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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
641

The characterisation of some South African water treatment residues and glasshouse pot experiments to investigate the potential of two residues for land disposal.

Titshall, Louis William. January 2003 (has links)
Water treatment residues (WTRs) are the by-product from the production of potable water. They consist mainly of the precipitated hydrous oxides of the treatment chemicals, and materials removed from the raw water. This study investigated the range of treatment processes and residues produced in South Africa, and two WTRs were selected for testing on selected soils and mine materials. A questionnaire was developed and sent to water treatment authorities across South Africa. Information on the treatment chemicals, dosages, volumes and current disposal practices, and a sample of WTR from each treatment plant were requested. Eleven, of 21 authorities, returned completed questionnaires, representing 37 water treatment facilities. Organic polymers were the most commonly used treatment chemical, with most plants also using lime. Other less frequently used chemicals and additives were Alz(S04)3.14I-hO, Fe2(S04)3, FeC!), sodium aluminate, activated silica, activated charcoal, CO2 and bentonite. Information given regarding residue thickening and disposal was poor. Samples from Rand Water, Umgeni Water (Midmar), Midvaal Water Company, Amatola Water and Cape Metropolitan Council (Faure) were received or collected. An additional sample from Faure was also received, representing a change in the treatment process. These samples were analysed for a range of chemical and physical characteristics. These analyses showed that the WTRs had the potential to supply some plant nutrients (Ca, Mg, Fe, S) but that metal toxicity may be a problem, in particular Mn in the Faure WTR, and that P adsorption may be severe. The samples selected to test the potential for land disposal were from Rand Water and Faure. A pot experiment tested the growth of Eragrostis tefJ, Cenchrus ciliaris and Digitaria eriantha in mixtures of Rand WTR and material from a coal mine i.e., a sandy soil material, spoil material and coal combustion ash, at rates of 0, 50, 100, 200 and 400 g kg" with a uniform fertiliser treatment applied to all mixtures. The grass was harvested on three occasions and the mean total yield (dry mass) determined, as well as nutrient uptake. The pots were leached after each harvest and the pH and electrical conductivity determined. The soil, spoil and ash were characterised and pH, EC and water retention characteristics of the mixtures determined. Growth of the grasses in the ash treatments was poor and these were terminated. Eragrostis tefJ grown in the soil showed a decrease in mean total yield with increasing WTR application rate, but yield was good up to the 200 g kg" treatment at the first harvest, declining substantially by the second harvest. In general C. ciliaris and D. eriantha grown in the soil showed a decrease in mean total yield for all harvests with increasing WTR application. The yield of E. /ejJ, grown in the spoil, increased up to 100 g kg,l WTR addition, but decreased thereafter. Digitaria eriantha showed a decrease in yield, and C. ciliaris an increase, with increasing WTR application rate , but for all treatments the differences were non-significant. The pH and EC of the leachates generally increased with increasing WTR addition. The concentration of nutrients in the grasses did not indicate any deficiencies or toxicities. As the growth of grass was poor in the ash treatments, another pot experiment was established to test the growth of two creeping grass species grown in the Rand WTR as a cover over the ash material. Cynodon dactylon and Stenotaphrum secundatum were grown in 20, 40 and 60 mm layers of Rand WTR, with and without a fertiliser treatment. Both species performed best in the 60 mm layer with fertiliser, and C. dactylon performed better than S. secundatum. The former species was more tolerant of the high pH, but both have potential as cover vegetation on the ash dumps when these are covered with Rand WTR. A further glasshouse study investigated the effect of Faure WTR mixed with a nutrient poor sandy soil on the nutrient uptake and seed yield of common dry beans (Phaseolus vulgaris). The WTR was added to the soil at 0, 50, 100, 200 and 400 g kg" each with five levels of fertiliser (0, 25, 50, 100 (recommended optimum) and 150 %). Bean pods were harvested once the plants had senesced. The number of pods and mass and number of seeds per treatment were determined. The seeds were analysed for nutrient uptake. Interveinal chlorosis and necrotic lesions were evident on cotylendonous and new leaves in the WTR treated soils, the severity of the symptoms increasing with increasing rate of WTR. Additional pots were established at the 400 g kg" rate (without fertiliser) and leaf material collected for chemical analysis. This showed that Mn toxicity was the cause, with leaf concentrations about 12 times the recommended 100 mg kg" upper limit. However, mass of bean seed was highest in the 400 g kg" Faure WTR treatment with 150 % fertiliser. Nutrient translocation to the seed seemed to be relatively consistent regardless of treatment, with little accumulation ofMn. The data collected illustrated the range of conditions and types of WTRs produced in South Africa, and that in some instances these residues have favourable characteristics for land application. The use of the Rand WTR showed that it could be applied to the spoil medium at relatively high concentrations without severely negatively impacting on grass growth, but more caution should be used when applying this material to the soil medium. While the grass did not grow in the ash treatments, it would seem that with suitable species the Rand WTR could be beneficially applied to ash material as a cover layer. The use of the Faure WTR on a sandy soil seemed to potentially improve the yield of the indicator crop, but caution should be exercised due to the possibility of Mn toxicity. The use of additional fertiliser would seem to be essential. Further research would require that field scale investigation of both WTRs be conducted, as well as further studies of applicat ion rates and techniques in laboratory and glasshouse investigations. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2003.
642

