Search results
Results from the WOW.Com Content Network
The important sulfur cycle is a biogeochemical cycle in which the sulfur moves between rocks, waterways and living systems. It is important in geology as it affects many minerals and in life because sulfur is an essential element (), being a constituent of many proteins and cofactors, and sulfur compounds can be used as oxidants or reductants in microbial respiration. [1]
Microbial sulfate reduction has been demonstrated to fractionate sulfur isotopes in bacteria, with some studies showing a dependence upon sulfate concentration [28] and/or temperature. [64] Studies examining dozens of species of dissimilatory sulfate reducing microbes have observed sulfur isotope fractionations ranging from −65.6‰ to 0‰.
Soil chemistry is the study of the chemical characteristics of soil.Soil chemistry is affected by mineral composition, organic matter and environmental factors. In the early 1870s a consulting chemist to the Royal Agricultural Society in England, named J. Thomas Way, performed many experiments on how soils exchange ions, and is considered the father of soil chemistry. [1]
They may have either a negative charge provided by the attached hydroxyl ion (OH −), which can attract a cation, or lose the hydrogen of the hydroxyl to solution and display a positive charge which can attract anions. As a result, they may display either high CEC in an acid soil solution, or high anion exchange capacity in a basic soil solution.
This picture depicts the initial appearance of three different Winogradsky columns. They are soil and water samples from a river, the later two columns have been modified with phosphate, nitrate, sulfur and oxygen additives. These additions promote the growth of various bacteria specific to the anaerobic and aerobic regions of the column.
Soil develops through a series of changes. [2] The starting point is weathering of freshly accumulated parent material.A variety of soil microbes (bacteria, archaea, fungi) feed on simple compounds released by weathering and produce organic acids and specialized proteins which contribute in turn to mineral weathering.
In general, organic matter contacting soil has too little nitrogen to support the biosynthetic needs of the decomposing soil microbial population. If the C:N ratio of the decomposing organic matter is above circa 30:1 then the decomposing microbes may absorb nitrogen in mineral form as, e. g., ammonium or nitrates. This mineral nitrogen is said ...
The sulfate minerals are a class of minerals that include the sulfate ion (SO 2− 4 ) within their structure. The sulfate minerals occur commonly in primary evaporite depositional environments , as gangue minerals in hydrothermal veins and as secondary minerals in the oxidizing zone of sulfide mineral deposits.