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This study focuses on the possible use and efficacy of the co-treatment of landfill leachate (intermediate-age) with municipal wastewater. The nitrification, denitrification, and dephosphatation capability of activated sludge acclimated with a mixture of raw municipal wastewater (RWW) with gradually increasing amounts of raw landfill leachate (RLL) (from 0.5 to 5% v/v) were tested. Biochemical tests were conducted simultaneously in batch reactors (BRs). According to the obtained data, the ammonia utilization rate (AUR) was 3.68 g N/(kg volatile suspended solids (VSS)·h) for RWW, and it increased to 5.78 g N/(kg VSS·h) with the addition of 5% RLL. The nitrate utilization rate under anoxic conditions (NURAX) remained at a comparable level of 1.55--1.98 g N/(kg VSS·h). During the anoxic phase, both nitrate utilization and phosphorus uptake occurred, suggesting that denitrifying phosphorus-accumulating organisms (DPAOs) utilized N--NO3. With the addition of RLL, the rates of anoxic and aerobic phosphate uptake (PURAX and PURAE) and phosphate release rate (PRR) decreased. The PRR was likely negatively influenced by high N--NO3 concentrations but not completely inhibited due to the availability of a biodegradable fraction of chemical oxygen demand (COD). Thus, monitoring the NH4--N load in wastewater treatment plant influent before co-treatment is more informative than that using hydraulic-based criteria. [ABSTRACT FROM AUTHOR]

In the sub-Saharan region of Africa, access to safe drinking water remains limited in many countries. This study provides an overview of the quality of surface water and groundwater in rural and peri-urban areas of Madagascar, Uganda, and Rwanda. Selected physico-chemical parameters, inorganic species (including inorganic ions), and organic pollution indicators, such as total organic carbon, non-ionic surfactants, cationic surfactants, anionic surfactants, sum of phenolic compounds and formaldehyde, were analysed. Principal component analysis was applied to assess the variability of the water quality and identify regional dependencies. The inorganic ion composition in the majority of the studied samples meets WHO and EU requirements for drinking water intended for human consumption and poses no human health risk. However, an individual non-cancer-causing health index for nitrates and the values of Water Quality Index show a possible threat of ingesting the studied drinking water. The presence of surfactants (0.1-0.65 mgL -1 ), phenolic compounds (0.025-1.76 mgL -1 ) and formaldehyde (0.04-0.32 mgL -1 ) may also pose a risk to human, animal, and aquatic life. Additionally, in-situ measurements for E. coli and Total Coliforms conducted during the last field campaign in Madagascar (2022) revealed that all studied drinking water sources ranged from intermediate risk to unsafe. This result calls for the urgent need to enhance WASH (water, sanitation, and hygiene) services in the studied areas. The presence of both chemical and microbiological pollutants shows the need for the local authorities to develop and implement a catchment management plan to ensure the protection of water resources from potential pollution, and raise community awareness about the impact of human activity on water resources., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Malgorzata Szopinska reports financial support was provided by The Civil Engineering Development Foundation. Malgorzata Szopinska reports equipment, drugs, or supplies was provided by Xylem Water Solutions Poland. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Electrochemical oxidation (EO), due to high efficiency and small carbon footprint, is regarded as an attractive option for on-site treatment of highly contaminated wastewater. This work shows the effectiveness of EO using three boron-doped diamond electrodes (BDDs) in sustainable management of landfill leachate (LL). The effect of the applied current density (25-100 mA cm -2 ) and boron doping concentration (B/C ratio: 500 ppm, 10,000 ppm and 15,000 ppm) on the performance of EO was investigated. It was found that, of the electrodes used, the one most effective at COD, BOD 20 and ammonia removal (97.1%, 98.8% and 62%, respectively) was the electrode with the lowest boron doping. Then, to better elucidate the ecological role of LLs, before and after EO, cultivation of faecal bacteria and microscopic analysis of total (prokaryotic) cell number, together with ecotoxicity assay (Daphnia magna, Thamnocephalus platyurus and Artemia salina) were combined for the two better-performing electrodes. The EO process was very effective at bacterial cell inactivation using each of the two anodes, even within 2 h of contact time. In a complex matrix of LLs, this is probably a combined effect of electrogenerated oxidants (hydroxyl radicals, active chlorine and sulphate radicals), which may penetrate into the bacterial cells and/or react with cellular components. The toxicity of EO-treated LLs proved to be lower than that of raw ones. Since toxicity drops with increased boron doping, it is believed that appropriate electrolysis parameters can diminish the toxicity effect without compromising the nutrient-removal and disinfection capability, although salinity of LLs and related multistep-oxidation pathways needs to be further elucidated., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Apart from chemical constituents, wastewater treatment plant (WWTP) effluents also release microorganisms that can be important to the receiving water bodies either from a sanitary point of view, or taking to the account the biogeochemical potential of the recipients. However, little is known about the treated wastewater microbial community, its composition, seasonal changes, functions and fate in the waters of the receiver. Thus, this study presents a synergistic approach coupling new and traditional methods: analytical chemistry, classical microbiology (cultivation- and microscopy-based methods), as well as Next Generation Sequencing and a quantitative real-time polymerase chain reaction (qPCR). The results show that in terms of bacterial community composition, treated wastewater differed from the environmental samples, irrespectively if they were related or unrelated to the WWTP effluent discharge. The canonical correspondence analysis (CCA) taking into account chemical parameters and taxonomical biodiversity indirectly confirmed the seasonal deterioration of the treated wastewater quality as a result of temperature-driven change of activated sludge community structure and biomass washout (observed also by DAPI staining). Despite seasonal fluctuations of total suspended solids and inter-related parameters (such as COD, BOD, TN, TP), the treated wastewater quality remained within current discharge limits. It was due to treatment processes intensively adjusted by WWTP operators, particularly those necessary to maintain an appropriate rate of autotrophic processes of nitrification and to support biological phosphorus removal. This can explain the observed microbiome composition similarity among WWTP effluents at high taxonomic levels. Obtained data also suggest that besides wastewater treatment efficiency, WWTP effluents are still sources of both human-related microorganisms as well as bacteria equipped in genes involved in N-cycling. Their potential of participation in nutrients cycling in the receivers is widely unknown and require critical attention and better understanding., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