Rekonstruotos Jurbarko nuotekų valyklos efektyvumas / Jurbarkas reconstructed sewer treatment plant efficiency

Venckus, Julius 16 June 2010 (has links)
Magistriniame darbe nagrinėjama rekonstruotos Jurbarko nuotekų valyklos efektyvumas. Tyrimo tikslas – nustatyti nuotekų valyklos darbo efektyvumą po aeracinės sistemos rekonstrukcijos. Tyrimo objektas – Jurbarko nuotekų valyklos iškeliama aeracinė sistema, kuri buvo sumontuota 2008 m. Šiems tikslams pasiekti buvo išsikelti šie uždaviniai: teoriškai apibūdinti biologinio valymo įrenginius, įtakojančius biologinio valymo proceso efektyvumą ir įvertinti veikliojo dumblo sistemos pokyčius; nustatyti nuotekų išvalymo efektyvumą Jurbarko nuotekų valykloje; atlikti palyginamąją analizę vamzdinės ir diskinės aeracinės sistemos; nustatyti Jurbarko nuotekų valyklos elektros energijos sąnaudas. Nuotekų valyklos efektyvumas tirtas, pagal BDS7, bendrojo azoto (Nb), bendrojo fosforo (Pb) pasišalinimą iš vandens prieš aeracinės sistemos pakeitimą ir po aeracinės sistemos pakeitimo. Atlikus tyrimus nustatyta, kad nuotekų valykla po rekonstrukcijos dirba patikimai. Nuotekų liekamoji tarša neviršija DLK. BDS7 valytame vandenyje sumažėjo 16 %, bendrojo azoto (Nb) – 27 %, o bendrojo fosforo (Pb) – 56 %, lyginant su BDS7, Nb ir Pb prieš aeracinės sistemos pakeitimą. Cheminio reagento proceso veiksmui sunaudojama 488,8 kg/m, mažiau, o tuo pačiu sudaro 22295,2 Lt/m. mažiau išlaidų. Elektros energijos sąnaudos sumažėjo apie 14%. / The paper examined the reconstructed Jurbarkas domestic wastewater treatment plants performance. Purpose of the survey - the wastewater treatment plant efficiency of aeration system reconstruction. The object of research - Jurbarkas domestic wastewater treatment plants enters an aeration system that was installed in 2008. To achieve these goals has been to move the following tasks: a theoretical description of the biological treatment plant, which affect the biological treatment process and evaluate the effectiveness of the active sludge system changes, the efficiency of wastewater remediation Jurbarkas wastewater treatment facilities, to carry out a comparative analysis of linear and circular aeration system, the sewage treatment plant Jurbarkas electricity costs. Sewage treatment plant efficiency has been studied by BOC7 nitrogen (Nb), phosphorus (Pb) elimination of the water before aeration system replacement and the replacement of aeration systems. The investigation showed that sewage treatment facilities after renovation work reliably. Effluent residual contamination does not exceed the MRL. BOC7 treated water decreased by 16%, total nitrogen (Nb) - 27%, and total phosphorus (Pb) - 56%, compared with BOC7, Nb and Pb before aeration system replacement. Chemical reagent process steps used 488.8 kg/m and less, while at the same time is 22295.2 Lt/m. less cost. Electricity costs have fallen about 14 percent.
643

New Perspectives on the Maintenance of Aqueous Ozone Residuals in Greenhouse and Nursery Irrigation Solutions

