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Abstract

The article describes problems related to intensification of energy production at a sewage treatment plant. The authors analyze anaerobic co-digestion of sludge from a water treatment plant and sewage treatment plant. The authors proposed a methodology of the research and analyzed the preliminary results, which showed that co-digestion of sewage and water sludge enhanced biogas production. The authors hope that the results of the study will provide a basis for development of methodology for sludge control and disposal.
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Abstract

The study of the possibility of removing organic compounds from wastewater originating from the biodiesel purification stage by two catalytic processes, HSO5-/transition metal and Fenton method has been presented. The source of the ion HSO5- is potassium monopersulphate (2KHSO5·KHSO4·K2SO4) (Oxone) that may be decomposed into radicals (OH., SO4-., SO5-.) by means of transition metal as Co(II). Different concentrations were used for both compounds and the combination ([Co2+] = 1.00μM/[HSO5-] = 5.00·10-2 M) achieved the highest COD removal (60%) and complete decomposition of the oxidant was verified for contact times of 45 min. This process has some advantages comparing to the conventional Fenton method such as the absence of the costly pH adjustment and the Fe(III) hydroxide sludge which characterize this treatment process. The Fenton process showed that the combination of [H2O2] = 2.00M/[Fe2+] = 0.70 M was the best and archived COD removal of 80%. The treatments studied in this research have achieved high COD removal, but the wastewater from the biodiesel purification stage presents very high parametric values of Chemical Oxygen Demand (667,000 mgO2/L), so the final COD concentration reached is still above the emission limit of discharge in surface water, according the Portuguese Law (Decree-Law 236/98). However, both treatments have proved to be feasible techniques for the pre-oxidation of the wastewater under study and can be considered as a suitable pre-treatment for this type of wastewaters. A rough economic analysis of both processes was, also, made.
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Abstract

To investigate and assess the effects of land use and its changes on concentrations of heavy metals (Pb, Zn, Cd, Cu, Mn, Ni, Fe) in the tributary of drinking water reservoir catchment, soils of different land use types (forest, arable land, meadows and pastures, residential areas), suspended sediment and bottom sediment were collected. Heavy metals were analyzed using atomic absorption spectrophotometry (AAS). The metal distribution pattern was observed, where Zn and Cd could be considered as main metal contaminants. The variation in the concentration level of Zn and Cd in studied soils showed the impact of pollution from anthropogenic activities. Also some seasonal variations were visible among the suspended sediment and bottom sediment samples which could be associated with land agricultural practices or meteorological conditions. The sediment fingerprints approach used for determining sources of the suspension in the catchment showed (Kruskal-Wallis H test, p<0.05), that only Mn and Ni were not able to be distinguished among the potential sediment sources. A multiple linear regression model described the relationship between suspended sediment and 4 types of soil samples. The results related suspended composition mostly to the samples from the residential land use. Considering the contemporary trend of observed changes in land use resulting in conversion of agricultural areas into residential and service structures these changes can be essential for the contamination of aquatic environment. This situation is a warning sign due to the rapid industrialization, urbanization and intensive agriculture in this region what can significantly affect the drinking water quality.
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Abstract

The objective of the paper is to use life cycle assessment to compare environmental impact of different technologies used in the process of water disinfection. Two scenarios are developed for water disinfection life cycle at ZUW Raba water treatment plant: (1) historical, in which gaseous chlorine is used as a disinfectant and (2) actual, in which UV radiation and electrolytically generated sodium hypochlorite are used for that purpose. Primary data is supplemented with ecoinvent 3 database records. Environmental impact is assessed by IMPACT2002+ method and its midpoint and endpoint indicators that are calculated with the use of SimaPro 8.4 software. The focus of the assessment is on selected life cycle phases: disinfection process itself and the water distribution process that follows. The assessment uses the data on flows and emissions streams as observed in the Raba plant. As the results of primal analysis show, a change of disinfectant results in quantitative changes in THMs and free chlorine in water supplied to the water supply network. The results of analysis confirm the higher potential of THMs formation and higher environmental impact of the combined method of UV/NaClO disinfection in distribution phase and in whole life cycle, mainly due to the increase of human toxicity factors. However, during the disinfection phase, gaseous chlorine use is more harmful for environment. But the final conclusion states that water quality indicators are not significant in the context of LCA, while both disinfection and distribution phases are concerned.
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Abstract