In Antarctica, waste is generated mainly during scientific research programmes and related logistics. In this study, the impact of wastewater on the western shore of Admiralty Bay was investigated during austral summer in 2017 and 2019. A range of physicochemical parameters and the presence of selected trace metals, formaldehyde and different groups of surfactants were determined in wastewater coming from Arctowski Station and in nearby coastal waters. The presence of selected trace metals (e.g., Cr: 2.7-4.4 μg/L; Zn: 15.2-37.3 μg/L; and Ni: 0.9-23.3 μg/L) and the sums of cationic (0.3-1.5 mg/L), anionic (3.1-1.7 mg/L), and non-ionic (0.6-2.4 mg/L) surfactants in wastewater indicated the potential influence of anthropogenic factors on sea water. The determined surfactants are found in many hygiene products that end up in the waste water tank after human use and, if untreated, can be released into surface waters with discharge. In addition, the levels of some trace metals indicate that they cannot come only from natural sources, but are the result of human activity. The reported data show disturbances in the marine environment caused by non-treated wastewater discharge, e.g. by comparing the obtained results from the values of the no observed effect concentrations (NOECs) on selected Antarctic bioindicators, and provide information for the implementation of proper wastewater treatment at any Antarctic station in the future., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Electrochemical oxidation (EO) of organic compounds and ammonium in the complex matrix of landfill leachates (LLs) was investigated using three different boron-doped diamond electrodes produced on silicon substrate (BDD/Si)(levels of boron doping [B]/[C] = 500, 10,000, and 15,000 ppm-0.5 k; 10 k, and 15 k, respectively) during 8-h tests. The LLs were collected from an old landfill in the Pomerania region (Northern Poland) and were characterized by a high concentration of N-NH 4 + (2069 ± 103 mg·L -1 ), chemical oxygen demand (COD) (3608 ± 123 mg·L -1 ), high salinity (2690 ± 70 mg Cl - ·L -1 , 1353 ± 70 mg SO 4 2- ·L -1 ), and poor biodegradability. The experiments revealed that electrochemical oxidation of LLs using BDD 0.5 k and current density (j) = 100 mA·cm -2 was the most effective amongst those tested (C 8h /C 0 : COD = 0.09 ± 0.14 mg·L -1 , N-NH 4 + = 0.39 ± 0.05 mg·L -1 ). COD removal fits the model of pseudo-first-order reactions and N-NH 4 + removal in most cases follows second-order kinetics. The double increase in biodegradability index-to 0.22 ± 0.05 (BDD 0.5 k, j = 50 mA·cm -2 ) shows the potential application of EO prior biological treatment. Despite EO still being an energy consuming process, optimum conditions (COD removal > 70%) might be achieved after 4 h of treatment with an energy consumption of 200 kW·m -3 (BDD 0.5 k, j = 100 mA·cm -2 ).

