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Since natural bioremediation is a lengthy process, new bioremediation techniques should be developed to accelerate and optimize the removal of soil contaminants such as polycyclic aromatic hydrocarbons (PAHs). One of the substances that can be used to enhance PAH removal is calcium peroxide, applied as an oxidizing agent to improve soil aeration. Here, we investigated the bioremediation of soil contaminated with fluoranthene. Two doses of calcium preparation (CP), 0.29 and 0.58 g/kg, composed of calcium peroxide and calcium hydroxide, and increasing the soil pH by one and two units, respectively, were used. Fluoranthene decline was 83% and 95% for CP-aided soils, and 80% for soil without calcium preparation. During the remediation process, dynamic changes in the sorption complex of soils were found, mainly due to changes in the sum of base exchangeable cations. These changes in the first experiment period were significantly influenced by the presence of calcium preparation while in the second period by the presence of fluoranthene. The presence of calcium preparation caused changes in the microbiocenosis, especially at the higher dose. There was no effect of calcium preparation on plant growth. [ABSTRACT FROM AUTHOR]

The aim of the study was to detect and quantify selected antibacterial drugs in the raw and treated wastewater collected under various temperature conditions (i.e. winter and summer period) from two urban wastewater treatment plants (WWTPs), located in the northern and southern part of Poland. An additional goal of the study was to estimate the effectiveness of the removal of these antibacterial drugs in the above-mentioned conditions. For the study were selected: clarithromycin (CLA), erythromycin (ERY), roxithromycin (ROX), sulfamethoxazole (SMX), N-acetyl-sulfamethoxazole (N-Ac-SMX), sulfamethoxine (SMN), sulfamerazine (SMR), tiamulin (TIA), and trimethoprim (TRP). The study showed that CLA, ERY, ROX, SMX, TRP, and N-Ac-SMX (main SMX metabolite) were detected in all wastewater samples, regardless of the place of collection and the season of the sampling, while SMN, SMR, and TIA were not detected in the investigated wastewater. The studies have shown that N-Ac-SMX was the most efficiently removed compound at both treatment plants, regardless of the process temperature (over 95%), however, this substance may reversibly transform into the origin form of SMX under the conditions prevailing at WWTPs, which means that the removal can be only apparent. In the study, the temperature was an important parameter affecting the removal efficiency of CLA, ROX, and TRP. The removal efficiency of these substances always has been higher in summer than in the winter period. The process was also slightly more effective at WWTP 2. At WWTP 2, the average removal for CLA, ROX, and TRP in the summer period was equal to 76%, 47%, and 38%, respectively. Erythromycin, was a substance that was not degraded in any of the investigated technological systems and no effect of temperature on the removal efficiency was observed. [ABSTRACT FROM AUTHOR]

Background: The study aimed to evaluate the influence of the duration times of anaerobic phases on the bacterial biocenosis characterisation while denitrifying dephosphatation in the Integrated Fixed-Film Activated Sludge – Moving-Bed Sequencing Batch Biofilm Reactor (IFAS-MBSBBR). The experiment was conducted in a laboratory model. The study consisted of four series, which differed in terms of the ratio of the anaerobic phases. duration concerning the overall reaction time in the cycle. The anaerobic phases covered from 18 to 30% of the whole cycle duration. During the reactor performance that took 9 months, the influent and effluent were monitored by analysis of COD, TKN, NH4-N, NO2-N, NO3-N, TP, PO4-P, pH, alkalinity and the phosphorus uptake batch tests. Characterisation of the activated sludge and the biofilm biocenosis was based on fluorescent in situ hybridisation (identification of PAO and GAO) and the denaturing gradient gel electrophoresis patterns. Results: The organic compounds removal was high (more than 95.7%) independently of cycle configuration. The best efficiency for nitrogen (91.1%) and phosphorus (98.8%) removal was achieved for the 30% share of the anaerobic phases in the reaction time. Denitrifying PAO (DPAO) covered more than 90% of PAO in the biofilm and usually around 70% of PAO in the activated sludge. A substantial part of the polyphosphate accumulating organisms (PAO) community were Actinobacteria. The denitrifying dephosphatation activity was performed mainly by Accumulibacter phosphatis. Conclusions: High nutrient removal efficiencies may be obtained in IFAS-MBSBBR using the denitrifying dephosphatation process. It was found that the length of anaerobic phases influenced denitrification and the biological phosphorus removal. The extension of the anaerobic phases duration time in the reaction time caused an increase in the percentage share of denitrifying PAO (DPAO) in PAO. The biocenosis of the biofilm and the activated sludge reveal different species patterns and domination of the EBPR community. [ABSTRACT FROM AUTHOR]

The article aims to show the increased interest in the applications of vacuum in the area of environmental biotechnology and the lack of research related to the effects of vacuum on bacteria and microbial communities. Information on the impact of vacuum on bacteria is limited and often comes from unrelated research fields. In most cases (astrobiology research, food preservation technologies), the exposure of microorganisms in vacuum is permanent for the whole life of a cell. In environmental science applications, the exposure of microorganisms containing media such as sludge or soil in vacuum is rather persistent, and lower values of vacuum are used. Vacuum is used or proposed to be used in wastewater treatment, anaerobic digestion, sludge treatment, soil remediation and mining. Usually, vacuum is used to remove gases from the test medium, so a purely physical process is applied. However, most reports show the influence of vacuum on biological processes and its efficiency, as well as on the community structure. [ABSTRACT FROM AUTHOR]