The substrates to biogas production in anaerobic digestion, except plant materials, can also be animal feces and manure. It should be highlighted that Poland is one of leaders in the European Union in animal breeding. However, there is no precise data in the literature on the potential of biogas production from animal feces in this country. The aim of the paper was to analyze the biogas production potential from manure in Poland. The aim of work included anaerobic digestion research following materials: cow manure, pig manure, poultry manure and sheep manure. In the next step, based on the obtained results of the biogas yield, energy potential calculations were made. The methane yield for the investigated feedstock materials in the batch culture technology was performed following the internal procedures developed based on the adapted standards, i.e. DIN 38 414-S8 and VDI 4630. Animal wastes were obtained from the Agricultural Experimental Stations of Poznan University of Life Sciences (Poznan, Poland). On a base of achieved results it was concluded that tested substrates have a high energy potential (approx. 28.52 GWh of electricity). The largest potential for electricity production was found in chicken manure (about 13.86 GWh) and cow manure (about 12.35 GWh). It was also shown which regions of Poland have the best chance for development of agriculture biogas plants (Wielkopolskie and Mazowieckie voivodships) and where the potential is the least (Lubuskie and Opolskie voivodeships).
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Abstract

The issue of air pollution, resulting to a large extent from the use of fossil fuels for energy purposes, is one of the most serious environmental threats in several Polish cities, but also outside of them. The amount of pollutants emitted into the atmosphere translates into the living conditions of the inhabitants. The utilization of geothermal energy, which is a renewable and ecological source of energy, brings noticeable improvement in the quality of atmospheric air, as evidenced by significant ecological effects achieved by working geothermal district heating plants. The paper presents results of comprehensive considerations focused on assessing the effects of utilization of geothermal water and energy in Poland. Issues related to the implementation of exploration works aimed at acquiring geothermal water resources, as well as environmental aspects of the use of geothermal waters and energy were discussed. The undertaken considerations have been directed at assessing whether the use of such a kind of renewable energy resources could have an impact on improving the living conditions of the local community.
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Abstract

In the present study, the novel quaternary ammonium salt (QAS+), 1-methyl-di-octyl-1 phenyl ammonium iodide (QAS1), was synthesized by complete alkylation reaction. Sodium montmorillonite (Mt) was modified via an ion-exchange reaction with QAS1+. The modified material and quarternary ammonium salt (Mt1 and QAS1) were analyzed by nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Removal capacity of hydrophobic organic pollutants such as 4-nitrophenol (4-NP) and 2,4-dinitrophenol (2,4-DNP) from solution media of synthesized organoclay was evaluated. The optimum conditions and batch kinetics of adsorption of 4-nitrophenol and 2,4-dinitrophenol from aqueous solutions are reported. It was shown that the adsorption capacity decreased in the order 4-NP> 2,4-DNP. The total mass loss during the drying process was 66% and 78%, respectively. Thermodynamic parameters enthalpy (∆H0) and entropy (∆S0) and the mean free energy (E) for the adsorption of nitrophenol compounds (NCP) were determined.
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Abstract

Multidimensional exploratory techniques, such as the Principal Component Analysis (PCA), have been used to analyze long-term changes in the flow regime and quality of water of the lowland dam reservoir Turawa (south-west Poland) in the catchment of the Mała Panew river (a tributary of the Odra). The paper proves that during the period of 1998–2016 the Turawa reservoir was equalizing the river’s water flow. Moreover, various physicochemical water quality indicators were analyzed at three measurement points (at the tributary’s mouth into the reservoir, in the reservoir itself and at the outflow from the reservoir). The water quality assessment was performed by analyzing physicochemical indicators such as water temperature, TSS, pH, dissolved oxygen, BOD5, NH4+, NO3-, NO2-, N, PO43-, P, electrolytic conductivity, DS, SO42- and Cl- . Furthermore, the correlations between all these water quality indicators were analyzed statistically at each measurement point, at the statistical signifi cance level of p ≤ 0.05. PCA was used to determine the structures between these water quality variables at each measurement point. As a result, a theoretical model was obtained that describes the regularities in the relationships between the indicators. PCA has shown that biogenic indicators have the strongest influence on the water quality in the Mała Panew. Lastly, the differences between the averages of the water quality indicators of the inflowing and of the outflowing water were considered and their significance was analyzed. PCA unveiled structure and complexity of interconnections between river flow and water quality. The paper shows that such statistical methods can be valuable tools for developing suitable water management strategies for the catchment and the reservoir itself.
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Abstract

