977 resultados para pulp and paper mill wastewater
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Effluents from pulp mill are usually toxic and mutagenic. This characteristic is mainly a consequence of xenobiotic compounds that are formed during the process. Global parameters such as chemical oxidation demand, total organic carbon and others, do not permit identify whether the toxic potential was remedied by the treatments or not. The objective of this research was to evaluate the performance of an horizontal-flow anaerobic immobilized biomass reactor (HAIB) treating the bleaching effluent from a Kraft pulp mill using toxicological (Daphnia similis - Ceriodaphnia sdvestrii) mutagenicity and citotoxicological assays (Allium cepa L). The results showed high sensibility of the test-organisms and capability of the anaerobic reactor to remove compounds that are exerting toxic and mutagenic effects. The bioassays represented an attractive alternative to water quality analyzes and the performance evaluation of treatments.
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Paper products show dimensional changes when subjected to moisture content modification. Hygroexpansivity was investigated in a commercial paper machine operating at 1256 m/min by a set of measurements on 75 g/m(2) reprographic bleached eucalyptus pulp paper samples. The present work shows hygroexpansivity development in different sections of the paper machine along the manufacturing direction. The measurement results demonstrate the effects of papermaking process operations on paper hygroexpansivity and lead to the confirmation of fiber orientation degree, drying restraint and shrinkage and paper tension as significant influencing factors. Structural, strength and elastic properties of paper were also measured as a function of machine direction position and presented for discussion purposes.
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The effects of acai pulp addition and different probiotic bacteria on the fatty acid profile of stirred yoghurt were examined. Skim milk was divided into two groups: one containing acai pulp and another without the fruit. Batches were inoculated with yoghurt starter culture and divided into five groups according to probiotic addition. Counts of viable microorganisms were measured at days 1, 14 and 28 of cold storage. Fatty acid profile was determined by gas chromatography at day 1. Acai pulp favoured an increase in Lactobacillus acidophilus L10, Bifidobacterium animalis ssp. lactis Bl04 and Bifidobacterium longum Bl05 counts at the end of 4 weeks of cold storage. This study demonstrated that acai pulp addition increased monounsaturated and polyunsaturated fatty acid contents in probiotic yoghurt and enhanced the production of cc-linolenic and conjugated linoleic acids during fermentation of skim milk prepared with B. animalis ssp. lactis Bl04 and B94 strains. (C) 2010 Elsevier Ltd. All rights reserved.
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Sugar is a determinant for the quality of mangoes, but information about its accumulation is scarce. Although starch can contribute to sugar production during ripening, not much is known about the enzymes involved. This work presents the changes in carbohydrate and enzymes during the development and ripening of Keitt mangoes. Starch disappearance was concomitant to a fivefold increase of sucrose, the most abundant sugar of the ripe fruits. The activities of alpha-amylase, beta-amylase, phosphorylase and isoamylase were detected in the pulp, and while alpha-amylase increased parallel to the starch content, beta-amylase presented a 20-fold increase during ripening. On the other hand, high phosphorylase activity was observed when fruits were still accumulating starch, and lowered during ripening. Isoamylase was detected during development and increased slightly during ripening, which would be in agreement to the expected role for isoamylases as acting on both subproduct of starch synthesis and degradation.
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Discharge grates play an important role in determining the performance of autogenous, semi-autogenous and grate discharge ball mills. The flow capacity (grinding capacity) of these mills is strongly influenced by the discharge grate design-open area and position of apertures, as well as the performance of the pulp lifters. As mill sizes have progressively increased and closed-circuiting has become more popular the importance of grate and pulp lifter design has grown. Unfortunately very few studies have concentrated on this aspect of mill performance. To remedy this a series of laboratory and pilot-scale tests were undertaken to study both the performance of grates on their own and in conjunction with pulp lifters. In this first paper of a two-part series the results from the grate-only experiments are presented and discussed, whilst the performance of the grate-pulp-lifter system is covered in the second paper. The results from the grate-only experiments have shown that the build-up of slurry (hold-up) inside the mill starts from the shoulder of the charge, while the toe position of the slurry progressively moves towards the toe of the charge with increasing flowrate. Besides grate design (open area and position of apertures), charge volume and mill speed were also found to have a strong influence on mill hold-up and interact with grate design variables. (C) 2003 Elsevier Science Ltd. All rights reserved.