Graham, Gary Thomas 24 August 2012 (has links)
Ozonation has been utilized for water treatment for over 100 years. During that time, the range of applications has grown considerably, and includes the remediation of nursery and greenhouse irrigation water. Ozone is dissolved into irrigation water to kill pathogens and degrade chemical contaminants. By convention, growers remove ozone from solutions, prior to distribution to the crop, to avoid phytotoxic effects. The available literature regarding aqueous ozone (O3(aq)) phytotoxicity is limited, making this a sagacious practice, although the removal does preclude any ancillary benefits beyond the point of treatment. The effects of applying O3(aq) under two irrigation systems are examined. Initial studies suggested O3(aq) concentrations as high as 20 mg⋅L-1 could be applied directly to mineral wool substrate in a limited (one time) fashion without a negative response. To be effective as a remediation tool, however, ozone would need to be applied more frequently (e.g. daily). The effects of daily O3(aq) application, via drip irrigation in mineral wool hydroponic tomato culture, was examined. In the first of two studies, daily applications of 3.0 mg⋅L-1 O3(aq) elicited an overall positive growth response. In a follow-up study, 6.0 mg L-1 elicited a negative response. Nursery operators often utilize overhead irrigation. A study was conducted to determine if overhead irrigation utilizing O3(aq) was compatible with select woody perennial nursery species. The amount of ozone lost from solution during application was examined, as well as crop response to the ozone environment generated. It was shown that 60 to 70% of the ozone was unaccounted for at canopy level, while phytotoxic effects were elicited at emitter concentrations above 1.5 mg L-1. Marchantia polymorpha is a significant weed species in greenhouse and nursery production; a species with few control options. Anatomical features of M. polymorpha suggested sensitivity to O3(aq). Studies were performed to examine contact time (CT) and exposure frequencies required for M. polymorpha suppression. A CT of 0.84 mg⋅L-1⋅min at an application frequency of 3-times/week achieved measurable suppression. / Natural Science and Engineering Research Council (NSEARC); Ontario Ministry of Agriculture Food and Rural Affairs (OMAFRA); Ontario Centres of Excellence (OCE); Purification Research Technologies INC (PRTI); Flowers Canada (Ontario).
644

The characterisation of some South African water treatment residues and glasshouse pot experiments to investigate the potential of two residues for land disposal.

Titshall, Louis William. January 2003 (has links)
Water treatment residues (WTRs) are the by-product from the production of potable water. They consist mainly of the precipitated hydrous oxides of the treatment chemicals, and materials removed from the raw water. This study investigated the range of treatment processes and residues produced in South Africa, and two WTRs were selected for testing on selected soils and mine materials. A questionnaire was developed and sent to water treatment authorities across South Africa. Information on the treatment chemicals, dosages, volumes and current disposal practices, and a sample of WTR from each treatment plant were requested. Eleven, of 21 authorities, returned completed questionnaires, representing 37 water treatment facilities. Organic polymers were the most commonly used treatment chemical, with most plants also using lime. Other less frequently used chemicals and additives were A12(SO4)3.14H2O, Fe2(SO4)3, FeC1), sodium aluminate, activated silica, activated charcoal, CO2 and bentonite. Information given regarding residue thickening and disposal was poor. Samples from Rand Water, Umgeni Water (Midmar), Midvaal Water Company, Amatola Water and Cape Metropolitan Council (Faure) were received or collected. An additional sample from Faure was also received, representing a change in the treatment process. These samples were analysed for a range of chemical and physical characteristics. These analyses showed that the WTRs had the potential to supply some plant nutrients (Ca, Mg, Fe, S) but that metal toxicity may be a problem, in particular Mn in the Faure WTR, and that P adsorption may be severe. The samples selected to test the potential for land disposal were from Rand Water and Faure. A pot experiment tested the growth of Eragrostis teff, Cenchrus ciliaris and Digitaria eriantha in mixtures of Rand WTR and material from a coal mine i.e., a sandy soil material, spoil material and coal combustion ash, at rates of 0, 50, 100, 200 and 400 g kg-1 with a uniform fertiliser treatment applied to all mixtures. The grass was harvested on three occasions and the mean total yield (dry mass) determined, as well as nutrient uptake. The pots were leached after each harvest and the pH and electrical conductivity determined. The soil, spoil and ash were characterised and pH, EC and water retention characteristics of the mixtures determined. Growth of the grasses in the ash treatments was poor and these were terminated. Eragrostis teff grown in the soil showed a decrease in mean total yield with increasing WTR application rate, but yield was good up to the 200 g kg-1 treatment at the first harvest, declining substantially by the second harvest. In general C. ciliaris and D. eriantha grown in the soil showed a decrease in mean total yield for all harvests with increasing WTR application. The yield of E. teff, grown in the spoil, increased up to 100 g kg-1 WTR addition, but decreased thereafter. Digitaria eriantha showed a decrease in yield, and C.ciliaris an increase, with increasing WTR application rate, but for all treatments the differences were non-significant. The pH and EC of the leachates generally increased with increasing WTR addition. The concentration of nutrients in the grasses did not indicate any deficiencies or toxicities. As the growth of grass was poor in the ash treatments, another pot experiment was established to test the growth of two creeping grass species grown in the Rand WTR as a cover over the ash material. Cynodon dactylon and Stenotaphrum secundatum were grown in 20, 40 and 60 mm layers of Rand WTR, with and without a fertiliser treatment. Both species performed best in the 60 mm layer with fertiliser, and C. dactylon performed better than S. secundatum. The former species was more tolerant of the high pH, but both have potential as cover vegetation on the ash dumps when these are covered with Rand WTR. A further glasshouse study investigated the effect of Faure WTR mixed with a nutrient poor sandy soil on the nutrient uptake and seed yield of common dry beans (Phaseolus vulgaris). The WTR was added to the soil at 0, 50, 100, 200 and 400 g kg-1 each with five levels of fertiliser (0, 25, 50, 100 (recommended optimum) and 150 %). Bean pods were harvested once the plants had senesced. The number of pods and mass and number of seeds per treatment were determined. The seeds were analysed for nutrient uptake. Interveinal chlorosis and necrotic lesions were evident on cotylendonous and new leaves in the WTR treated soils, the severity of the symptoms increasing with increasing rate of WTR. Additional pots were established at the 400 g kg-1 rate (without fertiliser) and leaf material collected for chemical analysis. This showed that Mn toxicity was the cause, with leaf concentrations about 12 times the recommended 100 mg kg-1 upper limit. However, mass of bean seed was highest in the 400 g kg-1 Faure WTR treatment with 150 % fertiliser. Nutrient translocation to the seed seemed to be relatively consistent regardless of treatment, with little accumulation of Mn. The data collected illustrated the range of conditions and types of WTRs produced in South Africa, and that in some instances these residues have favourable characteristics for land application. The use of the Rand WTR showed that it could be applied to the spoil medium at relatively high concentrations without severely negatively impacting on grass growth, but that more caution should be used when applying this material to the soil medium. While the grass did not grow in the ash treatments, it would seem that with suitable species the Rand WTR could be beneficially applied to ash material as a cover layer. The use of the Faure WTR on a sandy soil seemed to potentially improve the yield of the indicator crop, but caution should be exercised due to the possibility of Mn toxicity. The use of additional fertiliser would seem to be essential. Further research would require that field scale investigation of both WTRs be conducted, as well as further studies of application rates and techniques in laboratory and glasshouse investigations. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2003.
645

