101 research outputs found
Indicadors de qualitat bioquĂmica, relacionats amb el cicle del carboni, en la restauraciĂł de sòls amb fang de depuradora sotmès a assecatge tèrmic i a compostatge
In our work we studied some aspects of biochemical quality in the rehabilitation process of degraded soils through the application of sewage sludge. As biochemical quality parameters we focused on the carbon cycle, through total (TCH), extractable (ECH) carbohydrate content, β-glucosidase (GLC), β-galactosidase (GAL), BAA-hydrolysing (BAA), and urease(UR) enzymatic activities, organic carbon (C) and amino acid nitrogen (AAN) contents. We conducted two experiments of sludge application (in containers and in plots) over soils of different texture. The study was supplemented by a work on the standard quality of natural soils of Catalonia and also with an approach to the analytical methodology used in the determination of two of the studied parameters. In the first part we studied the biochemical characteristics of ten natural soils which were representative of Catalan soils. The results showed the wide range of values of carbon and the high dispersion of biochemical parameters, and also that the ranges of obtained values were similar to those of other soils also belonging to Mediterranean areas. Biochemical parameters showed high positive correlations among them. The TCH content was more correlated with organic C and organic N than the enzyme activities. GLC was the activity showing the highest correlation with the organic carbon content. The four enzymatic activities (GLC, GAL, BAA and UR) were more related to the labile than to the total fraction of carbohydrates. The study confirmed the influence of soil type, vegetation or bedrock on the biochemical
characteristics of the forest soils group. With respect to the application of sludge, in the first experiment we studied the effect of three sludge types, dehydrated (D), thermally dried (T) and composted (C), added in two different proportions on the biochemical parameters of two degraded soils (clay and sand) from quarrying. Initially an increased value was detected for all biochemical variables (except the UR activity) in the amended soils, CHE being the most enhanced variable. At the end of the experiment the carbohydrates content and the enzyme activities of the mixtures had increased, compared to the control, in a similar value than C, AAN being the most enhanced parameter. The initial differences in the values of GLC depending on the type of sludge (T> D> C) were a reflection of the lability of organic matter provided by the sludge. The overall results indicate that: i) thermal drying accelerates the initial decomposition process of the organic matter which takes place in the soil, ii) composting provides a less labile but more active organic matter, which results in increased mineralization and eventually a more stable organic matter iii) when the sludge was applied in a clay soil a slowing on the development of organic matter was detected. The second experiment consisted of a trial with two degraded soils. Initial (4 days) and final (295 days) samples were analysed in plots where we applied the same sludges with a single dose. In the case of the
application of sludge to a sandy-loam soil, the dynamics of mineralization was intense and the impact on biochemical properties one year after the application was not very important. In contrast, the effects on a loam soil, where the dynamics of organic matter was lower, were more important and primarily consisted of an increase of ready available organic carbon.Organic carbon determination by the combustion method was proved to be effective and it was confirmed the inappropriateness of the oxidation method for sludge-soil mixtures.En la restauraciĂł d’activitats extractives Ă©s imprescindible la utilitzaciĂł d’un material edĂ fic de qualitat per abordar degudament la revegetaciĂł. Els fangs procedents de EDARs, convenientment dosificats i ben incorporats, poden ser molt Ăştils com a esmena orgĂ nica. En el nostre treball hem estudiat alguns aspectes de qualitat bioquĂmica en el procĂ©s de rehabilitaciĂł de sòls degradats a travĂ©s de l’aplicaciĂł de fangs d’EDARs. Com a parĂ metres de qualitat bioquĂmica del sòl ens hem centrat en el cicle del carboni, a travĂ©s del contingut en carbohidrats totals (CHT) i extractables (CHE) i de les activitats enzimĂ tiques β-glucosidasa (GLC) i β-galactosidasa (GAL) i com a parĂ metres auxiliars en el contingut en Carboni orgĂ nic (C) i Nitrogen aminoacĂdic (NAA). TambĂ© hem treballat amb resultats de dues activitats enzimĂ tiques relacionades amb el cicle del nitrogen, la proteolĂtica de BAA (BAA) i la ureĂ sica (UR). Hem portat a terme dues experiències d’aplicaciĂł de fangs, una primera en lisĂmetres i una segona en parcel·les i ambdues amb sòls de diferent textura. El disseny experimental de les dues experiències Ă©s d’especial interès ja que planteja estudiar en paral·lel els efectes de l’assecatge tèrmic i el compostatge d’un mateix fang deshidratat. Aquest estudi central de la tesi es complementa amb un treball sobre l’estĂ ndard de qualitat en sòls naturals de Catalunya aixĂ com amb aportacions sobre la metodologia analĂtica per a la determinaciĂł de dos dels parĂ metres estudiats (C i GLC).