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Cork processing involves a boiling step to make the cork softer, which consumes a high volume of water and generates a wastewater with a high organic content, rich in tannins. An assessment of the final wastewater characteristics and of the boiling water composition along the boiling process was performed. The parameters studied were pH, color, total organic carbon (TOC), chemical and biochemical oxygen demands (COD, BOD5, BOD20), total suspended solids (TSS), total phenols and tannins (TP, TT). It was observed that the water solutes extraction power is significantly reduced for higher quantities of cork processed. Valid relationships between parameters were established not only envisaging wastewater characterization but also to provide an important tool for wastewater monitoring and for process control/optimization. Boiling water biodegradability presented decreasing values with the increase of cork processed and for the final wastewater its value is always lower than 0.5, indicating that these wastewaters are very difficult to treat by biological processes. The biodegradability was associated with the increase of tannin content that can rise up to 0.7 g/L. These compounds can be used by other industries when concentrated and the clarified wastewater can be reused, which is a potential asset in this wastewater treatment.
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Dissertação apresentada para obtenção do Grau de Doutor em Ciências do Ambiente, pela Universidade Nova de Lisboa, Faculdade de Ciências e Tecnologia
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In this study a citrate-buffered version of QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) method for determination of 14 organochlorine pesticides (OCPs) residues in tamarind peel, fruit and commercial pulp was optimized using gas chromatography (GC) coupled with electron-capture detector (ECD) and confirmation by GC tandem mass spectrometry (GC–MS/MS). Five procedures were tested based on the original QuEChERS method. The best one was achieved with increased time in ultrasonic bath. For the extract clean-up, primary secondary amine (PSA), octadecyl-bonded silica (C18) and magnesium sulphate (MgSO4) were used as sorbents for tamarind fruit and commercial pulp and for peel was also added graphitized carbon black (GCB). The samples mass was optimized according to the best recoveries (1.0 g for peel and fruit; 0.5 g for pulp). The method results showed the matrix-matched calibration curve linearity was r2 > 0.99 for all target analytes in all samples. The overall average recoveries (spiked at 20, 40 and 60 μg kg−1) have been considered satisfactory presenting values between 70 and 115% with RSD of 2–15 % (n = 3) for all analytes, with the exception of HCB (in peel sample). The ranges of limits of detection (LOD) and quantification (LOQ) for OCPs were for peel (LOD: 8.0–21 μg kg−1; LOQ: 27–98 μg kg−1); for fruit (LOD: 4–10 μg kg−1; LOQ: 15–49 μg kg−1) and for commercial pulp (LOD: 2–5 μg kg−1; LOQ: 7–27 μg kg−1). The method was successfully applied in tamarind samples being considered a rapid, sensitive and reliable procedure.
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The main objective of this thesis is to study the developing fields of aquaponics and its potential for aquaculture wastewater treatment and human urine treatment. Aquaponics is a food production system which combines fish farming (aquaculture) with soilless crop farming (hydroponics). In this thesis the concept of aquaponics and the underlying processes are explained. Research on aquaculture wastewater and human urine wastewater is reviewed and its potential application with aquaponic systems is studied. An overview of the different types of aquaponic systems and current research on the field is also presented. A case study was conducted in a farm in Askeröd, Sweden, which involved building two aquaponic systems (System 1 and System 2) and a human urine-based aquaponic system (System 3), with different degrees of component complexity and sizes. The design, building and monitoring of System 1, System 2 and System 3 was documented and described in detail. Four day experiments were conducted which tested the evolution in concentration of Total Ammonia Nitrogen (NH4+/NH3), Nitrite (NO2-), Nitrate (NO3-), Phosphate (PO43-), and Dissolved Oxygen (O2) after an initial nutrient input. The goal was to assess the concentrations of these parameters after four days and compare them with relevant literature examples in the aquaculture industry and in source-separated urine research. Neither of the two aquaponic systems (System 1 and System 2) displayed all of the parameter concentrations in the last day of testing below reference values found in literature. The best performing of the aquaponic systems was the more complex system (System 2) combining the hydroponic Nutrient Film Technique with a Deep Water Culture component, with a Total Ammonia Nitrogen concentration of 0,20 mg/L, a Nitrite concentration of 0,05 mg/L, a Nitrate concentration of 1,00-5,00 mg/L, a Phosphate concentration of <0,02 mg/L and a Dissolved Oxygen concentration of 8,00 mg/L. The human urine-based aquaponic system (System 3) underperformed in achieving the reference concentration values in literature for most parameters. The removal percentage between the higher recorded values after the input addition and the final day of testing was calculated for two literature examples of separated urine treatment and System 3. The system had a removal percentage of 75% for Total Ammonia Nitrogen, 98% for Nitrite, 25% for Nitrate and 50% for Phosphate. These percentages still underperformed literature examples in most of the tested parameters. The results gathered allowed to conclude that while aquaculture wastewater treatment and human urine treatment is possible with aquaponics systems, overall these did not perform as well as some examples found in recirculating aquaculture systems and source-separated urine treatment literature. However, better measuring techniques, longer testing periods and more research is recommended in this field in order to draw an improved representative conclusion.
