Gryaab AB

Göteborg, Sweden

Gryaab AB

Göteborg, Sweden
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Mattsson A.,Chalmers University of Technology | Finnson A.,Svenskt Vatten | I'Ons D.,Gryaab AB
Water Science and Technology | Year: 2017

In 2014, 25% of the sludge produced at Swedish municipal wastewater treatment plants was applied to agricultural land. Even though the Swedish heavy metal limits for sludge to be used in agriculture are amongst the most stringent in the EU, more stringent heavy metal limits are proposed. Most sludge applied to agricultural land is recycled within a certification system, Revaq. Revaq has targets for control at source management and improvement of sludge quality. Statistics based on data collected within the Revaq system was used to differentiate between local and general sources of heavy metals and assess the need to improve sludge quality. The analysis indicates that proposed future national limits on the quality of the sludge can be met by most of the sludge. The improvement needed for about 20% of the sludge is feasible through local control at source management. The levels of cadmium, copper and mercury need to be reduced if these metals are not to limit the amount of sludge that may be applied per unit area of arable land. Finally, the long term Revaq targets for cadmium and silver will be difficult to meet. © IWA Publishing 2017.


Wahlberg C.,Stockholm Water Co. | Bjorlenius B.,Stockholm Water Co. | Paxeus N.,Gryaab AB
Water Science and Technology | Year: 2011

Mass flows of 13 pharmaceutical active ingredients (APIs) found in drinking water were studied in the water cycle of Stockholm. Data were collected by analyzing samples of surface water, raw water and drinking water as well as influents, effluents and sludges from waste water treatment plants (WWTPs) in Stockholm area. A mass balance was performed, based on sold amounts of pharmaceuticals and the measured concentrations in water and sludge. The selected APIs were all present in WWTP effluents and the removal rates for many of them were poor. Mass balance calculations showed that the three studied WWTPs in Stockholm release considerable amounts of the selected APIs into the Baltic Sea while the portions ending up in WWTP sludge were significantly lower. The levels of APIs found in drinking water are low at present, but may increase in the future unless the releases from WWTPs in the catchment of Lake Mälaren are mitigated. © IWA Publishing 2011.


Mattsson J.,Lulea University of Technology | Mattsson A.,Gryaab AB | Davidsson F.,Gryaab AB | Hedstrom A.,Lulea University of Technology | And 2 more authors.
Journal of Environmental Engineering (United States) | Year: 2016

The quality of wastewater varies between catchments due to variation in urbanisation, sewer system properties, and pollution levels. This study was conducted to identify wastewater quality parameters that could be normalized to estimate levels of infiltration/inflow (I/I) in selected catchments and to investigate the geographic origins of metals entering sewer systems. Two sampling campaigns were conducted in the five catchments of the Gothenburg area focusing on 14 water quality parameters. Data from a reference study on domestic wastewater quality to normalize the mass flows associated with pure domestic wastewater was applied. The level of dilution due to I/I in wastewater entering Rya Wastewater Treatment Plant, estimated using Tot-N and Tot-P as indicators, provided the closest fit among the water quality parameters with results obtained by established methods for the two campaigns. The results from the study also indicated which catchments generated nondomestic wastewater with higher mass flows of specified metals. © 2016 American Society of Civil Engineers.


PubMed | Gryaab AB and University of Aarhus
Type: Journal Article | Journal: Water science and technology : a journal of the International Association on Water Pollution Research | Year: 2016