Filamentous bacteria in addition to wastewater treatment are responsible for the shape of flocs and sedimentation properties of activated sludge. Their dynamics in activated sludge influences the performance of the whole sewage treatment plant. Therefore the composition of activated sludge biocenosis and its dynamics in the nitrification process were investigated. Four laboratory-scale activated sludge membrane bioreactors fed with wastewater highly concentrated with ammonium (synthetic wastewater imitating landfill leachate) were operated to obtain a high rate of nitrification. The sludge age was 8, 12, 24 and 32 days. An additional fifth reactor was conventionally ammonium loaded at 12-day sludge age and served as the reference. A shift in filamentous bacteria population was observed in all operated reactors. There was no influence of sludge age on composition or abundance of filamentous biocenosis. In high ammonium loaded activated sludge Nostocoida limicola, Haliscomenobacter hydrossis and also Type 021N were the most abundant filamentous bacteria. In the reference reactor Type 021N and Sphaerotilus natans dominated the activated sludge. [ABSTRACT FROM AUTHOR]

Copyright of Archives of Environmental Protection is the property of Polish Academy of Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The paper deals with the problem of the determination of the effects of temperature on the efficiency of the nitrification process of industrial wastewater, as well as its toxicity to the test organisms. The study on nitrification efficiency was performed using wastewater from one of Polish chemical factories. The chemical factory produces nitrogen fertilizers and various chemicals. The investigated wastewater was taken from the influent to the industrial mechanical-biological wastewater treatment plant (WWTP). The WWTP guaranteed high removal efficiency of organic compounds defined as chemical oxygen demand (COD) but periodical failure of nitrification performance was noted in last years of the WWTP operation. The research aim was to establish the cause of recurring failures of nitrification process in the above mentioned WWTP. The tested wastewater was not acutely toxic to activated sludge microorganisms. However, the wastewater was genotoxic to activated sludge microorganisms and the genotoxicity was greater in winter than in spring time. Analysis of almost 3 years' period of the WWTP operation data and laboratory batch tests showed that activated sludge from the WWTP under study is very sensitive to temperature changes and the nitrification efficiency collapses rapidly under 16°C. Additionally, it was calculated that in order to provide the stable nitrification, in winter period the sludge age (SRT) in the WWTP should be higher than 35 days. [ABSTRACT FROM AUTHOR]

Copyright of Archives of Environmental Protection is the property of Polish Academy of Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Archives of Environmental Protection is the property of Polish Academy of Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, the susceptibility to erythromycin (E) and to trimethoprim/sulfamethoxazole (SXT) among isolates of Enterococcus spp. and Escherichia coli was tested, respectively. Both fecal indicators were detected and isolated from raw(RW) and treated wastewater (TW) as well as from samples of activated sludge (AS) collected in a local wastewater treatment plant (WWTP). Biodiversity of bacterial community in AS was also monitored using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). Additionally, distribution of sul1-3 genes conferring sulfonamide resistance was tested among SXT-resistant E. coli. Simultaneously, basic physicochemical parameters and concentrations of eight antimicrobial compounds (belonging to folate pathway inhibitors and macrolides class) were analyzed in RW and TW samples. Six of the selected antimicrobial agents, namely: erythromycin, clarithromycin, trimethoprim, roxithromycin, sulfamethoxazole, and N-acetylsulfamethoxazole were detected in the wastewater samples. Bacterial biodiversity of AS samples were comparable with no relevant differences. Among tested Enterococcus spp., E-resistant isolates constituted 41%. SXT resistance was less prevalent in E. coli with 11% of isolates. The genes conferring resistance to sulfonamides (sul1-3) were detected in SXT-resistant E. coli of wastewater origin with similar frequencies as in other environmental compartments, including clinical ones. [ABSTRACT FROM AUTHOR]

The occurrence of clarithromycin in wastewater samples and of the activated sludge bacteria possibly resistant to this pharmaceutical was the object of the study. Samples of wastewater or activated sludge were taken from a municipal wastewater treatment plant in summer and winter and characterised regarding their clarithromycin concentrations and the presence of nucleic acid fragments (Cla-sequences) known to be responsible for clarithromycin resistance in Helicobacter pylori. The concentrations of clarithromycin in raw wastewater were about 1086–2271 ng/L. Around 50–60% less of the pharmaceutical was found in treated wastewater. The concentrations were much higher in winter samples, as compared to summer samples. The clarithromycin resistance markers in H. pylori were detected by fluorescence in situ hybridisation in activated sludge bacterial cells. Cla-sequences were found in all the detected Proteobacteria, independently of the sampling season. Among nitrifying or phosphate or glycogen accumulating bacteria only Nitrosomonas spp. revealed presence of the clarithromycin sequences. [ABSTRACT FROM AUTHOR]