The sustainable management of small human communities in the Arctic is challenging. In this study, both a water supply system (Lake 1) under the natural impact of a bird-nesting area, and a wastewater receiver (Lake 2) were analysed in the vicinity of the Polish Polar Station on West Spitsbergen. Microbial community composition, abundance and activity were assessed in samples of the treated wastewater, lake water and sediments using next-generation sequencing and direct microscope counts. Special attention was given to the faecal indicator, Enterococcus spp., whose occurrence and antimicrobial resistance were tested in water and wastewater samples. The results indicate that Lake 1, at a tundra stream discharge (L-TS) and a water supply point (L-WS) were dominated by three phyla: Proteobacteria (57-58%) Bacteroidetes (27-29%) and Actinobacteria (9-10%), showing similar microbial composition up to the genus level. This suggests that nutrient-rich runoff from the bird colony was retained by surrounding tundra vegetation and reached Lake 1 at L-TS to a limited extent. Lake 2, being the wastewater recipient (WW-R), mirrors to some extent the core phyla of treated wastewater (WW-E), but in different shares. This suggests the possible washout of wastewater-related bacteria with activated sludge flocs, which was also supported by the microscopic observations. Compared to Lake 1, in WW-R an increase in all tested parameters was noted: total prokaryotic cell number, average cell volume, prokaryotic biomass and live cell percentage. The presence of Enterococcus spp. antibiotic resistance patterns highlight the importance of human associated microbiome and resistome dissemination via wastewater discharge. Moreover, it can be expected that temperature-related biochemical processes (e.g. nutrient cycling) may be accelerated by the ongoing climate change. Thus, proper wastewater treatment requires locally adapted solutions in increasingly visited and inhabited polar regions. Additionally, microbial community discharged to the environment with the treated wastewater, requires critical attention., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

In this study, wastewater from municipal services, such as a port wastewater reception facility (PRF-WW) and a municipal solid waste plant (MSWP), was tested for the presence of the suspected endocrine-disrupting compounds phthalates (PAEs) and bisphenol A (BPA). PAEs and BPA were found in this study in high concentrations in raw wastewater obtained from passenger ships (RMT-WWs) (up to 738 μg/L and 957 μg/L, respectively) collected in the Port of Gdynia and in landfill leachates (LLs) (up to 536 μg/L and up to 2202 μg/L, respectively) from a MSWP located near Gdynia. In particular, the presence of reprotoxic di(2-ethylhexyl) phthalate (DEHP, up to 536 μg/L in LLs and up to 738 μg/L in RMT-WWs) requires further action because if this compound, as well as other PAEs and BPA, is not degraded by activated sludge microorganisms, it may reach receiving waters and adversely impact aquatic organisms. Therefore, PAEs and BPA should be removed either during the onsite pretreatment of tested industrial wastewater or during tertiary treatment at municipal wastewater treatment plants (WWTPs, representing end-of-pipe technology). Graphical abstract.

