مقدرة القصب Phragmites communis و الحور الأسود Populus nigra المنتشرة على جانبي نهر الرميلة في جبلة (سورية)‎ على مراكمة عنصري النحاس و الكادميوم

Abstract EN

The importance of this research lies in the identification of the ability of some plant species that grow naturally in the contaminated sites to absorb and accumulate heavy metals and thus purify the surrounding medium as much as possible.

The aim of the research is to study the ability of reed (Phragmites communis) and the poplar (Populus nigra) to accumulate Cd and Cu.

These species naturally prevail on both sides of the Rumaila River in Jableh town (research site) during the years 2014-2015.

Plant samples were collected from the leaves, wood and bark of studied plant species.

Soil samples were taken from soil surrounding the plants at 0-30 cm deep.

This was carried out in four replicates each sample.

The concentrations of ^udied heavy elements (Cd and Cu) were assessed by using atomic absorption spectrophotometer.

Average amount of Cd on the ^udied site was 3.081 mg/kg of dry weight.

Comparing this amount with the normal range of soil content from Cd (0.06-1.1 mg/kg), we find that it is higher than the normal upper limit of about three times, indicating the contamination of the site with Cd.

The findings showed that the Cd concentration in the branches of reed was 0.031 mg/kg.

Thus, leaves predominated the shoots in terms of Cd concentration reaching 0.055 mg/kg.

The value of bio-accumulation factor (BF) was 0.014.

As for poplar, the findings revealed that the Cd concentration was 0.016 mg/kg the bark followed by 0.031 mg/kg in the wood.

However, the leaves predominated other parts, where the Cd concentration was 0.034 mg/kg.

BF value was 0.03, Average amount of Cu in the soil of studied site was 132.22 mg/kg of dry weight.

Comparing this amount with the medium range of Cu in different types of soil (13-24 mg/kg), we find that it is higher than the normal upper limit several times, indicating contamination of site with Cu.

The findings ^ated that the Cu concentration in reed leaves was 3.87 mg/kg versus 4.26 for the shoots.

BF value was 0.06.

Cu concentration in poplar wood was the lowe'st at 4.49 mg/kg, followed by that of the leaves at 5.46 mg/kg while the bark predominated other parts with Cu concentration of 6.08 mg/kg.

We note from these findings that the Cu amount in the parts of poplar plant is very approximate with BF value 0.12.

The statistical analysis showed significant superiority of reed to poplar for Cd accumulation, while the opposite was for Cu where the polar was superior to reed in Cu accumulation with a significant variation.

However, it is concluded that the site soil is contaminated with Cd and Cu and the studied species are not considered as good accumulators of these two elements.