni, Sb, Pb, Ti and Zn ions was trace (to below 2.1 mg/kg dm) in sludge after two-step coagulation.
EN
At present, the sludge drying beds of the Kyiv wastewater treatment plants are operated as a sludge accumulator in an emergency mode, practically without free volume. The purpose of the work was to determine the equation for the evaporation losses calculation from sludge drying beds and the required free volume for sludge accumulation for the next 7 years. The required free volume was calculated using the water budget method which takes into account evaporation from the water surface and evapotranspiration during the vegetation. The total losses from sludge drying beds is 1076 mm/year in normal year and is 920 mm/year in a cold year. The required free volume was calculated considering the trend of increasing average temperature over the last decade and considering the significant environmental risk. A correction was made for one unfavourable year with cold summer and warm winter and an additional rain rate of 1% probability. The additional free volume required is 3.24 million m3 for 7 years if all three sludge drying beds are operated.
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