ABSTRACT
Background: Various industries produce and discharge wastes containing different heavy metals into the environment. Apart from using living biomass, dead and dried biomasses have been introduced as a new field of biotreatment technology
Method: The cadmium [Cd] [II] removal characteristics of live [growing], dead [autoclaved], and oven-dried biomasses of Aspergillus versicolor were examined as a function of initial pH, contact time, and initial Cd concentration
Result: Maximum bioaccumulation of Cd for live biomass [11.63 [mg g[-1]]] occurred at an optimal pH of 4 and incubation time of 4 days. The maximum biosorption of 27.56 [mg g[-1]] for dead biomass occurred at 1.5 h and at a pH of 4. The maximum biosorption [18.08 [mg g[-1]]] with dried biomass was reached at an equilibrium time of 3 h at a pH of 6
Conclusion: The present study confirmed that heat treatment promoted the removal capacity of fungi. Cd removal was increased by decreasing the pH in live and dead-mode experiments. Inversely, Cd removal was increased with increasing pH for the dried biomass of A. versicolor. Varying responses to environmental conditions [pH and contact time] clearly proved the different removal mechanisms used by three biomasses of A. versicolor. Higher Cd concentration increased the removal ability of three types of biomasses. The results indicated that all biomasses of A. versicolor used in this study, particularly dead biomass, are a suitable biosorbent for the removal of Cd [II] ions from aqueous solution
ABSTRACT
Background: Turbidity removal using inorganic coagulants such as iron and aluminum salts in water treatment processes causes environmental and human health concern. Historically, the use of natural coagulant to purify turbid water has been practiced for a long time. Recent research indicates that Descurainia Sophia seed can be effectively used as a natural coagulant to remove water turbidity
Method: In this work, turbidity removal efficiency of Descurainia Sophia seed extract was compared with Ferric chloride. Experiments were performed in laboratory scale. The coagulation experiments were done with kaolin as a model soil to produce turbidity in distilled water. The turbidity removal efficiency of Descurainia Sophia seed extract and Ferric chloride were conducted with jar test apparatus. In all experiments, initial turbidity was kept constant 100[NTU]. Optimum combination of independent variables was used to compare two different types of coagulants
Result: The obtained results showed that Ferric chloride could remove 89.75% of the initial turbidity, while in case of Descurainia Sophia this value was 43.13%. The total organic carbon [TOC] analysis of the treated water using seed extract showed an increased concentration of TOC equal to 0.99 mg/L
Conclusions:This research has shown that Descurainia Sophia seed extract has an acceptable potential in the coagulation/flocculation process to treat turbid water