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A Consortium of Sulfate-Reducing Bacteria Used for Lead, Copper, and Cadmium Bioremediation
Published in Vineet Kumar, Vinod Kumar Garg, Sunil Kumar, Jayanta Kumar Biswas, Omics for Environmental Engineering and Microbiology Systems, 2023
Julia Mariana Márquez-Reyes, Julián Gamboa-Delgado, Fatima Estefanía Soto-Zamora, Juan Antonio Vidales-Contreras, Humberto Rodríguez-Fuentes, Alejandro Isabel Luna-Maldonado, Celestino García-Gómez
The reaction of soluble lead with hydrogen sulfide produces lead sulfide precipitates, which have an ocher tonality. The H2S production increased in the presence of lead, regardless of the concentration (Figure 15.5); however, from day 20 until the end of the experimental period, the hydrogen sulfide production decreased for all treatments, except for the concentration of 5 mg/L where it continued to increase. This behavior is different from that previously reported, where regardless of the lead concentration, the production of hydrogen sulfide does not decrease (Martins et al., 2009). The decreasing effect must be directly related to the microbial diversity present in the consortium, since it showed a higher sensitivity at longer exposure times; similar results were obtained by Hwang and Jho (2018). On the other hand, the production of hydrogen sulfide continued to increase with the lower concentration of lead, indicating that this is a tolerable concentration for the SRB of the consortium since the production of hydrogen sulfide was not inhibited.
Fire Safety in Design and Construction
Published in Peter M. Bochnak, Fire Loss Control, 2020
The proper application of flame detection is important and the following general comments are presented, although they are by no means to be considered a complete covering of this topic. Lead sulfide cells, commonly used for both fuel oil and gas, detect infrared radiation. This type of sensor can be “fooled” by hot refractories that also give off infrared radiation. Ultraviolet-type detectors are not “fooled” by hot refractories but can, however, detect ultraviolet rays from electric sparks such as from electric ignition, which could result in the premature opening of the main fuel valve.
Physical Methods
Published in Jerome Greyson, Carbon, Nitrogen, and Sulfur Pollutants and Their Determination in Air and Water, 2020
Reflectance spectrometry serves as the basis of a large number of medical diagnostic tests. Perhaps more familiar, however, is its implicit use for testing the acidity of materials with graded pH papers, where the eye serves as a color analyzer analogous to a spectrometer. Its pertinence to our discussion is its application to the determination of hydrogen sulfide in the atmosphere (ASTM D 4323-84). The gas is measured by means of a paper strip which is impregnated with lead acetate and exposed to ambient air. Hydrogen sulfide reacts with the lead acetate to form black lead sulfide. In the ASTM method, measurement of the rate of formation of the black color is made with the use of the simpler form of reflectance spectrometer discussed above. The rate is then related to the concentration of the gas in the atmosphere. The method is sufficiently sensitive to detect volumes of H2S in air as low as one part per billion.
Preparation of spin coated PbS thin films using bis-tetrahydroquinolinedithiocarbamatolead(II) complex as a single source precursor
Published in Inorganic and Nano-Metal Chemistry, 2022
Sixberth Mlowe, Neerish Revaprasadu
Lead sulfide (PbS), a IV-VI semiconductor material with a narrow band gap of 0.41 eV is well employed in temperature and gas sensors,[1,2] infrared detectors,[3,4] photoresistors,[5] photovoltaic [6,7] and photocatalysis [8,9] applications. It is a well explored semiconductor material having fascinating morphologies. Interestingly, PbS materials display physical and chemical properties, which strongly depend on their morphologies. Several reports have been published regarding the influence of morphologies on the chemical and physical properties of PbS thin films.[10]
Heavy metals in municipal waste: the content and leaching ability by waste fraction
Published in Journal of Environmental Science and Health, Part A, 2019
The use of lead in decorative paints has noticeably reduced, while lead sulfur and lead chromate remain in demand because of low cost and good anti-corrosion properties [22]. Today, most household paints usually contain less than 90 ppm of lead. Lead may be discarded in municipal waste or directly with residual paints or along with dust, for example, during the walls processing. Lead naphthenate and lead oxide Pb3O4 are used in alkyd paints to accelerate drying and in primer paints to prevent corrosion. Many organometallic lead compounds (e.g. lead arsenate AsHO4Pb) are still used in pesticides [7]. Glass is another source of lead: lead (II) oxide is used to strengthen the color and brightness of glass. Besides, lead-antimony and lead-acid batteries contain much lead. Lead is sometimes added to the zinc anode of household batteries to reduce corrosion. Some authors [20] have found lead oxides in lead crystal glass. Also, lead-silicate glass is used in fluorescent lamps. The release of lead from other WEEE was reported by Lincoln et al. [23]. For example, an old monitor or TV with cathode-ray tube contains 1–3 kg of lead accounting up to 10% of the total lead in household waste [18, 24]. According to Morf et al. [17], the average lead concentration in e-waste is 2.9 g kg−1. Some lead compounds (e.g. lead sulfide) are used in transistors of electrical devices, as well as in some cosmetic products, e.g. creams [17]. It is important to know which compounds are soluble and therefore pose a greater danger to the environment. Among lead compounds mentioned above, very low solubility have lead arsenate and lead sulfate have very low solubility while, other substances are insoluble.