Development Of A Membrane Based Treatment Scheme For Water Recovery From Textile Effluents

Capar, Goksen 01 January 2005 (has links) (PDF)
A membrane based treatment scheme was developed for the recovery of the print dyeing wastewaters (PDWs) and the acid dye bath wastewaters (ADBWs) of carpet manufacturing industry. The treatment schemes were developed by selecting the best pre-treatment and treatment processes among the alternatives of chemical precipitation (CP), microfiltration (MF), ultrafiltration (UF) and nanofiltration (NF). The best process train for PDW was CP+NF, where organic matter, color, turbidity and total hardness were removed at &gt / 95%. The alternative process train CP+UF also removed color and turbidity almost completely, however organic matter rejection was low, being 25% at highest. The quality of NF permeates were suitable for dyeing of light colors whereas UF permeates were suggested for washing of the printed carpets or dyeing of the dark colors. The best process train for ADBW was MF (1.0 mm)+NF, where organic matter rejection increased from 65% to 97% due to pH neutralization. Alternatively, sequential NF was required up to three stages in order to achieve similarly high rejections at the acidic pH of ADBW. Therefore, pH neutralization was realized to be a very important operational parameter affecting the treatment scheme. Although pH neutralization increased the flux declines by almost 5%, chemical cleaning was very effective to restore the original fluxes. Finally, ADBW was mixed with PDW, which already had a pH around neutral, so that the pH of ADBW would rise towards neutral without chemical consumption. The results suggested that these wastewaters could be treated together as long as they were mixed up to equal volumes at pH around neutral. Therefore, a final treatment scheme, which involved single NF for the mixture of PDW and ADBW, following their individual pre-treatment stages, was proposed as the most efficient process train.
646

Dispersion of fullerenes in natural water and their behavior in water treatment process

