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Water/Wastewater Math Operations
Published in Frank R. Spellman, Handbook of Water and Wastewater Treatment Plant Operations, 2020
If a teaspoon of salt is dropped into a glass of water the salt gradually disappears. The salt dissolves in the water. A microscopic examination of the water would not show the salt. Only examination at the molecular level, which is not easily done, would show salt and water molecules intimately mixed. If we taste the liquid, of course, we would know that the salt is there. And we could recover the salt by evaporating the water. In a solution, the molecules of the salt, the solute, are homogeneously dispersed among the molecules of water, the solvent. This mixture of salt and water is homogenous on a molecular level. Such a homogenous mixture is called a solution. The composition of a solution can be varied within certain limits. The three common states of matter are gas, liquid, and solid. In this discussion, of course, we are only concerned, at the moment, with solids (calcium hypochlorite) and liquid (sodium hypochlorite) states.
Air Pollutants and Their Adverse Effects
Published in Jeff Kuo, Air Pollution Control Engineering for Environmental Engineers, 2018
Many terms are being used to describe the state of an air pollutant. Air is a mixture of gases. Gas is a state of matter that has no fixed shape and volume. Vapor refers to a gas phase where the same substance also exists in its liquid and/or solid state under that condition. For example, we say that our ambient air contains nitrogen gas and water vapor. It is because no liquid or solid nitrogen coexists with the nitrogen gas, while water and/or ice is present with water vapor under ambient conditions.
Soil Gas Movement—Monitoring Under Natural and Remediation Conditions
Published in Donald L. Wise, Debra J. Trantolo, Remediation of Hazardous Waste Contaminated Soils, 2018
A new solution evolved through investigation of the composition of the ground beneath us. Three basic states of matter exist: gas, liquid, and solid. Porous soil presents a medium for dynamic interactions between all three forms. In a sense it breathes, eliminates and absorbs gases, exhibits healthy and unhealthy oxygen conditions, and has structure. The composition of gases, their rates of transfer (fluxes), and their spatial positioning provide a window of what lies below the surface and what can actually be manipulated to flush out or decompose unwanted substances.
Synthesis and characterisation of ionic liquid crystals based on substituted pyridinium cations
Published in Liquid Crystals, 2022
Andreia F. M. Santos, Carlos Cruz, Maria H. Godinho, Madalena Dionísio, João L. Figueirinhas, Luis C. Branco
Most chemical compounds exist in three states of matter: crystal, liquid or gas, having each one their own characteristics. However, there is a ‘fourth state of matter’ known as liquid crystal that, as the name suggests, has properties of both crystals and liquids, such as anisotropy, optical birefringence, anisotropic electrical and magnetic properties, fluidity and the inability to support shear [1–4]. In fact, in a liquid crystal (LC) phase, the positional order characteristic of the crystal state is lost, at least partially, while keeping the long distance orientational order, and thus the molecular mobility is increased, turning the material fluidic or plastic [5]. Multiple mesophases can be formed, as nematic (the one with higher fluidity), smectic, columnar, among others. One possible mechanism of mesophase formation results from the balance between electrostatic (polar moieties) and Van der Waals (alkyl chain) interactions [6]. Mesomorphic compounds with thermally induced liquid crystalline phases are classified as thermotropic. In the last 40 years, liquid crystals have been applied in many areas of science and engineering, with particular impact in device technologies [3,7]. They are mostly known for their use in liquid crystal displays [8], but they also provide several and useful applications [9,10], such as: sensors [11] or biosensors [12,13], films [14,15], lasers [16,17], photovoltaics [18,19], smart windows [20,21], cosmetics [22,23] and detergent formulations [24], among others. Nevertheless, their distinctive physical properties are still pointed out as a solution for many different problems and new applications are under development [25], as novel functional materials [26].
Technology for mercury removal from flue gas of coal based thermal power plants: A comprehensive review
Published in Critical Reviews in Environmental Science and Technology, 2019
Karthik Balasundaram, Mukesh Sharma
Plasma is the fourth state of matter, representing an ionized gas with sufficient energy to free electrons from atoms or molecules and allow species, ions and electrons to coexist. The energy required to create plasma can be thermal or non-thermal (electric current or electromagnetic radiations). There are two broad approaches to remove Hg0 using NTP. In the first approach, the NTP is used to generate different free radicals (O, O3, OH and Cl) from the flue gas components. The generated free radicals interact with Hg0 in flue gas resulting in oxidation of Hg0 to Hg+2 and subsequent removal (An et al., 2014; Zhang et al., 2017).
Properties and suitability of liquid electrode plasma optical emission spectrometry (LEP-OES) for the determination of potassium, lithium, iron, and zinc in aqueous sample solutions
Published in Instrumentation Science & Technology, 2022
Ilkka Vesavaara, Anssi Mäkynen, Paavo Perämäki
Plasma is a state of matter at a high temperature (at least 2000 K), consisting of free electrons and ions. The most common source in the elemental analysis is inductively coupled plasma (ICP).[1] An argon ICP is an excellent ionization/excitation source for both optical emission spectrometry (OES) and mass spectrometry (MS). Other types of plasmas used in OES include the direct current plasma (DCP) and the microwave-induced plasma (MIP).