Thesis (MTech (Chemical Engineering))--Cape Peninsula University of Technology, 2016. / Polymers used as flocculants in the secondary sludge dewatering process are one of the most expensive inputs in these plants. The disadvantage is that these polymers cannot be recycled. Currently, controlling of polymer dosing rate is done by trial and error method. It has been shown that huge savings can be made by optimising the polymer dosing using rheological properties. It is not an easy task to optimise this process because of changing sludge characteristics on a daily, seasonal and annual basis. To try and optimise polymer dosing and polymer concentration, the variation in rheological properties needs to be understood first. The correlation between the process parameters and the rheological properties needs to be determined. There is currently no database of rheological properties of secondary wastewater sludge feeding belt filter presses available. To address these issues, a 12 week assessment of the rheological properties of the sludge feed to the belt filter press before and after conditioning in four wastewater treatment plants in Cape Town was conducted. The rheological properties were determined using an MCR-51 rheometer with parallel plate geometry under controlled temperature. After concluding the assessment, a 3-level Box-Behnken factorial trial was conducted at Plant K wastewater treatment plant to statistically analyse the correlation and/or interactions between the process parameters (sludge feed flow rate, polymer dosing concentration, polymer dosing rate and belt press speed) and the rheological properties of the sludge to optimise the plant performance.

Submitted by Jean Medeiros (jeanletras@uepb.edu.br) on 2017-11-13T13:30:12Z No. of bitstreams: 1 PDF - Ysa Helena Diniz Morais de Luna.pdf: 14969298 bytes, checksum: 0533a4f938f12c09a36b687414201b77 (MD5) / Made available in DSpace on 2017-11-13T13:30:12Z (GMT). No. of bitstreams: 1 PDF - Ysa Helena Diniz Morais de Luna.pdf: 14969298 bytes, checksum: 0533a4f938f12c09a36b687414201b77 (MD5) Previous issue date: 2017-04-11 / Conselho Nacional de Desenvolvimento Científico e Tecnológico - CNPq / The biological sludge approprieate treatment must be developed in order to take advantages of the products generated during the process. However, the anaerobic sludge treatment is arduous due to the complexity of the substances present in sludge flakes, granules and biofilms, becoming indispensable a pre-treatment step in order to raise the solubilization of the materials. At this study, anaerobic sludges produced by anaerobic reactos with low cell retention time (CRT) (2, 4, 6, 8, 10 and 20 days) were characterized and the 2 and 8 day sludge were submitted to solubilization from pre- treatment commonly called alkaline hydrolysis, consisting of the use of NaOH to reach pH 12, and subjected to stirring for 48 hours at room temperature. The objective of this study was to characterize the anaerobic sludges and evaluate the increase of organic materials solubilization, and make comparisons. The results of the soluble organic materials at 2 and 8 days, showed an increase in the concentrations of 14 and 28 times COD, 20 and 40 times to DQOS, 21 and 63 times to carbohydrates and 31 to 60 times to proteins respectively The solubilization of the 8-day solubilized sludge showed higher solubilization than the 2-day sludge, showing that the use of anaerobic low-CRT reactor to generate sludge is interesting in order to produce a sludge that releases higher amounts of soluble materials after a hidrolisis process, be rapidly degradeted by the anaerobic digestion. / O tratamento adequado do lodo biológico deve ocorrer visando tirar proveito dos produtos gerados durante o processo. No entanto o tratamento anaeróbio do lodo biológico é dificultado pela complexidade das substâncias formadoras dos flocos, grânulos e biofilmes, fazendo-se indispensável uma etapa de pré-tratamento empregada de modo a elevar a solubilização dos materiais. No presente trabalho foram caracterizados 6 lodos anaeróbios provenientes de reatores com baixo tempo de retenção celular (2, 4, 6, 8, 10 e 20 dias) e destes, os lodos de 2 e 8 dias (fase acidogênica) foram submetidos à solubilização a partir do pré-tratamento químico comumente chamado de hidrólise alcalina, consistindo na utilização de NaOH para alcançar pH 12, sob agitação por 48 horas em 28°C. Objetivou-se caracterizar os lodos anaeróbios de baixo tempo de retenção celular (TRC) e avaliar o aumento da solubilização dos materiais orgânicos nos lodos de 2 e 8 dias. Os resultados dos materiais orgânicos solúveis nos lodos de 2 e 8 dias, apresentaram incremento nas concentrações de 14 e 28 vezes para COD, 20 e 40 vezes para DQOS, 21 e 63 vezes para carboidratos e 31 e 60 vezes para proteínas respectivamente. Evidencia-se em todos os parâmetros analisados uma maior solubilização do lodo solubilizado de 8 dias em relação ao lodo de 2 dias, mostrando assim ser interessante a utilização de reatores anaeróbios de baixo TRC para gerar um lodo que após hidrolisado, se solubilize seus materiais e seja degradado mais rapidamente.