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Laser desorption ionisation mass spectrometry (LDI-MS) has demonstrated to be an excellent analytical method for the forensic analysis of inks on a questioned document. The ink can be analysed directly on its substrate (paper) and hence offers a fast method of analysis as sample preparation is kept to a minimum and more importantly, damage to the document is minimised. LDI-MS has also previously been reported to provide a high power of discrimination in the statistical comparison of ink samples and has the potential to be introduced as part of routine ink analysis. This paper looks into the methodology further and evaluates statistically the reproducibility and the influence of paper on black gel pen ink LDI-MS spectra; by comparing spectra of three different black gel pen inks on three different paper substrates. Although generally minimal, the influences of sample homogeneity and paper type were found to be sample dependent. This should be taken into account to avoid the risk of false differentiation of black gel pen ink samples. Other statistical approaches such as principal component analysis (PCA) proved to be a good alternative to correlation coefficients for the comparison of whole mass spectra.
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This study was designed to check for the equivalence of the ZKPQ-50-CC (Spanish and French versions) through Internet on-line (OL) and paper and pencil (PP) answer format. Differences in means and devia- tions were significant in some scales, but effect sizes are minimal except for Sociability in the Spanish sample. Alpha reliabilities are also very similar in both versions with no significant differences between formats. A robust factorial structure was found for the two formats and the average congruency coefficients were 0.98. The goodness-of-fit indexes obtained by confirmatory factorial analysis are very similar to those obtained in the ZKPQ-50-CC validation study and they do not differ between the two formats. The multi-group analysis confirms the equivalence among the OL-PP formats in both countries. These results in general support the validity and reliability of the Internet as a method in investigations using the ZKPQ-50-CC.
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Myllykoski Paper Oy:n hiokkeen laadussa ja prosessivesien ominaisuuksissa tapahtuu vaihtelua ajan suhteen. Tämä käy ilmi useiden vuosien aikana kerätyistä laatuseurantatiedoista. Diplomityön tavoitteena oli selvittää hiokkeen ja kierto-vesien laatuun vaikuttavat tekijät ja kehittää laadunvaihtelua hillitseviä toimenpi-teitä. Työn kirjallisuusosassa pyrittiin löytämään tekijöitä, jotka voivat aiheuttaa valmiin hiokkeen laatuun vaihtelua. Lähtökohtaisesti laatuvaihteluita aiheuttavat tekijät jaettiin raaka-aine- tai prosessivaihteluksi. Työn kokeellisessa osassa selvitettiin eri hioke- ja prosessivesiominaisuuksien kehittymistä tarkastelemalla eri mittaussuureista kerättyjä aineistoja erilaisin aika-välein. Aluksi tarkasteltiin hiokkeen ja vesien ominaisuuksia viiden vuoden ajan-jaksolla, josta siirryttiin tarkastelemaan lyhyempiä aikavälejä. Käytetty mittausaineisto oli peräisin DW-tietovarastosta ja PHD-reaaliaikatietokannasta. Työn tuloksista kävi muun muassa ilmi, että painehiokkeen lujuusominaisuudet ovat hienoisesti alentuneet viimeisen viiden vuoden aikana. Muutos selittyy hiokkeen pitkäkuituosuuden ja kuitupuun keskimääräisen läpimitan alenemisella. Lisäksi valkaisemattomien hiokkeiden vaaleudet ovat alentuneet samallakun prosessivedet ovat muuttuneet likaisemmiksi. Kehitykseen on vaikuttanut vesikiertojen kasvanut sulkemisaste ja uusi peroksidivalkaisulaitos. Jatkotoimenpide-ehdotukset painottuvat pääosin vesiajotilanteiden hallintaan. Vesiajoaiheuttaa aina suuria muutoksia niin hiokkeen kuin myös kiertovesien laatuun.
