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Applied Chemistry and Physics
Published in Robert A. Burke, Applied Chemistry and Physics, 2020
There are two basic types of acids: organic and inorganic. Inorganic acids are sometimes referred to as mineral acids. Organic acids as a group are generally not as strong as inorganic acids. The main difference between the two is the presence of carbon in the compound. Inorganic acids do not have carbon in the compound. Inorganic acids are corrosive, but they do not burn. They may be oxidizers and support combustion or may react with organic materials and spontaneously combust the organic material. Inorganic acids have hydrogen in the formula such as H2SO4 for sulfuric acid, HCl for hydrochloric acid and HNO3 for nitric acid. Organic acids are hydrocarbon derivatives.
Determination of Metals in Non Saline Sediments
Published in T. R. Crompton, Determination of Metals and Anions in Soils, Sediments and Sludges, 2020
Five mineral acids, namely hydrochloric, nitric, sulphuric, perchloric and hydrofluoric acids, have been very widely used. For the simultaneous extraction of a large number of metals, sulphuric acid has the one notable property of dissolving silica. Thus, it has been used in conjunction with nitric, hydrochloric or perchloric acid in the total decomposition of silicates. Nitric acid has been used separately or with either hydrochloric or perchloric acid. Such methods provide a high degree of metal extraction but do not dissolve silicates completely; they destroy organic matter, dissolve all precipitated and adsorbed metals, and leach out a certain amount of the metals from the silicate lattice.
Antineoplastic Drugs and Other Chemical Wastes
Published in Peter A. Reinhardt, Judith G. Gordon, Infectious and Medical Waste Management, 2018
Peter A. Reinhardt, Judith G. Gordon
First, since elementary neutralization is not considered a treatment process (see 40 CFR 264.1(g)(6)), waste mineral acids such as sulfuric, nitric, and hydrochloric acid can be neutralized to solutions of mineral salts and disposed of in the sanitary sewer. Bases like ammonium hydroxide can also be neutralized.
Electropolishing of nickel and cobalt in deep eutectic solvents
Published in Transactions of the IMF, 2018
W. O. Karim, A. P. Abbott, S. Cihangir, K. S. Ryder
Electropolishing is essentially the controlled electrochemical corrosion of a metal to bring about a decrease in surface roughness. Electropolishing an item can increase the corrosion resistance of the component as it enables better, more homogeneous passivation and it can also decrease wear in moving systems. It has most commonly been studied in aqueous solutions primarily using concentrated mineral acids such as sulphuric, hydrochloric and phosphoric acids. The large scale usage of electropolishing is most frequently applied to stainless steel1 although other metals such as nickel, copper and titanium are also electropolished.2–4 The fundamental and practical aspects of electropolishing have been covered in two reviews.5,6 It is known that for electropolishing to occur, a viscous film generally forms on the metal surface.5 It is therefore essential to choose an electrolyte that will enable film formation on the metal surface.6 This process is not free from some practical issues, such as the corrosivity of the electrolyte, gas evolution and low current efficiency.
Two-step biodiesel production using high free fatty acid containing pig fat
Published in International Journal of Green Energy, 2021
Mohammed Takase, Paul Kwame Essandoh
Pre-esterification conditions were studied using HCl as a catalyst. As mineral acids, HCl, phosphoric and sulfuric acids are the most familiar. Sulfuric acid usually has 35 wt.% of assay, hence large water amount is introduced in the reaction media, which works against the reaction. HCl and phosphoric acids mostly have higher assay and lower impurity amount. On the other hand, previous research indicates that p-Toluenesulfonic acid could be a good catalyst for esterification reaction (Bolonio et al. 2018).
Assessment of the Bassia muricata extract as a green corrosion inhibitor for aluminum in acidic solution
Published in Green Chemistry Letters and Reviews, 2019
Emad E. El-Katori, Saedah Al-Mhyawi
Aluminum (Al) is one of the most used metals for abundant industrial and engineering applications as a result of its cost value and excellent functional features. Aluminum has a perfect resistance to petroleum products, and Al/2Mg alloy is applied for tank heating coils in crude-oil carriers (1–4). Al is categorized as the 2nd most widely used metal, after iron. It has several applications and is also used in various alloys. It has been established that to resist high corrosion, this metal is mainly dependent on the presence of an in the artificial film of surface oxide. On the other hand, it was also observed that alkaline solutions play a major role in reducing the oxide film. This is due to the fact that the protective oxide is dissolved by the OH- ion and the surface of Al develops a negative potential (5,6). Mineral acids are broadly applied in acid pickling, acid cleaning and oil well acidizing. The study of aluminum corrosion phenomena is becoming very significant, especially in acidic media because of the more industrial applications of acid solutions. As a result, it’s substantial to order inhibitors for the aluminum corrosion in H2SO4 solution. The metal protection versus sulfuric acid corrosion has been the subject. A lot of research was specified to study the corrosion of aluminum and its alloys in various aqueous and acidic solutions via organic and inorganic inhibitors (7,8). Otherwise, acids promote the rate of metal dissolution and are responsible for material failure indirectly. Therefore, inserting a corrosion inhibitor is a significant method in order to reduce metal dissolution in that solution. The majority of familiar acid inhibitors are organic compounds involving nitrogen, sulfur and oxygen, but the largest part of the applied organic inhibitors are toxic, hazard to the environment (9–11). Therefore, it is necessary to advance eco-friendly corrosion inhibitors for aluminum in acidic mediums. Hence, we have selected the plant extracts as eco-friendly inhibitors that may be extracted via simple techniques and the cost is very cheap. The photochemical (involves flavonoids and alkaloids) which represent in the plant extract involves hetero atoms such as N, S, O, aromatic ring and π-electrons, through which they will be adsorbed on the metal surface and mitigate corrosion process (12). Newly, the most of the plant extracts have been confirmed to be good inhibitors for aluminum acidic corrosion (13–15). So they are applied in order to resolve the corrosion problem associated without any environmental problems. Hence, the extract from the leaves, heartwood, bark, seeds, fruits and roots of plants have been investigated to mitigate metallic corrosion in acidic environments (16–20). Medicinal plants were previously used as green corrosion inhibitors of aluminum alloys in different media (21–24).