Hyung, Hoon 01 July 2008 (has links)
Environmental impact of fullerenes such as C60 and carbon nanotubes is of great concern due to the projection for widespread application and mass production in near future. Understanding their fate in the aqueous phase is prerequisite for accurate assessment of their ecotoxicological and human health effects upon unintended release to environment. This research addresses outstanding questions related to the behavior of fullerenes in natural and engineered water environments. Specifically, this research focuses on investigating: 1) the stability of fullerenes in the natural water, 2) interaction between fullerenes and natural organic matter (NOM), and 3) treatability of water stable fullerenes by conventional water treatment process. The experimental results suggested that NOM readily interacts with fullerenes leading to the formation of water stable fullerene suspensions. The adsorptive interaction between NOM and fullerenes was largely affected by NOM characteristics as well as water quality parameters. The fate of fullerenes in water environments was also greatly influenced by the types of fullerenes (e.g., single walled carbon nanotubes, multi-walled carbon nanotubes, and C60) and the pathway they are introduced into the aqueous phase. These water stable fullerene suspensions were found to be relatively well removed by conventional water treatment processes while the presence of NOM could negatively impact the removal efficiency. The outcomes of this study collectively imply that the dispersion of fullerenes in the natural water can occur beyond the level predicted only based on their extreme hydrophobicity and NOM plays a critical role on the fate of fullerenes both in natural and engineered water environments.
647

Infrared and photocatalytic studies of model bacterial species for water treatment

Ede, Sarah Melinda January 2006 (has links)
The use of a CO2 infrared (IR) laser and photocatalysis for water treatment microorganism disinfection purposes was investigated. During CO2 infrared (IR) laser treatment E. cloacae inactivation was comparable to inactivation via ultraviolet (UV) treatment; however no inactivation of the more resistant B. subtilis endospores occurred. Fourier Transform Infrared-Attenuated Total Reflectance (FTIR-ATR) spectroscopy of the bacterial cells displayed increased polysaccharide contents after IR treatment. FTIR and Raman spectroscopy of simple carbohydrates before and after IR laser treatment displayed no spectral changes, with the exception of N-acetyl-D-glucosamine (NAG), which was partially attributed to sampling techniques. E. cloacae inactivation during IR treatment was attributed to localised and overall temperature increases within the water. Due to the inability to inactivate B. subtilis endospores this technique is not suitable for water treatment purposes. Photocatalytic water treatment using novel TiO2 colloids prepared via a postsynthetic microwave-modification process (MW-treated) was also examined. These colloids were characterised using X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and Brunauer-Emmett-Teller (BET) analyses and compared to Degussa P25 and convection hydrothermally-treated (HT-treated) TiO2. Slurry suspensions displayed comparable E. coli inactivation rates, so the colloids were examined in immobilised form using both a model organic degradant, oxalic acid, and E. coli. Oxalic acid degradation studies showed that the MW-treated colloids displayed similar inactivation rates to the HT-treated TiO2, due to their pure anatase composition, while Degussa P25 displayed higher inactivation rates. Investigations into the effect of shortening UV wavelength were also performed. Degussa P25 was the only catalyst which displayed higher apparent quantum yields upon shortening the UV wavelength, which was attributed to its mixed-phase anatase-rutile composition. As E. coli inactivation was observed using distilled water, photocatalysis in natural river water was trailed. It was discovered that the pH had to be lowered from 7.5 to 5.0 and the initial cell concentration must be approximately 1 x 103 colony forming units (CFU) per cm3 or less for inactivation to be observed during a 5 hour treatment period. At a catalyst loading of 1.0 mg per cm2, Degussa P25 absorbed all the applied UVA irradiation; however the MW- and HT-treated TiO2 colloids did not due to their smaller particle size. Therefore sandwich experiments were devised to evaluate the effect of unabsorbed UV irradiation within the system. Small colony variants were identified after photocatalytic and UV treatment, which pose a potential threat to public health. Further investigation of the different TiO2 colloids was performed using in situ FTIR, both with and without an applied potential and compared to a thermally prepared TiO2 catalyst. The latter displayed potential dependent photocatalysis, while the mesoporous TiO2 catalysts displayed potential independent photocatalysis. All catalyst types displayed increased degradation rates upon the application of a positive bias, which was followed in situ via the production of CO2. Sodium oxalate and NAG was examined for photocatalytic degradation, both of which were degraded to CO2, with proposed break-down products identified when using NAG.
648

Διερεύνηση της συμπεριφοράς μακροθρεπτικών και βαρέων μετάλλων στο σπανάκι με την επαναχρησιμοποίηση της ιλύος του βιολογικού καθαρισμού Καλαμάτας

