Suchergebnisse

Stringent environmental legislation in Europe, especially in the Baltic Sea area, limits the discharge of nutrients to natural water bodies, limiting the aquaculture production in the region. Therefore, cost-efficient end-of-pipe treatment technologies to reduce nitrogen (N) discharge are required for the sustainable growth of marine land-based RAS. The following study examined the potential of fed batch reactors (FBR) in treating saline RAS effluents, aiming to define optimal operational conditions and evaluate the activated sludge denitrification capacity using external (acetate, propionate and ethanol) and internal carbon sources (RAS fish organic waste (FOW) and RAS fermented fish organic waste (FFOW)). The results show that between the evaluated operation cycle times (2, 4, and 6 h), the highest nitrate/nitrite removal rate was achieved at an operation cycle time of 2 h (corresponding to a hydraulic retention time of 2.5 h) when acetate was used as a carbon source. The specific denitrification rates were 98.7±3.4 mg NO 3 --N/(h g biomass) and 93.2±13.6 mg NOx--N/(h g biomass), with a resulting volumetric denitrification capacity of 1.20 kg NO 3 --N/(m 3 reactor d). The usage of external and internal carbon sources at an operation cycle time of 4 h demonstrated that acetate had the highest nitrate removal rate (57.6±6.6 mg N/(h g biomass)), followed by propionate (37.5±6.3 mg NO 3 --N/(h g biomass)), ethanol (25.5±6.0 mg NO 3 --N/(h g biomass)) and internal carbon sources (7.7±1.6 to 14.1±2.2 mg NO 3 --N/(h g biomass)). No TAN (Total Ammonia Nitrogen) or PO 4 3- accumulation was observed in the effluent when using the external carbon sources, while 0.9±0.5 mg TAN/L and 3.9±1.5 mg PO 4 3- -P/L was found in the effluent when using the FOW, and 8.1±0.7 mg TAN/L and 7.3±0.9 mg PO 4 3- -P/L when using FFOW. Average sulfide concentrations varied between 0.002 and 0.008 mg S 2- /L when using the acetate, propionate and FOW, while using ethanol resulted in the accumulation of sulfide (0.26±0.17 mg S 2- /L). ...

"The transition from a mineral dependent economy to one in which biogenic resources form the basis of biobased products and production processes relies both on scientific innovative knowledge and on the capacity of agricultural, aquacultural, and forestry ecosystems to deliver biomass for food and non-food uses. Agricultural policy is expected to play a critical role in facilitating such a transition, being one of the few highly harmonized EU policies, with a substantial budget and a strong experience base. Within the EU, the question often raised is twofold: to what extent the Common Agricultural Policy (CAP) shapes alternative pathways to sustainable bioeconomy transition, and conversely how bioeconomy development is paving the way for new potential areas for reform of the CAP and related research challenges. This also brings in the topic of coordination between the CAP and the EU bioeconomy strategy. The demand of biomass for non-food uses further intensifies agricultural activity. The need to reduce land footprints strengthens the call for smart and innovative approaches, beyond the traditional ways of producing and consuming biomass, and therefore beyond traditional land use patterns. Targeting sustainable bioeconomy development is the object of a multi-policy landscape. In this landscape, policy coherence is a key topic; its achievement is attempted through strategic documents encompassing the main relevant policy areas and authorities. Built on the original strategic guidelines and experience acquired since 2012, the updated European Bioeconomy Strategy (European Commission [EC], 2018) advocates the deployment of circular and sustainable supply chains. Integral to this is the adoption of the cascading principle, defined as using biomass as an input first, then recovering its energy content at its end-of life, and promoting the development of biorefineries that focus on high value products and organic waste re-use."--First page. ; Stelios Rozakis (Technical University of Crete, Greece, Institute of Soil Science and Plant Cultivation (IUNG-PIB), Poland), Davide Viaggi (University of Bologna, Italy), Wieslaw Oleszek (Institute of Soil Science and Plant Cultivation (IUNG-PIB), Poland) ; Includes bibliographical references

This study assessed the physico-chemical quality of River Ogun, Abeokuta, Ogun state, Southwestern Nigeria. Four locations were chosen spatially along the water course to reflect a consideration of all possible human activities that are capable of changing the quality of river water. The water samples were collected monthly for seven consecutive months (December 2011 – June 2012) at the four sampling stations. pH, air temperature (℃), water temperature (℃), conductivity (µs/cm) and total dissolved solids (mg/L) were conducted in-situ with the use of HANNA Combo pH and EC multi meter Hi 98129 and Mercury-in-glass thermometer while dissolved oxygen (mg/L), nitrate (mg/L), phosphate (mg/L), alkalinity (mg/L) and hardness (mg/L) were determined ex-situ using standard methods. Results showed that dissolved oxygen, hydrogen ion concentration, total hardness and nitrate were above the maximum permissible limit of National Administration for Food, Drugs and Control (NAFDAC), Standard Organization of Nigeria (SON), Federal Environmental Protection Agency (FEPA), United States Environmental Protection Agency (USEPA), European Union (EU) and World Health Organization (WHO) for drinking water during certain months of the study period. Results also showed that water temperature and conductivity were within the permissible limits of all the standards excluding FEPA. However, total dissolved solids and alkalinity were within the permissible limits of all the standards. Adejuwon and Adelakun, (2012) also reported similar findings on Rivers Lala, Yobo and Agodo in Ewekoro local government area of Ogun state, Nigeria. Since most of the parameters measured were above the maximum permissible limits of the national and international standards, it can be concluded that the water is unfit for domestic uses, drinking and aquacultural purposes and therefore needs to be treated if it is to be used at all. The low dissolved oxygen values for the first four months was too low i.e. < 5 mg/L. This is most likely as a result of the amount of effluents discharged into the river. To prevent mass extinction of aquatic organisms due to anoxic conditions, proper regulations should be implemented to reduce the organic load the river receives.