Loads of individual commonly used analgesics (ibuprofen, diclofenac), antibiotics (sulfamethoxazole, trimethoprim), -blockers (atenolol, metoprolol, sotalol, propranolol) and neuroleptics (carbamazepine, citalopram) to a large-scale operating wastewater treatment plant (WWTP) in Sweden (Ryaverket) were studied by monitoring concentrations and flows during a 9-year period (2006-2015). Variations in loads due to sampling and possible errors in chemical analyses were estimated to be below 40%. The variations in loads were analyzed and discussed in terms of the design of collecting wastewater system as an integrated part of the water treatment at the WWTP as well as the prescription and use of individual pharmaceuticals. Trend analysis in daily loads of individual pharmaceuticals indicated an increase for diclofenac, no significant changes for ibuprofen and metoprolol and a decrease for the other pharmaceuticals. The latter was ascribed to a decrease in their prescription and use. The increase in loads of diclofenac was ascribed to its growing topical use not requiring prescription. In view of future regulations by the EU, growing loads of diclofenac to WWTPs and its low removal rates in WWTPs may require an upgrade of WWTPs to achieve quality standards for diclofenac in receiving waters.


Hellmer M.,Gothenburg University | Paxeus N.,Gryaab AB | Magnius L.,Karolinska Institutet | Enache L.,Gryaab AB | And 5 more authors.
Applied and Environmental Microbiology | Year: 2014

Most persons infected with enterically transmitted viruses shed large amounts of virus in feces for days or weeks, both before and after onset of symptoms. Therefore, viruses causing gastroenteritis may be detected in wastewater, even if only a few persons are infected. In this study, the presence of eight pathogenic viruses (norovirus, astrovirus, rotavirus, adenovirus, Aichi virus, parechovirus, hepatitis A virus [HAV], and hepatitis E virus) was investigated in sewage to explore whether their identification could be used as an early warning of outbreaks. Samples of the untreated sewage were collected in proportion to flow at Ryaverket, Gothenburg, Sweden. Daily samples collected during every second week between January and May 2013 were pooled and analyzed for detection of viruses by concentration through adsorption to milk proteins and PCR. The largest amount of noroviruses was detected in sewage 2 to 3 weeks before most patients were diagnosed with this infection in Gothenburg. The other viruses were detected at lower levels. HAV was detected between weeks 5 and 13, and partial sequencing of the structural VP1protein identified three different strains. Two strains were involved in an ongoing outbreak in Scandinavia and were also identified in samples from patients with acute hepatitis A in Gothenburg during spring of 2013. The third strain was unique and was not detected in any patient sample. The method used may thus be a tool to detect incipient outbreaks of these viruses and provide early warning before the causative pathogens have been recognized in health care. © 2014, American Society for Microbiology.


PubMed | Gryaab AB, Karolinska Institutet, Gothenburg University and Vastra Gotaland Region
Type: Journal Article | Journal: Applied and environmental microbiology | Year: 2014

Most persons infected with enterically transmitted viruses shed large amounts of virus in feces for days or weeks, both before and after onset of symptoms. Therefore, viruses causing gastroenteritis may be detected in wastewater, even if only a few persons are infected. In this study, the presence of eight pathogenic viruses (norovirus, astrovirus, rotavirus, adenovirus, Aichi virus, parechovirus, hepatitis A virus [HAV], and hepatitis E virus) was investigated in sewage to explore whether their identification could be used as an early warning of outbreaks. Samples of the untreated sewage were collected in proportion to flow at Ryaverket, Gothenburg, Sweden. Daily samples collected during every second week between January and May 2013 were pooled and analyzed for detection of viruses by concentration through adsorption to milk proteins and PCR. The largest amount of noroviruses was detected in sewage 2 to 3 weeks before most patients were diagnosed with this infection in Gothenburg. The other viruses were detected at lower levels. HAV was detected between weeks 5 and 13, and partial sequencing of the structural VP1protein identified three different strains. Two strains were involved in an ongoing outbreak in Scandinavia and were also identified in samples from patients with acute hepatitis A in Gothenburg during spring of 2013. The third strain was unique and was not detected in any patient sample. The method used may thus be a tool to detect incipient outbreaks of these viruses and provide early warning before the causative pathogens have been recognized in health care.