Com a primera part de la tesi estudiem les caracterĂstiques bioquĂmiques en deu sòls naturals representatius dels sòls catalans. Els resultats mostren ampli rang de valors de carboni i alta dispersiĂł dels parĂ metres bioquĂmics i els rangs obtinguts sĂłn similars als de sòls d’altres zones de clima mediterrani. Els parĂ metres bioquĂmics presenten correlacions altes i positives entre ells i alhora una gran dependència del contingut en matèria orgĂ nica del sòl aixĂ com del contingut en biomassa microbiana. El contingut en CHT estĂ mĂ©s correlacionat que les activitats enzimĂ tiques, amb els continguts de C orgĂ nic i N orgĂ nic del sòl. La GLC Ă©s l’activitat enzimĂ tica mĂ©s relacionada amb el contingut de carboni orgĂ nic del sòl. Les quatre activitats enzimĂ tiques (GLC, GAL, BAA i UR) estan mĂ©s lligades a la fracciĂł lĂ bil de carbohidrats que a la total i les activitats GAL, UR i BAA estan molt relacionades entre elles. L’estudi ha permès constatar la influència del tipus de sòl, roca mare o vegetaciĂł en les caracterĂstiques bioquĂmiques del grup de sòls forestals.
Pel que fa a l’aplicaciĂł de fangs, en la primera experiència hem estudiat l’efecte de tres fangs: deshidratat (D), assecat tèrmicament (T) i compostat (C) en dues dosis (per assolir un 3 % i 6 % de matèria orgĂ nica) sobre els parĂ metres bioquĂmics de dos sòls control degradats (argilĂłs i saulĂł) provinents de pedreres (1% C i 0,1% C). L’assaig es realitza en condicions de laboratori i consta de tres mostreigs (7, 67 i 267 dies). Inicialment es detecta un increment del valor per totes les variables bioquĂmiques (a excepciĂł de l’activitat UR) en les barreges sòl-fang i el contingut en CHE Ă©s la variable mĂ©s incrementada. Al final de l'experiència les barreges tenen uns valors de carbohidrats i activitats enzimĂ tiques incrementats respecte del control de forma similar a l’increment final en matèria orgĂ nica, i el contingut en NAA Ă©s la variable mĂ©s incrementada respecte del sòl control. Les diferències en els valors de l’activitat enzimĂ tica GLC a l’inici en funciĂł del tipus de fang (T>D>C) sĂłn un reflex de la labilitat de la matèria orgĂ nica aportada pels fangs. El conjunt de resultats indiquen que: i) l’assecat tèrmic accelera el primer procĂ©s de descomposiciĂł de la matèria orgĂ nica; ii) el compostatge proporciona una matèria orgĂ nica no tan lĂ bil, però amb mĂ©s activitat enzimĂ tica que comporta mĂ©s mineralitzaciĂł i, amb el temps, una matèria orgĂ nica mĂ©s estable i iii) l’evoluciĂł de la matèria orgĂ nica es frena quan els fangs s’apliquen en un sòl argilĂłs.