A study was conducted to characterize the raw wastewater entering a modern cost effective municipal WWTP in Poland using two approaches; 1) a combination of modeling and carbonaceous oxygen demand (COD) fractionation using respirometric test coupled with model estimation (RT-ME) and 2) flocculation/filtration COD fractionation method combined with BOD measurements (FF-BOD). It was observed that the particulate fractions of COD obtained using FF-BOD method was higher than those estimated by RT-ME approach. Contrary to the above, the values of inert soluble fraction evaluated by FF-BOD method was significantly lower than RT-ME approach (2.4% and 3.9% respectively). Furthermore, the values for low colloidal and particulate fractions as well as soluble inert fractions were different than expected from a typical municipal wastewater. These observations suggest that even at low load (10% of the total wastewater treatment inflow), the industrial wastewater composition can significantly affect the characteristics of municipal wastewater which could also affect the performance and accuracy of respirometric tests. Therefore, in such cases, comparison of the respirometric tests with flocculation/filtration COD/BOD measurements are recommended. Oxygen uptake rate profile with settled wastewater and/or after coagulation-flocculation, however, could still be recommended as a "rapid" control method for monitoring/optimising modern cost-effective wastewater treatment plants.

In this study, a pilot-scale membrane bioreactor (MBR) was operated at a municipal solid waste plant (MSWP) to treat a mixture of landfill leachates (LLs) obtained from modern (MP-LLs) and previous (PP-LLs) waste cells. The MBR unit combined anoxic and aerobic zones with external ultra- and nanofiltration (MBR/UF and MBR/UF/NF, respectively). In addition to the removal of macropollutants, special attention was given to phthalates (PAEs) and bisphenol A (BPA). According to the obtained results, the MBR/UF system with acclimated biomass was effective for treating LLs, and the obtained effluent was generally similar in quality to raw municipal wastewater. The MBR biomass showed high potential for BPA and PAEs biodegradation/biotransformation as confirmed by a metagenomic approach. Only a high chloride concentration (1960 mg Cl - /L), which was twice the value acceptable by Polish regulations for industrial wastewater entering the municipal wastewater system, justifies the additional usage of the NF unit. Notably, a decreasing amount of biodegradable organic matter in MBR influent is expected with time because of changes in the biochemistry of modern waste cells; therefore, an external carbon source would probably be needed to support denitrification. However, the cooccurrence of an aerobic and anaerobic ammonia-oxidizing community with denitrifying bacteria provides the opportunity for advanced removal of nitrogen and organic carbon., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Samples of liquid by-products generated by municipal solid waste plants (MSWPs) were tested for the presence of phthalates (PAEs) and bisphenol A (BPA). The results indicated that the wastewater generated during mechanical (sorting unit - SU) and biological (composting unit - CU) pre-treatment (MBT) of residual (mixed) solid waste is a significant source of these compounds. The concentrations of PAEs (up to 32222μg/L) and BPA (up to 1795μg/L) in the SU and CU wastewaters were generally higher than those in landfill leachates tested in this and other studies. To date, MBT wastewaters have been poorly studied and are usually overlooked. However, in this study, despite their relatively small quantities, they constituted an important load of ammonia (up to 1610mg/L) and organic matter (COD up to 52980mg/L). Thus, to apply an effective treatment, it is critical to monitor the current quality and quantity of all liquid by-products generated at MSWPs and to prioritize the (micro)pollutants of concern., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

