Estimating subsoil resistance to nitrate leaching from easily measurable pedological properties

Leaching of nitrate (NO3-) can increase the groundwater concentration of this anion and reduce the agronomical effectiveness of nitrogen fertilizers. The main soil property inversely related to NO3- leaching is the anion exchange capacity (AEC), whose determination is however too time-consuming for being carried out in soil testing laboratories. For this reason, this study evaluated if more easily measurable soil properties could be used to estimate the resistance of subsoils to NO3- leaching. Samples from the subsurface layer (20-40 cm) of 24 representative soils of São Paulo State were characterized for particle-size distribution and for chemical and electrochemical properties. The subsoil content of adsorbed NO3- was calculated from the difference between the NO3- contents extracted with 1 mol L-1 KCl and with water; furthermore, NO3- leaching was studied in miscible displacement experiments. The results of both adsorption and leaching experiments were consistent with the well-known role exerted by AEC on the nitrate behavior in weathered soils. Multiple regression analysis indicated that in subsoils with (i) low values of remaining phosphorus (Prem), (ii) low soil pH values measured in water (pH H2O), and (iii) high pH values measured in 1 moL L-1 KCl (pH KCl), the amounts of surface positive charges tend to be greater. For this reason, NO3- leaching tends to be slower in these subsoils, even under saturated flow condition.

Pedotransfer functions to estimate water retention parameters of soils in northeastern Brazil

Pedotransfer functions (PTF) were developed to estimate the parameters (α, n, θr and θs) of the van Genuchten model (1980) to describe soil water retention curves. The data came from various sources, mainly from studies conducted by universities in Northeast Brazil, by the Brazilian Agricultural Research Corporation (Embrapa) and by a corporation for the development of the São Francisco and Parnaíba river basins (Codevasf), totaling 786 retention curves, which were divided into two data sets: 85 % for the development of PTFs, and 15 % for testing and validation, considered independent data. Aside from the development of general PTFs for all soils together, specific PTFs were developed for the soil classes Ultisols, Oxisols, Entisols, and Alfisols by multiple regression techniques, using a stepwise procedure (forward and backward) to select the best predictors. Two types of PTFs were developed: the first included all predictors (soil density, proportions of sand, silt, clay, and organic matter), and the second only the proportions of sand, silt and clay. The evaluation of adequacy of the PTFs was based on the correlation coefficient (R) and Willmott index (d). To evaluate the PTF for the moisture content at specific pressure heads, we used the root mean square error (RMSE). The PTF-predicted retention curve is relatively poor, except for the residual water content. The inclusion of organic matter as a PTF predictor improved the prediction of parameter a of van Genuchten. The performance of soil-class-specific PTFs was not better than of the general PTF. Except for the water content of saturated soil estimated by particle size distribution, the tested models for water content prediction at specific pressure heads proved satisfactory. Predictions of water content at pressure heads more negative than -0.6 m, using a PTF considering particle size distribution, are only slightly lower than those obtained by PTFs including bulk density and organic matter content.

Soil functioning in a toposequence under rainforest in São Paulo, Brazil

Studies of soil-water dynamics using toposequences are essential to improve the understanding of soil-water-vegetation relationships. This study assessed the hydro-physical and morphological characteristics of soils of Atlantic Rainforest in the Parque Estadual de Carlos Botelho, state of São Paulo, Brazil. The study area of 10.24 ha (320 x 320 m) was covered by dense tropical rainforest (Atlantic Rainforest). Based on soil maps and topographic maps of the area, a representative transect of the soil in this plot was chosen and five soil trenches were opened to determine morphological properties. To evaluate the soil hydro-physical functioning, soil particle size distribution, bulk density (r), particle density (r s), soil water retention curves (SWRC), field saturated hydraulic conductivity (Ks), macroporosity (macro), and microporosity (micro) and total porosity (TP) were determined. Undisturbed samples were collected for micromorphometric image analysis, to determine pore size, shape, and connectivity. The soils in the study area were predominantly Inceptisols, and secondly Entisols and Epiaquic Haplustult. In the soil hydro-physical characterization of the selected transect, a change was observed in Ks between the surface and subsurface layers, from high/intermediate to intermediate/low permeability. This variation in soil-water dynamics was also observed in the SWRC, with higher water retention in the subsurface horizons. The soil hydro-physical behavior was influenced by the morphogenetic characteristics of the soils.