The complexity and uncontrolled formation of struvite (MgNH4PO4·6H2O) and its deposition in the technological equipment of wastewater treatment plants (WWTPs) are still the subject of research aimed at understanding the causes and proposing a remedial action. In order to reduce the intensity of the precipitation of struvite in wastewater treatment plants, it is recommended, among others, to limit flow velocity to below 1.5 m·s-1. Literature analysis showed that there are no studies on the precipitation of struvite deposits in pipelines. Most studies focus on the deliberate precipitation of struvite, for example phosphorus recovery, resulting in a molar ratio of 1:1:1 (NH4+:PO43-:Mg2+). In fact, in WWTPs, such concentrations do not occur, but there have been cases of the precipitation of this mineral (and its mixtures) in the sludge parts. In this paper, the study aimed at determining conditions for the precipitation of deposits with a significant participation of struvite on the inner walls of steel pipes. The study was conducted at a non-stoichiometric concentration of ingredients at different pH values, as well as under dynamic conditions with flow velocity below 1.5 m·s-1. A mathematical formula (ANOVA) that can be used to determine the mass of deposits in relation to the concentration of ammonium, phosphate, pH and flow velocity was developed. Computational models were developed on to investigate struvite precipitation under different pH levels (8.0–9.5) and ionic concentrations. The studies were carried out on solutions containing ammonium (NH4+), phosphate (PO43-), and magnesium (Mg2+), at a flow velocities of 0.4, 0.9 and 1.4 m·s-1. In order to determine the mathematical formula thanks to which the mass of precipitates can be determined, a special pilot study installation was constructed. The XPS surface analysis of sludge from sewage treatment plants showed a similar composition of compounds with sediments obtained in own research. The presence of struvite was suggested, but the share of atomic percentage of bonds to which struvite was classified is small and amounts to less than 4%. This means that sediments precipitated in the technological installations are a mixture of various compounds of which pure struvite may constitute only a small part.
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Abstract

The essence of the methane fermentation course is the phase nature of changes taking place during the process. The biodegradation degree of sewage sludge is determined by the effectiveness of the hydrolysis phase. Excess sludge, in the form of a flocculent suspension of microorganisms, subjected to the methane fermentation process show limited susceptibility to the biodegradation. Excess sludge is characterized by a significant content of volatile suspended solids equal about 65 ÷ 75%. Promising technological solution in terms of increasing the efficiency of fermentation process is the application of thermal modification of sludge with the use of dry ice. As a result of excess sludge disintegration by dry ice, denaturation of microbial cells with a mechanical support occurs. The crystallization process takes place and microorganisms of excess sludge undergo the so-called “thermal shock”. The aim of the study was to determine the effect of dry ice disintegration on the course of the methane fermentation process of the modified excess sludge. In the case of dry ice modification reagent in a granular form with a grain diameter of 0.6 mm was used. Dry ice was mixed with excess sludge in a volume ratio of 0.15/1, 0.25/1, 0.35/1, 0.45/1, 0.55/1, 0.65/1, 0.75/1, respectively. The methane fermentation process lasting for 8 and 28 days, respectively, was carried out in mesophilic conditions at 37°C. In the first series untreated sludge was used, and for the second and third series the following treatment parameters were applied: the dose of dry ice in a volume ratio to excess sludge equal 0.55/1, pretreatment time 12 hours. The increase of the excess sludge disintegration degree, as well as the increase of the digestion degree and biogas yield, was a confirmation of the supporting operation of the applied modification. The mixture of reactant and excess sludge in a volume ratio of 0.55/1 was considered the most favorable combination. In relation to not prepared sludge for the selected most favorable conditions of excess sludge modification, about 2.7 and 3-fold increase of TOC and SCOD values and a 2.8-fold increase in VFAs concentration were obtained respectively. In relation to the effects of the methane fermentation of non-prepared sludge, for modified sludge, about 33 percentage increase of the sludge digestion degree and about 31 percentage increase of the biogas yield was noticed.
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Abstract