Σωτηρόπουλος, Σταύρος 28 February 2013 (has links)
Στην παρούσα μεταπτυχιακή εργασία παρουσιάζονται τα αποτελέσματα της διερεύνησης της επίδρασης της ιλύος βιολογικού καθαρισμού Καλαμάτας (Β.Κ.Κ.) στην ανάπτυξη του σπανακιού (Spinacia Oleracea) καθώς και στην απαορρόφηση N, P, K, Ca, Mg, ιχοστοιχείων Fe, Mn, Cu, Zn, βαρέων μετάλλων Pb, Ni, Cd και Cο από τα διάφορα μέρη του φυτού. Επιπλέον, η εργασία αυτή αποτελεί μια μελέτη της επίδρασης της συγκεκριμένης ιλύος και σε ορισμένους δείκτες ποιότητας των μιγμάτων ιλύος-εδάφους, όπως pH, αλατότητα, οργανική ουσία, ολικό ανθρακικό ασβέστιο, αλλά και σε ποσοτικούς δείκτες όπως η περιεκτικότητα σε ολικό άζωτο (Ν%), διαθέσιμο φωσφόρο (Ρ κατά Olsen), ανταλλάξιμα κατιόντα K, Ca, Mg, και συγκέντρωση ολικών, διαθέσιμων και ανταλλάξιμων ιχνοστοιχείων Fe, Mn, Cu, Zn, "βαρέων μετάλλων" Pb, Ni, Cd, Cr, Co. Τα αποτελέσματα προέρχονται μετά από πειραματική μελέτη που έγινε σε φυτά σπανακιού, αναπτυσσόμενα σε υποστρώματα που προέκυψαν από ανάμιξη εδάφους και ιλύος σε διάφορες αναλογίες, σε υπαίθριο προστατευμένο χώρο. Σκοπός της πειραματικής αυτής μελέτης είναι να ελεγχθούν και να αξιολογηθούν οι ιδιότητες που αποκτούν τα υπό εξέταση υποστρώματα από την προσθήκη ιλύος στο έδαφος ταυτόχρονα με την επίδραση στην ανάπτυξη του σπανακιού. Έτσι σε αδρές γραμμές μπορούμε να συμπεράνουμε ότι τα αποτελέσματα και η αξιολόγησή τους κατατείνουν στο ότι η ιλύς της μονάδας βιολογικού καθαρισμού της Καλαμάτας μπορεί να αξιοποιηθεί ως λίπασμα σε μικρές αναλογίες ιλύος/εδάφους και φαίνεται ότι η διάθεσή της στο έδαφος για γεωργικούς σκοπούς αποτελεί μια πολύ καλή μέθοδο διάθεσης, που πρέπει να εξετάζεται κατά προτεραιότητα. Ταυτόχρονα, επιβάλλεται η συνέχιση και επέκταση της σχετικής έρευνας, για αξιοποίηση και οικολογική διαχείριση της εν λόγω ιλύος. / This study investigates the effects of the sewage sludge of Kalamata Waste Water Treatment Plant (WWTP) both in the development of spinach (Spinacia oleracea) and the absorption of N, P, K, Ca, Mg, Fe, Mn, Cu, Zn, Pb, Ni, Cd and Co from various spinach plant parts. Parameters of soil - sludge mixtures are also considered during this study. Especially the effect of sludge on parameters such as pH, salinity, organic matter, total CaCO3, total nitrogen content (N%), available phosphorus, exchangeable K, Ca, Mg, and concentration of total, available and exchangeable Fe, Mn, Cu, Zn, Pb, Ni, Cd, Cr, Co. The experiments where conducted in Messinia and the results showed that sludge improves soil fertility. The application of sludge does not cause environmental problems in small proportions of sludge – soil mixture. In large quantities the addition of sludge is associated with potential toxicities and increased salinity in the soil as well as potential environmental problems from over-concentration of phosphorus but also heavy metals such as Pb, Ni and Cr. Special attention is need for Cd, not because of high concentration, but because of the special mobility it presents. Finally this study confirms the presence of a large number of interactions between nutrients, heavy metals and soil properties in soil and spinach. The evaluation of these interactions are of great importance because they help us to quantify elemental contribution of soil and plants, helps in understanding the problems of nutrition in preventing the occurrence of toxic problems at the expense of consumer health, the environment and ultimately to effective use of sludge. Finally, the sludge of Kalamata WWTP can be used as fertilizer in small proportions of sludge / soil mixtures and it seems that the disposal of sludge in soils for agricultural purposes is a very good method of disposal that must be considered.
649

