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While tire wear and tear is known to be a major source of microplastics in the environment, its monitoring is still hampered by the lack of analytical methods able to provide concentrations in environmental matrices. Tire wear particles (TWP) present in road runoff enter the drainage system through gully pots, built to prevent sediment deposition in the drainage system, and eventually protect downstream receiving waters. The aim of this study was to detect and quantify TWP in gully pot sediments, by using a novel method combining Simultaneous Thermal Analysis (STA), Fourier Transform Infrared (FTIR) spectroscopy and Parallel Factor Analysis (PARAFAC). The method was applied to samples from five sites in Southern Norway, characterized by different traffic densities and patterns. The method involved no sample pretreatment, the whole sediment sample was submitted to thermal decomposition in STA, and gases generated during pyrolysis were continuously transferred to FTIR. The FTIR data were arranged in a trilinear multi-way dataset (samples × IR spectra wavenumber × pyrolysis temperature) and then analyzed by PARAFAC. The results showed that TWP concentrations in gully pots varied greatly across sites, ranging from below 1 mg TWP/g sediment in streets with the lowest traffic densities, to 150 mg TWP/g sediment at the most trafficked study site. The results also indicated that other traffic conditions, such as driving patterns influence TWP concentrations. Finally, by enabling quantification of TWP in gully pot sediments, the approach presented here supports environmental monitoring of TWP and safe disposal of gully pot sediments, which is critical for environmental pollution management.

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Detection and quantification of tread wear particles in the environment have been a challenge owing to lack of a robust method. This study investigated the applicability of a combination of Simultaneous Thermal Analysis (STA), Fourier Transform Infra-Red (FTIR), and Parallel Factor Analysis (PARAFAC) in the detection and quantification of tire particles from formulated sediments. FTIR spectral data were obtained by heating 20 samples in STA. Among the 20 samples, 12 were tire granules in formulated sediments (TGIS) containing 1%, 2%, 5%, and 10% by mass of tire granules, while the remaining eight contained 0.5, 1, 2.5, and 5 mg of tire granules only (TGO). The PARAFAC models decomposed the trilinear data into three components. Tire rubber materials in tire granules (RM) and a combination of water and carbon dioxide were the components identified in all samples. The linear regression analysis of score values from the PARAFAC models showed that the RM quantity predicted were comparable to measured values in both TGIS and TGO. Decomposing the overlying components in the spectral data into different components, and predicting unknown quantity in both sample types, the method proves robust in identifying and quantifying tire particles from sediments.

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Microorganism removal efficiencies in deep bed filters vary with time and depth in the filter bed as the filter collects particles. Improved knowledge of such dynamics is relevant for the design, operation and microbial risk assessment of filtration processes for drinking water treatment. Here we report on a high-resolution spatio-temporal characterization of virus and bacteria removal in a pilot-scale dual-media filter, operated in contact-filtration mode. Microorganisms investigated were bacteriophage Salmonella typhimurium 28B (plaque assay, n=154)), fRNA phage MS2 (plaque assay/RT-qPCR, n=87) and E. coli (Colilert-18, n=73). Microscopic and macroscopic filtration models were used to investigate and characterize the removal dynamics. Results show that ripening/breakthrough fronts for turbidity, viruses and E. coli migrated in a wave-like manner across the depth of the filter. Virus removal improved continuously throughout the filter cycle and viruses broke through almost simultaneously with turbidity. Ripening for E. coli took longer than ripening for turbidity, but the bacteria broke through before turbidity breakthrough. Instantaneous log-removal peaked at 3.2, 3.0 and 4.5 for 28B, MS2 and E. coli, respectively. However, true average log-removal during the period of stable effluent turbidity was significantly lower at 2.5, 2.3 and 3.6, respectively. Peak observed filter coefficients λ were higher than predicted by ideal filtration theory. This study demonstrates the importance of carefully designed sampling regimes when characterizing microorganism removal efficiencies of deep bed filters.

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The transmission of pathogens from partially or fully treated wastewater to different water sources are a pervasive risk to public health. To reduce the risk, the integration of source separation, on-site greywater treatment system, and an efficient disposal scheme are the most critical approaches. This study intended to evaluate the removal of nutrient and microbial suspension in the filtration systems used for effluent disposal. The effluent from an on-site greywater treatment plant was loaded into the columns, and the effluent from the columns was monitored for nutrients, total coliform bacteria, Escherichia coli, and Salmonella typhimurium phage 28B (St28B) for one year. Thus, from the range of infiltration systems tested, column-B (15 cm layer of each, Filtralite, fine sand, and till soil) showed the highest removal of total coliforms and E. coli, 3-4 log10 reduction, while the lowest removal observed in column-C (a layer of 25 cm crushed stone and 50 cm till soil), 2-3 log10 reduction. The virus removal efficiency of the columns reduced from 19% to 70% during the simulation of a rainfall event. Moreover, the rise of St28B concentration after rainfall experiment may probably the sign of detachment enhanced by low ionic strength rainwater.

