Sistema de controle discreto no tempo aplicável a processo aeróbio de tratamento de efluentes líquidos

Neste trabalho, com auxílio da Teoria de Controle Ótimo, foi estabelecido um controlador discreto no tempo aplicável aos tanques de aeração dos processos de lodos ativados, processo largamente empregado para o tratamento de efluentes líquidos de origem sanitária ou industrial. O comportamento dinâmico das variáveis de estados empregadas para descrever o tanque de aeração foi descrito com auxílio do modelo proposto pela International Water Association. Concentração de biomassa, concentração de substrato e vazão efluente do tanque de aeração constituíram as variáveis de estado. Vazão de recirculação e vazão de descarte de lodo atuaram como variáveis de controle. As simulações computacionais conduzidas indicaram que o controlador proposto permite reduzir substancialmente os tempos de oscilação e as variações nas concentrações das variáveis de estado em relação as suas condições de equilíbrio.

Modeling interspecific competition of the microbial community during anaerobic digestion based on cellular automata and ADM1

Interspecific competition for substrate and space gives rise to considerable variation in biomass distribution within the microbial community. To study microbial community in depth, we employed such research methods as sampling and analytical measurements, and developed a cellular automata (CA) model that would facilitates description of the microbial growth process based on the Anaerobic Digestion Model No. 1 (ADM1) of the International Water Association (IWA). Using the CA model, we aimed to determine whether interspecific competition occurs among acidogens, acetogens and methanogens, and examine the influence of interspecific competition on the spatial structure of microbial communities. We found that acetogens and methanogens competed for core space, resulting in a multi-layer structure. Butyrate-degrading acetogens increased in number, resulting in inhibition of propionate-degrading acetogens. Hydrogenotrophic methanogens showed stronger competitive advantage than acetotrophic methanogens. The simulation showed that the multi-layer structure of the microbial community was formed by interspecific competition.

Modeling of Thermophilic Anaerobic Digestion of Municipal Sludge Waste using Anaerobic Digestion Model No. 1 (ADM1)

Anaerobic digestion model no. 1 (ADM1) model of international water association was applied to a lab-scale thermophilic anaerobic digestion process for the treatment of activated sludge wastes originating from a municipal wastewater treatment plant. The aim of the present study is to compare the results obtained from the simulation with the experimental values. The simulated results showed a good fit for cumulative produced methane gas volume and the concentration profile of total volatile fatty acids (VFAs).

“Water Association” Band in Saccharide Amorphous Matrices: Role of Residual Water on Bioprotection

Saccharides protect biostructures against adverse environmental conditions mainly by preventing large scale motions leading to unfolding. The efficiency of this molecular mechanism, which is higher in trehalose with respect to other sugars, strongly depends on hydration and sugar/protein ratio. Here we report an Infrared Spectroscopy study on dry amorphous matrices of the disaccharides trehalose, maltose, sucrose and lactose, and the trisaccharide raffinose. Samples with and without embedded protein (Myoglobin) are investigated at different sugar/protein ratios, and compared. To inspect matrix properties we analyse the Water Association Band (WAB), and carefully decompose it into sub-bands, since their relative population has been shown to effectively probe water structure and dynamics in different matrices. In this work the analysis is extended to investigate the structure of protein-sugar-water samples, for the first time. Results show that several classes of water molecules can be identified in the protein and sugar environment and that their relative population is dependent on the type of sugar and, most important, on the sugar/protein ratio. This gives relevant information on how the molecular interplay between residual waters, sugar and protein molecules affect the biopreserving properties of saccharides matrices.

Role of wastewater treatment in COVID-19 control

The International Water Association (IWA) initiated a Task Force in April 2020 to serve as a leadership team within IWA whose role is to keep abreast and communicate the emerging science, technology, and applications for understanding the impact and the ability to respond to the COVID-19 pandemic and specifically designed for water professionals and industries. Expertise was nominated across the world with the purpose of collectively providing the water sector with knowledge products for the guidance on the control of COVID-19 and other viruses. This review paper developed by a working group of the IWA Task Force focuses on the control of COVID-19. The purpose of this review paper is to provide an understanding of existing knowledge with regards to COVID-19 and provide the necessary guidance of risk mitigation based on currently available knowledge of viruses in wastewater. This review paper considered various scenarios for both the developed world and the developing world and provided recommendations for managing risk. The review paper serves to pool the knowledge with regards to the pandemic and in relation to other viruses. The IWA Task Team envisage that this review paper provides the necessary guidance to the global response to the ongoing pandemic.

