Bacterial invasion potential in water is determined by nutrient availability and the indigenous community

In drinking water (DW) and the distribution systems, bacterial growth and biofilm formation have to be controlled both for limiting taste or odour development and preventing clogging or biocorrosion problems. After a contamination with undesired bacteria, factors like nutrient availability and temperature will influence the survival of these invaders. Understanding the conditions enabling invaders to proliferate is essential for a holistic approach towards microbial risk assessment in DW. Pseudomonas putida was used as a model invader because this easy-growing bacterium can use a wide range of substrates. Invasion experiments in oligo- to eutrophic waters showed the requirement of both a carbon and phosphate source for survival of P.putida in DW. Addition of C, N and P enabled P.putida to grow in DW from 5.80x10(4) to 1.84x10(8)cellsmL(-1) and survive for at least 12days. However, in surface water with similar nutrient concentrations, P.putida did not survive, indicating the concomitant importance of the present indigenous microbial community of the specific water sample. Either extensive carbon or phosphate limitation can be used in water treatment design in order to obtain a DW which is not susceptible for unwanted bacterial growth

Occurrence of transparent exopolymer particles (TEP) through drinking water treatment plants

Numerous membrane fouling studies have been conducted to predict and prevent membrane fouling. It was only recently that a new parameter, TEP, was introduced in this research. The deposition of TEP on reverse osmosis (RO) membranes has already been imaged, correlations between ultrafiltration (UF) fouling and TEP concentrations have been reported. Furthermore, TEP deposition takes place in an early stage of biofilms formation, making TEP one of the accused in search for biofilm initiation factors. After literature reporting about TEP in marine, surface and wastewater, this is the first research focusing on TEP through in drinking water. Each treatment step in three completely different drinking water production plants was evaluated on TEP removal and it could be concluded that a limited restfraction or no TEP could reach the drinking water. Coagulation + sand filtration proved efficient in strongly reducing TEP levels, UF + RO can provide a total TEP removal

Occurrence of transparent exopolymer particles (TEP) in drinking water systems

Numerous membrane fouling studies have been conducted to predict and prevent membrane fouling. It was only recently that a new parameter, TEP, was introduced in this research. The deposition of TEP on reverse osmosis (RO) membranes has already been imaged, correlations between ultrafiltration (UF) fouling and TEP concentrations have been reported. Furthermore, TEP deposition takes place in an early stage of aquatic biofilm formation, making TEP one of the accused in search for biofilm initiation factors. After literature reporting about TEP in marine, surface and wastewater, this is the very first research focusing on TEP through in drinking water. Every single treatment step in three completely different drinking water production plants was scored on TEP removal. It could be concluded that TEP concentrations were very dependent of the raw water source but in none of the installations, TEP was able to reach the final drinking water in significant concentrations. The combination of coagulation and sand filtration proved efficient in strongly reducing TEP levels, while the combination of UF and RO could provide a total TEP removal

Bacterial exchange in household washing machines

Household washing machines (WMs) launder soiled clothes and textiles, but do not sterilize them. We investigated the microbial exchange occurring in five household WMs. Samples from a new cotton T-shirt were laundered together with a normal laundry load. Analyses were performed on the influent water and the ingoing cotton samples, as well as the greywater and the washed cotton samples. The number of living bacteria was generally not lower in the WM effluent water as compared to the influent water. The laundering process caused a microbial exchange of influent water bacteria, skin-, and clothes related bacteria and biofilm-related bacteria in the WM. A variety of biofilm-producing bacteria were enriched in the effluent after laundering, although their presence in the cotton sample was low. Nearly all bacterial genera detected on the initial cotton sample were still present in the washed cotton samples. A selection for typical skin- and clothes related microbial species occurred in the cotton samples after laundering. Accordingly, malodour-causing microbial species might be further distributed to other clothes. The bacteria on the ingoing textiles contributed for a large part to the microbiome found in the textiles after laundering

Impact of mechanized harvesting on compaction of sandy and clayey forest soils : results of a meta-analysis

Nowadays, harvest operations are predominantly performed fully mechanized using heavy tractors or forestry machines. The resulting soil compaction may negatively affect the soil ecosystem. We wanted to draw general conclusions concerning the impact of mechanized harvesting on forest soil bulk density and the influencing factors. Therefore, we combined the data of several studies using a meta-analysis approach. The impact decreased from the surface towards deeper soil layers. At 0-10 cm depth, the impact on clayey soils was highest although not significantly different from the impact on sandy soils. Higher initial bulk densities, i.e., on already compacted forest soils, generally led to smaller extra increases of bulk density after machine traffic. For sandy soils, the impact was also significantly smaller when machines were lighter. No significant relationship was observed between the compaction degree and traffic intensity. We observed clear compaction on both clayey and sandy soils, especially in case of low initial soil compaction degrees and heavy machines. The compacted initial state of many forest soils, the long recovery period, and the generally high impact of the first passes that is frequently mentioned in literature all count in favour of designated skid trails and an adjustment of the machine type to the job

Development on National Metrology, Standardisation, Conformity Assessment and Accreditation System - Final Report - CARDS 2004 Croatia

The final report of the CARDS programme 2004 project "Development of National Metrology, Standardisation, Conformity Assessment and Accreditation System" - offers an overview of the conducted activities during the period: from the 6th October 2008 to the 16th June 2009. Furthermore, this document is giving a sum-up of the overall achievements of the project over the entire duration of the project (16th May 2006 to 15th June 2009). Evaluation, eventual feedbacks, encountered problems, modifications and further recommendations are also elaborated. Finally, the last chapter is meant to provide a synthetic view on the targets of the project, derive conclusions and list the key issues / experiences and proposes further improvement possibilities for beneficiary institutions.JRC.DDG.D.4-Isotope measurement

Development of National Metrology, Standardisation, Conformity Assessment and Accreditation System in Croatia: 3rd INTERIM REPORT CARDS 2004 - Croatia, Project No 116536

The CARDS 2004 - Croatia project entitled "Development of National Metrology, Standardisation, Conformity Assessment and Accreditation System in Croatia" is providing targeted assistance on predefined topics having as an overall objective the further development of the Quality Infrastructure in Croatia. The 3rd interim report provides the overview on the project's progress during the period October 2007 to April 2008. It also offers a plan for the activities to be conducted within the following (fourth) reporting period, corresponding to April 2008 - October 2008.JRC.D.4-Isotope measurement

Development of National Metrology, Standardisation, Conformity Assessment and Accreditation System. 4th Interim Report CARDS 2004

The CARDS 2004 - Croatia project entitled " Development of National Metrology, Standardisation, Conformity Assessment and Accreditation System" is providing targeted assistance on predefined topics having as overall objective further developmet of the Quality Infrastructure in Croatia. The 4th interim report provides the overview on the project's progress during the period April to October 2008. It also offers a plan for the activities to be conducted within the following (fifth) reporting period, corresponding to October 2008 - April 2009.JRC.D.4 - Isotope measurement