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The performance of a sludge blanket anaerobic baffled reactor was tested as an integrated treatment system for source-separated blackwater. The system consists of a stirred equalization tank, a buffer inlet tank, and two identical reactors, each with a working volume of 16.4 L, operated in parallel. Both reactors run at 3-days hydraulic retention time with different intermittent pulse feeding. Pulse lengths of 12 and 24 seconds per feed were set with respective rates of 114 L h-1 and 52 L h-1 for the short-pulse fed reactor (RI) and the long-pulse fed reactor (RII). Stable performance of the reactors was attained after 120 and 90 days, for RI and RII, respectively. After stable conditions attained, total chemical oxygen demand (COD) removal efficiency stabilized above 78%. Biogas production ranged from 0.52 to 1.16 L d-1 L-1 reactor volume, with 67-82% methane concentration and an average conversion of 0.69 ± 0.2 and 0.73 ± 0.2 g CH4-COD g-1CODin for RI and RII, respectively. The results imply that source-separated blackwater can be treated effectively in an anaerobic sludge blanket process on average loading rate of 2.3 ± 0.5 g COD d-1 L-1 reactor volume with high methane production potential and more than 80% removal of organic and particulate matter.

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The present work evaluates the effect of contact filtration, preceded by coagulation with zirconium (Zr) and chitosan coagulants, on model microorganisms and waterborne pathogens. River water intended for potable water production was spiked with MS2 and Salmonella Typhimurium 28B bacteriophages, Escherichia coli, and Cryptosporidium parvum oocysts prior to coagulation. The hygienic performance demonstrated by Zr comprised 3.0-4.0 log10 removal of viruses and 5.0-6.0 log10 removal of E. coli and C. parvum oocysts. Treatment with chitosan resulted in a removal of 2.5-3.0 log10 of viruses and parasites, and 4.5-5.0 log10 of bacteria. A reference coagulant, polyaluminium chloride (PACl), gave a 2.5-3.0 log10 removal of viruses and 4.5 log10 of E. coli. These results indicate that both Zr and chitosan enable adequate removal of microorganisms from surface water. The present study also attempts to assess removal rates of the selected microorganisms with regard to their size and surface properties. The isoelectric point of the Salmonella Typhimurium 28B bacteriophage is reported for the first time. The retention of the selected microorganisms in the filter bed appeared to have some correlation with their size, but the effect of the charge remained unclear.

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This study investigated the public health risk from exposure to infectious microorganisms at Sandvika recreational beaches, Norway and dose-response relationships by combining hydrodynamic modelling with Quantitative Microbial Risk Assessment (QMRA). Meteorological and hydrological data were collected to produce a calibrated hydrodynamic model using Escherichia coli as an indicator of faecal contamination. Based on average concentrations of reference pathogens (norovirus, Campylobacter, Salmonella, Giardia and Cryptosporidium) relative to E. coli in Norwegian sewage from previous studies, the hydrodynamic model was used for simulating the concentrations of pathogens at the local beaches during and after a heavy rainfall event, using three different decay rates. The simulated concentrations were used as input for QMRA and the public health risk was estimated as probability of infection from a single exposure of bathers during the three consecutive days after the rainfall event. The level of risk on the first day after the rainfall event was acceptable for the bacterial and parasitic reference pathogens, but high for the viral reference pathogen at all beaches, and severe at Kalvøya-small and Kalvøya-big beaches, supporting the advice of avoiding swimming in the day(s) after heavy rainfall. The study demonstrates the potential of combining discharge-based hydrodynamic modelling with QMRA in the context of bathing water as a tool to evaluate public health risk and support beach management decisions.

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Household wastewater is originated from common people's activities and has a potential harmful impact on the environment if discharged directly without proper treatment. Toilet wastewater or black water (BW) contains urine, faeces, toilet paper and flushing water and it contains the majority of pollutants obtained from a single household. In this study, the focus was on BW treatment using chemical methods. The main goal of current research was to define the possibility and applicability of conventional coagulants and flocculants in direct chemical treatment of vacuum-collected BW to remove particles, organic matter and phosphorous. After the definition of dosing ranges, based on the equivalent doses in conventional municipal and industrial wastewater treatment data, aluminium and iron coagulants, organic polyelectrolytes (polymers with anionic, neutral and cationic charge with different molecular weights) and their various combinations were tested using the well-known jar-test laboratory method to study aggregation and solid-liquid separation processes in raw BW. The most important process parameter during the coagulation was pH level, dependent on the type and doses of metal salts. Some side processes were found to occur while using iron-based coagulants. Dosing of either single coagulants or single polymers did not give satisfactory results, while a combination of aluminium salts and cationic polymers showed high removal rates in total suspended solids, total chemical oxygen demand and ortho-phosphates, reaching 97.8%, 92% and 98.6%, respectively, with the optimal doses of chemicals. Cationic polymers with the lowest molecular weight and highest charge density were the most efficient in combination with aluminium coagulants.