Submitted by Jean Medeiros (jeanletras@uepb.edu.br) on 2018-05-10T14:20:27Z No. of bitstreams: 1 PDF - Nathália Nunes de Melo.pdf: 18947535 bytes, checksum: 4cfce3961def8f699d9241cbcdbd3859 (MD5) / Made available in DSpace on 2018-05-10T14:20:27Z (GMT). No. of bitstreams: 1 PDF - Nathália Nunes de Melo.pdf: 18947535 bytes, checksum: 4cfce3961def8f699d9241cbcdbd3859 (MD5) Previous issue date: 2018-02-27 / Conselho Nacional de Desenvolvimento Científico e Tecnológico - CNPq / The treatment of sewage sludge is a challenge for environmental sanitation due to its difficulty to stabilize and large number of undesirable elements. On the other hand, it is found in its composition a high concentration of nutrients that can be reused in the nature in a beneficial way, but that end up being wasted in the conventional treatments. In the present work the treatment of sewage sludge in an anaerobic dynamic membrane bioreactor (AnDMBR) was carried out, in which it was possible to verify that the use of the dynamic membrane provided an excellent performance for the sludge filtration, producing turbidity permeate below 1 NTU after the formation of the separation layer. In addition, 53.2% of the phosphorus concentration and 35.6% of the nitrogen concentration were found in its composition, demonstrating that the use of this technology is a very interesting alternative for the recovery of these nutrients. As long as produced a less pollutant and nutrient-recovering permeate, there was also a marked stabilization of the concentrate, which showed a reduction of the organic fraction from 0.76 to 0.54 and the F/M ratio of 0.07 kgCOD/KgVSS to 0.02 KgCOD/KgVSS, furthermore a considerable methane production was observed. / O tratamento do lodo de esgoto consiste em um desafio na área de saneamento ambiental por se tratar de um resíduo de difícil estabilização e com grande quantidade de elementos indesejáveis. Por outro lado, é encontrada na sua composição uma elevada concentração de nutrientes que podem ser reutilizados na natureza de maneira benéfica, mas que acabam sendo desperdiçados nos tratamentos convencionais. No presente trabalho foi realizado o tratamento do lodo de esgoto em um biorreator anaeróbio de membrana dinâmica (BRAnMD), no qual foi possível verificar que a utilização da membrana dinâmica proporcionou um ótimo desempenho para a filtração do lodo, produzindo um permeado com turbidez abaixo de 1 NTU após o período de formação da camada de separação. Além disso, na sua composição foi encontrada 53,2% da concentração do fósforo afluente e 35,6% da concentração de nitrogênio, demonstrando, dessa forma, que a utilização dessa tecnologia consiste em uma alternativa bastante interessante para a recuperação desses nutrientes. À medida que produzia um permeado menos poluente e recuperava de nutrientes, verificou-se também uma estabilização acentuada do concentrado, que apresentou uma redução da fração orgânica de 0,76 para 0,54 e da relação A/M de 0,07 KgDQO/KgSSV para 0,02 KgDQO/KgSSV além de possibilitar uma considerável produção de metano.

This Diploma’s thesis is addressing the issues of technical drying, principles and types of technical drying, solar drying possible usefulness of sewage sludge in the Czech Republic, its availability during the season, the legislation related to the processing of sewage sludge and design of pilot scale solar dryer.

Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第15720号 / 工博第3334号 / 新制||工||1504(附属図書館) / 28265 / 京都大学大学院工学研究科都市環境工学専攻 / (主査)教授 津野 洋, 教授 田中 宏明, 教授 清水 芳久 / 学位規則第4条第1項該当

The activated sludge process comprises a complex and enriched culture of a mixture of generalist and specialist organisms. The lack of knowledge on species diversity of microbial communities is due to the simplicity of bacterial morphology and the phenotypic characters, and the unculturable portion of microbial cells in natural habitats. Although a wide range of bacteria can be isolated using conventional microbiological techniques of sample dilution and spread plate inoculation, many well-known activated sludge bacteria can not be isolated using them. The individual microbial cells in activated sludge grow in aggregates that consist of floc-forming organisms together with filamentous microorganisms that form the backbone of the activated sludge floes. Overgrowth of these filamentous microorganisms often causes settling problems called bulking and foaming. These problems consist of slow settling, poor compaction of solids and foam overflow into the effluent. Although methods for the isolation of filamentous bacteria from mixed liquor samples have been investigated, the attempts have been largely unsuccessful. In this study we investigated bulking and foaming activated sludge to identify the dominant filamentous organisms using microscopy and molecular techniques. Using microscopy, the dominant filament associated with the foaming sample was "Microthrix parvicella" and in the bulking sample was Nocardia spp. The foaming sample was investigated using molecular techniques that involved 165 rDNA sequencing. Although some of the clones isolated from the sludge foam were associated with filamentous bacteria causing foam, no positive identification could be made. In the part of the study that was conducted in Australia, a rRNA-targeted oligonucleotide probe was designed for the identification of a filamentous organism occurring in activated sludge foam. This organism resembled Eikelboom Type 0041 and was classified in the candidate bacterial division TM7. The discrepancy that the sequence data did not indicate the dominant filamentous organisms observed by microscopy, highlights the fact that natural microbial communities need to be studied using a combination of techniques since none of the techniques available are sufficient to determine the complete community structure of complex communities such as activated sludge. / Dissertation (MSc (Microbiology))--University of Pretoria, 2005. / Microbiology and Plant Pathology / unrestricted

Submitted in fulfilment of the requirements of the degree of Master of Technology: Biotechnology, Durban University of Technology, Durban, South Africa, 2014. / Wastewater treatment plants (WWTPs) frequently experience bulking and foaming episodes, which present operational challenges by affecting sludge settling due to the excessive proliferation of filamentous bacteria. Various control strategies have been implemented over the years to minimize filamentous growth, however, filamentous bulking still remains an unresolved problem in many WWTPs worldwide. The current study focused on developing and optimizing remedial measures viz., specific and non-specific methods to reduce problematic filamentous bacteria in a full-scale WWTP. Specific methods demonstrated the influence of plant operational parameters viz. chemical oxygen demand, influent N-NH4+, food to microorganism ratio, dissolved oxygen, temperature and pH on the abundance of filamentous bacteria. A cumulative logit model was used to determine the significant relationships between the individual filamentous bacteria at present and the prevailing plant operational parameters. Using the above statistical approach, significant observations and predictions were made with respect to the individual filamentous growth under certain operational parameters. With further validation, this model could be successfully applied to other full-scale WWTPs identifying specific parameters that could contribute to filamentous bulking, thus providing a useful guide for regulating specific filamentous growth. Non-specific control methods such as chlorine, ultraviolet irradiation and ozone treatment were investigated on filamentous bacteria using a live/dead staining technique. To achieve at least 50% reduction of filamentous bacteria, a chlorine dose of 10 mg Cl2/L was required, all filaments were killed at a dose of 22 mg Cl2/L. In addition, an effective UV and ozone dose of 4418.91 μw seconds/cm2 and ±20 mg O3/L respectively, was required to kill 50% of the filamentous bacterial population. Among the three non-specific methods, ozone treatment seemed to be an effective method in controlling the filamentous population with a low negative impact to the surrounding environment. This study serves as a useful guide on the problems and control of filamentous bulking in activated sludge plants. / M