To benefit the environment and society, EU legislation has introduced a 'zero waste' strategy, in which waste material should be converted to resources. Such legislation is supported by the solid waste hierarchy concept, which is a set of priorities in waste management. Under this concept, municipal solid waste plants (MSWPs) should be equipped with sorting and recycling facilities, composting/incineration units and landfill prisms for residual bulk disposal. However, each of the aforementioned facilities generates by-products that must be treated. This project focuses on the leachates from landfill prisms, including modern prism (MP) that meet EU requirements and previous prism (PP) that provide for the storage of permitted biodegradable waste as well as technological wastewaters from sorting unit (SU) and composting unit (CU), which are usually overlooked. The physico-chemical parameters of the liquid by-products collected over 38 months were supported by quantitative real-time PCR (qPCR) amplifications of functional genes transcripts and a metagenomic approach that describes the archaeal and bacterial community in the MP. The obtained data show that SU and especially CU generate wastewater that is rich in nutrients, organic matter and heavy metals. Through their on-site pre-treatment and recirculation via landfill prisms, the landfill waste decomposition process may be accelerated because of the introduction of organic matter and greenhouse gas emissions may be increased. These results have been confirmed by the progressive abundance of both archaeal community and the methyl coenzyme M reductase (mcrA) gene. The resulting multivariate data set, supported by a principal component analysis, provides useful information for the design, operation and risk assessment of modern MSWPs., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

In this study, species distribution and antimicrobial susceptibility of cultivated Pseudomonas spp. were studied in influent (INF), effluent (EFF), and marine outfall (MOut) of wastewater treatment plant (WWTP). The susceptibility was tested against 8 antimicrobial classes, active against Pseudomonas spp.: aminoglycosides, carbapenems, broad-spectrum cephalosporins from the 3rd and 4th generation, extended-spectrum penicillins, as well as their combination with the β-lactamase inhibitors, monobactams, fluoroquinolones, and polymyxins. Among identified species, resistance to all antimicrobials but colistin was shown by Pseudomonas putida, the predominant species in all sampling points. In other species, resistance was observed mainly against ceftazidime, ticarcillin, ticarcillin-clavulanate, and aztreonam, although some isolates of Pseudomonas aeruginosa, Pseudomonas fluorescens, Pseudomonas pseudoalcaligenes, and Pseudomonas protegens showed multidrug-resistance (MDR) phenotype. Among P. putida, resistance to β-lactams and to fluoroquinolones as well as multidrug resistance become more prevalent after wastewater treatment, but the resistance rate decreased in marine water samples. Obtained data, however, suggests that Pseudomonas spp. are equipped or are able to acquire a wide range of antibiotic resistance mechanisms, and thus should be monitored as possible source of resistance genes.

The occurrence of resistance patterns among wastewater fecal coliforms was determined in the study. Susceptibility of the isolates was tested against 19 antimicrobial agents: aminoglycosides, aztreonam, carbapenems, cephalosporines, beta-lactam/beta-lactamase inhibitors, penicillines, tetracycline, trimethoprim/sulfamethoxazole, and fluoroquinolones. Additionally the removal of resistant isolates was evaluated in the laboratory-scale wastewater treatment model plant (M-WWTP), continuously supplied with the wastewater obtained from the full-scale WWTP. Number of fecal coliforms in raw (after mechanical treatment) and treated wastewater, as well as in aerobic chamber effluent was determined using selective medium. The selected strains were identified and examined for antibiotic resistance using Phoenix Automated Microbiology System (BD Biosciences, USA). The strains were identified as Escherichia coli (n=222), Klebsiella pneumoniae ssp. ozaenae (n=9), and Pantoea agglomerans (n=1). The isolate of P. agglomerans as well as 48% of E. coli isolates were sensitive to all antimicrobials tested. The most frequent resistance patterns were found for ampicillin: 100% of K. pneumoniae ssp. ozaenae and 41% of E. coli isolates. Among E. coli isolates 12% was regarded as multiple antimicrobial resistant (MAR). In the studied M-WWTP, the applied activated sludge processes reduced considerably the number of fecal coliforms, but increased the ratio of antimicrobial-resistant E. coli isolates to sensitive ones, especially among strains with MAR patterns.