Gustavsson D.J.I.,VA SYD | Tumlin S.,Gryaab
Water Science and Technology | Year: 2013

This study estimates the carbon footprints of 16 municipal wastewater treatment plants (WWTPs), all situated in Scandinavian countries, by using a simple model. The carbon footprint calculations were based on operational data, literature emission factors (efs) and measurements of greenhouse gas emissions at some of the studied WWTPs. No carbon neutral WWTPs were found. The carbon footprints ranged between 7 and 108 kg CO2e P.E.-1 year-1. Generally, the major positive contributors to the carbon footprint were direct emissions of nitrous oxide from wastewater treatment. Whether heat pumps for effluents have high coefficient of performance or not is extremely important for the carbon footprint. The choice of efs largely influenced the carbon footprint. Increased biogas production, efficient biogas usage, and decreased addition of external fossil carbon source for denitrification are important activities to decrease the carbon footprint of a WWTP. © IWA Publishing 2013.


Holmberg A.,Gothenburg University | Fogel J.,Gothenburg University | Albertsson E.,Gothenburg University | Fick J.,Umeå University | And 5 more authors.
Journal of Hazardous Materials | Year: 2011

Citalopram is one of several selective serotonin reuptake inhibitors (SSRIs) commonly found in treated sewage effluents. Accordingly, there are concerns about possible adverse effects of SSRIs on aquatic organisms, particularly behavioural effects similar to those associated with SSRI use in humans. Rainbow trout fry and adult male guppies were therefore exposed to waterborne citalopram, ranging from environmentally relevant to high concentrations (1, 10, 100 μg/L) for 3-7 days. Under these experimental conditions citalopram does not appear to cause significant effects on aggression in rainbow trout fry or on sexual behaviour in male guppies. This may be explained by a relatively low uptake of citalopram from water to fish. © 2011 Elsevier B.V.


Wilen B.-M.,Chalmers University of Technology | Lumley D.,Gryaab AB | Mattsson A.,Gryaab AB | Mino T.,University of Tokyo
Water Environment Research | Year: 2010

A comprehensive study of the dynamics in settling and flocculation properties at a full-scale activated sludge treatment plant with secondary settlers operated at their maximum capacity is presented. An extensive set of process data was analyzed to assess physical parameters affecting the capacity and performance of the secondary settlers. There was a large variation in the settling and compaction properties, and they changed quickly, as a result of the short sludge age. Even though the flocculation properties changed throughout the year, they were generally improved during the summer, with lower values of effluent turbidity and effluent suspended solids concentration. The shear sensitivity, which is a measure of floc stability, was higher during the winter, when the water temperatures were lower. The sludge floc morphology had, in general, a different internal structure, with more round microbial colonies during the warmer summer months and a more net-like open structure during the winter.


Wilen B.-M.,Chalmers University of Technology | Johansen A.,Chalmers University of Technology | Mattsson A.,Gryaab AB
Water Practice and Technology | Year: 2012

To meet stricter effluent discharge limits of total phosphorus, microscreens can be applied for tertiary effluent treatment. The Rya WWTP has recently been upgraded with microscreens in the form of disc filters. Extensive characterisation of the wastewater from different locations in the plant (influent, after primary settling) and secondary settler effluent, was performed to increase the understanding of the potential of removing different components from the wastewater. The wastewater was fractionated by filtration through filter cloths with pore sizes 40, 20, 15, and 10 μm and through finer filters with pore size 1.2, 0.45, 0.2 and 0.1 μm. Particle size analysis (PSA) was used to assess the removal efficiency of the filter cloths. High removal degrees were achieved were particles larger or equal in size to the pore size were strained. Some floc break-up took place leading to an increased number of small particles (1-5 μm) after filtration. The suspended solids concentration could be reduced to 1 mg/l with total phosphorus concentrations of <0.2 mg/l. Some removal of metals could be observed when filtering wastewater with higher concentrations (influent and secondary settler effluent) whereas no effect could be seen for the effluent wastewater, probably due to the low concentrations present. The results from this study indicate a poor removal efficiency of pathogens measured as indicator microorganisms. © IWA Publishing 2012.

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