Dijk, E.J.H. van \ Pronk, M. \ Loosdrecht, M.C.M. van \ 2018
water pollution - water quality - water supply - waste water treatment - government policy - environmental policy - environmental legislation - air pollution - soil pollution - aquatic environment
Abstract: The main processes contributing to elevated effluent suspended solids in the full-scale aerobic granular sludge process were studied. The two processes found to be most important were (1) rising of sludge due to degasification of nitrogen gas (produced by denitrification) and (2) wash-out of particles that intrinsically do not settle such as certain fats and foams. A mathematical model was made to describe the process of degasification of nitrogen gas during the feeding phase in an AGS reactor. The process of rising sludge due to degasification could be limited by stripping out the nitrogen gas before starting the settling phase in the process cycle. The wash-out of scum particles could be reduced by introducing a vertical scum baffle in front of the effluent weir, similar to weirs in traditional clarifiers. A full-scale Nereda® reactor in the municipality of Utrecht, The Netherlands, was operated with a nitrogen stripping phase and scum baffles for 9 months at an average biomass concentration of 10 g L-1 and an average granulation grade of 84%. In this period the influent suspended solids concentration was 230±118 mg L-1 and the concentration of effluent suspended solids was 7:8±3:8 mg L-1.
Mannina, G. \ Chandran, K. \ Capodici, M. \ Cosenza, A. \ Di Trapani, D. \ Loosdrecht, M.C.M. van \ 2018
water treatment - waste water treatment - sewage effluent disposal - water resources - water supply - water pollution - water quality - damage - environment - purification plants - Water quality management - Sewage Purification - Water Pollution - Water quality management
Abstract: This study aimed at evaluating the nitrous oxide (N2O) emissions from membrane bioreactors (MBRs) for wastewater treatment. The study investigated the N2O emissions considering multiple influential factors over a two-year period: (i) different MBR based process configurations; (ii) wastewater composition (municipal or industrial); (iii) operational conditions (i.e. sludge retention time, carbonto- nitrogen ratio, C/N, hydraulic retention time); (iv) membrane modules.
Abstract: Circular solutions for nutrients in biowaste Oscar Schoumans, Inge Regelink, Wageningen Environmental Research Arjan Prinsen, Groot Zevert Vergisting Kees Kroes, LTO -Noord Projectbureau Introduction The Dutch intensive agriculture highly depend on the import of nutrients as feed and fertiliser. Consequently, large amounts of organic waste streams (‘biowaste ’) are produced mainly as manure but also as sewage sludge and food waste. In order to prevent nutrient losses to the environment limited amounts of manure, other waste streams and mineral fertilisers can be applied on agricultural land. Valuable components of organic waste like nitrogen (N), phosphorus (P) and potassium (K) and organic matter are exported over large distances (manure and compost of food waste or sewage sludge) or incinerated (mainly poultry manure and sewage sludge).
Abstract: Ammoniumrijk afvalwater wordt veelal geproduceerd door gemeentelijk, industrieel en landbouwafval, en effluent uit anaerobe afvalwaterzuiveringsmethoden. Dit vormt een risico voor het milieu vanwege de hoge concentratie aan voedingsstoffen (stikstof en fosfor), wat eutrofiëring in waterpartijen kan bevorderen en daarmee de kwaliteit van ecosystemen kan aantasten. Als innovatieve oplossing hierop is een nieuw biologisch verwerkingsmechanisme genaamd Photo-Activated Sludge (PAS) geëvalueerd, wat gebruik maakt van een consortium van microalgen en bacteriën voor de zuivering van ammoniumrijk afvalwater.
Abstract: Nitrate loss from bioenergy crop fields has attracted considerable attention during the last few years because of its potential negative impact on aquatic and human health. Both controllable and uncontrollable factors for nitrate loss have been the subject of several previous studies. Due to differences in climate, biophysical dissimilarities and land management characteristics in different parts of the world the factors affecting nitrate loss are often inconsistent and hence difficult to generalize. Therefore, reanalyzing the experimental field or plot scale studies to understand the nitrate loss factors in crop fields is useful and necessary in developing management strategies for reducing nitrate loss. This research synthesized and investigated 36 peer reviewed scientific journal articles related to selected bioenergy crop fields that included: continuous corn, corn in rotation with soybean, switchgrass and Miscanthus to conduct a meta-analysis of the available research. In this study, factors such as drain tile spacing, tillage practices, type and timing of the fertilization rate, irrigation and various other factors, which are challenging to represent in regression equations, were also systematically analyzed. In addition, various other agronomic characteristics that are attributed too nitrate loss are caused by perennially planted bio energized crops such as Miscanthus and switchgrass. Results indicated that 49% of nitrate loss through surface runoff from corn fields is directly related to the annual precipitation and fertilization rate. Multiple linear regression equations were developed to estimate the annual subsurface nitrate loss for the continuous corn fields with a R2 value of 0.65, 0.58 and 0.26 for sandy loam, silty loam and clay loam, respectively. Our analysis resulted in the conclusion that corn has a 2 to 3 times higher nitrate loss in surface runoff compared to switchgrass. Likewise, continuous corn and corn in rotation with soybean contributed more than 9 times the subsurface loss of nitrate compared to the established subsurface loss attributed to the Miscanthus and switchgrass
Abstract: Dit proefschrift draagt bij tot een beter begrip van de interacties tussen de bodem-waterplant systemen en tot meer geavanceerde procesgerichte modelmatige benaderingen. Bovendien wordt antwoord gegeven op vier onderzoeksvragen: 1. Wat is de rol van de verticale waterstromen zoals capillaire opstijging en recirculerend percolatiewater op de gewasopbrengsten? 2. Hoe kunnen we droogte-, zout- en zuurstof-stress modelleren en wat is hun invloed op de gewasopbrengsten? 3. Kunnen we de impact van verschillende stress-vormen op de graslandproductie in Nederland voorspellen? 4. Wat is de invloed van veranderingen in grondwaterstanden en landgebruik op gewasopbrengsten en grondwateraanvulling?
