Hopp til hovedinnholdet

Publications

NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.

2017

Abstract

The major fraction of engineered nanomaterials (ENMs) released in the environment are transiting through wastewater treatment plants (WWTPs). How do the microorganisms responsible for the removal of nitrogen in WWTPs react when exposed to wastewater-borne ENMs? We investigated the potential for Ag and TiO2 nanoparticles (and their transformation products) to cause a decrease in the operational efficiency of WWTPs, more specifically on nitrogen removal by denitrification. To gain a mechanistic understanding of the potential effects of Ag and TiO2 NPs on denitrifying bacteria, we exposed pure cultures of bacteria isolated from activated sludge to various concentrations of NPs, and monitored gas kinetics during the transition from oxic to anoxic respiration. We also conducted similar exposure experiments on indigenous bacterial communities present in actively operating WWTPs. Results obtained with suspended and biofilm associated microorganisms will be presented, in order to complement eco-physiological studies on single organisms.

To document

Abstract

This work presents the outcomes from two independent studies evaluating the chemical quality of groundwater in agricultural areas irrigated with wastewater from sugar and yeast industries. The evaluation was determined using chemical parameters representing typical contaminants of sugar industry wastewater (SIWW) and yeast industry wastewater (YIWW), and characterising the content of organic matter (BOD5), nutrients (NH4-N, NO3-N, TN and TP) and salts (Cl, SO4, Na and K). The studies reveal that food industry wastewater constitutes a valuable water-nutrient-rich medium that can be reused in agricultural applications as an alternative water resource for irrigation and nutrients for fertilisation. Furthermore, the reuse facilitates the sustainable discharge of wastewater through a soil-aquifer zone to the natural environment. This does not affect chemical quality of groundwater, which was comparable in areas irrigated and non-irrigated with SIWW and YIWW. Although some parameters (NO3-N, NH4-N, SO4, Cl and Na) displayed higher concentrations in groundwater from the fields irrigated with wastewater, these contents were within recommended healthbased guideline limits defined in either the groundwater quality standards or the drinking water quality norms. Only the contents of K revealed an exclusive groundwater impact from wastewater irrigation. This was confirmed in statistical tests employing theWard’s hierarchical clustering method, which exposed excessive amounts of K introduced into groundwater through irrigation with both SIWW and YIWW. However, this parameter is not considered to pose any health risk to humans or the environment, and its content is not restricted by quality guideline values for either groundwater or drinking water.

To document

Abstract

This work focuses on modelling soil water reserves using an Artificial Neural Net-work (ANN). Four model variants were established based on 843 records (verifiedthrough 268 measurements) of soil water content (SWC) measured at full-scale fieldsites located in Southwest Poland. It is revealed that commonly recorded climaticdata (precipitation and temperature) linked with SWC and field water capacity(FWC) are applicable in the ANN modelling. The basic model (utilising the meteoro-logical data) was the most suitable for soil profiles with thicknesses of 0–25 cm,while in profiles with thicknesses of 0–50 cm and 0–100 cm the comprehensiveANN model (linking climatic data, FWC and SWC) was the most appropriate. Fur-thermore, comparative studies of the measured and modelled data indicated theirstatistical convergence, thus providing support for the practical implementation ofthe proposed ANN modelling.

To document

Abstract

Several studies focus on the effects of climate variability on female and male gender relations as perceived through various biophysical and socio-economic aspects. More emphasis is given on the impacts of extreme weather events on rural communities of less developed regions. The results are often interpreted in a qualitative manner through policy measures that may reduce gender inequalities. However, the interpretation of the qualitative results to more crisp and measurable outputs is often not attained while the validation of the findings is rarely ensured. The current study suggests a gender-differentiated impact framework based on qualitative and quantitative components for the assessment of climate variability effects on rural communities in South India. Fifteen villages mostly practicing rice farming in Andhra Pradesh and Telangana states were selected as representative drought-prone case studies. The study results advocate that the qualitative outcomes were validated from the quantitative approach but for a few cases which could be attributed to methodological and case-specific differentiations. Policy recommendations are made on common gender trainings in water-resistant crops and livestock activities for the alleviation of drought impact and abatement of gender inequalities. Also, entrepreneurship workshops for women could enhance gender balance and diverse family income from the current sole dependence on farming revenues. Regional climate adaptation programs could be better implemented when the specific features and capacities of local communities are taken into consideration.

To document

Abstract

Extensive green roofs have become a frequently used option for stormwater retention across manydifferent climates including cold and wet regions. Despite the extensive documentation of green rooftechnology for stormwater management, the knowledge about their function and potential use in wetand cold regions is deficient. Using historic data on daily temperature and precipitation in a green roofwater balance model coupled with the Oudin model of evapotranspiration (ET), we evaluated the effects ofmaximum green roof storage capacities (Smax) and ET on stormwater retention along climatic gradientsin Northern Europe. Large differences in potential annual stormwater retention were found betweenlocations, driven by differences in temperature and precipitation amounts. Highest retention in abso-lute values was found for the wettest locations, while the warmest and driest locations showed highestretention in percentage of annual precipitation (up to 58% compared to 17% for the lower range). Alllocations showed a considerable retention of stormwater during summer, ranging from 52% to 91%. Stor-age capacities accepting drought conditions once every 3.3–3.9 year were found to be about 25 mm inthe cold and wet locations increasing to 40–50 mm in the warmer and drier locations. Correspondingstorage capacities to prevent wilting of non-succulent vegetation was on average a factor of 1.5 larger(not including Sheffield and Malmö). Annual retention increased both with an increase in plant wateruse (specific crop factors, Kc) and with an increase in Smax, but was found to be more sensitive to changesin Kcthan to changes in Smax. Hence, ET was the limiting factor for green roof retention capacity in thecold and wet locations, but relatively large changes in evapotranspiration would be needed to have animpact on retention. The potential to use vegetation with higher water use to better restore the storagecapacity between storm-events in these regions was however limited by the risk of permanent wilting ofnon-succulent vegetation, even on the wettest locations. A considerable increase in roof storage capacityand substrate thickness would be required to reduce this risk; still the increase in stormwater retentionwould be marginal.