This study investigated the occurrence and removal of 12 antibiotics (ciprofloxacin, enrofloxacin, levofloxacin, norfloxacin, nalidixic acid, azithromycin, clarithromycin, roxithromycin, lincomycin, novobiocin, sulfamethoxazole, trimethoprim) at four sewage treatment plants (STPs): two STPs in Kyoto, Japan and two STPs in Beijing, China. The STPs differed in design and operation conditions, utilized a variety of secondary treatment processes. The antibiotics were frequently detected in influents and effluents, and ranged from ng/L up to lower μg/L. In influent, clarithromycin (1.1–1.6 μg/L) and levofloxacin (3.6–6.8 μg/L) were detected in the highest concentration in Japanese and Chinese STPs, respectively. The overall elimination of the antibiotics were differed between STPs and ranged from negative to >90%. These data demonstrate that there are detectable levels of antibiotics are discharging from STPs, and only some of these antibiotics are being removed in a significant proportion by STPs. It was also observed that biological nutrient removal based sewage treatment processes (anaerobic–anoxic–oxic: A2O; and anoxic–oxic: AO) have relatively higher antibiotics removal efficiencies than oxidation ditch (OD) processes.

International audience | An inter-laboratory comparison exercise was organized among European laboratories, under the aegis of EU COST Action 636: "Xenobiotics in Urban Water Cycle" The objective was to evaluate the performance of testing laboratories determining "Endocrine Disrupting Compounds" (EDC) in various aqueous matrices. As the main task three steroid estrogens. 17 alpha-ethinylestradiol, 17 beta-estradiol and estrone were determined in four spiked aqueous matrices' tap water, river water and wastewater treatment plant influent and effluent using GC-MS and LC-MS/MS Results were compared and discussed according to the analytical techniques applied, the accuracy and reproducibility of the analytical methods and the nature of the sample matrices. Overall, the results obtained in this inter-laboratory exercise reveal a high level of competence among the participating laboratories for the detection of steroid estrogens in water samples indicating that GC-MS as well as LC-MS/MS can equally be employed for the analysis of natural and synthetic hormones.

The aim of this study was to assess the impact of treated wastewaters on native wild Prussian carp inhabiting effluent-receiving waters (ERC) receiving municipal and sugar plant treated wastewaters, further downstream waters (DW), and a detached canal unaffected by the WWTP activities. To that end, general fish health status was determined, including plasma biochemical, haematological, oxidative stress and tissue histopathological indices, over three seasons. The greatest tissue alterations were in fall in ERC during sugar beet processing, as hypertrophy of gill epithelial and interlamellar cells, necrosis and lymphocytic infiltration, hyperplasia and hypertrophy of renal tubules, distention of hepatic sinusoids. In fall the lowest leukocytes, lymphocytes and granulocytes (2467 ± 565, 1333 ± 264, 1133 ± 488 cells/μL respectively), as well as highest plasma ALP (52.7 ± 19.39 U/L) were measured. ERC in fall had the highest ammonium (20 mg/L), nitrite (1.48 mg/L), nitrate (13.4 mg/L), and lowest dissolved O2 (1.23 mg/L). Gill, kidney and liver alterations, and the highest plasma cholesterol (9.1 ± 1.98 mmol/L) were noted in DW fish in fall. Tissue morphology during sugar cane processing seems a consequence of cellular and structural tissue integrity loss. Structural heterogeneity of gills and spleen was enhanced with increasing concentrations of heavy metals and correlated with oxidative stress (SOD 392.5 ± 77.28 U/L). Monogenean infestation was moderate in ERC fish in all seasons compared with DW fish. Prussian carp biological responses to multiple stressors, measured by the effects of WWTP on blood and tissue parameters, reached far downstream and were not of localized nature. This study demonstrated that in aquatic environments impacted with complex contaminants acting synergistically, causal relationships between biological responses and environmental stressors should be interpreted. Integrated histopathological, haematological and biochemical findings are valuable biomarkers for native fish adaptive patterns and monitoring of water quality/pollution of freshwater ecosystems.

In reverse osmosis, a frequently used technology in water desalination processes, wastewater (RO concentrate) is generated containing the retained solutes as well as so-called antiscalants (AS), i.e. chemical substances that are commonly applied to prevent membrane-blocking. In this study, a risk assessment of a possible discharge of concentrate into a small stream was conducted. The acute toxicity of two concentrates containing two different ASs and of concentrate without AS to the amphipods Gammarus pulex and Gammarus roeseli was studied. Mortality of gammarids exposed to the concentrate without AS was not different to the control, whereas concentrates including ASs caused mortality rates up to 100% at the highest test concentrations after 168 h. Resulting EC50-values were 36.2–39.4% (v/v) after 96 h and 26.6–58.0% (v/v) after 168 h. These results suggest that the ecotoxicological relevance of antiscalants is greater than currently assumed.