La segona experiència consta d’un assaig d’aplicaciĂł de fangs en dos terrenys degradats i analitzem les mostres inicials (4 dies) i finals (295 dies) de parcel·les on s’han aplicat els mateixos tres fangs de l’experiència en lisĂmetres, però amb una Ăşnica dosi (10 Mg/ha, en matèria seca). En el cas de l’aplicaciĂł de fangs al sòl franc-arenĂłs (sòl amb baix contingut en matèria orgĂ nica i alta activitat enzimĂ tica) la dinĂ mica de mineralitzaciĂł ha estat intensa i la incidència sobre les propietats bioquĂmiques del sòl, un any desprĂ©s de l’aplicaciĂł dels fangs, ha estat molt poc acusada. ContrĂ riament, els efectes sobre el sòl franc, on la dinĂ mica de la matèria orgĂ nica ha estat menor, sĂłn mĂ©s importants i bĂ sicament han significat l’augment del contingut en matèria orgĂ nica i la millora de la potencialitat de la matèria orgĂ nica d’obtenir formes assimilables de carboni.
Els resultats dels aspectes metodològics indiquen que la determinaciĂł de carboni orgĂ nic per combustiĂł ha resultat eficaç i confirmen la manca d’idoneĂŻtat del mètode d’oxidaciĂł per a mostres de sòl-fang. Pel que fa a l’estudi de l’activitat β-glucosidasa i β-galactosidasa en sòls, el nostre treball representa una contribuciĂł a la descripciĂł detallada del procediment analĂtic i a la incidència sobre el valor de l’activitat de la determinaciĂł a partir de mostra humida o bĂ© assecada a l’aire.Postprint (published version
UtilitzaciĂł del "compost" en el cultiu de tomĂ quets en hivernacle. Estudi de certs parĂ metres de qualitat
Peer Reviewe
Experimental colonization of Ulva spp. with algal-epiphytic antagonistic bacteria as a strategy for pathogen control in integrated multi-trophic aquaculture recirculating systems
Probiotics are a potential tool for bacterial control in aquaculture (Pintado et al. 2011), decreasing the use of disinfectants and
antibiotics and contributing to an ecosystem approach, which is more sustainable and respectful to the environment.Postprint (published version
Biological effect of the addition of thermally dried and composted sewage sludges to residual soils from a limestone quarry
Peer Reviewe
Growth and nutrient uptake of the seaweed Ulva ohnoi integrated in a Solea senegalensis recirculating system: influence of lighting, stocking density and CO2
The integrated production of fish and seaweeds can improve the sustainability of the marine aquaculture industry. Seaweeds remove the nutrients dissolved in fish-farm effluents and can become a good source of proteins, carbohydrates and bioactive
compounds of commercial interestPostprint (published version
Comparision of two water agitation methods in seaweed culture tanks: influence of the rotating velocity in the seaweed growth and energy requirement
Integrating seaweed production into land-based marine fish-farms allows removing dissolved nutrients and improves the sustainability of the coastal marine aquaculture. Free-floating seaweed culture in tanks, with suspension provided by tumbling, is the most usual cultivation technique used in this kind of facilitiesPostprint (published version
Evaluation of the near infrared spectroscopy (NIRS) to predict chemical composition in Ulva ohnoi
Green algae of the genus Ulva have been identified as suitable organisms for biomass production and good candidates for the development of seaweed blue-biotech industries. The fluctuation of chemical composition during the growth of the algae, which depends largely on environmental factors, makes the development of rapid phenotyping protocols necessary. In this work the efficacy of Near Infrared Spectroscopy (NIRS) to predict dry matter, mineral fraction, nitrogen, and carbon contents directly from wet untreated samples and from dried samples was studied. Partial least square (PLS) models from spectra recorded on 80 samples were used to predict dry matter, and 44 samples to predict carbon, nitrogen and mineral fraction on a wet and dry weight basis.Postprint (published version
Evaluating the dose effect of a differently treated sewage sludge over two degraded soils coming from working quarries
Peer Reviewe
Effect of differently post-treated dewatered sewage sludge on beta-glucosidase activity, microbial biomass carbon, basal respiration and carbohydrates contents of soils from limestone quarries
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