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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.
41

Uso de composto orgânico de lodo de esgoto para adubação de plantio de essênciais florestais / Use of organic compost of sewage sludge to fertilizer planting forest essences

Padovani, Vera Cristina Ramalho, 1965- 07 May 2013 (has links)
Orientador: Durval Rodrigues de Paula Junior / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agrícola / Made available in DSpace on 2018-08-23T09:19:32Z (GMT). No. of bitstreams: 1 Padovani_VeraCristinaRamalho_D.pdf: 3929608 bytes, checksum: 7486cc17cc63c5040d3493cce947d41d (MD5) Previous issue date: 2013 / Resumo: O objetivo deste trabalho foi avaliar em condições de campo o comportamento de três espécies florestais produzidas em dois tipos substratos, submetidas a diferentes dosagens de adubação de cova (2,0; 4,0 e 8,0 kg), utilizando o composto orgânico de lodo de esgoto (COLE) em comparação com a testemunha (0,0 kg), e testar a viabilidade de uso do lodo de esgoto como adubo orgânico na adubação pós - plantio de mudas de árvores. O lodo de esgoto foi submetido à análise química de macro e micronturientes, pH, sólidos voláteis, umidade, relação C/N e metais pesados, antes de ser higienizado e estabilizado através da compostagem, com restos de capim roçados das áreas verdes e recebeu a denominação de COLE. Após o término do processo de compostagem, o composto foi submetido a análises químicas, microbiológicas e parasitológicas, além da condutividade elétrica. As mudas de árvores nativas utilizadas no experimento foram às espécies Platypodium elegans (Amendoim bravo), Pterocarpus violaceus (Aldrago) e Poecilanthe parviflora (Coração de negro), que representam respectivamente os grupos ecológicos das pioneiras, secundárias e clímax, e foram produzidas no viveiro municipal da Faculdade Municipal Professor Franco Montoro /Mogi Guaçu, em dois substratos diferentes, sendo um à base de COLE e outro de esterco de curral curtido (tradicional). O delineamento experimental foi o de parcelas subdivididas no tempo com blocos casualizados, com cinco repetições por parcelas, utilizando três espécies diferentes produzidas em dois substratos diferentes (à base de COLE e esterco de curral curtido) e quatro tratamentos diferentes que correspondem a dosagens de COLE que variaram de 0,0 Kg, 2,0 Kg, 4,0 Kg e 8,0 Kg/ cova. Foram avaliadas as características químicas e físicas do solo e as medidas de crescimento das mudas como altura, diâmetro das plantas aos 24 meses após o plantio e análise química do tecido vegetal para determinação da concentração de macro e micronutrientes, aos 36 meses após o plantio. Os resultados das análises microbiológica, parasitológica e química indicaram que o composto de lodo de esgoto é adequado para ser utilizado como composto orgânico em adubação de cova para essências florestais. As plantas da espécie Poecilanthe parviflora produzidas à base de substrato COLE, apresentaram redução na altura, nos teores de Ca e Mg com adição do COLE, além do desequilíbrio nutricional. A adição do COLE na cova de plantio das espécies Platypodium elegans e Pterocarpus violaceus não promoveu aumento significativo da altura e diâmetro em comparação com a testemunha. O uso do COLE como adubo orgânico para fertilização de espécies nativas e exóticas plantadas em áreas verdes apresenta-se como uma alternativa para destinação e disposição dos resíduos gerados no município / Abstract: The purpose of this research was to evaluate under field conditions the behavior of three forest species produced in two types substratum exposed to different dosages of fertilizer pits (2.0, 4.0 and 8.0 kg) using the organic compost sewage sludge (COLE) compared to control (0.0 kg) and test the feasibility of using sewage sludge as a fertilizer in organic fertilization post plantation of tree seedlings. The sewage sludge was subjected to chemical analysis for micronutrients, pH, volatile solids, humidity, the C / N relation and heavy metals before being sanitized and stabilized through composting, with the remains of green areas scuffed grass and received the denomination COLE (sewage sludge organic compound). After completion of the composting process, the compound was subjected to microbiological, parasitological and chemical analyzes additionally to electrical conductivity. The seedlings used in the experiment are native trees species Platypodium Elegans, Pterocarpus violaceus Poecilanthe parviflora, which respectively represents the pioneer, secondary and climax ecological groups. They were produced at the municipal nursery of the Municipal University "Professor Franco Montoro" in Mogi Guaçu using two different substratum: one based in COLE and the other cattle manure (traditional). The experimental outline used was plots subdivided in time into random blocks of five repetitions per plot using three different species produced in two different substratum (based COLE and cattle manure) and four different treatments that correspond to doses of COLE ranging from 0.0, 2.0, 4.0 and 8.0 kg / pit. We evaluated the chemical and physical characteristics of the soil and seedling growth measurements such as height, diameter of plant at 24 months after planting and chemical analysis of plant tissue to determine the concentration of macro and micronutrients at 36 months after planting. The results of the microbiological, parasitological and chemical analyses indicate that the compost of sewage sludge is suitable for use as a fertilizer in the organic compound pit for forest species. The plants of the species Poecilanthe parviflora produced based on substratum COLE, besides nutritional imbalance, presented reduction in height based on levels of Ca and Mg adding COLE. The addition of the organic compound sewage sludge (COLE) in the planting pit of the remaining species did not cause a significant increase in height and diameter when compared with the dosage control, but increasing doses of COLE promoted increase in height and diameter of plants compared to the dosage control. The use of sewage sludge compound (COLE) an organic fertilizer canbecame reduces costs with the fertilization of native. Exotic species planted in green areas becoming a viable alternative for the destination and disposal of waste generated in the municipality / Doutorado / Agua e Solo / Doutora em Engenharia Agrícola
42