Due to insufficient operation efficiency, the studied treatment plant has undergone modernization. The aim of this study was to assess whether this modernization improved quality of the STP effluent and water quality in the receiver. The research period of fifty months covered time before and after the modernization. Samples were collected in four sites – upstream and downstream of the STP and by the sewage discharge. Electrolytic conductivity, water temperature and pH were measured onsite. Chemical analyzes were based on ion chromatography and determined the concentration of NH4+, NO3-, NO2-, PO43-, TDS. Microbiological analysis comprised serial dilutions to assess the number of mesophilic and psychrophilic bacteria and membrane filtration to enumerate E. faecalis, total and fecal coliforms as well as total and fecal E. coli. Values of most analyzed parameters did not improve after the modernization, or improved for a very short period of time (NH4+), while some of them even increased, such as PO43-, total and thermotolerant coliforms and E. coli. The maximum value of thermotolerant E. coli reached nearly 7 million CFU/100 ml and was observed after modernization. Also at the sites situated downstream of the STP some of analyzed parameters increased. The conducted modernization did not improve the quality of treated sewage and even a further deterioration was observed. It could have been a result of rapidly growing number of tourists visiting the studied area, thus generating large amounts of sewage causing STP overload coupled with poor water and wastewater management. Significant percentage of unregistered tourists hinders proper assessment of the STP target efficiency.
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Abstract

Azo dye wastewater treatment is urgent necessary nowadays. Electrochemical technologies commonly enable more efficient degradation of recalcitrant organic contaminants than biological methods, but those rely greatly on the energy consumption. A novel process of biofilm coupled with electrolysis, i.e., bioelectrochemical system (BES), for methyl orange (MO) dye wastewater treatment was proposed and optimization of main influence factors was performed in this study. The results showed that BES had a positive effect on enhancement of color removal of MO wastewater and 81.9% of color removal efficiency was achieved at the optimum process parameters: applied voltage of 2.0 V, initial MO concentration of 20 mg/L, glucose loads of 0.5 g/L and pH of 8.0 when the hydraulic retention time (HRT) was maintained at 3 d, displaying an excellent color removal performance. Importantly, a wide range of effective pH, ranging from 6 to 9, was found, thus greatly favoring the practical application of BES described here. The absence of a peak at 463 nm showed that the azo bond of MO was almost completely cleaved after degradation in BES. From these results, the proposed method of biodegradation combined with electrochemical technique can be an effective technology for dye wastewater treatment and may hopefully be also applied for treatment of other recalcitrant compounds in water and wastewater.
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Abstract

Recent studies have shown that over half of the world’s population lives in urban areas, with the number of people living in slums growing by over 20 million per year and people living in urban areas lacking access to adequate sanitation. This study presents a review of the challenges facing fecal sludge management (FSM). A globally relevant issue in developing urban centers, especially in selected developing countries in West Africa was discussed. Some key findings of the review are that effective sanitation in developing areas depends on the chain of services and that one of the largest problems in sanitation is FSM. This study presents the initial steps toward understanding the main issues involving FSM in developing cities of West Africa. Results are intended to be used as a support for decisions on policies, strategies for FSM, and investments for improved treatment facilities in the region. The study suggests that governments and private sector organizations should develop adequate measures for handling fecal sludge.
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Abstract

The aim of the study was to determine the impact of selected factors on the reduction of organic pollutants, expressed in BOD5 and CODCr, in wastewater treated in a laboratory scale model of moving bed biofilm reactor (MBBR). The factors included in the experiment: the degree of filling the fluidized bed with biomass carriers, hydraulic load, and aeration intensity. The tested model of the bioreactor consisted of five independent chambers with diameter D = 0.14 m and height H = 2.0 m, which were filled with biomass carriers at 0%, 20%, 40%, 60%, 70% of their active volume. During the test period, hydraulic loads at the level of Qh1 = 0.073 m3·m-2·h-1 and Qh2 = 0.036 m3·m-2·h-1 were applied, which ensured one-day and two-day sewage retention, respectively.The said reactors were subjected to constant aeration at P1 = 3.0 dm3·min-1 and P2 = 5.0 dm3·min-1. The highest efficiency of the reduction of the analysed indicators was demonstrated by reactors filled with carriers in the degree of 40–60%. Based on the statistical analyses (the analyses of the ANOVA variations and the Kruskal-Wallis test) carried out, it was found that the studied factors significantly modified the mutual interaction in the process of reducing BOD5 in treated wastewater of the reactors tested. The significance of the impact of the discussed factors on the values of the studied indicators in treated wastewater depends on mutual interactions between the investigated factors.
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Abstract