The prevalence of pharmaceuticals and personal care products (PPCPs) in lotic habitats is increasing, with the main source of these contaminants being effluent from waste water treatment works (WwTW). There is still much uncertainty about the impacts of these PPCPs at environmentally relevant concentrations and their potential effects on aquatic ecology. Behaviour is a sensitive endpoint which can help evaluate possible population level effects from changes in physiology. This paper evaluates the effects of WwTW effluent on a range of behaviours in the freshwater invertebrate, Gammarus pulex. Effluent taken from the outflow of two WwTW in southern England was used in the study. Behavioural analyses, namely feeding rate, phototaxis, activity, velocity and precopula pairing, were measured in G. pulex following a period of one and three weeks after exposure to a 50% or 100% effluent and a control. Mortality remained very low throughout the 3 week experiment (0–10%, n = 20) and no significant changes in moulting frequency were observed (p > 0.05). No significant effects on feeding or velocity or phototaxis following 3 weeks of effluent exposures were observed (p > 0.05). However, significant reductions were observed in the overall activity over 3 weeks across which appeared to be exacerbated by exposure to effluents. Interestingly, males exposed for 3 weeks to WwTW effluent re-paired with unexposed females significantly faster (4-6x) than control animals. This result was consistent between the effluents taken from the two WwTW. The implications of these behavioural changes are currently unknown but highlight the need for a varied set of tools to study the behavioural changes in wildlife.

The arrival and discharge of seven antibiotics were monitored at two trickling filter sewage treatment plants of 6000 and 11,000 population equivalents (PE) and two activated sludge plants of 33,000 and 162,000 PE in Southern England. The investigation consisted of 24 h composite samples taken on two separate days every summer from 2012 to 2015 and in the winter of 2015 (January) from influent and effluent. The average influent concentrations generally matched predictions based on England-wide prescription data for trimethoprim, sulfamethoxazole, azithromycin, oxytetracycline and levofloxacin (within 3-fold), but were 3–10 times less for clarithromycin, whilst tetracycline influent concentrations were 5–17 times greater than expected. Over the four years, effluent concentrations at a single sewage plant varied by up to 16-fold for clarithromycin, 10-fold for levofloxacin and sulfamethoxazole, 7-fold for oxytetracycline, 6-fold for tetracycline, 4-fold for azithromycin and 3-fold for trimethoprim. The study attempted to identify the principal reasons for this variation in effluent concentration. By measuring carbamazepine and using it as a conservative indicator of transport through the treatment process, it was found that flow and hence concentration could alter by up to 5-fold. Measuring influent and effluent concentrations allowed assessments to be made of removal efficiency. In the two activated sludge plants, antibiotic removal rates were similar for the tested antibiotics but could vary by several-fold at the trickling filter plants. However, for clarithromycin and levofloxacin the variations in effluent concentration were above that which could be explained by either flow and/or removal alone so here year on year changes in consumption are likely to have played a role.

Intermittent, fluctuating and pulsed contaminant discharges may result in organisms receiving highly variable contaminant exposures. This study investigated the effects of dissolved copper pulse concentration and exposure duration on the toxicity to two freshwater green algae species. The effects of single copper pulses of between 1 and 48 h duration and continuous exposures (72 h) on growth rate inhibition of Pseudokirchneriella subcapitata and Chlorella sp. were compared on a time-averaged concentration (TAC) basis. Relationships were then derived between the exposure concentration and duration required to elicit different levels of toxicity expressed as inhibition concentration (IC). Continuous exposure IC50's of 3.0 and 1.9 μg/L were measured on a TAC basis for P. subcapitata and Chlorella sp., respectively. Algal growth rates generally recovered to control levels within 24–48 h of the copper pulse removal, with some treatments exhibiting significantly (p < 0.05) higher rates of cell division than controls in this recovery period. For both algae, when exposed to treatments with equivalent TACs, the continuous exposure elicited similar or slightly greater growth rate inhibition than the pulsed exposures. To elicit equivalent inhibition, the exposure concentration increased as the exposure duration decreased, and power models fitted this relationship reasonably well for both species. Water quality guideline values (WQGVs) are predominantly derived using data from continuous exposure toxicity bioassays, despite intermittent contaminant exposures often occurring in aquatic systems. The results indicate the WQGV for copper may be relaxed for pulsed exposures by a factor less than or equivalent to the TAC and still achieve a protection to these sensitive algae species.

