Heavy Metal Analysis in the Vegetable Farm Soil in the Kingdom of Bahrain

Abstract

Soil serves as deposits and filters all substances. It has limitless size and capable of absorbing all harmful and deadly materials washed and flushed in it so careful determination on what are thrown and absorb should be taken into consideration. This study aimed to determine the presence of heavy metals and to assess the physico-chemical properties of vegetable farm soil in Budaiya, Kingdom of Bahrain and the results on the physicochemical analysis were compared against the environmental standard composition of farm soil. The physico-chemical analysis on the soil samples was done in the biochemistry laboratory while the analysis of heavy metals and macronutrients was done in an ISO certified laboratory. Atomic Absorption Spectroscopy was done in assessing the amount  of Lead, Cadmium, S0₄^-2, N0₃^-1and P0₄^-3 while the spectrophotometer was used to determine the amount of Ca⁺² , Mg⁺², K⁺, and Fe⁺²and have been found out through T-test that there is no significant difference on  these components thus, they are comparable to the normal composition though Mg⁺²and N0₃^- is quite higher when compared to the normal composition of vegetable farm soil indicating the soil is slightly acidic and has that ability to absorb most of the micro-nutrients. Further, the determination of pH was carried out with an average pH of 6.87 which is still within the standard pH for garden soils ranging from 6.5 to 7.5. This value is attributed to the organic fertilizer applied and to nature of the soil in an area. However, this value must be monitored since the amount of dissolved carbon dioxide in soils may lead to decrease in pH making it acidic. Extreme pH values can result from depletion of some micronutrients and some plants may suffer from iron chlorosis at basic soil pH. It was also analyzed that the vegetable farm soil was found to be positive with heavy metal lead and found negative with heavy metal cadmium. As such, it is recommended that soil samples in other sites be done and subjected for parallel study to monitor the same  parameters included in the study.

Keywords: Heavy metals, physic-chemical properties, elemental composition, Polyatomic ions, micronutrients, macronutrients, Atomic Absorption Spectroscopy