Iranian Journal of

Background and Objective: Today, landfill management of municipal waste and soil pollution with heavy metals are major environmental problems. This research was conducted to evaluate the effect of Shazand municipal waste compost and Saveh pomegranate peel biochar on decreasing Pb availability in soil and sorghum plant.
Materials and Methods: Treatments consisted of applying Shazand municipal waste compost (0, 10 and 20 ton/‌ha^‌) and Saveh pomegranate peel biochar (0 and 15 g/‌kg^‌) in a Pb polluted soil (0, 600, 800 and 1000 mg Pb/‌kg soil). After 8 weeks of sorghum planting (Kimya CV.), the soil physio-chemical properties and soil and plant Pb concentration were measured. 
Results: Applying 20 ton/ha‌ municipal waste compost with 15 g/‌kg^‌ biochar increased soil pH by 0.4 units and decreased soil Pb availability by 11%. The similar results were observed for the root and shoot Pb concentrations, when the same amount of  manure in a Pb polluted soil was applied (1000mg Pb/‌kg soil) that decreased the root and shoot Pb concentration by 1.8 and 2.2 times, respectively.
Conclusion: The result of this experiment showed that applying Shazand municipal waste compost and biochar can increase soil sorption properties and decrease soil or plant Pb concentration. However, the role of these organic amendments on supplying plant nutritional needs cannot be ignored.
 

Background and Objective: Nowadays, the use of biochar as a new and suitable adsorbent to remove inorganic pollutants from water sources has grown significantly. The present study was conducted to evaluate the effects of biochar physical modifications compared to unmodified biochar on nickel (Ni) removal efficiency in aqueous solutions.
Materials and Methods: After the production of cypress cones biochar (RB), biochar particles (<164 µm) were crushed into very small (<26 µm) dimensions (BMB) using a planetary ball mill and after evaluation their various properties by SLS, BET, FTIR and SEM techniques, their application (RB and BMB) in optimizing the Ni removal from aqueous solutions were evaluated using the response surface methodology (RSM: Box-Behnken design).
Results: Based on the results, the physical modification of biochar (BMB) decreased the particle size by 6.2 times, increased the specific surface area by 4.9 times, increased (containing oxygen) and decreased (aliphatic and OH stretching groups) of specific functional groups and finer surface morphology, compared to RB. The use of BMB in the aqueous solution caused an increase of 9.7% (on average) in the removal of Ni compared to the RB sample. The fitting of the data obtained from Ni removal in the Box-Benken model in both adsorbents shows the appropriate prediction of this model in the optimization of Ni removal from aqueous solutions.
Conclusion: According to the results of this research, the physical modification of biochar, as a simple, cheap, and environmentally friendly method, due to the increase in the efficiency of Ni pollutant removal, can be introduced as a suitable method in the activation of biochar, which further research is required based on the type of biochar and various pollutants.