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Tehokkain tapavalkaista mekaanisesti kuidutettua puumassaa on suorittaa se hapettavasti peroksidikemikaalilla vahvasti alkalisissa oloissa. Perinteisesti alkalisuus on aikaansaatu natriumhydroksidin ja -silikaatin avulla. Se kuitenkin liuottaa massasta merkittävästi ligniiniä, mikä huonontaa saantoa ja suurentaa valkaisun jätevesien orgaanisen hiilen määrää sekä kemiallista hapenkulutusta. Yhä kovenevien vaaleustavoitteiden ja tiukentuneen vedenkäytön seurauksena on syntynyt tarve etsiä parempia valkaisun alkaleja. Kirjallisuuden pohjalta valittiinkokeellisesti tutkittaviksi alkaleiksi magnesiumhydroksidi, magnesiumoksidi, kalsiumhydroksidi sekä kalsiumoksidi. Niiden toimivuutta hapettavan vetyperoksidivalkaisun alkaleina tutkittiin valkaisukokein natriumsilikaattilisäyksen kanssa sekä ilman. Näistä parhaiten toimivaksi osoittautui Mg(OH)2. Sen avulla suoritettiin jatkoksi laboratoriokoevalkaisuja korkeassa sakeudessa. Keski- ja korkeasakeusvalkaisukokeiden tulosten mukaan käytettäessä Mg(OH)2 -alkalia natriumydroksidin ja -silikaatin asemesta jää massan loppuvaaleus noin yhden ISO-prosentin verran heikommaksi. Tällöin valkaisusuodoksessa oli vain varsin vähäinen määrä massasta liuennutta orgaanista hiiliainesta, noin 45 % siitä, mitä natriumin yhdisteiden käyttö vertailukokeessa tuotti. Tulosta varmennettiin suorittamalla korkea-sakeusvalkaisukokeita hiokemassatehtaan olosuhteissa, massoilla ja kiertovesillä.Myös tehdaskokeiden mukaan valkaistun massan loppuvaaleus jää noin yhden ISO-prosentin alhaisemmaksi, mutta valkaisusuodoksen orgaanisen hiilen määrä (TOC) jääalle puoleen Na-kemikaalein suoritetusta vertailukokeesta.
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Diplomityössä selvitettiin Andritz Oy:n Pulp & Paper Mill Services -divisioonan myynnin analysointiin tarkoitettuja työkaluja ja tunnuslukuja varaosa- ja projektiliiketoiminnassa. Diplomityön aikana toteutetut haastattelut ja sähköpostin välityksellä lähetettävä kyselytutkimus kohdennettiin ennen kaikkea myynnistä vastuussa oleville ihmisille, kuten myyntipäälliköille, divisioonan johtohenkilöille ja tuoteryhmäjohtajille. Diplomityön aikana rakennettiin myynnin analysoinnissa käytettävät raportit SAP Business Intelligence -tietojärjestelmään. Tulevaisuudessa kohdeorganisaatio pystyy diplomityön aikana rakennettujen myynnin analysointiraporttien avulla seuraamaan ja analysoimaan myyntiä. Tutkimus oli luonteeltaan kvalitatiivinen, jossa ensin luotiin teoreettinen viitekehys tutkimalla Business Intelligence:ä, varaosa- ja projektiliiketoimintaa sekä myynnin analysoinnissa käytettäviä työkaluja. Tämän jälkeen suoritettiin kysely- ja haastattelututkimukset, joiden pohjalta saatiin tietoa kuinka Andritz:lla tällä hetkellä myyntiä analysoidaanja kuinka sitä halutaan tulevaisuudessa analysoida. Työn tuloksena saatiin teoriaa sekä haastattelu- ja kyselytutkimusta yhdistämällä rakennettua SAP Business Intelligence -tietojärjestelmään myynnin analysoinnissa käytettävät raportit. Raportit ovat myynnin perusraportti sisältäen myynnin keskei-simmät tunnusluvut, abc-analyysi myynnistä asiakkaittain ja abc-analyysi myynnistä nimikkeittäin. Työn lopussa on myös pohdittu, mitä SAP Business Intelligence -tietojärjestelmään kannattaa tulevaisuudessa rakentaa raporttien osalta ja kuinka raportteja kannattaa lähteä hyödyntämään myynnin analysoinnin näkökulmasta.