Marcos von Sperling

Sludge treatment and disposal

Sludge Treatment and Disposal is the sixth volume in the series Biological Wastewater Treatment. The book covers in a clear and informative way the sludge characteristics, production, treatment (thickening, dewatering, stabilisation, pathogens removal) and disposal (land application for agricultural purposes, sanitary landfills, landfarming and other methods). Environmental and public health issues are also fully described. About the series: The series is based on a highly acclaimed set of best selling textbooks. This international version is comprised by six textbooks giving a state-of-the-art presentation of the science and technology of biological wastewater treatment. Other titles in the series are: Volume 1: Waste Stabilisation Ponds; Volume 2: Basic Principles of Wastewater Treatment; Volume 3: Waste Stabilization Ponds; Volume 4: Anaerobic Reactors; Volume 5: Activated Sludge and Aerobic Biofilm Reactors

Urban wastewater treatment technologies and the implementation of discharge standards in developing countries

The paper analyses the practical implementation of standards for treated urban wastewater and receiving water bodies with a special focus on the following points of concern for developing countries: (a) typical problems with setting up and implementing standards in developing countries; (b) the need for a stepwise implementation of the measures necessary to achieve the standards; (c) the need for institutional development; and (d) the availability of wastewater treatment technologies. The treatment technologies are presented in a simple and practical way (tabular form), showing their expected effluent quality in terms of important parameters such as BOD, COD, suspended solids, ammonia, total nitrogen, total phosphorus, faecal coliforms and helminth eggs.

Comparison and evaluation of empirical zone settling velocity parameters based on sludge volume index using a unified settling characteristics database

Over the past few decades classic and contemporary research on the process of secondary clarification in activated sludge plants has illuminated several aspects of the solids-flux theory which actually require a closer examination. Inter alia the most challenging and controversial part in the field has been the development of reliable models for the settling properties of the activated sludge in the settler. Numerous studies have been performed aiming at the evolvement of reliable mathematical formulas that would satisfactorily describe this behaviour, but no universally accepted solution seems to exist to date. That is mostly because different experimental conditions, sludge types and instrumentation have been employed, thus complicating the process of reaching a conclusive result. In order to bring theoretical and practical developments of secondary settling tank design and simulation closer together, a number of related tasks are addressed in this study by the use of an integrated and unified settling characteristics database. Several drawbacks and advantages of the methodologies published hitherto are examined on a universal basis and under the same assumptions in order to reveal artifacts that complicate the procedure of settling velocity estimation. It is suggested that universally accepted solutions may be feasible especially for design purposes. For simulation analysis real-time data of settling velocity should be tested rather than values derived from laboratory experiments which are shown to produce different results depending on the applied approach. In conclusion, an integrated database is proposed as a means for a more robust and universally accepted design procedure.

Waste stabilisation ponds

Waste Stabilisation Ponds is the third volume in the series Biological Wastewater Treatment. The major variants of pond systems are fully covered, namely: facultative ponds anaerobic ponds aerated lagoons maturation ponds The book presents in a clear and informative way the main concepts, working principles, expected removal efficiencies, design criteria, design examples, construction aspects, operational guidelines and sludge managment for pond systems. About the series: The series is based on a highly acclaimed set of best selling textbooks. This international version is comprised by six textbooks giving a state-of-the-art presentation of the science and technology of biological wastewater treatment. Other titles in the series are: Volume 1: Waste Stabilisation Ponds Volume; 2: Basic Principles of Wastewater Treatment; Volume 4: Anaerobic Reactors; Volume 5: Activated Sludge and Aerobic Biofilm Reactors; Volume 6: Sludge Treatment and Disposal

Performance evaluation and mathematical modelling of coliform die-off in tropical and subtropical waste stabilization ponds

Abstract The paper investigates the coliform removal in 33 facultative and maturation ponds in Brazil. The ponds were located in different parts of the country, with climates ranging from tropical to subtropical and latitude from 7 to 24°S. The ponds had different physical configurations, temperature and detention times. The total number of data used in the study, mostly comprising long-term averages, was 66. Two flow regimes were investigated: CSTR and dispersed flow. In the dispersed-flow model, the dispersion number was estimated using the formulae by Agunwamba et al. and Yanez, and both were found to give similar results. The coliform die-off coefficient Kb was correlated with the pond depth and hydraulic detention time in the dispersed-flow model (R2=0.847). A regression equation, using theoretically generated data, was proposed, correlating Kb for the CSTR model with Kb for dispersed-flow model, using the length-to-breadth ratio and detention time of the pond (R2=0.997). Use of this equation yields virtually the same removal efficiency values as those obtained directly by the dispersed-flow model. Utilisation of the Kb values calculated by the proposed regression models gave a very good prediction of the log effluent coliform concentration of the 33 ponds (R2=0.951 for the CSTR model and R2=0.959 for the dispersed-flow model). Applying the proposed model for dispersed flow, it was concluded that, for a given removal efficiency, a shallow pond, due to its larger Kb, requires less surface area, compared to a deep pond, even though the latter has a higher detention time.