Sulphide-enhanced hydrolysis of primary sewage sludge : implications for the bioremediation of sulphate-enriched wastewaters

Whittington-Jones, Kevin John January 2000 (has links)
The potential application of sulphate reducing bacteria for the bioremediation of acid mine drainage has already been recognised, and offers significant financial advantages over conventional chemical treatment approaches. Although the technology has been demonstrated successfully on both small- and large-scale, it’s extensive implementation has been constrained by the provision of suitable and cost effective electron donor and carbon sources. Primary sewage sludge is readily available in large quantities, but the slow rate of solubilization and low yield of soluble products do not apparently favour its use for this application. A number of pre-treatment steps have been introduced in an attempt to improve the yield and rates under methanogenic conditions. However, although early work suggested that degradation of lignocellulose and proteins may be more rapid under sulphate reducing conditions, the fate of primary sewage sludge under these conditions has been ignored. It was proposed that by combining the hydrolysis of primary sewage sludge and biological sulphate reduction, in a settling sludge bed, both processes would be enhanced. The aim of this study was to test this hypothesis on laboratory- and pilot-scale, and attempt to elucidate the underlying mechanism involved. The solubilization of primary sewage sludge was enhanced in the presence of sulphate reduction in continuous laboratory-scale reactors. Particulate matter accumulated in the bed of non-sulphidogenic systems, but not in sulphidogenic ones. This was attributed to increased solubilization and the smaller average floc size in the latter. Solubilization occurred within the settling sludge bed of the reactors, and offered a possible explanation for the better performance of the multiple- over single-stage reactor. A pilot-scale Falling Sludge Bed Reactor was constructed at Grootvlei Gold Mine, Springs, South Africa, and resulted in the solubilization of more than 70% of the influent primary sewage sludge. The system was also found to be highly resilient to severe perturbations, and returned rapidly to steady-state. Flask studies revealed that the hydrolysis of both proteins and complex carbohydrates was accelerated in the presence of biological sulphate reduction or sulphide. A study of the enzymology of sludge digestion revealed that sulphate reduction had little direct effect on the activity of the hydrolytic enzymes, but that reactor design was critical in the prevention of washout of these enzymes. Finally, a descriptive model was developed to explain the enhanced hydrolysis of primary sewage sludge. The model incorporated the effect of sulphidogenesis on floc fracture and reflocculation, and likely implications for mass transfer limitations.
43

