Kaivo-opas

Kaivo-opas on laadittu erityisesti uuden kaivon rakentamista tai vanhan kunnostamista suunnitteleville. Oppaaseen on koottu tiivistettyä tietoa pohjaveden esiintymisestä maa- ja kallioperässä, pohjaveden laadusta ja sitä heikentävistä tekijöistä sekä kaivon paikan valinnasta. Tavallisen rengaskaivon rakentaminen on kuvattu yksityiskohtaisesti piirroksilla havainnollistettuna. Piirroksia on myös porakaivosta ja eräistä muista kaivotyypeistä. Oppaassa selostetaan lisäksi vanhan kaivon kunnostus- ja huoltotoimenpiteet. Liitteissä on esitetty yksityisten kaivojen talousveden laatuvaatimukset ja -suositukset, yleisimmät veden laatuhaitat ja niiden poistamismahdollisuudet

Brunnsguide

Brunnsguiden har gjorts särskilt med tanke på dem som planerar att bygga en ny brunn eller restaurera en gammal. I guiden har man samlat information om grundvattenförekomst i mark och i berggrund, grundvattnets kvalitet och faktorer som försämrar kvaliteten samt valet av brunnsplatsens geografiska läge. Byggande av vanliga brunnar med cementringar finns detaljerat beskrivet och detta har illustrerats med bilder. Det finns också bilder av borrbrunnar och några övriga brunnstyper. I guiden finns dessutom beskrivet restaurerings- och underhållsåtgerder för gamla brunnar. I bilagorna finns förevisat kvalitetskrav och rekommedationer för hushållsvatten från privata brunnar, de vanligaste kvalitativa bristerna i vattnet samt åtgerder för att avhjälpa dem

INFLUENCE OF ADSORBED AND DISSOLVED CARBOXYMETHYL CELLULOSE ON FIBRE SUSPENSION DISPERSING, DEWATERABILITY, AND FINES RETENTION

The effect of adsorbed and soluble carboxymethyl cellulose (CMC) on dispersing, dewaterability, and fines retention of pulp fibre suspensions was investigated. CMC was added to a suspension in the presence of electrolytes, causing its adsorption to the fibre surfaces, or to a suspension without electrolytes, so that it stayed in the liquid phase. Both the CMC adsorbed on fibre surfaces and that in the liquid phase were able to disperse the fibre suspension due to the ability of CMC to reduce fibre-to-fibre friction in both phases. Adsorbed CMC promoted the formation of a water-rich microfibrillar gel on the fibre surfaces through the spreading out of microfibrils, leading to a decrease in friction at the fibre-fibre contact points and to the increased dispersion of fibres. CMC in the liquid phase of the suspension was in turn thought to prevent fibre-to-fibre contacts due to the large physical size of the CMC molecules. CMC in both phases had detrimental effects on dewatering of the pulp suspension, but adsorbed CMC caused more plugging of the filter cake, and this was attributed to its ability to disperse fibre fines, in particular. Thus, adsorbed CMC also reduced fines retention considerably more than did CMC in the liquid phase of a suspension

Distinctive green recovery of silver species from modified cellulose: Mechanism and spectroscopic studies

The present study aimed to recover precious silver in order to identify the adsorption coupled reduction pathways that determine this process. A combination technique of adsorption and nanocrystallization was used to investigate the recovery of silver species from taurine-cellulose (T-DAC) samples. The non-synthetic route of nanocrystallization yielded spherical zero-valent silver sized ~18. nm. Rate-controlling steps were modeled by adsorption parameters by the best fit of Langmuir capacity (55. mg/g), pseudo-second order curves, and exothermic chemical reactions. The T-DAC was an excellent sorbing phase for the treatment of silver-polluted waters over a broad range of pH (2.1-10.1) and varying ionic strengths (8.5-850. mM, as NaCl), which are the conditions often encountered in industrial and mining effluents. A good recovery of silver (40-65%) was also obtained in the presence of Cd(II), Co(II), Cr(VI), Ni(II), and As(V) at lower or equivalent concentrations with Ag(I), either from individually added metals or from all metal ions mixed together. Desorption was compared with a series of five eluents including complexing agents. In these experiments acidified thiourea yielded 86% desorption of Ag(I). Aqueous silver reduced to metallic silver on the surface of the T-DAC samples, which was confirmed by X-ray photo electron spectroscopy. © 2015 Elsevier B.Vclose1

Enhancement of the Nanofibrillation of Wood Cellulose through Sequential Periodate–Chlorite Oxidation

Sequential regioselective periodate–chlorite oxidation was employed as a new and efficient pretreatment to enhance the nanofibrillation of hardwood cellulose pulp through homogenization. The oxidized celluloses with carboxyl contents ranging from 0.38 to 1.75 mmol/g could nanofibrillate to highly viscous and transparent gels with yields of 100–85% without clogging the homogenizer (one to four passes). On the basis of field-emission scanning electron microscopy images, the nanofibrils obtained were of typical widths of approximately 25 ± 6 nm. All of the nanofibrillar samples maintained their cellulose I crystalline structure according to wide-angle X-ray diffraction results, and the crystallinity index was approximately 40% for all samples

Strong, Self-Standing Oxygen Barrier Films from Nanocelluloses Modified with Regioselective Oxidative Treatments

In this work, three self-standing nanocellulose films were produced from birch pulp using regioselective oxidation and further derivatization treatments. The modified celluloses were synthesized using periodate oxidation, followed by chlorite oxidation, bisulfite addition, or reductive amination with amino acid taurine, which resulted in dicarboxylic acid cellulose (DCC), α-hydroxy sulfonic acid cellulose (HSAC), and taurine-modified cellulose (TC), respectively. The nanocelluloses were fabricated by mechanical disintegration using high-pressure homogenization. Mechanical and barrier properties of the nanocellulose films were characterized. Two (2,2,6,6-tetramethyl-piperidin-1-yl)­oxyl (TEMPO) oxidation-based nanocellulose films were also produced, and their properties were compared to the periodate-based nanocellulose films. All of the periodate-based nanocellulose films showed high tensile strength (130–163 MPa) and modulus (19–22 GPa). Oxygen barrier properties of the films were superior to many synthetic and composite materials; in particular, the nanofibrillated DCC films had oxygen permeability as low as 0.12 cm³ μm/(m² d kPa) at 50% relative humidity. Compared to films of TEMPO-oxidized nanocelluloses, all of the periodate-based nanocellulose films had similar or even better mechanical and barrier properties, demonstrating versatility of periodate oxidation to obtain nanocellulose films with adjustable properties. Also, for the first time, amino-acid-based cellulose modification was used in the production of nanocellulose