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Wastewater use for vegetable production is widespread across the cities of many developing countries. Studies on the microbial health risks associated with the practice have largely depended on faecal indicator organisms with potential underestimation or overestimation of the microbial health risks and disease burdens. This study assessed the Escherichia coli O157:H7 infection risk and diarrhoeal disease burden measured in disability-adjusted life years (DALYs) associated with the consumption of wastewater-irrigated lettuce in Kumasi, Ghana using data on E. coli O157:H7 in ready-to-harvest, wastewater-irrigated lettuce. Two exposure scenarios - best case and worst case - associated with a single consumption of wastewater-irrigated lettuce were assessed. The assessment revealed wastewater-irrigated lettuce is contributing to the transmission of E. coli O157:H7 in Kumasi, Ghana. The mean E. coli O157:H7 infection risk and DALYs in the wet and dry seasons, irrespective of the exposure scenario, were above the World Health Organization tolerable daily infection risk of 2.7 × 10⁻7 per person per day and 10⁻6 DALYs per person per year. It is recommended that legislation with clear monitoring indicators and penalties is implemented to ensure that farmers and food sellers fully implement risk mitigating measures.

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Wastewater from a source-separated sanitation system connected to 24 residential flats was analysed for the content of organic matter and nutrients and other key parameters for microbiological processes used in the treatment and reuse of wastewater. Black water (BW) was the major contributor to the total load of organic matter and nutrients in the wastewater, accounting for 69% of chemical oxygen demand (COD), 83% of total nitrogen (N) and 87% of phosphorus (P). With a low COD/N ratio and high content of free ammonia, treating BW alone is a challenge in traditional biological nitrogen removal approaches. However, its high nitrogen concentration (1.4-1.7 g L(-1)) open up for nutrient reuse as well as for novel, more energy efficient N-removal technologies. Grey water (GW) contained low amounts of nutrients relative to organic matter, and this may limit biological treatment processes under certain conditions. GW contains a higher proportion of soluble, readily degradable organic substances compared with BW, which facilitates simple, decentralized treatment approaches. The concentration of organic matter and nutrients varied considerably between our study and other studies, which could be related to different toilet flushing volumes and water use habits. The daily load per capita, on the other hand, was found to be in line with most of the reported studies.

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The long-term use of a filter-based, on-site wastewater treatment system increases nutrient discharge to receiving waters and may reduce its hygienic barrier efficiency. The main purpose of this research was to assess the hygienic barrier efficiency and the associated health risks of an on-site system that had exceeded its 5-yr design capacity with respect to phosphorus (P) removal. The system was investigated for bacteria and virus removal and assessed with respect to potential health risks in relation to reuse of effluent for irrigation. The system consists of a septic tank, a pressure-dosed vertical flow biofilter, and an up-flow filter unit with lightweight clay aggregates. The total P concentration in the effluent had increased gradually from initially <0.1 mg P L(-1) during the first 2 yr of operation to 1.8 mg P L(-1) after 5.3 yr. Escherichia coli was used as an indicator organism for fecal bacteria removal, whereas bacteriophages phiX174 and Salmonella typhimurium phage 28B (S.t. 28B) were used to model enteric virus removal. An overall decrease in E. coli removal occurred from a complete (approximately 5.6 log10) reduction during the first 3 yr of operation to 2.6 log10 reduction. The removal amounts of the bacteriophages phiX174 and S.t. 28B were 3.9 and 3.7 log10, respectively. Based on removal of S.t. 28B, the risks of rotavirus infection and disease for the investigated scenarios were above the acceptable level of 10(-4) and 10(-3), respectively, as defined by the World Health Organization.

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Quantitative Microbial Risk Assessment (QMRA) models with 10,000 Monte Carlo simulations were applied to ascertain the risks of rotavirus and Ascaris infections for farmers using different irrigation water qualities and consumers of lettuce irrigated with the different water qualities after allowing post-harvest handling. A tolerable risk (TR) of infection of 7.7 x 10(-4) and 1 x 10(-2) per person per year were used for rotavirus and Ascaris respectively. The risk of Ascaris infection was within a magnitude of 10(-2) for farmers accidentally ingesting drain or stream irrigation water; approximately 10(0) for farmers accidentally ingesting farm soil and 10(0) for farmers ingesting any of the irrigation waters and contaminated soil. There was a very low risk (10(-5)) of Ascaris infection for farmers using pipe-water. For consumers, the annual risks of Ascaris and rotavirus infections were 10(0) and 10(-3) for drain and stream irrigated lettuce respectively with slight increases for rotavirus infections along the post-harvest handling chain. Pipe irrigated lettuce recorded a rotavirus infection of 10(-4) with no changes due to post harvest handling. The assessment identified on-farm soil contamination as the most significant health hazard.

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