Anaerobic digestion of cheese whey in an upflow anaerobic sludge blanket reactor

Yan, Jing-Qing January 1991 (has links)
The anaerobic digestion of cheese whey was studied in an upfiow anaerobic sludge blanket reactor for its start-up characteristics, the effects of various process parameters, the effect of sulfate addition and the determination of optimal operating conditions. Start-up of an UASB reactor treating cheese whey was extremely difficult due to its tendency to acidify. Various start-up strategies were tested to facilitate start-up and to ensure stable operation. Among the operating parameters, sludge loading rate was the most critical for proper start-up of the UASB reactor. The initial sludge loading rate during start-up period should not exceed 0.25 g COD/g VSS. The response of whey digestion to several process parameters was investigated. Without pH-control, over 97% COD removal was obtained for influent concentrations from 5 to 28.8 g COD/1 and HRT of 5 days. However, instability was observed when the influent concentration was increased to 38.1 g COD/1. Gas production from whey is affected by organic loading rate (OLR). At an OLR less than 4 g COD/l-d, higher influent strength resulted in a higher methane production rate. When the OLR was greater than 6, higher strength feed or shorter hydraulic retention time (HRT) produced less methane. From the profiles of substrate concentration measured at various levels above the bottom of the reactor, two reaction stages, acidogenesis and methanogenesis were distinguished. It was experimentally illustrated that the rate of acidogenesis is much faster than the rate of methanogenesis in a whey anaerobic digestion system. The accumulation of VFAs in the first stage being faster than its assimilation in the second stage creates a distinct acidogenic phase in the bottom of the reactor. The instability caused by high influent concentration could be attributed to the accumulation of VFAs beyond the assimilative capacity of the methanogenic stage. A set of empirical models for accumulation and degradation of VFAs was developed using linear regression analysis. The requirement for maintaining this system in a dynamic balance was that the degradation capacity for VFA in the second stage be greater than the accumulation of VFA in the first stage. Based on this idea, the optimal influent concentration was given as between 25 to 30 g COD/1 for system stability. A hypothesis was proposed in this study that a proper amount of sulfate may be applied to moderate the detrimental influence of excess hydrogen on a stressed anaerobic reactor. The effect of sulfate was tested to study the biochemical mechanism. The permissible influent COD concentration was increased from 30 g COD/1 to 50 g COD/1 by using sulfate addition. The pH in the reactor was on the average 0.8 units higher and the concentration of butyric acid in the acidogenic phase much lower with added sulfate than without sulfate addition. The significant improvement of process stability and treatment efficiency made by the addition of sulfate clearly illustrated that sulfate acted like a stimulator which helped to maintain conditions favorable to methanogenesis. The mechanism of this stimulation is explained according to thermodynamics and hydrogen regulation which suggested that sulfate is able to promote the β-oxidation of VFAs by consuming hydrogen. A two-stage inhibition mechanism was proposed to explain the inhibition of high VFA concentrations and the stimulation of sulfate. Higher hydrogen pressure is the cause of preliminary inhibition, resulting in the accumulation of VFAs, which subsequently inhibit the activity and growth of methanogens in the second inhibition stage. The mechanism of inhibition of methanogens from VFAs was interpreted as being caused by the acidification of the internal cytoplasm and destruction of the pH gradient by non-ionized acids based on the theory of bacterial membrane transport. A new control strategy for stabilization of an anaerobic system is recommended. Under the optimal operating conditions based on the results in the first three steps, over 97% reduction of COD was achieved when the influent COD was 30 g /l using an HRT of 2 days, an OLR of 16.61 g COD/l-d and sulfate concentration of 0.2 g/1. / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate
44

Oxygen transport and reaction kinetics in activated sludge /

Roche, Robert Emmett January 1970 (has links)
No description available.
45

Selective Removal of Color, TOC, and THM Precursors from a Highly Colored Recycled Magnesium Sludge Using Granular Activated Carbon

Gill, Kathleen O. 01 October 1981 (has links) (PDF)
The study investigated the ability of granular activated carbon (F-400) to remove organic color, TOCk and THM precursors from a highly organic-laden recycled magnesium sludge without reducing the magnesium concentration. This treatment was attempted in order to render the sludge a more effective coagulant for surface water purification. Adsorption effectiveness was assessed through Freundlich isotherms and continuous-flow GAC columns, with both procedures conducted at three pH values. Color and TOC were adsorbed more effectively at lower pH values, while adsorption of THM precursors was inhibited at low pH. Magnesium was not significantly adsorbed by the carbon. The carbon treatment of magnesium sludge did little to improve its coagulation effectiveness.
46

Impact of Alum Sludge on Lake Sediment Phosphorus Release and Benthic Communities

Jellerson, David B. 01 October 1981 (has links) (PDF)
Alum sludge from a Tampa water treatment plant was found to significantly reduce phosphorus release from anaerobic bottom sediments. The kinetics of phosphorus uptake by the sludge was evaluated in batch reactors. Further, the impact of the sludge on benthic organisms was determined in aquarium systems. Aquariums were set up with sediments and organisms from various lake habitats. Organisms were allowed to establish themselves and then test aquaria were dosed with alum sludge to cover the sediments. Benthic survival and heavy metal uptake were evaluated. Favorable phosphorus uptake was demonstrated in the batch reactors. The uptake kinetics were found to closely follow both Freundlich and Langmuir isotherms over a wide range of sludge dose and phosphorus concentrations. Benthic organisms typical of polluted environments were not adversely affected by the sludge additions. However, oligochaetes exposed to the sludge had elevated metal concentrations. Clean water organisms were somewhat less tolerant of the sludge and did not significantly concentrate heavy metals.
47

An investigation into the potential of faecal sludge for plant production.

Taylor, Craig Robert. 12 September 2014 (has links)
Abstract available in PDF file. / Thesis (M.Sc.)-University of KwaZulu-Natal, Durban, 2012.
48

Detection of enteric viruses in treated wastewater sludge using cell culture and molecular methods

Sabalos, Constantine Marc. January 1998 (has links) (PDF)
Thesis (M.S. - Soil, Water and Environmental Science)--University of Arizona. / Includes bibliographical references (leaves [64]-69).
49

Effect of centrifugal dewatering on the regrowth of fecal coliforms and Salmonella in anaerobically digested biosolids

Qi, Yinan. January 2008 (has links)
Thesis (Ph.D.)--University of Delaware, 2008. / Principal faculty advisors: Steven K. Dentel, Dept. of Civil & Environmental Engineering; and Diane S. Herson, Dept. of Biological Sciences. Includes bibliographical references.
50

Dewatering and treatment of sewage sludge before landfill /

Ng, Yue-hang. January 1995 (has links)
Thesis (M. Sc.)--University of Hong Kong, 1995. / Includes bibliographical references.

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