Because calcium sulfide contained in the black ash had a highly unpleasant odour, methods were developed to remove it by recovering the sulfur, thereby providing at least part of the raw material for the sulfuric acid required in the first part of the process. This method was developed in the 1970s [18,19] but was mostly displayed by wire feeding in the 1980–1990s. Decomposes in boiling water and strong acids. developed graphite brush bioanodes for cubic and bottle air cathode MFCs24 (Fig. (D) Energy dispersive X-ray spectrum of RCF-PP. According to them the paper by van Arsdale and Maier is the first to study the electrolytic deposition of manganese dioxide from aqueous solution of manganese sulfate (MnSO4), followed by Nichols who investigated the EMD production from rhodochrosite. Interestingly, reports of the homoleptic heavier chalcogenides appeared in a reverse order starting with the tellurides [M{(TeSi(SiMe3)3}2(thf)x] (M = Ca, Sr, x = 4; M = Ba, x = 5) prepared from [M(HMDS)2] and HTeSi(SiMe3)3.178 The same route gives the selenides [M{SeSi(SiMe3)3}2(tmeda)2] (M = Ca, Sr, Ba) as bis-TMEDA adducts.179 Salt metathesis gives the strontium sulfide and selenide [M(EAr′)2(thf)4] (M = Ca, Sr, Ba; Ar′ = 2,4,6-tBu3-C6H2; E = S, Se).180 The calcium sulfides [Ca(18-c-6)(NH3)3][SAr′]2 and [Ca(SAr′)2(18-c-6)] are obtained by treating ammonia solvated calcium with the thiol in the presence of 18-c-6.181 The former being a solvent-separated ion triple highlights the polar nature of such metal-chalcogenides. 29. Surface modification of the SS is also proved to be an effective strategy to improve the performance of SS-based bioanodes.38 Liang et al. (A), (B), and (C) Scanning electron microscopic (SEM) images of reticulated carbon foam-pomelo peel (RCF-PP) at different magnifications; the inset of A is a digital image of a peeled Pomelo. The figures before show the position of the liquid window which is important in avoiding nozzle clogging in continuous casting, i.e., to assure good castability. Recovered from ncbi.nlm.nih.gov. The liquid window gets wider at higher oxygen content and moves upward to higher Ca contents [24]. Principally, these requirements are at least partly contradictory. Calcium is commonly taken by mouth for the treatment and prevention of low calcium levels. Contents. Calcium sulfide has been considered in medical scientific studies as a drug to treat high blood pressure (high pressure in the arteries). K. Takahashi, after examining the study by Arsdale and Maier and that by Nichols, investigated the electrolysis condition precisely for the effect of temperature, electrolyte contents, and current density. CaS is considered a “donor” of H2S. The calcium sulfide It is an inorganic solid formed by the element calcium (Ca) and the element sulfur (S), the chemical formula is CaS. https://www.webmd.com/drugs/2/drug-5758/calcium-sulfate-bulk/details Conversion of calcium sulphide to calcium carbonate during the process of recovery of elemental sulfur from gypsum waste. Copyright © 2020 Elsevier B.V. or its licensors or contributors. As the negative electrode material for the electrolysis, Pb–Sb alloys or graphite are preferred. The ‘luminous’ calcium sulfide is used in phosphors, luminous paints and varnishes. For obtaining the cathode mix the dried powder is mixed with an appropriate amount of pure synthetic graphite powder. Yellowish white crystalline solid, cubic crystals like those of sodium chloride. 6. The literature values of DH+ scatter in a wide range between 10−14 and 10−6 m2 s−1. 5 Chemical Vendors. Calcium sulfide definition, a yellow to light-gray, slightly water-soluble powder, CaS, having the odor of rotten eggs when moist: used chiefly in the preparation of luminous paint, hydrogen sulfide, and as a depilatory in cosmetics. Occurrence of Sulfur. The product EMD deposits tightly on the positive electrode surface as a hard solid so that enforced stripping and crushing of the product are necessary processes. 3 Chemical and Physical Properties Expand this section. Hence, the surface of bioanodes should be pretreated prior to their applications in MFCs for better biofilm formation. Leblanc process. Examples of the first type include carbon fiber-based anodes such as carbon fiber brushes24 and electrospun carbon fiber mats (maximum current achieved 3 mA/cm2).39 In comparison to the commercial carbon cloth and felt materials, these materials possessed more organized structures, higher surface area, and better conductivities, which led to an improved bioelectrocatalytic performance in terms of current or power densities. They are also used in current light-emitting diode, or LED, lamps. S. Kalathil, ... D. Pant, in Encyclopedia of Interfacial Chemistry, 2018. As the calculation examples before showed, the amount of Ca that is added to the steel is very important for a successful result. The graphite brush electrode significantly reduced internal resistance of the cubic MFC by producing a power density of 2400 mW/m2. In addition, this study provided explanations on why acid, thermal, ammonia, and plasma pretreatments improved the bioanode performances. It crystallizes in a cubic structure like rock salt. When adding sulfur content from “normal” levels 0.010–0.015%, problems start to appear, and if sulfur content is up to 0.030–0.040%, severe problems have been observed in continuous casting [26–29]. (2005). The SH– can take another proton H+ from water, forming hydrogen sulfide, which is a very toxic compound. Fourth Edition. Calcium sulfide is a highly ionic compound formed by a calcium ion Ca 2+ and a sulfide ion S 2-. 6). The figure was calculated with constant O-content, 20 ppm. For low silicon steels, other products are for sale like CaFe and pure Ca. reported that simple soaking of carbon cloth in formic acid could boost the performance of bioanode by creating a cleaner surface and reducing oxygen content.33 Similarly, pretreatment of carbon cloth with hydrogen peroxide, isopropanol, and sodium hypochlorite improved the performance of MFCs.34. At low S and Al contents in steel, CaS formation can take place only with high Ca addition and there exists a wide liquid region of Ca-aluminate inclusions. Generally, bacterial cell surfaces are negatively charged and hydrophilic in nature.20 Hence, the introduction of positive charges and hydrophilicity on the bioanode surface is a good strategy to develop efficient biofilm for better MFC performances. House J.E. Adding Ca is usually performed in the form of a silicon alloy, CaSi (for instance 30%Ca).