Carbon disulfide natural emissions

A U. S. national biogenic sulfur emissions inventory with county spatial and monthly temporal scales has been developed using temperature dependent emission algorithms and available biomass, land use and climatic data. Emissions of dimethyl sulfide (DMS), carbonyl sulfide (COS), hydrogen sulfide (H2S), carbon disulfide (CS2), and dimethyl disulfide (DMDS) were estimated for natural sources which include water and soil surfaces, deciduous and coniferous leaf biomass, and agricultural crops. The best estimate of 16100 MT of sulfur per year was predicted with emission algorithms developed from emission rate data reported by Lamb et al. (1) and is a factor of 22 lower than an upper bound estimate based on data reported by Adams et al. 

In the last 150 years the anthropogenic emission of sulfur has increased dramatically, primarily due to combustion processes [1]. In the 1950s anthropogenic emission surpassed natural emission and the atmospheric sulfur cycle is one of the most perturbed biogeochemical cycles [1,2]. The oceans are the largest natural source of atmospheric sulfur emissions, where sulfur is emitted in a reduced form, predominantly as dimethyl sulfide (DMS) and to a much lesser extent carbonyl sulfide (OCS) and carbon disulfide (CS2) [3]. Ocean emitted DMS and CS2 are initially oxidised to OCS, which diffuses through the troposphere into the stratosphere where further oxidation to sulfur dioxide (SO2), sulfur trioxide (SO3) and finally sulfuric acid (H2SO4) occurs [1-4]. 

The experiments I to III demonstrate the pyrophoric nature of the white modi ficaiion of phosphorus (melting point 44.1 °C). The reactivity of P4 is mainly due to the extremely small bond angles in the tetrahedral Ph molecule, which is thus subject to considerable ring strain. White phosphorus is oxidised to P Oic via various intermediate phosphorus oxides. During the oxidation a pale light emission is observed. When white phosphorus is dissolved in carbon disulfide the molecules are dispersed in the solveiu, and the rapid evaporation of CS2 (boiling point 46.2""C) is also accompanied by the oxidation of the phosphorus. Red phosphorus, 111 contrast, does not melt until about 600 C and... 

In order to avoid the difficulties of naturally occurring variations in study conditions, Fall et al. (1988) studied the emission of sulfur gases from several plant/soil systems using a flux chamber. The study was designed so that emissions from soil could be separated from emissions from plants. Variable amounts of carbon disulfide were emitted from wheat. The effects of light and temperature were observed. Further work was proposed so that systematic investigation could accurately measure the contributions of a number of sulfur compounds under varying conditions. 

An increasing interest in the protection of the natural enviromnent was manifested at the close of the twentieth century and continues in the early twenty-first century. Many different industrial technologies are characterised by the emission of highly dangerous substances, e.g. carbon disulfide and hydrogen sulphide, which continue to poison the environment. 

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