Per- and polyfl uoroalkyl substances (PFASs) are human-invented chemicals that were created in the middle of the 20th century. They were synthesized for the fi rst time in 1949, and because of their exceptional surfactant properties, they have been widely used in many industrial applications and daily life products. The common use of PFASs resulted in their worldwide dissemination in natural environment. PFASs are reported to be ubiquitous in surface and drinking waters, but also may be present in soils, animals, milk and milk-products, plants, food. Contaminated drinking water and food are the most signifi cant exposure sources to these chemicals. Ingested PFASs are bio-accumulative and have adverse eff ect on health of humans as well as animal organisms. This paper reviews the most signifi cant information on the origin, properties, distribution, environmental fate, human exposure, health eff ects, and the environmental regulations on PFASs and summarizes the latest advances in the development of novel methods for the eff ective removal of these chemicals from the aqueous environment. Recognized (reverse osmosis, adsorption on activated carbon) and most promising developing removal methods such as adsorption on biomaterials (plant proteins, chitosan beds), mineral adsorbents (LDHs, hydrotalcite), ionexchange resins, and photocatalytic degradation have been emphasized.
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.
The aim of the work was to analyze the effi ciency and reliability of pollutants removal (total suspended solids – TSS, BOD5, COD) in a collective wastewater treatment plant with activated sludge and hydroponic lagoon during its long term operation. The tested object was designed to treat wastewater in flowing through the sewerage system and wastewater delivered by the septic truck. The projected capacity of the treatment plant was 1200 m3∙d-1. The technological system for wastewater treatment consisted of a mechanical part, a flowing biological reactor working according to the BARDENPHO process, a secondary settling tank and a hydroponic lagoon. The efficiency and reliability of pollutants removal in the analyzed treatment plant were assessed on the basis of the data concerning influent and effluent wastewater collected during the years 2011–2018. On the basis of the measurements results, there were determined characteristic values of the selected pollution indicators in wastewater and the average efficiency of pollutants removal. The technological reliability of the wastewater treatment plant was assessed for the basic pollution parameters (BOD5, COD, TSS) in accordance with the elements of the Weibull’s reliability theory, with regard to normative values of the indicators specified in the Regulation of the Minister of Environment. The analysis was carried out using the Statistica 13.1 software. It was proved that in the wastewater treatment plant with an activated sludge and hydroponic lagoon the level of organic pollutants removal expressed by BOD5 was on average 99.5%, COD – 98.1% and TSS – 99.4%. The technological reliability of the system was 100% in terms of the removal of pollutants from the basic group, which means that during the long term operation (8 years) it provided failure-free operation and guaranteed the fulfillment of the requirements that can be found in the Polish law regulations concerning the analyzed pollutants.
This paper discusses design, evaluation, and application for the use of swirl/vortex technologies as liquid purifi cation system. A study was performed using modifi ed swirl sedimentation tanks. The vortex separators containing baffle have been studied under laboratory conditions at hydraulic load from 21 to 64 [m3/(m2·h)]. Analyzed disperser phases were municipal water and glycerol solutions of varying concentration. The pressure drop and the efficiency of purification of liquid stream were analyzed. The suspended particles of different diameters were successfully removed from liquid with the application of swirl chambers of proposed constructions. It was found that damming of liquid in the tank increases alongside liquid stream at the inlet and depends on the tank construction. The efficiency of the sedimentation tanks increases alongside the diameters of solid particles and decrease in the liquid flow rate. The best construction proved to be the one where baffle is located in the middle of in- and outlet due to the highest efficiency of the purification liquid stream for solid particles of the smallest diameter. The proposed solution is an alternative to the constructions of heavy fraction separators.
An increasing number of municipal sewage treatment plants in Poland, desirable from an environmental perspective, raises the problem of managing the growing volume of sewage sludge. The thermal treatment of municipal sewage sludge (TTMSS) method, by greatly reducing the waste volume, increases the heavy metal concentration in fly ash (primary, end product of the treatment process), which may constitute a risk factor when attempting to utilize them economically. The research paper concentrates on determining the TTMSS fly ash heavy metal leaching level. For this purpose, ash samples were subjected to leaching with the batch and percolation tests, and the heavy metal content in eluates was determined by the FAAS method. The obtained results served as a base to determine the level of heavy metal immobilization in the ash, the element release mechanism (percolation test), and the impact of the L/S (liquid to solid) ratio and pH on the heavy metal leaching intensity (percolation test). The conducted research indicated high immobilization of heavy metals in TTMSS fly ash, regardless of the applied study method, which corresponds to the results of other researchers. Lead was the most intensively eluted metal.