Pedotransfer functions to estimate retention and availability of water in soils of the state of Santa Catarina, Brazil

Studies on water retention and availability are scarce for subtropical or humid temperate climate regions of the southern hemisphere. The aims of this study were to evaluate the relations of the soil physical, chemical, and mineralogical properties with water retention and availability for the generation and validation of continuous point pedotransfer functions (PTFs) for soils of the State of Santa Catarina (SC) in the South of Brazil. Horizons of 44 profiles were sampled in areas under different cover crops and regions of SC, to determine: field capacity (FC, 10 kPa), permanent wilting point (PWP, 1,500 kPa), available water content (AW, by difference), saturated hydraulic conductivity, bulk density, aggregate stability, particle size distribution (seven classes), organic matter content, and particle density. Chemical and mineralogical properties were obtained from the literature. Spearman's rank correlation analysis and path analysis were used in the statistical analyses. The point PTFs for estimation of FC, PWP and AW were generated for the soil surface and subsurface through multiple regression analysis, followed by robust regression analysis, using two sets of predictive variables. Soils with finer texture and/or greater organic matter content retain more moisture, and organic matter is the property that mainly controls the water availability to plants in soil surface horizons. Path analysis was useful in understanding the relationships between soil properties for FC, PWP and AW. The predictive power of the generated PTFs to estimate FC and PWP was good for all horizons, while AW was best estimated by more complex models with better prediction for the surface horizons of soils in Santa Catarina.

Chemical properties and mineralogy of soils with plinthite and petroplinthite in Iranduba (AM), Brazil

Large areas of Plinthosols with ferruginous materials such as plinthite and/or petroplinthite are fairly common in the Brazilian Amazon basin. This work was carried out to investigate the chemical behavior, mineralogical composition and weathering stage of four representative soil profiles with plinthite and petroplinthite, in Iranduba, AM (Central Amazon). Three well-drained soil profiles at high elevations were studied (P1, Plinthic Vetic Ferralsol; P2 and P3, Vetic Endopetric Plinthosol) and a contrasting poorly drained soil (P4 Haplic Plinthosol), located at low elevation. After profile descriptions, soil samples were collected from each horizon, air-dried, sieved (2 mm), and analyzed for particle-size distribution, pH, exchangeable cations (Al3+, Ca2+, Mg2+, K+, and Na+), as well as available P and total organic carbon (TOC) content. The minerals present in the clay and sand fractions, as well as in the ferruginous materials were identified by X-ray Diffraction (XRD). The weathering stage of these soils was assessed by means of Ki and Kr indexes, and the amounts of free and amorphous Fe and Al oxides by using dithionite citrate bicarbonate (DBC) and ammonium oxalate dissolution procedures, respectively. The results showed that all soils were extremely unfertile, with pH levels ranging between strong and moderate acidity, very low sum of bases and organic matter content, and of available P. The mineralogy of the soil profiles was very similar, mainly of the well-drained soils, with predominance of kaolinite and quartz in the clay and sand fractions, respectively. In the poorly-drained P4, 2:1 clay particles were also observed. These profiles can be considered highly developed according to the Ki index, however, the Ki value of P4 was higher, indicating that this soil was less developed than the others. In summary, these profiles with plinthite and petroplinthite can be characterized as highly developed and infertile soils and are, with exception of P4, well-drained.

Water storage variability in a vineyard soil in the southern highlands of Santa Catarina state

In the subtropical regions of southern Brazil, rainfall distribution is uneven, which results in temporal variability of soil water storage. For grapes, water is generally available in excess and water deficiency occurs only occasionally. Furthermore, on the Southern Plateau of Santa Catarina, there are differences in soil properties, which results in high spatial variability. These two factors affect the composition of wine grapes. Spatio-temporal analyses are therefore useful in the selection of cultural practices as well as of adequate soils for vineyards. In this way, well-suited areas can produce grapes with a more appropriate composition for the production of quality wines. The aim of this study was to evaluate the spatio-temporal variability of water storage in a Cambisol during the growth cycle of a Cabernet Sauvignon vineyard and its relation to selected soil properties. The experimental area consisted of a commercial 8-year-old vineyard in São Joaquim, Santa Catarina, Brazil. A sampling grid with five rows and seven points per row, spaced 12 m apart, was outlined on an area of 3,456 m². Soil samples were collected with an auger at these points, 0.30 m away from the grapevines, in the 0.00-0.30 m layer, to determine gravimetric soil moisture. Measurements were taken once a week from December 2008 to April 2009, and every two weeks from December 2009 to March 2010. In December 2008, undisturbed soil samples were collected to determine bulk density, macro- and microporosity, and disturbed samples were used to quantify particle size distribution and organic carbon content. Results were subjected to descriptive analysis and semivariogram analysis, calculating the mean relative difference and the Pearson correlation. The average water storage in a Cambisol under grapevine on ridges had variable spatial dependence, i.e., the lower the average water storage, the higher the range of spatial dependence. Water storage had a stable spatial pattern during the trial period, indicating that the points with lower water storage or points with higher water storage during a certain period maintain these conditions throughout the experimental period. The relative difference is a simple method to identify positions that represent the average soil water storage more adequately at any time for a given area.