The treatment of water for human consumption results in the production of residual waste flows that vary depending on source waters and water treatment technologies. Water treatment plant residual waste is defined as a pollutant that requires treatment either on site or through other means. Due to strict and evolving regulatory requirements, treatment of water treatment plant residual waste several common methods of disposing of water plant residuals exist including discharge to surface waters, discharge to sanitary sewers, and sanitary landfill disposal of dewatered wastes. Although originally discharged to the neighboring City Reservoir, the Carbondale Water Treatment Plant (CWTP) conducted an initial study to determine if plant residual waste could be treated at one of the City’s two wastewater treatment plants. No negative impacts were identified as part of this study and infrastructure was put in place to divert CWTP residual waste from the City Reservoir to the Carbondale Southeast Wastewater Treatment Plant (SEWWTP). This study focused on accessing and quantifying any impacts of Carbondale Water Treatment Plant (CWTP) residual solids sewer discharge on biological treatment processes, effluent water quality, and sludge production at the SEWWTP. The Carbondale SEWWTP treats raw water influent through a number of physical and biological processes including screening, clarification, nitrification/denitrification, and aeration. Of the tests run as part of this study daily samples were collected of SEWWTP influent, mixed liquor, return sludge, and effluent and measured for changes in pH, biochemical oxygen demand (BOD), solids, sludge volume index (SVI), dissolved oxygen (DO), and nitrogen. No significant changes were documented other than percent BOD removal did improve after the introduction of the residuals. Anions were also tested weekly. Samples were collected from the SEWWTP’s oxidation ditch to monitor biological life using biological activity reaction tests (BART) for nitrifying, denitrifying, and heterotrophically active bacteria. BART testing showed no decline in biological activity and increased populations of denitrifying bacteria. Additionally, both metals and acute toxicity of SEWWTP effluent were tested by outside testing facilities to confirm that CWTP residual solids sewer discharge did not interfere with discharge limits established as part of the plant’s permits. No significant changes were observed during testing but plant staff did indicate that more extensive cleaning of the basins was implemented post-introduction. Overall, the case study confirmed that the treatment of CWTP residual solids sewer discharge did not negatively impact treatment processes at the SEWWTP and is sustainable.

A big challenge within pulp and paper mills is the large quantities of waste activated sludge (WAS) that is produced during the wastewater treatment. The WAS is made up of biological cells and extra polymeric substances (EPS) and can bind a large amount of water causing difficulties to dewater the WAS. This study aimed to determine how to improve the dewatering properties of the WAS by using hydrolysis. Hydrolysis will cause the cells to disrupt and the bound water in the cells and the water trapped by the EPS can be released. Specifically, this study investigated what impact hydrolysis with heat, alkalis, and acids had on the WAS dewatering properties. In addition to the impact on the dewatering properties, the release of organic material and nutrients from the cells has also been important for biomethane production. In this study, it was specifically NH4-N, PO43- and COD that have been studied. WAS from paper mills have in general poor methane potential so it was of interest to see how the WAS was affected by hydrolysis and how hydrolysis could improve the methane production. To test the hypothesis of whether hydrolysis could affect the WAS and improve the dewatering properties, several experiments were performed. The experiments included thermal hydrolysis at temperatures of 70-90 °C, acidic hydrolysis with acids such as spent acid and acid water, and alkalis such as green liquor sludge and EOP. All acids and alkalis used in the study were chemicals that exist at the paper mills included in this study. To test the dewatering properties, methods such as TS analysis on the accept, CST-analysis, and a belt press were used. Analyses were also performed on the reject to measure the suspended solids and the nutrients NH4 – N, PO43– and COD in the WAS. This study did also determine what effect hydrolysed WAS had on the biomethane potential. In this study were the paper mills BillerudKorsnäs in Skärblacka and SCA in Östrand included. Hence was sludge from the two mills of interest to analyse. This study has shown better dewatering properties with an increase in the total solids (in the accept) after the thermal hydrolysis, the acidic hydrolysis with spent acid, and the alkali hydrolysis with green liquor sludge. Specifically did the acidic hydrolysis with spent acid improve the dewatering properties in terms of an increase in TS in %. The biggest increase in TS in % could be seen after using 10% spent acid ratio. The TS for the WAS from SCA Östrand increased in this experiment by 107 %. The thermal hydrolysis also showed promising results both in terms of dewatering properties and in the release of organic material. The biochemical methane potential test results showed a better and more rapid stabilized production of biomethane after hydrolysis of WAS compared to untreated WAS. The thermal hydrolysis both increased the rate of production and the total amount of methane produced. The thermally hydrolysed WAS from SCA Östrand improved the methane production from 77 Nml methane/g VS to 95 Nml methane/ g VS. The WAS from BillerudKorsnäs improved the methane production from 40 Nml methane/ g VS to 55 Nml methane/ g VS. These results, both from the methane potential tests and the results of the increased dewatering properties, show that the concept with hydrolysing should be evaluated further for improving the dewatering of the WAS.

No description available.