Production of sanitary safe water of high quality with membrane technology is an alternative for conventional disinfection methods, as UF and MF membranes are found to be an effective barrier for pathogenic protozoa cysts, bacteria, and partially, viruses. The application of membranes in water treatment enables the reduction of chlorine consumption during final disinfection, what is especially recommended for long water distribution systems, in which microbiological quality of water needs to be effectively maintained. Membrane filtration, especially ultrafiltration and microfiltration, can be applied to enhance and improve disinfection of water and biologically treated wastewater, as ultrafiltration act as a barrier for viruses, bacteria and protozoa, but microfiltration does not remove viruses. As an example of direct application of UF/MF to wastewater treatment, including disinfection, membrane bioreactors can be mentioned. Additionally, membrane techniques are used in removal of disinfection byproducts from water. For this purpose, high pressure driven membrane processes, i.e. reverse osmosis and nanofiltration are mainly applied, however, in the case of inorganic DBPs, electrodialysis or Donnan dialysis can also be considered.
The aim of this study was to examine the changes in the chemical composition of shallow groundwater and its quality that have occurred in the last decade in an agriculturally used, heavily populated and characterized by a complex geological structure, catchment of the Stara Rzeka river, located in the flysch part of the Outer Carpathians. Water samples were collected during 2013 from 19 still operating wells. Analyses of pH, electrolytic conductivity and chemical composition by ion chromatography were conducted. The obtained results were compared with the results of studies conducted in 2003 for the same wells. The quality of groundwater and its suitability for consumption was assessed based on the regulations currently existing in Poland. 21% of the wells still do not meet the requirements for drinking water in terms of at least one component. However, there was a decrease in the concentration of mineral forms of nitrogen and phosphorus in most of the wells and their mean concentration as compared to 2003 was reduced. In terms of physical and chemical characteristics groundwater of this region is typical of the hypergenic zone of the temperate climate. The highest concentrations were observed for Ca2+ and HCO3- ions, while K+ and Cl- were characterized by the largest variability. Principal Component Analysis (PCA) demonstrated that the factors determining the quality and chemical composition of the analyzed waters include the composition of bedrock (mineralogy of the rock environment) and human economic activity, and that they have not been significantly changed over the past decade.
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.
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.
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.
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.
Biogas production has a big potential to provide clean energy. To evaluate the future production and maturity of biogas technology the generalized Weng model was proved to be effective, due to it has the minimum error. The simple algorithms to determine its parameters have been proposed. The simulation results for China, USA, and EU have been presented. The quantity and quality analysis for biogas feedstock has been carried out. Energy Return on Energy Invested (EROEI) indicator for different biofuels was considered. According to analysis done biogas from maize residue and chicken manure has high EROEI. Shannon Index was suggested to evaluate the diversity of feedstock supply. Biomass energy cost indicator was grounded to be used for feedstock energy and cost assessment. Biogas utilization pathways have been shown. Biogas boilers and CHP have the highest thermal efficiency, but biogas (biomethane) has the highest potential to earn as a petrol substitute. Utilization of biogas upgrading by-product (carbon dioxide) enhances profitability of biogas projects. Methods to assess the optimal pathways have been described.
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.
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.
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.
The focus of this study is to investigate the applicability of natural mineral iron disulfide (pyrite) in degradation of aromatic compounds including benzene and several chlorinated benzenes (from mono-chlorinated benzene (CB), di-chlorinated benzenes (di-CBs) to tri-chlorobenzenes (tri-CBs) in aerobic pyrite suspension by using laboratory batch experiments at 25°C and room pressure. At first, chlorobenzene was studied as a model compound for all considered aromatic compounds. CB was degraded in aerobic pyrite suspension, transformed to several organic acids and finally to CO2 and Cl-. Transformations of remaining aromatic compounds were pursued by measuring their degradation rates and CO2 and Cl- released with time. Transformation kinetics was fitted to the pseudo-first-order reactions to calculate degradation rate constant of each compound. Degradation rates of the aromatic compounds were different depending on their chemical structures, specifically the number and position of chlorine substituents on the benzene ring in this study. Compounds with the highest number of chlorine substituent at m-positions have highest degradation rate (1,3,5-triCB > 1,3-diCB > others). Three chlorine substituents closed together (1,2,3-triCB) generated steric hindrance effects. Therefore 1,2,3-triCB wasthe least degraded compound. The degradation rates of all compounds were in the following order: 1,3,5-triCB > 1,3-diCB > 1,2,4-triCB ≅ 1,2-diCB ≅ CB ≅ benzene > 1,4-diCB > 1,2,3-triCB. The final products of the transformations were CO2 and Cl-. Oxygen was the common oxidant for pyrite and aromatic compounds. The presence of aromatic compounds reduced the oxidation rate of pyrite, which reduced the amount of ferrous and sulfate ions release to aqueous solution.
Geopolymers are a new class of materials that can be synthesized using natural minerals, and waste materials. Among these substrates, the use of fly ash is desirable as it involves the conversion of a copious waste material into a useful product. The aim of the research was geopolymers synthesis from coal fly ash and biomass ash. Concentrated sodium hydroxide and sodium silicate solutions were used as activators in geopolymerisation reaction. The results show that both coal fly ash and biomass ash can be utilized as source materials for the production of geopolymers. The surface morphology and chemical composition analysis were examined for the obtained geopolymers and ashes from coal and biomass combustion by SEM-EDS methods. It was found almost total disappearance of spherical forms of grains and reduction the porosity of structure for geopolymer based on fly ash from coal combustion. While the structure of the geopolymer based ash from biomass combustion is more porous. The UV-VIS-NIR spectra were performed on the coal fly ash, biomass ash and geopolymers. They showed that the obtained geopolymers possess optical and photocatalytic properties. The similarity of the geopolymer network and the zeolite framework in relation to ion exchange and accommodation of metal ions open questions on possibilities for the application of geopolymer materials as amorphous analogues of zeolite. The FT-IR spectra analyses were used on the geopolymers before and after metals sorption. It was found that geopolymer based on ash from biomass combustion has better sorption properties compared to geopolymer based on ash from coal combustion.