Wastewater characteristics, treatment and disposal

Wastewater Characteristics, Treatment and Disposal is the first volume in the series Biological Wastewater Treatment, presenting an integrated view of water quality and wastewater treatment. The book covers the following topics: wastewater characteristics (flow and major constituents) impact of wastewater discharges to rivers and lakes overview of wastewater treatment systems complementary items in planning studies. This book, with its clear and practical approach, lays the foundations for the topics that are analysed in more detail in the other books of the series. About the series: The series is based on a highly acclaimed set of best selling textbooks. This international version is comprised by six textbooks giving a state-of-the-art presentation of the science and technology of biological wastewater treatment. Other titles in the series are: Volume 2: Basic Principles of Wastewater Treatment; Volume 3: Waste Stabilisation Ponds; Volume 4: Anaerobic Reactors; Volume 5: Activated Sludge and Aerobic Biofilm Reactors; Volume 6: Sludge Treatment and Disposal

Activated Sludge and Aerobic Biofilm Reactors

Activated Sludge and Aerobic Biofilm Reactors is the fifth volume in the series Biological Wastewater Treatment. The first part of the book is devoted to the activated sludge process, covering the removal of organic matter, nitrogen and phosphorus.A detailed analysis of the biological reactor (aeration tank) and the final sedimentation tanks is provided. The second part of the book covers aerobic biofilm reactors, especially trickling filters, rotating biological contractors and submerged aerated biofilters. For all the systems, the book presents in a clear and informative way the main concepts, working principles, expected removal efficiencies, design criteria, design examples, construction aspects and operational guidelines. About the series: The series is based on a highly acclaimed set of best selling textbooks. This international version is comprised by six textbooks giving a state-of-the-art presentation of the science and technology of biological wastewater treatment. Other titles in the series are: Volume 1: Waste Stabilisation Ponds; Volume 2: Basic Principles of Wastewater Treatment; Volume 3: Waste Stabilization Ponds; Volume 4: Anaerobic Reactors; Volume 6: Sludge Treatment and Disposal

Avaliação de 166 ETEs em operação no país, compreendendo diversas tecnologias. Parte 1: análise de desempenho

The paper analyses the performance of 166 wastewater treatment plants operating in Brazil. Six different treatment technologies have been investigated, comprising the following processes: septic tank + anaerobic filter, facultative pond, anaerobic pond + facultative pond, activated sludge, UASB reactors alone, UASB reactors followed by post-treatment. The objective of the research was to evaluate the effluent quality and the removal efficiencies of the parameters BOD, COD, TSS, coliforms, TKN and phosphorus. The paper compares the effluent quality and the removal efficiencies with typical values reported by the technical literature. In general, the performance in the removal of organic matter was as expected. TSS removal efficiencies were lower than reported, but coliform removal was higher than described in the literature. Nutrient removal was low, but none of the treatment processes have been designed with this objective.

Evaluation of performance of UASB reactor in swine wastewater treatment

This research presents the development and evaluation of a system for treatment of swine wastewaters constituted by slat settler, followed by upflow anaerobic sludge blanket (UASB) reactor, at full scale. The UASB reactor was completely made of masonry and reinforced concrete. The evaluation of the treatment system was carried out through samples collected in the influent and effluent from the settler and UASB reactor. The following parameters were analyzed: temperature, pH, alkalinity, total volatile acids (VFA), suspended solids (TSS), volatile suspended solids (VSS), biochemical oxygen demand (BOD), chemical oxygen demand (COD), according to the methods established by the Standard Methods (APHA, 1998). The mean results of COD and BOD removal were 93 and 92%, respectively. The mean concentrations of COD, BOD and TSS in the final effluent were 790, 1818 and 854 g L-1, respectively. The volumetric organic load (VOL) in the UASB reactor ranged from 1.1 to 17.5 kg COD m-3 d-1. The system slat settler-UASB reactor showed itself to be a promising alternative for the treatment of swine wastewaters.

Performance evaluation of planted and unplanted subsurface-flow constructed wetlands for the post-treatment of UASB reactor effluents.

A system comprised by a UASB (Upflow Anaerobic Sludge Blanket) reactor followed by two horizontal subsurface-flow constructed wetlands in parallel was evaluated for the treatment of the wastewater generated in the city of Belo Horizonte, Brazil (50 inhabitants each unit). One unit was planted (Typha latifolia) and the other was unplanted. Influent and effluent samples were collected for a period of seven months. The systems were able to produce final effluents with low concentrations of organic matter and suspended solids, but showed not to be efficient in the removal of nutrients. Mean effluent concentrations for the planted and unplanted units were, respectively: BOD: 15 and 19 mg/L; COD: 42 and 64 mg/L; TSS: 3 and 5 mg/L; TN: 27 and 33 mg/L; N-NH(3): 25 and 29 mg/L; P Total: 1.2 and 1.5 mg/L. The planted wetland presented effluent concentrations and removal efficiencies significantly (Wilcoxon matched-pairs test, 5% significance level) better than the unplanted unit for most constituents. The study shows that horizontal subsurface-flow constructed wetlands can be effectively used as a post-treatment option for the effluent from UASB reactors.