Remoção de fluoretos em amostras de água utilizando lodo de ETA como adsorvente

Araujo, Diego Erieudes 06 June 2016 (has links)
Submitted by Milena Rubi (milenarubi@ufscar.br) on 2017-08-16T14:49:46Z No. of bitstreams: 1 ARAUJO_Diego_2016.pdf: 24101509 bytes, checksum: 492307eea8861ce7d88418638e6b6051 (MD5) / Approved for entry into archive by Milena Rubi (milenarubi@ufscar.br) on 2017-08-16T14:49:53Z (GMT) No. of bitstreams: 1 ARAUJO_Diego_2016.pdf: 24101509 bytes, checksum: 492307eea8861ce7d88418638e6b6051 (MD5) / Approved for entry into archive by Milena Rubi (milenarubi@ufscar.br) on 2017-08-16T14:50:00Z (GMT) No. of bitstreams: 1 ARAUJO_Diego_2016.pdf: 24101509 bytes, checksum: 492307eea8861ce7d88418638e6b6051 (MD5) / Made available in DSpace on 2017-08-16T14:50:07Z (GMT). No. of bitstreams: 1 ARAUJO_Diego_2016.pdf: 24101509 bytes, checksum: 492307eea8861ce7d88418638e6b6051 (MD5) Previous issue date: 2016-06-06 / Não recebi financiamento / Water sludge is a solid waste produced during the water treatment. The volume of sludge produced in a water treatment plant can reach tons of material per month, depending of the quantity of water treated in the plant. Water sludge characteristics can vary depending of the water source and chemical products used in the water treatment. This material is rich in iron oxides, alum oxides, minerals and humic substances. Nowadays all this waste doesn’t have an application, being usually discharged in landfills, after a drying process, or into rivers. On the other hand, fluoride: an ion commonly founded in water samples from drilled wells. According to the current potability standard, administrative order number 2914/11 from Brazilian Govern Health Department, fluoride is necessary for water quality, being indispensable to avoid caries, primarily in children. However, in high concentrations – above 1,5 mg F?.L-1 –, fluoride causes health problems to the consumers, as dental fluorosis and skeletal fluorosis. Moreover, in a high concentration level, fluoride interferes or even hinders the application of this water to public supply, because most of the disposable technologies for fluoride removal have a high financial cost. That said, this work was planned to look for and combine a solution for both problems: utilization for water sludge and an alternative to fluoride removal with low cost. For this purpose, fluoride removal tests were done using fluoride standard samples in a jar-test equipment. These experiments were lead in different pH, to verify the pH influence in the fluoride removal process on the water sludge surface. After the experiments with the fluoride standard samples, a groundwater sample from the city of Capela do Alto, São Paulo state, was used to verify the efficiency of the material in a raw water sample with high fluoride, 2,8 ± 0,02 mg F?.L-1. The maximum adsorption result reached in fluoride standard sample was 0,36 ± 0,02 mg F?/g sludge, in pH 4. The minimum adsorption capacity was reached in pH 6, 0,30 ± 0,02 mg F?/g sludge. In the experiment with groundwater (pH 8,3), the maximum adsorption was 0,34 ± 0,02 mg F?/g sludge, showing the low pH influence in the fluoride adsorption onto water sludge. / O lodo de ETA é um resíduo sólido gerado durante o processo de tratamento da água, cujo volume gerado em uma estação de tratamento pode chegar a toneladas por mês, dependendo da quantidade de água tratada. Apesar de suas características variarem de acordo com a fonte de água utilizada e produtos empregados no tratamento da água, este material é rico em óxidos de ferro, de alumínio, minerais e materiais húmicos. Atualmente todo esse resíduo não possui um uso, sendo frequentemente descartado em aterros sanitários após processo de secagem ou lançado in natura nos corpos d’água. Outra questão comum da área de saneamento, o fluoreto: um íon comumente encontrado em amostras de águas subterrâneas. De acordo com o padrão de potabilidade vigente, Portaria 2914/11 do Ministério da Saúde, o fluoreto é necessário para a qualidade da água, sendo indispensável no combate às cáries, principalmente em crianças. Entretanto, quando em concentrações acima da máxima permitida, 1,5 mg F?.L-1, pode acarretar em problemas de saúde aos usuários do manancial, como fluorose dentária e óssea. Por este motivo, a concentração deste íon acima dos limites estabelecidos, pode inviabilizar o uso desta água para abastecimento público, visto que muitas das tecnologias utilizadas para sua remoção apresentam um alto custo. Sendo assim, este trabalho foi elaborado como forma de unir e buscar uma solução para ambos os problemas: uso para o lodo de ETA e alternativa de remoção de fluoreto à baixo custo. Para tanto, realizou-se ensaios de remoção em jar-test (teste de jarros) com padrões de fluoreto. Esses testes foram conduzidos em diferentes valores de pH, a fim de que se verificasse o grau de influência deste parâmetro no processo de adsorção do fluoreto pelo lodo de ETA. Após os testes em soluções padronizadas, utilizou-se uma amostra de água com concentração de fluoreto acima da permitida, 2,80 ± 0,02 mg F?.L-1, de um poço da cidade de Capela do Alto, estado de São Paulo, para se verificar o rendimento adsortivo do lodo em uma amostra de água in natura. Utilizando-se a solução padrão, o valor máximo de adsorção obtido foi de 0,36 ± 0,02 mg F?/g de lodo em pH 4. O menor rendimento, experimento em pH 6, foi de 0,30 ± 0,02 mg F?/g de lodo. No ensaio com a amostra de água de poço (pH 8,3), alcançou-se uma adsorção de 0,34 ± 0,02 mg F?/g de lodo. Os resultados sinalizam uma alternativa aos adsorventes utilizados atualmente, que alia eficiência de processo e reuso de um rejeito sólido com pouca, ou nenhuma, utilização.
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Despoluição de águas superficiais e efluentes de piscicultura através de sistemas construídos de áreas alagadas (Constructed Wetland)

