Hydrogen sulfide membranes

Because hydrogen sulfide is a gas, it is not rejected by an RO membrane. For systems that do not remove the compound prior to the RO membranes, hydrogen sulfide will be present in the permeate. Exposure to air on the permeate side of the membrane, such... 

Because hydrogen sulfide is a gas, it is not rejected by an RO membrane. For systems that do not remove the compound prior to the RO membranes, hydrogen sulfide will be present in the permeate. Exposure to air on the permeate side of the membrane, such as during shut down of the system, can result in an ivory to yellow precipitate of sulfur on the permeate side of the membrane. This will result in a loss of flux (increase in operating pressure) over time, ft is not possible to remove the precipitate on the permeate side with manual techniques. However, due to the corrosive nature of the RO permeate, the precipitate will eventually be remove by the permeate stream, provided no additional sulfur precipitate is added. 

Adsorption systems employing molecular sieves are available for feed gases having low acid gas concentrations. Another option is based on the use of polymeric, semipermeable membranes which rely on the higher solubiHties and diffusion rates of carbon dioxide and hydrogen sulfide in the polymeric material relative to methane for membrane selectivity and separation of the various constituents. Membrane units have been designed that are effective at small and medium flow rates for the bulk removal of carbon dioxide. 

Ion-selective electrodes can also become sensors (qv) for gases such as carbon dioxide (qv), ammonia (qv), and hydrogen sulfide by isolating the gas in buffered solutions protected from the sample atmosphere by gas-permeable membranes. Typically, pH glass electrodes are used, but electrodes selective to carbonate or sulfide may be more selective. 

Robinson AV. 1982. Effect of in vitro exposure to hydrogen sulfide on rabbit alveolar macrophages cultured on gas-permeable membranes. Environ Res 27 491-500. 

Ronk R, White MK. 1985. Hydrogen sulfide and the probabilities of inhalation through a tympanic membrane defect. J Occup Med 27 337-340. 

Edlund, D.J. and W. Pledger, Thermolysis of hydrogen sulfide in a metal membrane reactor, /. Membr. Sci., 77, 255-264, 1993. 

Kameyama, T.. K. Fukuda, M. Fujishige, H. Yokokawa and M. Dokiya and Y. Kotera. 1981. Production of hydrogen from hydrogen sulfide by means of selective diffusion membranes Adv. Hydrogen Energy Prog. 2 569 19. 

Decomposition of Hydrogen Sulfide Porous ir-AljOj/MoSj membranes Porous Y-AI2O3 membranes Porous Vycor glass membranes Abe (1987) Kameyama et al. (1981) Kameyama et al. (1979, 1981a, b)... 

Kameyama, T., M. Dokiya, K. Fukuda and Y. Kotera. 1979. Differential permeation of hydrogen sulfide through a microporous vycor-type glass membrane in the separation system of hydrogen and hydrogen sulfide. Separ. Sci. Technol. 14(10) 953-957. 

When a solution of ferric chloride is poured into a relatively large volume of boiling water, colloidal ferric hydruxide is furmed The ferric hydroxide sol does nol react with hydrogen sulfide nor with potassium hcxacyanoferralc(ll), and like all colloidal substances does nol pass readily through animal membranes or parchment. 

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