The aim of this study was to determine the impact of the temperature of wastewater in a biological reactor with activated sludge and the BOD5/N-NH4 ratio in the influent to the treatment plant on nitrification efficiency and the concentration of ammonium nitrogen in treated wastewater. Tests were carried out in a household wastewater treatment plant which collects and treats sewage from a school building and a teacher’s house. During the 3-year study, large fluctuations in the sewage temperature in bioreactor were noted which was closely related to the ambient temperature. There were also large fluctuations in the concentration of organic matter and the concentration of ammonium nitrogen in inflowing sewage. The influence of wastewater temperature in the bioreactor and the BOD5/N-NH4 ratio on the concentration of ammonium nitrogen in treated wastewater was determined using Pearson’s linear correlation. A statistical analysis showed that a 1°C decrease in the temperature of wastewater in the bioreactor increased the concentration of ammonium nitrogen in treated wastewater by 2.64 mgN-NH4·L-1. Moreover, it was found that nitrification depended on the ratio of BOD5 to the concentration of ammonium nitrogen in wastewater flowing into the bioreactor. An increase in the BOD5/N-NH4 ratio by 1 value led to a 5.41 mgN-NH4·L-1 decrease in the concentration of ammonium nitrogen.
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Abstract

The sustainable development of human activities is directly related to the protection of the environment by lowering the anthropogenic stress. Pharmaceuticals – due to their growing consumption (use in medicine, veterinary, animal production, cosmetics) and their incomplete removal in wastewater treatment plants – are classified as a group of new and rapidly emerging pollutants which have been proven to have a negative impact onto water organisms. In order to ensure the proper protection of human health and the environment there is an urgent necessity of determining pharmaceuticals in clinical, cosmetic, food and environmental samples. Gas (GC) and high performance liquid chromatography (HPLC) are valuable techniques for such determination, especially when they are coupled with mass spectrometry (GC-MS; LC-MS) or tandem mass spectrometry (GC-MS/MS; LC-MS/MS). The purpose of this paper is to present an analysis of sustainability features of analytical techniques in the light of necessity to determine trace amounts of pharmaceuticals in the aforementioned different matrices. Using the Delphi method we performed an analysis of the key sources of the competitive advantages of the application of GC and GC-MS techniques for determining the pharmaceutical residue in clinical, cosmetic, food and environmental samples – compared to techniques based on HPLC or LC-MS. The analysis covered the following areas: (i) the features of the technique, (ii) the price, and (iii) the applicability in various sectors of economy.
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Abstract

The objective of this study was to determine the suitability of the nanofi ltration (NF) process to recover the regenerating agent (NaOH) from spent solutions contaminated with organic compounds. NaOH recovery from 2 spent regenerant solutions after cleaning ultrafiltration (UF) membranes (polymeric 30 kDa, ceramic 300 kDa) fouled with natural humic water was carried out using 2 types of NF membranes: NP010P (Na2SO4 rejection: 35–75%) and NP030P (Na2SO4 rejection: 80–95%). It has been shown that the use of the NP030P membrane allows for very high separation effi ciency of organic compounds (up to 97% of color intensity reduction) from the tested solutions. It was also observed that the effectiveness of the process, in addition to the type of membrane used, also depends on the time of NF process – along with the elapsed time of the process, the hydraulic and separation properties of the tested membranes deteriorated. The obtained results showed that the use of both tested NF membranes allows for the recovery of NaOH to a degree that allows its re-use.
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Abstract

The aim of this work was to determine the influence of various variants of bioleaching on effectivity of releasing chosen critical metals: rhodium, cadmium, indium, niobium and chromium from ashes which are a byproduct of municipal waste and sewage sludge thermal processing. The research was conducted in 3 variants that considered different process factors such as temperature (24ºC and 37ºC), mixing intensity and aeration. After 5 days of the process the analyses were made of metals content, sulfate concentration, pH, general number of bacteria number, index of sulfur oxidizing bacteria. The best results of bioleaching were achieved by running the process at the temperature of 24ºC with aeration. The efficiency of rhodium and cadmium release from the byproduct of municipal waste thermal processing was above 90%. The efficiency of indium and chromium release reached 50–60%. Only niobium leached better in mixing conditions. The byproduct of sewage sludge thermal processing was far less susceptible to bioleaching. The highest effectivity (on a level of 50%) was reached for indium in temperature of 24°C with aeration. The efficiency of bioleaching depended on waste’s physiochemical properties and type of metal which will be released. Aeration with compressed air had a positive influence on the increase of sulfur oxidizing bacteria what corresponded with almost double increase of sulfate concentration in leaching culture. Such conditions had a positive influence on the increase of the efficiency of bioleaching process. Heightening the temperature to 37°C and slowly mixing did not impact bioleaching in a positive way.
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Abstract