Borges, Ana Kleiber Pessoa [UNESP] 16 September 2005 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:32:54Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-09-16Bitstream added on 2014-06-13T19:03:39Z : No. of bitstreams: 1 borges_akp_dr_rcla.pdf: 2350052 bytes, checksum: fde2c9778415ba8a3337e7ce1b0ddf78 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A disponibilidade de água no globo terrestre tende a estar comprometida devido à atividade antrópica desordenada. Grande proporção da água doce encontra-se muito prejudicada em decorrência da crescente poluição, que poderia ser minimizada pela ampliação de programas de investimentos na área de saneamento. O grande problema enfrentado pelos países do terceiro mundo e também por aqueles em desenvolvimento em relação ao saneamento, é o alto custo atual dos projetos e de suas implantações, envolvendo maior endividamento e remanejamento de recursos de outros setores, também considerados essenciais e prioritários, como saúde e educação. Trata-se do sistema construído de área alagada Constructed Wetland (CWs), que internacionalmente se expandiu nestas ultimas três décadas. O objetivo deste presente projeto foi verificar a eficácia deste tipo de sistema, em escala de laboratório, mantido em fluxo contínuo, vegetado com Eichhornia crassipes e/ou Pistia stratiotes em diferentes tempos de detecção hidráulica, no tratamento de águas superficiais contaminadas com esgotos domésticos, do Rio Corumbataí, município de Rio Claro, SP. A eficiência do sistema CWs variou com o tempo de tratamento e foi dependente do parâmetro estudado da água do rio Corumbataí. O CWs usado neste estudo mostrou-se eficiente para o tratamento da água do rio Corumbataí. O reator contendo E. crassipes foi mais eficiente para a remoção de poluentes da água que aquele com P. stratiotes. Verificou-se que o conhecimento prévio da composição do efluente a ser tratado é importante para o estabelecimento dos parâmetros a serem analisados, como também para definição do projeto de construção dos CWs. Além disso, tais características também contribuem para a definição do tempo de residência no intuito de se obter maior eficiência do tratamento utilizado. / The availability of water on Earth could be compromised due to the disordered human activity. Large proportion of the fresh water is damaged due to growing pollution, which could be minimized by increasing investments in area of sanitization. The major problem faced by the countries of the third world and also for those in development, in relation to the sanitation, it is the high cost of projects and their implantations that leads to increase the debt and consequently less resources for health and education. The possibility of conciliation of an efficient project with low cost has been developed intensely in Europe and in the United States, since 1970. This project is the Constructed Wetland (CWs) that is increasing its use internationally since three decades ago. The objective of this present project was to verify the effectiveness of this system in laboratory scale using vegetation with Eichhornia crassipes and Pistia stratiotes and continuous flow in different times of hydraulic detention. The treatment was applied for superficial waters from river Rio Corumbataí located at Rio Claro - SP, and polluted by domestic sewers. The efficiency of the system CWs varied with the time of treatment and it was dependent of the analyzed parameter of the water from river Corumbataí. CWs used in this study were shown efficient for the treatment of the water from river Corumbataí. The reactor containing E. crassipes went more efficient for the removal of pollutant of the water rather than with P. stratiotes. It was verified that the previous knowledge of the composition of the effluent to be treated is important for establishment of the parameters to be analyzed, as well as for definition of the project based in construction of CWs. Besides, such characteristics also contribute to the definition of the residence time with intention of obtaining better efficiency for the chosen treatment. / FAPESP: 02/08559-2

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