Nano Engineering
Research Project | 2025
About
This project proposes a sustainable remediation material made from animal manure that has been ball milled and magnetically modified to create nano biochar, referred to as B-M-M-N-BC. It is intended to treat cadmium (Cd²⁺) and lead (Pb²⁺) contamination in wastewater from artisanal and small-scale mining.
The material would provide a low cost and energy efficient alternative to conventional treatments by avoiding harmful chemicals and using abundant waste resources. The study begins by analysing B-M-M-N-BC, then outlines its fabrication method and the comprehensive two-phase testing process used to validate its performance.
Project Aims (Investigated through theoretical methods):
i) To investigate the adsorption efficacy of B- M-M-N-BC under laboratory-controlled conditions by testing its ability to remediate Cd2+ and Pb2+ individually in prepared polluted water, as well as in scenarios where both pollutants are present simultaneously.
ii) To determine if B-M-M-N-BC can effectively remediate Cd2+ and Pb2+ from ASM-polluted water on its own or must it be combined with activated carbon to develop a hybrid pollution remediation material.
Properties: Smaller particles result in a high concentration of surface-active sites formed by functional groups capable of adsorbing heavy metal ions. However, some existing literature suggests that an increase in charge density could increase the repulsion between nanoparticles thereby, negatively impacting their adsorption. Since the characteristics of B-M-M-N-BC are not yet fully understood, evaluating the adsorption efficacy across a range of N-BC diameters (70-90 nm) is proposed.
Production Facility: The pathogenic nature of animal manure, necessitates that it is converted to stable B-M-M-N-BC at or near to the site of rearing before being transported to the ASM for pollution remediation.
End of Life: After the reaction, the N-BC could be collected by applying a voltage across an electromagnetic collection rod. The N-BC would then be reused to process additional ASM wastewater.
Extract from Analysis of B-M-M-N-BC
Proposed Lab-Scale Fabrication Method
1. Raw Material
Collect 500 g of animal manure.
If immediate use is not possible, freeze during transport to prevent mineralisation.
2. Magnetic Doping
Disperse 200 g manure in 4000 mL of 0.04 M FeCl₂·4H₂O for 8 hours with orbital shaking.
Strain, wash with distilled water, sieve (1 cm mesh) and dry at 80°C for 8 hours.
3. Pyrolysis
Heat the impregnated sample in a vacuum furnace at 600°C, 7°C/min, for 3 hours under anaerobic conditions.
4. Ball Milling
Mix 60 g biochar (BC) with 15 mL water.
Wet mill in a planetary zirconia-ball mill.
5. Vacuum Drying
Dry final N-BC in a vacuum chamber at 120°C for 12 hours to remove moisture and produce B-M-M-N-BC.
Note: Full methodology is outlined in the project report.
Proposed Method for Evaluating Efficacy
Project aim i) Pour 15 grams of the required B-M-M-N-BC specimen into 100 mL of the contaminated solution. Leave the mixture in an orbital shaker for 24 hours to allow sufficient time for the N- BC to adsorb the pollutants. Finally, use an electromagnet collect and remove the HM - B-M-M-N- BC particles.
Project aim ii) Mix 15 grams activated carbon and B-M-M-N- BC. Use the B-M-M-N- BC particle size that demonstrated the highest adsorption efficiency in the Project Aim 1 study. Add the prepared mixture to 100 mL of the real-world ASM- contaminated water sample and place in an orbital shaker for 24 hours to enable the B-M-M-N-BC to adsorb the pollutants. Finally, use an electromagnet collect and remove the HM - B-M-M-N-BC particles. Use precise measurements throughout to maintain consistency across iterations for reliable comparative analysis.
Using is relatively straight forward, the user must simply pour the proposed nano material into the contaminated water, leave it to react and then remove the adsorbent with an electromagnet.
Fabrication does not involve toxic chemicals and makes use of the toxic contaminant, manure. This reduces the risk of manure contaminating local land and water potentially improving the sanitation of the area.
Potential opportunity to recover and recycle HMs to meet ever-growing demand.
Unknown impact of magnetic doping on adsorption efficacy
Recyclability Route of B-M-M-N-BC is Not Fully Defined
Proposal Does Not Utilise the Bio-oil or Biogas Byproducts
Uncertainty Surrounding the Scalability Potential of B-M-M-N-BC