Biogas plants processing municipal waste are very important investments from the point of view of waste management and also the sustainable development of urban infrastructures. They may also have a potentially negative impact on the environment in the form of odour emission. Olfactometry is the main method for odour impact assessment. Field olfactometry allows for performing a wide range of tests, the results of which are practically instantaneous. The purpose of this work is to provide a tool for assessing the odour impacts of municipal management facilities, including biogas plants processing municipal waste and evaluating the correctness of processes carried out in these plants, namely the method of field olfactometry. In order to compare obtained olfactometric results with the concentration of chemical compounds, chromatographic tests were also carried out using the Photovac Voyager portable chromatograph (hydrogen sulphide – H2S and dimethyl sulphide – (CH3)2S. The results of the odour concentration tests are in line with the results of odorant concentration tests and indicate that cod is strongly related to the concentration of hydrogen sulphide. Thanks to this method, it is possible to find a relationship between odour nuisance, technological processes used in the plant and the type of treated waste.
The aim of this study was the application of the geo-accumulation index and geostatistical methods to the assessment of forest soil contamination with heavy metals in the Babia Góra National Park (BGNP). For the study, 59 sample plots were selected to reflect all soil units (soil subtypes) in the studied area and take into account various forms of terrain. The content of organic carbon and total nitrogen, pH, hydrolytic acidity, the base cations and heavy metals content were determined in the soil samples. The geo-accumulation index (Igeo) was calculated, enabling estimation of the degree of soil pollution. The tested soils are characterized by strong contamination with heavy metals, especially with lead. The concentration of heavy metals in the surface horizons of the tested soils exceeds allowable concentration. The content of heavy metals was related to the content of soil organic matter, soil acidity and altitude. Higher altitudes are dominated by coniferous tree stands, which are accompanied by acidic, poorly decomposed organic horizons. Our study has confirmed the impact of pollutants transported from industrial areas on the amount of heavy metals in soils of the BGNP.
The pesticide persistence, in particular in soils, often significantly exceeding the declarations of their manufacturers is surprising. There are many publications devoted to the explanation of this phenomenon in the field literature, but the diverse research methodologies used may lead to the ambiguous conclusions. On the basis of the collected literature, the attempt was made to systematize the available information on the interactions of commonly used groups of pesticides with individual soil components. The complex mechanisms of interactions between pesticides and soil based on van der Waals forces, ionic and covalent bonding, ligand exchange and charge transfer complexes formation were demonstrated. It was also proved that the nature of interactions is strictly dependent on the structure of the pesticide molecule. The conclusion of the review may contribute to the choice of plant protection products that, in addition to their effectiveness, are as little ballast for the environment as possible.
The purpose of this study was to validate the applicability of specialized microbial consortium for the degradation of lipids in wastewater. An experimental model of the process is proposed that enables prediction of the required batch length. This model can be used for supervision of the process and to control cycles of the batch reactor. The study involved 4 reactors with microbial consortium obtained by inoculation from a commercially available biopreparate. Each reactor was fed a different load of lipid containing substrate. The biodiversity, settling characteristics and COD reductions were measured. The biodiversity of the microbial consortium changed within a range of ±15% depending on lipids concentration, as shown by the Shannon index and increasing amount of β-proteobacteria. Higher concentrations of lipids increased the biodiversity suggesting higher growth of microorganisms capable of utilizing lipids as energy and carbon source by producing lipid hydrolyzing enzymes. High lipid concentrations degrade the settling capabilities of the biomass. Higher lipid concentrations (0.5–2.0 [g/l]) increase the final COD (1445–2160 [mg O2/l]). The time necessary for substrate degradation changes with the initial concentration and can be predicted using the proposed model. The study showed that specialized microbial consortium is capable of reducing the lipids containing substrate and maintains its biodiversity suggesting that utilization of such consortia in multiple cycles of a batch reactor is possible. Future research should concentrate on assessing the biodiversity and effectiveness of substrate reduction after an increased number of batch reactor cycles.
Cytostatic drugs have become one of the greatest environmental hazards. They exhibit toxic, carcinogenic, mutagenic and teratogenic effects on flora and fauna, including people. They are poorly eliminated in conventional wastewater treatment plants and their mixtures could possess higher ecotoxicity than individual drugs. Fungi are organisms with enormous potential for biodegradation of a variety of toxic chemical pollutants. The aim of this work was to estimate tolerance of five fungal strains to selected anticancer drugs, which will be useful to determine the potential for their possible use in cytostatics removal and may be significant in the context of wastewater treatment application. Test was conducted on Fomes fomentarius (CB13), Hypholoma fasciculare (CB15), Phyllotopsis nidulans (CB14), Pleurotus ostreatus (BWPH) and Trametes versicolor (CB8) and the chosen drugs were bleomycin and vincristine. Their ability to grow in the presence of selected cytostatics was evaluated in cultures conducted on two solid media which differed in the richness of nutrient compounds. Fungal strains tolerance was expressed as a half maximal effective concentration. Results showed that fungi display better tolerance to high cytostatics’ concentrations in the medium rich in carbon source. Regardless of the medium used, the differences in growth ability were lower for bleomycin (the tolerance was higher). The greatest tolerance for bleomycin was shown by Pleurotus ostreatus. Results suggest that more efficient elimination of bleomycin would be possible to obtain, strain BWPH seems to be the best fungal candidate for this drug degradation assay and, probably, in wastewater treatment application tests in a longer perspective.
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