Chemical specification and bioavailability of metals in soils and plants samples taken from agricultural areas exposed to industrial waste in Gaziantep province

The main purpose of this thesis is to investigate the effects of chemical pollutants (metals) from industrial and domestic wastewaters in Gaziantep on soil and plant. In the researches carried out on agricultural soils irrigated by wastewaters and food crops grown in these lands, the following objectives are focused on: (1) To investigate the forms and species of metals in soils, determine their bioavailable and phytotoxic levels for plants, and (2) To examine effectiveness (or suitability) of the structure the geochemical structure of soils on natural remediation of metals. For this; (1) Physicochemical properties of soil such as pH, cation exchange capacity (CEC) and organic matter (OM) were determined. (2) Bureau Reference Committee (BCR) sequential extraction procedure and single extraction processes were applied to soils. (3) X-ray diffraction (XRD) mineralogical analyzes of soil samples were performed. When the results of all these processes are evaluated together, desorption of them is difficult under natural conditions since heavy metal pollutants are strongly sorption on calcite mineral in Gaziantep. Thus, it was concluded that heavy metal ions were subjected to natural remediation in the soil of the region. Metal concentrations of 'clean' and 'dirty' groups of the soils and plants of the region are very close to each other. It was determined that some of them had higher average concentrations in the 'dirty' group and in others the 'clean' group. In addition, it was determined that the element concentrations determined from Gaziantep soil and plant samples did not exceed the allowed national and international standard concentration values in most of the samples. This situation can be explained by several factors such as: (1) The transformation of heavy metal ions into immobile (unfavorable) forms for plants by sorption on soil components, (2) Factors such as the accumulation of heavy metal species in other regions without being transported to the consumed parts of the plants.