Evaluating the Effects of Municipal Waste and Wastewater on Absorption of Nickel and Cadmium of Helianthus Annuus Plant
The present study is an attempt to examine the effects of municipal waste and wastewater on absorption of nickel and cadmium of helianthus annuus plant. In order to determine cadmium and nickel in different organs of the plant in soil with organic fertilizers of municipal waste and municipal sewage sludge, we conducted a split plot study. The study was in form of randomized complete block from 2011 to 2015 under farm conditions. We considered the main factor in five levels of control, 10 and 20 tons of sewage sludge and municipal waste compost per hectare besides the minor factor of yearly treatment during four years. The results showed that using 20 tons of sewage sludge and waste per hectare increased absorbable soil nickel and cadmium up to approximately 220%. Also, the amount of cadmium and nickel in root was about 400% more than the control group. Bacteria found in soil contaminated to heavy metals showed remarkable resistance against higher concentration of these elements. Both bioaccumulation and biosorption techniques indicated high potential to refine aquatic environments. However, the bioaccumulation technique showed better efficiency in lower concentrations and the biosorption revealed better efficiency in higher concentrations of metals.