Applied Techniques for Wastewater Treatment: Physicochemical and Biological Methods

Polluted water is one of the significant challenges facing the world nowadays, especially with the noticed water shortage recorded in the last period. Different treatment methods, physicochemical and biological, were presented for pollutant removal from polluted wastewater. This review discusses the treatment methods starting from the biological part to help reduction of organics, which are solids that appear in the wastewater. After that, the physicochemical techniques will be discussed as a second part of the treatment process to minimize the heavy metal, dyes, and other pollutants. Additionally, filtration techniques and advanced treatment processes will be discussed as the final steps in the water treatment systems and how they were used to finally sterilize the water after the treatment processes. © 2023 selection and editorial matter, Irene Samy Fahim and Lobna A. Said; individual chapters, the contributors.

Adsorption as an Emerging Technology and Its New Advances of Eco-Friendly Characteristics: Isotherm, Kinetic, and Thermodynamic Analysis

Water contamination with paints causes a colour agent to the water that negatively affects the environment, organisms, and humans. Different physicochemical processes are applied for wastewater treatment; however, they have many drawbacks such as high cost, generating toxic waste, and non-effective at low concentrations. Adsorption is considered a promising technique for pollutant removal from polluted wastewater. Commercial activated carbon, nano-materials, and natural biological materials are used as adsorbents in adsorption. This chapter focuses on discussing the adsorption process, the factors affecting the adsorption, different adsorption materials, and the isothermal, kinetic, and thermodynamic models. © 2023 selection and editorial matter, Irene Samy Fahim and Lobna A. Said; individual chapters, the contributors.

Observability of speed DC motor with self-tuning fuzzy-fractional-order controller

The DC motor is one of the simplest electrical machines used in industry since it is controlled by direct voltages and currents. These configurations have various advantages, allowing the machine to be adapted to the constraints of its specific application. The present chapter analyzes the DC motor with separate excitation without the use of a speed sensor to approximate the rotor speed. An analysis of the stability of the rotor speed estimation is performed. Enhanced control of the direct action is integrated into the adaptive observer to decrease the roundness capability of the model and simplify implementation. Design guidelines for the feedback gain and speed fractional controller whose parameters are automatically adjusted using intelligent fuzzy logic techniques are also provided to ensure system stability throughout the operating region. The results given in this study verify the validity and effectiveness of the proposed control technique. © 2022 Elsevier Inc. All rights reserved.

A survey on memristor active emulation circuits in the fractional-order domain

Chua postulated a new element called a memristor, contributing flux and charge link. The main characteristic of the memristor is a pinched hysteresis double loop with one pinched point. The memristor’s realization in the fractional-order domain increases the hysteresis loop area’s controllability and frequency range. Besides, the fractional-higher-order memristor is realized, achieving more than a pinched point with changes of the pinched point’s location at different values of a. The commercial memristor device is absent until now. For this purpose, scientists concentrated on modeling the memristor achieving its characteristics, and applied it with other circuit elements. This chapter is intended to study the previously proposed memristor emulator in a fractional-order domain dependent on commercial active building blocks. The memristance emulation circuits are classified into four categories: circuits based on operational amplifiers, second-generation current conveyor family circuits, current-feedback operational amplifiers, and complementary metal-oxide semiconductors. The introduced circuits are compared, also the PSPICE, and experimental results confirm the selected circuits. © 2022 Elsevier Inc. All rights reserved.