-This work focuses on enhancement of the performance of an anaerobic sequencing batch reactor with a six-vertical-blade-disk-turbine impeller, containing granulated biomass treating low-strength synthetic wastewater, through a study of the feasibility of implementing a variable stirring rate program. The reactor was operated at 30 o C and a six-hour cycle was used to treat approximately 2.0 L of the synthetic substrate with a chemical oxygen demand (COD) of nearly 500 mg/L. Two different stirring rate program were implemented: a constant rate of 50 rpm and a variable rate consisting of 75 rpm for one hour, 50 rpm for four hours and 25 rpm for 0.5 hour. The last 0.5 hour of the cycle was used for the settling step. In both cases, a very short start-up period and unfiltered and filtered substrate removal efficiencies of 81% and 88%, respectively, were attained. However, use of the variable stirring rate enhanced efficiency of the reactor dynamics without impairing biomass morphology, thus resulting in a reduction in the total cycle time and a possible decrease in energy consumption. Additionally, a simplified model of the anaerobic metabolic activity, using apparent kinetic parameters, was proposed as a consecutive first-order kinetic model with substrate and total volatile acid residual concentrations in order to analyze how the variable stirring rate affects reactor performance.

Robust optimization is an approach for modeling optimization problems under uncertainty where the modeler aims at finding decisions that are optimal for the worst‐case realization of the uncertainties within a given set of values. Typically, the original uncertain optimization problem is converted into an equivalent deterministic form, called the robust counterpart, using strong duality arguments and then solved by standard optimization algorithms. A methodology is proposed for the treatment of optimal control problems applying the multiobjective optimization differential evolution algorithm associated with the concept of mean effective for the insertion of robustness. The results obtained with applications in chemical systems demonstrate that the method conveyed is configured as an interesting approach for the solution of robust optimization problems.

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Milk is one of the main foods and possesses considerable nutritional richness. In this sense, the consumption of industrialized food products has increased significantly and with this it is important to know and improve the processes of hygiene of the industry. Clean in Place (CIP) is a useful technology for cleaning equipment and pipes because it avoids dismantling and is made up of several steps, such as cleaning with alkaline detergent, rinsing, applying acid, rinse, sanitize and rinse. The objective of this work was to evaluate the water consumption and the consequent generation of effluent in the alkaline detergent rinsing stage using constant flow and pulsed flow rates and also to propose an optimal configuration of the pulsed flow to minimize the consumption of water and effluent generated. The tests were conducted in a CIP system prototype and executed based on a central composite planning (CCP) changing the variables amplitude, period and duration of the high part. The response surface technique was used to evaluate the effects of each variable on water consumption. It was verified that there is an optimum condition for the operation of the rinse in pulsed form with amplitude 1.5 L / min, period 138 seconds and duration of the high part of 53 seconds. In addition, it has been found that the rinse with pulsed flow produces an economy of approximately 14.52% in relation to the constant flow operation.

This paper presents the use of a remote access laboratory, a WebLab, with real equipments and systems that can be controlled remotely by the web. At the approach, the WebLab allows the development of multidisciplinary experiments in control and automation areas that can be used as a tool for engineering education and for research projects. This first WebLab includes an application that allows the remote access using a page on internet for drive control of a DC motor. Using this application the user can perform experiments as the open loop test in DC motor in order to obtain non-parametric system model and tuning of PID controller to ensure efficient speed and position motor control.