Comparison of methods for calculating biological wastewater treatment

Due to the increase in the discharge of nitrogen and phosphorus compounds into water bodies in many countries, the problem of eutrophication has become the most relevant in the field of biological treatment technologies. To solve this problem, many technological schemes for purification from biogenic elements have been developed, based on different methods. The concept of biological purification, the composition and process of nutrition of heterotrophic microorganisms, as well as the course of the process of methanogenesis are analyzed. The analysis of the methods of the two countries, Russia and Germany. Most of the facilities in Russia are designed in accordance with SNiP 2.04.03.85, while Germany offers a different biological treatment method developed by the German Water Association DWA A131.

Developing a Financial Sustainability Model of the Performance Indicators Applied by Jordan Water Company (Miyahuna)

Jordan is now facing real challenges to satisfy the current population water needs due to limited resources. Moreover, unfortunately, as a result of the increased demand for water in developing countries, water resources become scarce, thus, the sustainable management of water resources is very important everywhere and especially in these areas. The Ministry of Water and Irrigation in Jordan is aiming to improve both its quality of service and financial sustainability, therefore, it started to apply the performance measurement system developed by the International Water Association (IWA) to monitor its performance towards achieving these goals. In this article, a model connecting a financial sustainability indicator (operating cost coverage ratio) with other performance indicators applied by the ministry is developed. To assess the performance indicators and to build the model secondary data are collected from the targeted company, the data are analyzed using SPSS and Excel computer programs. Non-revenue water (NRW), speed of repair of bursts, and training per employee are found to be the indicators that have a major impact on Miyahuna’s financial sustainability, the NRW is found to have a negative relationship with the financial sustainability, whereas the other two indicators have a positive relationship. As a conclusion, reducing the NRW and increasing both the speed of repair and training per employee are recommended, by applying some methods that continuously diagnose problems in the water systems and defining clear and strict policies to control the water theft. Furthermore, using Active Leakage Control (ALC) methods, providing the needed equipment, tools and resources, and adopting new methods for training.

Some Physicochemical Parameters of Wastewater from an Oil Industry at Point of Discharge in Port Harcourt, Rivers State, Nigeria

Wastewater samples were collected from an oil industry at the point of discharge for a period of two years, from January 2018 – December 2019. The wastewater samples were analyzed for different physicochemical parameters such as temperature, turbidity, total dissolved solids (TDS), total suspended solids (TSS), conductivity, pH, alkalinity, salinity, total hydrocarbon content (THC), biochemical oxygen demand (BOD) and chemical oxygen demand (COD) to examine their conformity to fulfill requirements as recommended by World Health Organization (WHO), Federal Ministry of Environment (FME) and Drinking Water Association (DWA). The results indicated that all the parameters in the discharged wastewater were within acceptable limits of the regulatory bodies. The field data showed that the investigated firm conformed to the law by carrying out proper procedures before discharging the effluents into the public drain and river. Therefore, the release of wastewater from the industry doesn't constitute a danger to the environment as well as aquatic organisms. Keywords: Physicochemical parameter, wastewater discharge, oil industry, environment, contaminants

An MPC-Enabled SWMM Implementation of the Astlingen RTC Benchmarking Network

The advanced control of urban drainage systems (UDS) has great potential in reducing pollution to the receiving waters by optimizing the operations of UDS infrastructural elements. Existing controls vary in complexity, including local and global strategies, Real-Time Control (RTC) and Model Predictive Control (MPC). Their results are, however, site-specific, hindering a direct comparison of their performance. Therefore, the working group ‘Integral Real-Time Control’ of the German Water Association (DWA) developed the Astlingen benchmark network, which has been implemented in conceptual hydrological models and applied to compare RTC strategies. However, the level of detail of such implementations is insufficient for testing more complex MPC strategies. In order to provide a benchmark for MPC, this paper presents: (1) The implementation of the conceptual Astlingen system in an open-source hydrodynamic model (EPA-SWMM), and (2) the application of an MPC strategy to the developed SWMM model. The MPC strategy was tested against traditional and well-established local and global RTC approaches, demonstrating how the proposed benchmark system can be used to test and compare complex control strategies.