| dc.description.abstract | The discharging of industrial effluent into irrigation system results in the high risk of soil and groundwater pollution,such as copper and zinc pollutants which triggers the endless incidents of farmland pollution in Taiwan. Phytoextraction is one of the soil remediation technologies. Compared with the traditional physical and chemical controlling technology, phytoextraction is More friendly to the environment and ecology, and has better cost effectiveness. The usage of heavy metal hyperaccumulator for uptaking pollutants and the removing of plants for incineration and consolidation by phytoaccumulation can reduce and control the produced waste as well as prevent secondary pollution.
This experiment selects the plants that have been planted in contaminated areas of Taiwan, namely impatiens (Impatiens walleriana Hook. f.) and sunflowers (Helianthus annuus Linn). The plnts are cultivated in the Yantunpo(Yp) and Homei(Hm) soil contaminated by Cu and Zn soil. Soil amendments treatments were as following:control group (CK), lime (L), compost (O), rice straw (R), plant ash (A), rice straw and lime (RL), rice straw and compost (RO), plant ash and lime (AL), as well as plant ash and compost (AO). After 60 days of planting, the soil and plants will both analyze the content of Cu and Zn to realize the relationship between the plants and the contaminated soils.
The results show that plants of impatiens and sunflowers in the Yp contaminated soils mainly uptake Zn. The treatments without adding improvers to the contaminated soils, Impatiens are not survival in the experiment due to the poison of heavy metals. In the Yp soil, treatments with plant ash and lime (AL) and lime (L) can raise the soil pH and substantial increase the Zn uptaked by the impatiens. In particular, the removal of Zn in the whole Impatiens plants treated with lime (L) is up to 11,939.5mg/kg (This meets the hyperaccumulator standard of over 10,000mg/kg). For the sunflowers planted in the Yp soil, the high concentration of heavy metals or various heavy metals exist at the same time cause the death of sunflowers with five different amendment treatments. The removal of Cu and Zn of sunflowers is lower than that of impatiens.
In this experiment, Zn was mostly stores in the impatiens roots planted in the Hm soil, and the highest Zn removal is the control group (CK). It is shown that the impatiens planted in the silty clay loam contaminated by Zn has the effect of removing Zn even without adding improvers. The sunflowers tend to accumulate Zn on the shoot parts planted in the contaminated Hm soil. The highest total removal of Zn is control group (CK) 2865.8 mg/kg and Compost (O) 2680.0 mg/kg. The total removal of Zn by sunflowers is four times as much then that of impatiens. (The total removal of Zn is control group (CK) 670.7 mg/kg). Adding improvers does not increase the total removal of Zn of impatiens and sunflowers. It is recommended to plant sunflowers for decorating the environment. The highest removal of Cu of sunflowers planted in the contaminated Hm soil is control group (CK) 358.4 mg/kg, which means that the adding improvers cannot promote the uptaking of Cu. The highest removal of Cu of impatiens is compost (O) 651.6 mg/kg and rice straw and lime (RL) 647.7 mg/kg. Furthermore, the removal of Cu by impatiens is twice as much as that of sunflowers. Therefore, it is recommended that the Hm soil contaminated by Cu can add compost (O) or rice and lime (RL) for planting Impatiens. | en_US |