Abstract: More isn’t necessarily better when it comes to protein levels in calf milk replacers. The latest research shows that lower concentrations of protein, but with a specific balance of amino acids, can improve growth rates in pre-weaned calves. And such a move can also reduce milk replacer costs and ‘waste’ nitrogen
Abstract: To achieve a more sustainable way of living, more plant - based protein instead of animal protein should be consumed. A good alternative for animal protein is soy protein. Soy beans have a high protein content, has a lot of micronutrients and an amino acid profile close to the human needs. Soy protein is already applied in different food products and the objective of this study was to find potential to apply soy protein as a food product to replace animal - based protein. Commercial soy protein isolate (SPI), commercial soy protein concentrate (SPC) and soy protein fraction (SPF) obtained via a mild aqueous fractionation that is more sustainable than commercial protein extraction methods. These powders were analysed with the shear rate sweep, time sweep and temperature sweep. Dispersions of 2%, 5%, 8%, 10%, 12%, 15% and 18% mass concentration were used to perform the shear rat e sweep, time sweep and temperature sweep. The same measurements were performed using 12% dispersions of pH 3.5, 4.5, 5.5, 6.5 and 7.5. The results of the shear rate sweep showed that an increase in mass concentration of soy protein powder resulted in an increase in viscosity. The quantitative height of the viscosity of SPI was the highest, then SPC and lastly SPF. From the shear rate sweep, it was determined that a 12 wt% concentration was suitable to apply as a soy yoghurt based on the viscosity, physical appearance and shear thinning behaviour. The SPI showed a viscosity - decreasing regime in the beginning of the time sweep, whereas SPC and SPF showed a constant viscosity in the beginning. The temperature sweep reached higher viscosities for SPF compared to SPI and SPC, as these samples reached comparable, but lower viscosities. The results of measurements of 12% dispersions at different pH values showed the influence of the pH on viscosity and physical appearance. The nitrogen solubility index and the wat er holding capacity were taken into account by explaining the results. The results indicated that the SPF at pH 7.5 had the most potential to be applied as a soy drink yoghurt, based on the viscosity, shear thinning behaviour, solubility and the physical appearance. However, more research should be done to determine how suitable SPF is for this application based on other requirements
Abstract: During the 20th century, the strong deterioration of the quality and the biodiversity of Dutch nature and woodlands slowly became eminent. At that time, the country was already densely populated and industrialized. This deterioration also occurred in the 162 Natura 2000 sites, in which many species and habitat types still have an unfavora - ble conservation status. Consequently, in 1989 the Ministry of Agriculture, Nature Conservation and Fisheries (currently: Ministry of Agriculture, Nature and Food Quality) started the ‘Survival Plan of Dutch Nature’, that included a budget for nature restoration measures. In the early nineties, this plan lead to a knowledge network that focused on the supervision and monitoring of these measures, and that slowly developed into the current OBN Knowledge Network. Until 2006, these measures solely focused on the reduction of the impact of desiccation, eutrophication, atmospheric nitrogen deposition, and acidification. Nowadays, a much wider focus has been established.