Properties of debris flow deposits and source materials compared: implications for debris flow characterization

In the Alps, debris flow deposits generally contain < 5% clay-size particles, and the role of the surface-charged < 2 mu m particles is often neglected, although these particles may have a significant impact on the rheological properties of the interstitial fluid. The objective of this study was to compare debris flow deposits and parent materials from two neighbouring catchments of the Swiss Alps, with special emphasis on the colloidal constituents. The catchments are small in area (4 km(2)), 2.5 km long, similar in morphology, but different in geology. The average slopes are 35-40%. The catchments were monitored for debris flow events and mapped for surface aspect and erosion activity. Debris flow deposits and parent materials were sampled, the clay and silt fractions extracted and the bulk density, < 2 mm fraction bulk density, particle size distribution, chemical composition, cation exchange capacity (CEC) and mineralogy analysed. The results show that the deposits are similar to the parent screes in terms of chemical composition, but differ in terms of: (i) particle size distribution; and (ii) mineralogy, reactivity and density of the < 2 mm fraction. In this fraction, compared with the parent materials the deposits show dense materials enriched in coarse monocrystalline particles, of which the smallest and more reactive particles were leached. The results suggest that deposit samples should not be considered as representative of source or flow materials, particularly with respect to their physical properties.

Quantitative Assessment of Soil Physical Quality in Northern China Based on S-theory

ABSTRACT Quantitative assessment of soil physical quality is of great importance for eco-environmental pollution and soil quality studies. In this paper, based on the S-theory, data from 16 collection sites in the Haihe River Basin in northern China were used, and the effects of soil particle size distribution and bulk density on three important indices of theS-theory were investigated on a regional scale. The relationships between unsaturated hydraulic conductivityKi at the inflection point and S values (S/hi) were also studied using two different types of fitting equations. The results showed that the polynomial equation was better than the linear equation for describing the relationships between -log Ki and -logS, and -log Kiand -log (S/hi)2; and clay content was the most important factor affecting the soil physical quality index (S). The variation in the S index according to soil clay content was able to be fitted using a double-linear-line approach, with decrease in the S index being much faster for clay content less than 20 %. In contrast, the bulk density index was found to be less important than clay content. The average S index was 0.077, indicating that soil physical quality in the Haihe River Basin was good.

Hydro-Physical Properties of a Typic Hapludult under the Effect of Rice Husk Ash

ABSTRACT The combustion of rice husk generates a partially burnt mixture called rice husk ash (RHA) that can be used as a source of nutrients to crops and as a conditioner of soil physical properties. The objective of this study was to evaluate the effect of RHA levels on the hydro-physical properties of a Typic Hapludult. The experimental design was composed of random blocks with four replications, which comprised plots of 24 m2 and treatments with increasing RHA rates: 0, 40, 80 and 120 Mg ha-1. Undisturbed soil samples were collected in the soil layers of 0.00-0.10 and 0.10-0.20 m after nine months of RHA application, using steel cylinders (0.03 m of height and 0.047 m of diameter). These samples were used to determine soil bulk density (Bd), total soil porosity (TP), soil macroporosity (Ma), soil microporosity (Mi) and the available water capacity (AWC). Disturbed soil samples were collected to determine the stability of soil aggregates in water, mean weight diameter of water stable aggregates (MWD), and soil particle size distribution. The results show that, as the RHA rate increased in the soil, Bd values decreased and TP, Ma and MWD values increased. No effect of RHA was found on Mi and AWC values. The effects of RHA on the S parameter (Dexter, 2004), precompression stress and compression index (Dias Junior and Pierce, 1995) values are consistent those shown for density and total porosity. Rice husk ash was shown to be an efficient residue to improve soil physical properties, mainly at rates between 40 and 80 Mg ha-1. Rice husk ash reduces bulk density and increases total porosity, macroporosity and soil aggregation, but does not affect microporosity, field capacity, permanent wilting point, and available water capacity of the soil. The effect of rice husk ash on the S parameter, precompression stress and index compressibility coefficient values are consistent with those observed for the bulk density and total porosity.