This study presents the rheological properties of sewage sludge after conditioning with the application of biomass ash. The impact of sewage sludge pre-treatment on its viscosity, flow curves and thixotropy was investigated. The increase of shear stress and the decrease of viscosity were observed with the increase of shear rate. Obtained results were compared with raw sewage sludge and the sludge after modification by means of polyelectrolyte in the dosage of 1.5 g (kg d.m.)-1. The findings proved that samples of raw and conditioned sewage sludge had thixotropic characteristics. The correlation between moisture content and capillary suction time reduction as well as selected rheological parameters were also determined. On the basis of the obtained results it was stated that the Ostwald de Vaele model best fits the experimental data.
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Abstract

Nine phyto-ashes from the biomass combustion of birch (Betula), oak (Quercus), red oak (Quercus rubra), horbeam (Carpinus), pine (Pinus sylvestris), poplar (Populus), maple (Acer), oilseed rape straw (Brassica napus) and wheat straw (Triticum aestivum) were blended with a biogas digestate at 1:1 mass ratio to give nine organic-mineral soil improvers. The concept of the research was to outline an eco-friendly and low cost soil improver for remediating degraded lands. These (i.e. phyto-ashes, improvers and the biogas digestate) were applied (0, 5, 10, 20, 40 t·ha-1) to a soil metallurgically contaminated with Cu, Zn, Pb and Cd. Of several tested parameters, pH changes revealed that organic-mineral soil improvers may efficiently replace (linear R2>0.90****, P<0.001) phyto-ashes in soil remedial goals. Buffering properties expressed by the cation exchange capacity (CEC) improved progressively: 29, 52, 71, 100% (phyto-ash treatments) and: 18, 37, 44, 73% (improvers treatments) for the rates 5, 10, 20, 40 t·ha-1, respectively as referred to the control CEC. The Dynamic Remediation Efficiency (DRE) indices for Cu, Zn, Pb, Cd revealed metal-specific geochemical reactions initiated by phyto-ashes, improvers and biogas digestate. The rates 5.0–10.0 t·ha-1 for phyto-ashes and about 20 t·ha-1 for improvers [1:1, i.e. Phyto-ash:Biogas digestate] are recommended. For biogas digestate, the rates 10–20 t·ha-1 were found more efficient.
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Abstract

The aim of the paper is to improve the phytoremediation features of the metallophyte Silene vulgaris through photo-stimulation of seeds using a semi-conductive laser. Seeds of two Silene vulgaris ecotypes were used in the experiment. One type of seeds – “Wiry” ecotype – originated from a site contaminated with heavy metals (a serpentinite waste heap), and the other ecotype – “Gajków” – was collected on a site with naturally low heavy metal content. The seeds of both types were preconditioned with laser light with previously fixed doses: C(D0), D1, D3, D5, D7, D9. The basic radiation dose was 2.5·10-1 J·cm-2. The soil for the experiment was serpentinite weathering waste. The seeds and plants were cultivated in the controlled conditions of a climatic chamber. Laser light indeed stimulated seed germinative capacity but better effects were obtained in “Wiry” ecotype, originating from a location contaminated with heavy metals. In the case of morphological features, a significant differentiation of stem length was found for different ecotypes, dosages and the interactions of these factors. The study showed a strong influence of laser radiation on selected element concentrations in above-ground parts of Silene vulgaris, though “Wiry” ecotype clearly accumulated more heavy metals and magnesium than the “Gajków” ecotype.
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Abstract