Abstract: In de regel wordt aangenomen dat in luchtwassers met een biologische behandelingsstap ammoniak uit stallucht wordt omgezet in nitraat en nitriet, dat vervolgens met het spuiwater wordt afgevoerd. Er zijn echter aanwijzingen dat onder bepaalde condities (grote) hoeveelheden andere gasvormige stikstofverbindingen kunnen ontstaan en emitteren. Uit de steekproef die is uitgevoerd, blijkt dat bij biologische luchtwassers met een lage pH (< 6,5) grote hoeveelheden stikstofoxyden (NOy) kunnen ontwijken naar de lucht. Voor dergelijk luchtwassers is de netto stikstofverwijdering veel lager dan de ammoniakverwijdering---In a biotrickling filter treating animal house exhaust air, ammonia is usually converted to dissolved nitrite and nitrate and subsequently removed with the discharge water. However, under certain operating conditions other types of gaseous nitrogen compounds may be emitted to the air. From the survey that was conducted it follows that at low pH values (< 6.5) large amounts of gaseous nitrogen oxides (NOy) may be emitted from biotrickling filters. As a result, the net nitrogen removal of these scrubbers is much lower than the ammonia removal efficiency
public green areas - non-crop weed control - landscape architecture - management of urban green areas - custom hiring - green roofs - green walls - urban areas
Abstract: De gemeente Sittard-Geleen bruist van ambitie en innovatiekracht. Het nieuwbouwproject Ligne in het centrum is daar een voorbeeld van. Hoewel de gemeente graag wijst naar de aanwezigheid van bedrijven zoals DSM, SABIC en OIC Nitrogen om haar claim op ambitie en innovatiekracht te ondersteunen, was het Nophadrain uit het naburige Kerkrade dat dit in het nieuwbouwproject Ligne ten uitvoer bracht.
Abstract: Bradyrhizobium spp. are well known for their capacity to initiate a beneficial relationship with a large variety of legume species and the non-legume Parasponia. Through initiation of nodulogenesis in plants, Bradyrhizobium spp. are able to utilize organic molecules derived from photosynthesis in exchange for fixed nitrogen. The genes essential for the nitrogen-fixation and nodulation trait are clustered chromosomally on so called symbiotic islands, which are wildly accepted to be of foreign origin. However, previously published Bradyrhizobium ecotypes have been shown to be non-symbiotic. These non-symbionts were found to be highly abundant in soils lacking legumes and do not harbour the nitrogen fixation and nodulation gene clusters. Recently, a study showed that a multitude of Bradyrhizobium strains are highly abundant in the root endophytic compartment of eight different plant species originating from the same ecological test field. From a single Arabidopsis thaliana (Arabidopsis) root, four genetically and functionally highly diverse Bradyrhizobium strains were isolated. These isolates, designated Bradyrhizobium sp. MOS001 to MOS004, were shown to be nonsymbiotic. However, the nature of the interaction between these non-symbiotic Bradyrhizobium isolates and the root endophytic compartment remained elusive. In this study, we show the first step to identify the nature of this host-microbe interaction through localization of these non-symbionts on roots of model species Arabidopsis. Moreover, we show the construction of strain specific plasmids which become stably integrated at a uniform locus in the chromosome of MOS001, MOS004 and type strain Bradyrhizobium diazoefficiens USDA110 (USDA110). These constructs enable expression of a single copy gene for a Bradyrhizobium optimized green fluorescent protein. Here, we reportsuccessful construction of green fluorescent protein-expressing USDA110, MOS001 and MOS004 strains. In our experimental setup, we were unable to detect these labelled strains in the root endophytic compartment of Arabidopsis.
Bruggen, C. van \ Bannink, A \ Groenestein, C.M. \ Huijsmans, J.F.M. \ Luesink, H.H. \ Sluis, S.M. van der \ Velthof, G.L. \ Vonk, J. \ 2018
Abstract: Agricultural activities are in the Netherlands a major source of ammonia (NH3), nitrogen oxide (NO), nitrous oxide (N2O), methane (CH4) and particulate matter (PM10 and PM2.5). The emissions in 2016 were calculated using the National Emission Model for Agriculture (NEMA). Some figures in the time series 1990-2015 were revised. The method calculates the NH3 emission from livestock manure based on the total ammonia nitrogen (TAN) content in manure. In 2016 NH3 emissions from livestock manure, fertilizer and other sources in agriculture, from hobby farms, private parties and manure disposal in nature areas amounted to 116.8 million kg NH3, 1.3 million kg more than in 2015. Nitrogen excretion increased due to expansion of the dairy herd, but because of a larger share of low emission housing and more manure exports outside agriculture, the increase in NH3 emission remained limited. N2O emissions in 2016 were 21.1 million kg at virtually the same level as in 2015 (21.2). NO emissions in 2016 totaled 22.8 million kg compared to 22.6 million kg in 2015. CH4 emissions increased from 496 to 512 million kg due to the expansion of the dairy herd. Emissions of particulate matter PM10 and PM2.5, 6.5 and 0.6 million kg respectively, did not change compared to 2015. NH3 emissions from livestock manure in the Netherlands dropped by almost two thirds since 1990, mainly as a result of lower nitrogen excretion rates by livestock and lowemission manure application. Emissions of N2O and NO also decreased over the same period, but less strongly(38% and 31% respectively), due to higher emissions from manure injection into the soil and the shift from poultry housing systems with liquid manure towards solid manure systems. CH4 emissions reduced by 13% between 1990 and 2016 caused by a decreasein livestock numbers and increased feed efficiency of dairy cattle.
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