The effects of Rhodopseudomonas capsulata (R. capsulata) in the treated effluent of soybean processing wastewater (SPW) on the remediation of imidacloprid in soil, soil fertility, and the microbial community structure in soil were studied. Compared with the control group, with the addition of effluent containing R. capsulata, imidacloprid was effectively removed, soil fertility was enhanced, and the microbial community structure was improved. Molecular analysis indicated that imidacloprid could exert induction effects on expression of cpm gene and regulation effects on the synthesis of cytochrome P450 monooxygenases (P450) by activating HKs gene in two-component system (TCS). For R. capsulata, this induction process required 1 day. The synthesis of P450 occurred 1 day after inoculation, because R. capsulata are a type of archaea and imidacloprid is an environmental stress. Before expression of the cpm gene and synthesis of P450, R. capsulata need a period of time to adapt to external imidacloprid stimulation. However, the lack of organic matter in the soil cannot sustain R. capsulata growth for more than 1 day. In four groups with added effluent, the remaining organic matter in the effluent provided a sufficient carbon source and energy for R. capsulata. Five days later, the microbial community structure was improved by R. capsulata in the soil. The new technique could be used to remediate imidacloprid, enhance soil fertility, treat SPW and realize the recycling and reuse of wastewater and R. capsulata cells.

This study determined the contamination levels of oil and grease (O/G) across nine (9) galamsey operations under different environmental media (background soil, surface drainage, slurry/sludge and galamsey wastes) in three galamsey hotspot assemblies (Tarkwa Nsuaem, Amenfi East and Prestea Huni Valley) within the Western region of Ghana. Triplicate samples each of the four environmental media for the nine galamsey types (Washing Board, Washing Plant, Anwona, Dig and Wash, Dredging, Underground Abandoned Shaft, Underground Sample Pit, Chamfi and Mill House) were collected and analysed using n-hexane extractable materials in acidic medium by extraction and gravimetry to determine O/G concentrations. From the comparison of mean ranked concentration of O/G, using Kruskal-Wallis Test, the observed differences in the ranking was significant across all four media. The O/G concentrations for Anwona, Chamfi, Mill House, Washing Board and Washing Plant galamsey recorded exceedances when compared to the Ghana EPA Effluent Guideline Value of 100 mg/L for water and The New Dutch Lists’ Target and Intervention Value of 50 mg/kg and 500 mg/kg for solid/semi-solid materials. Consistently and for all environmental media types, the levels of O/G across the galamsey types were in the descending order of: Washing Board, Chamfi, Anwona, Mill House, Washing Plant, Underground Sample Pit, River Dredging, Dig and Wash, Underground Abandoned Shaft and Control Sample (non-galamseyed areas). In general, the surface drainage medium was predominantly found to be the most impacted upon medium from hydrocarbons by seven of the nine galamsey operations (Washing Board, Anwona, Chamfi, Mill House, Dredging, Dig and Wash and Underground Sample Pit). This was followed by slurry/sludge, background soil and waste media in that order. Expectedly, there were no exceedances for the Reference or Control Samples (non-galamseyed areas).

Ny-Ålesund, one of four permanent settlements on Spitsbergen in Svalbard, is a research town that includes scientific institutes from many countries. Because of daily-used chemicals (e.g., pharmaceutical and personal care products (PPCPs)) used by residents in the area, generated sewage is considered as a point source in the Kongsfjorden. The aim of the present study was to identify and quantify organic pollutants in the effluent and along the shoreline and offshore via target, suspect, and non-target screening using liquid chromatography–high-resolution mass spectrometry. We tentatively identified 30 compounds using the suspect and non-target screening methods in effluent samples from our first visit to the settlement in 2016. Among these, 3 were false positive, 24 were confirmed, and the 3 remaining compounds were not confirmed because of a lack of reference standards. Of the confirmed, 21 were quantifiable and considered target compounds for the 2nd year study. The quantified compounds in the effluent samples in 2017 totaled 17, including PPCPs, pesticides, perfluorinated compounds, and their metabolites. Some of the compounds, such as caffeine, paraxanthine/theophylline, acetaminophen, cetirizine, diethyl toluamide (DEET), and icaridin, were also detected in the receiving seawater. The concentration range was from 4 to 280,000 ng/L in the effluent and 2–98 ng/L in the seawater. Other 24 compounds were tentatively identified in the second-year effluent samples. Five were further confirmed using reference standards. Prioritization was performed on the 47 substances screened in Ny-Ålesund using the exposure and toxicity index. As the result, the top seven substances of concern present were perfluorooctanesulfonic acid (PFOS), triphenyl phosphate (TPHP), irbesartan, DEET, acetaminophen, caffeine, and paraxanthine/theophylline. As the effluent was identified as a source of the concerned organic pollutants, an emission reduction strategy should take place for protection of Arctic Fjorden environment.