The potential of five plants namely Atriplex halimus L., A. canescens (Pursh) Nutt., Suaeda fruticosa (Forssk. ex J.F. Gmel.), Marrubium vulgare L. and Dittrichia viscosa (L.) Greuter from two selected wetlands in northwest Algeria subjected to house and industrial effluents were examined to assess their arbuscular mycorrhizal fungal (AMF) diversity and colonization, as well as to determine their tolerance and ability in accumulating metallic trace elements (MTEs). The purpose was to investigate whether, or not, these fungi are related to metallic uptake. Arbuscular mycorrhizal association was observed in all plant species, since the dual association between AMF and dark septate endophytes (DSE) was found in roots of 80% plants species. Hence, the decreasing trend of metal accumulation in most plant organs was Zn>Cu>Pb, and the most effi cient species were M. vulgare> S. fruticosa> A. canescens> D. viscosa> A. halimus. The bioaccumulator factors exceeded the critical value (1.0) and the transport factors indicated that all these species were phytoremediators. Pearson correlation showed that Cd bioaccumulation and translocation were inhibited by AMF infection; meanwhile Zn, Pb and Cd accumulation were affected by AMF spore density and species richness, DSE frequency, pH, AMF and plant host. Native halophytes showed a multi-metallic resistance capacity in polluted wetlands. M. vulgare was the most efficient in metal accumulation and the best host for mycorrhizal fungi. AMF played a major role in metal accumulation and translocation.
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Abstract

In this study, non-sintered ceramsite was prepared using coal gasification coarse slag obtained from a methanol plant. The basic performance and heavy metal leaching toxicity were analyzed. The results showed that seven out of nine non-sintered ceramsite groups were in accordance with the national standard of compressive strength (5 MPa), while only three groups met the national standard of water absorption index of less than 22%. The heavy metal concentrations in these three groups were found to be lower than that specified in National Class IV of surface water environment standards. The concentration of Cr was found to be 16.45 μg/L, which represents only 1% of the IV standard. The optimum mixing ratio, which showed high compressive strength (6.76 MPa) and low water absorption (20.12%), was found to be 73% coal gasification coarse slag, 15% cement, and 12% quartz sand. The characterization using Fourier transform infrared spectroscopy showed that the formation of gelatin in ceramsite enhances the performance of the ceramsite base and increases the immobilization of heavy metal. The study proved that the preparation of non-sintered ceramsite using coal gasification coarse slag reduces its environmental risk and achieves efficient utilization of the slag. Therefore, it can be concluded that it is a feasible and environmental friendly method for the disposal of coal slag.
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Abstract

The study focused on environmental evaluation of the disposed wooden railway sleeper gasification system used for electrical energy production. The aforementioned base technology was referred to the system producing electricity from disposed wooden railway sleepers through combustion. The evaluation was carried out using the LCA technique. The results show that in scope of impact on human health and ecosystems, the technology based on sleeper gasification is friendlier to the environment than the alternative technology. The technology of reference produces a lower environmental burden in scope of depletion of non-renewable natural resources. In comparison of the base technology (gasification) and the alternative technology (combustion), the end environmental effect shows that in scope of the analysis the base technology, i.e. the technology involving gasification of disposed railway sleepers, is more friendly to the environment.
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Abstract

The article presents results of an input-output data inventory and life cycle assessment (LCA) for individual wastewater treatment plants (IWWTPs), considering their whole life cycle, including the stage of construction, use and end-of-life. IWWTPs located in the area of a medium-sized town in Poland, were assessed from a systemic perspective. The research was conducted basing on actual data concerning performance of 304 individual wastewater treatment plants in Żory. Environmental assessment was conducted with ReCiPe and TRACI methods. Greenhouse gases (GHG) emission, eutrophication, fossil fuel and metal depletion were calculated. The LCA was conducted basing on ISO 14040 standard with SimaPro 8 software and Ecoinvent 3 database. The system boundary ranged from cradle to grave. It was shown that, at the construction stage, GHG emission depends on the amount of used cement, polyethylene, concrete, PVC and polypropylene. At the use stage, the GHG emission is determined by the sewage treatment technology and application of a bio-reactor in IWWTPs. At the construction stage, the fossil fuel depletion is determined by the amount of used polyethylene, PVC, cement, polypropylene and concrete; while the metal depletion is determined by the amount of used stainless steel, copper and cast iron. Data inventory and LCA of IWWTPs are presented for the first time. Conclusions of the work may support decisions taken by local governments concerning wastewater management in their area and promote and support solutions of high ecological standards.
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