Testing of Vacuum Drum Filter

Tämän diplomityön tavoitteena oli testata ja optimoida erään alipainerumpusuodattimen toimivuutta, ja lisäksi maksimoida tuottavuus ja vertailla erilaisten pesumenetelmientehokkuutta. Testilietteiden ¿ rautarikasteen ja täyteainepastan ¿ karakterisointi oli myös tärkeää. Kirjallisuusosassa tarkasteltiin lyhyesti neste-kiintoaine-erotuksen teoriaa, erityisesti alipainesuodatusta ja alipainerumpusuodattimia. Lisäksi käsiteltiin kapillaarisuodatuksen toimintaperiaatteita sekä selvitettiin kaivosteollisuuden veden talteenottokeinoja, kiintoainejäämien käsittelymenetelmiä ja Chilen kaivosteollisuuden nykytilaa. Työn kokeellinen osa suoritettiin käyttämällä raskaita ja kiintoainepitoisuuksiltaan korkeita lietteitä, eli rautarikastetta ja täyteainepastaa. Kokeet suoritettiin erityisellä alipainerumpusuodattimella, joka oli muokattu perinteisestäpäältä syötettävästä alipainerumpusuodattimesta. Kokeissa tutkittiin pyörimisnopeuden ja erilaisten pesumenetelmien vaikutusta kakun kosteuteen ja suodatuskapasiteettiin. Koelietteiden karakterisointi suoritettiin analysoimalla partikkelikokojakauma, kiintoainepitoisuus, metallipitoisuus ja koostumus. Kokeiden perusteella havaittiin, että rummun pyörimisnopeudella ja lietteen kiintoainepitoisuudella on merkittävä vaikutus suodatuskapasiteettiin ja kakun kosteuspitoisuuteen. Havaittiin myös, että kakun kosteuspitoisuuksissa ja rummun suodatuskapasiteeteissa oli eroja, kun verrattiin eri suodatinväliaineen pesumenetelmiä. Täten oikean pesumenetelmän valinta on tärkeää, ja sillä pystytään lisäämään suodatinväliaineen käyttöikää.

Eräiden paperinvalmistuksessa käytettävien vahadispersioiden stabiilisuuden hallinta

Diplomityön tavoitteena oli selvittää millainen laaduntarkastus AKD-dispersioille tulisi suorittaa kuormien vastaanotossa ja tulisiko dispersioiden laatu tarkastaa uudelleen ennen annostelua. Tätä varten seurattiin toimituserien laadun tasaisuutta ja tarkasteltiin varastointiolosuhteiden vaikutusta dispersioiden säilyvyyteen. Lisäksi kartoitettiin dispersioiden käsittelyssä ja kartonginvalmistusprosessissa esiintyvien riskitekijöiden vaikutuksia kaupallisten dispersioiden stabiilisuuteen. Kirjallisuusosassa perehdyttiin kolloidisiin dispersioihin sekä niiden stabiilisuuteen vaikuttaviin tekijöihin. AKD-dispersiot valmistetaan emulgointitekniikoiden avulla, joten dispergointimenetelmien ohella käsiteltiin myös emulsioiden valmistamista. Lisäksi luotiin katsaus dispersioteknologian tärkeimpiin analyysimenetelmiin. Alkyyliketeenidimeerin osalta käsiteltiin emulgoinnin lisäksi vahan ja muiden lisäaineiden vaikutuksia dispersioiden stabiilisuuteen ja myös niiden merkitystä dispersioiden formuloinnissa. AKD-liimauksen osalta esiin tuotiin AKD:n tärkeimmät reaktiomekanismit, sillä ne liittyvät osittain myös dispersioiden stabiilisuuteen. Lopuksi luotiin lyhyt katsaus AKD-dispersioiden stabiilisuutta käsittelevään tutkimukseen, jota on toistaiseksi julkaistu varsin niukasti. Kokeellisessaosassa tarkastelun kohteeksi valittiin neljä kaupallista alkyyliketeenidimeerinvesidispersiota, joiden koostumus ja ominaisuudet selvitettiin perusteellisesti. Tarkoituksena oli auttaa ymmärtämään dispersioiden stabiilisuudessa mahdollisesti esiintyviä eroja. Laajamittainen dispersioiden karakterisointi näyttää olevan tarpeen ainakin otettaessa uutta AKD-laatua käyttöön, sillä dispersioiden koostumus ja ominaisuudet voivat vaihdella merkittävästi. AKD-dispersioiden laadussa esiintyi vaihtelua eri toimituserien välillä. Suurimmat vaihtelut havaittiin dispersioiden varaustiloissa ja partikkelikokojakaumissa. Laadun epätasaisuuden vuoksi vastaanottotarkastuksen merkitys korostuu. Vastaanottotarkastuksessa syytä olisi kiinnittää dispersion kuiva-ainepitoisuuden ohella sen viskositeettiin, varaustilaan, tehoainepitoisuuteen sekä rakenteeseen. Rakenteen tarkastelussa optinen mikroskooppi voi rutiininomaisessa seurannassa korvata partikkelikokojakauman määrittämisen. Varastointilämpötilan vaikutus dispersioidenlaatuun on merkittävä. Dispersiot säilyvät parhaiten viileässä, joten jos varastosäiliöissä ei ole jäähdytystä, on dispersioiden laadun tarkastus tarpeen myös ennen annostelua. Jotta dispersion kunnosta saadaan luotettava arvio, on viskositeetin määrittämiseen yhdistettävä vähintään rakenteen tarkastelu optisella mikroskoopilla. Mekaaninen rasitus voi dominoivasta stabilointimekanismistariippuen aiheuttaa dispersiossa hienoaineen muodostumista tai partikkelien flokkaantumista. Stabilointimekanismi vaikuttaa niin ikään partikkelien käyttäytymiseen korkeissa lämpötiloissa. Dispersioiden stabiilisuuden todettiin heikkenevän pH:n kohotessa emäksiselle alueelle. Elektrolyyttikonsentraatio vaikuttaa partikkelien mikroelektroforeettiseen ioniliikkuvuuteen merkittävästi. Kartonkikoneen märkäosan kemikaaleista anionisen retentioaineen (BMA) todettiin vuorovaikuttavan kationisten AKD-partikkelien kanssa selvimmin. Mikroelektroforeettisen ioniliikkuvuuden mittaaminen kiertovedessä todettiin tärkeäksi, sillä se kuvaa dispersion käyttäytymistä sen käyttöympäristössä.

Partikkelikokoanalyysimenetelmän kehittäminen

Päällystettyä paperia valmistettaessa syntyy päällystettyä hylkyä, joka kierrätetään takaisin prosessiin raaka-aineen tehokkaaksi hyödyntämiseksi. Hylyn mukana takaisin paperikoneen lyhyeen kiertoon päätyy myös pigmenttiaines levymäisinä partikkeleina. Nämä partikkelit rejektoituvat lyhyen kierron pyörrepuhdistimilla. Raaka-aineen hävikin pienentämiseksi käytetään lyhyessä kierrossa täyteaineen talteenottojärjestelmää, jonka tehtävänä on hienontaa päällystysainepartikkelit tasakokoisiksi, jotta ne voitaisiin palauttaa prosessiin. Talteenottolaitteistojen toiminnan tarkkailun kannalta on keskeistä tietää pyörrepuhdistuslaitoksen eri jakeiden partikkelikokojakaumat juuri pigmenttipartikkelien osalta. Tätä määritystä häiritsee näytteissä oleva kuitu. Tässä työssä pyrittiin löytämään partikkelikokoanalyysimenetelmä, jolla pigmenttien partikkelikokojakauma saataisiin selvitettyä kuidusta huolimatta. Aiemmin käytetty näytteen tuhkaus esikäsittelynä ennen partikkelikokoanalyysiä laserdiffraktiometrillä on osoittautunut toimimattomaksi. Kokeiden pääpaino keskittyi näytteen esikäsittelyyn fraktioinnilla ennen laserdiffraktioanalyysiä ja virtaussytometriamittauksiin. Fraktiointiin käytettiin DDJ-laitetta (dynamic drainage jar), joka oli varustettu metalliviiralla. Kumpikaan menetelmistä ei ollut täysin toimiva partikkelikokoanalyysiin, fraktioinnilla saadaan vähennettyä kuidun partikkelikokojakaumaan aiheuttamaa virhettä, mutta sen toimivuus riippuu paljolti näytteestä. Virtaussytometrialla väriainetta SYTO13 käyttämällä saadaan pigmenttipartikkelit tunnistettua ja näin rajattua kuidut pois mittauksista, mutta pigmenttiä ei saada erotettua puuperäisestä hienoaineesta, mikä vääristää mittaustulosta.

Puun ja turpeen sekapolton vaikutus leijukerroskattilan hiukkaspäästöihin

Työn tavoitteena oli tutkia vaikuttaako puupolttoaineen lisääminen turpeen joukkoon leijukerroskattilan hiukkaspäästöihin tai sähkösuodattimen erotusasteeseen. Työn teoriaosassa selvitettiin hiukkaspäästöjen muodostumista leijukerrospoltossa ja vertailtiin eri polttotekniikoiden hiukkaspäästöjä. Lisäksi esiteltiin erilaisia hiukkasten erottamiseen soveltuvia erotuslaitteita. Tarkastelussa keskityttiin sähkösuodattimeen, joka on yleisin hiukkasten erottamiseen käytettävä erotuslaite. Työn kokeellinen osa suoritettiin turvetta ja puuta polttavalla kuplivalla leijukerroskattilalla. Kokeellisessa osassa tutkittiin vaikuttaako puun lisäys syntyvien hiukkasten kokojakaumiin, sähkösuodattimen jälkeiseen kokonaishiukkaspäästöön tai sähkösuodattimen erotusasteeseen. Kokeet suoritettiin sekä pelkkänä turpeenpolttona (2 koetta), että kahdella eri puu/turve-polttoainesuhteella. Kokojakaumamittaukset suoritettiin lisäksi kahdella eri menetelmällä. Kokojakaumamittausten perusteella todettiin puun lisäyksen kasvattavan pienhiukkasten muodostumista. Pienhiukkasten osuus kasvoi sekapolton myötä myös sähkösuodattimen jälkeen. Sekapoltolla ei sen sijaan ollut selvää vaikutusta kokonaishiukkaspäästöön tai sähkösuodattimen erotusasteeseen.

Jäännöshiilen ja kalkkikiven reaktiokinetiikan mallinnus kiertoleijukattilan tulipesässä

Työn tavoitteena oli kehittää mallit jäännöshiilen ja kalkkikiven reaktiokinetiikan sekä jäännöshiilen jauhautumisen ennustamiseksi kiertoleijukattilan tulipesässä. Kehitetyt mallit toimivat tulipesämallin osamalleina. Perustuen mallinnettuihin reaktionopeuksiin ja jauhautumiskäyttäytymiseen tulipesämalli ennustaa kalkkikivihiukkasten rikinsidonnan ja jäännöshiilen jakautumisen erikokoisiksi hiukkasiksi tulipesässä ja tuhkissa. Työssä kehitetyt mallit perustuvat olemassa oleviin kalkkikiven ja polttoaineen reaktiivisuustesteihin laboratorio-kokoluokan leijukerrosreaktorissa. Mallit huomioivat myös tulipesän olosuhteet. Menetelmät kelpoistettiin onnistuneesti kaupallisen kokoluokan kiertoleijukattiloista mitattujen ja tulipesämallilla laskettujen taseiden avulla. Mallien kehittämistä tullaan jatkamaan.

A system to assess the stability of airborne nanoparticle agglomerates under aerodynamic shear

Stability of airborne nanoparticle agglomerates is important for occupational exposure and risk assessment in determining particle size distribution of nanomaterials. In this study, we developed an integrated method to test the stability of aerosols created using different types of nanomaterials. An aerosolization method, that resembles an industrial fluidized bed process, was used to aerosolize dry nanopowders. We produced aerosols with stable particle number concentrations and size distributions, which was important for the characterization of the aerosols' properties. Next, in order to test their potential for deagglomeration, a critical orifice was used to apply a range of shear forces to them. The mean particle size of tested aerosols became smaller, whereas the total number of particles generated grew. The fraction of particles in the lower size range increased, and the fraction in the upper size range decreased. The reproducibility and repeatability of the results were good. Transmission electron microscopy imaging showed that most of the nanoparticles were still agglomerated after passing through the orifice. However, primary particle geometry was very different. These results are encouraging for the use of our system for routine tests of the deagglomeration potential of nanomaterials. Furthermore, the particle concentrations and small quantities of raw materials used suggested that our system might also be able to serve as an alternative method to test dustiness in existing processes.