Electrochemical Detection And Water Adsorption Of Heavy Metal Ions By Camphor Base Biochar

More and more attention has been paid to the diversification and resource utilization of forestry biomass waste,and it has become a research hotspot.Heavy metal ion pollution can lead to soil,water or biosecurity problems,especially the safety of agricultural products and drinking water,and ultimately affect human health safety.In this paper,based on the forestry residue--camphor branches as raw materials to prepare biochar preparation electrochemical sensor,using anoditic stripping voltammetry for the detection of heavy metal ions in water.In addition,the composite biochar material was also used as an adsorbent for the adsorption of heavy metal ion Cd²⁺in water,and achieved good adsorption effect.This paper mainly studies the electrochemical detection of heavy metal ions and water adsorption from the following three aspects.The diversification of forestry biomass waste has attracted more and more attention and become a research hotspot.Heavy metal ion pollution can lead to soil,water or biosecurity problems,especially the safety of agricultural products and drinking water,and ultimately affect human health safety.In this paper,based on the forestry residue--camphor branches as raw materials to prepare biochar preparation electrochemical sensor,using anoditic stripping voltammetry for the detection of heavy metal ions in water.In addition,the composite biochar material was also used as an adsorbent for the adsorption of heavy metal ion Cd²⁺in water,and achieved good adsorption effect.In this paper,the electrochemical detection of heavy metal ions and water adsorption are studied in the following three aspects:（1）Determination of ultra-trace Cd²⁺,Pb²⁺and Hg²⁺based on magnetic Fe₃O₄particle doped biochar composite modified electrode.Due to environmental safety problems,forestry waste and heavy metal pollution have attracted more and more attention.Magnetic Fe₃O₄ nanoparticles modified phosphorus-containing biochar-attapulgite/bismuth film electrode（MBA-Bi FE）was prepared by extraction of camphor tree essential oil as forest waste.Ultratrace voltammetry of multiple heavy metal ions(Cd²⁺,Pb²⁺and Hg²⁺)was detected simultaneously by wireless portable sensors of smart phones.The linear ranges of Cd²⁺,Pb²⁺and Hg²⁺were 0.1 n M-5μM,0.01 n M-7μM and 0.1 n M-3μM.The detection limits of Cd²⁺,Pb²⁺and Hg²⁺were 0.011 n M,0.006 n M and 0.007 n M,respectively.In addition,a machine learning model based on artificial neural network algorithm is constructed to realize intelligent analysis of ultra-trace harmful polymetallic ions.Compared with traditional MBA-Bi FE sensors,the portable sensor based on MBA-Bi FE modified screen printing with three electrodes shows good outdoor detection advantages and practicability.This work will provide a smartphone-operated wireless portable sensing technology that offers promising applications for multi-element-doped biochar extracted from forestry waste in environmental or agricultural metalomics.（2）A novel CaAl layered double hydroxide modified porous biochar composite（CaAl-LDH-BC）is used for the determination of trace Cd²⁺.The harm of Cd²⁺to the natural environment and human society has gradually become a huge hidden danger worldwide.Simultaneous sensitive detection and efficient removal of Cd²⁺in water systems is a major challenge.We proposed a calcium/aluminum layered porous biochar composite（CaAl-LDH-BC）with high sensitivity and selectivity for electrochemical detection and high adsorption capacity for Cd²⁺in water samples.The CaAl-LDH-BC modified glass carbon electrode has good selectivity and stability for the electrochemical detection of Cd²⁺.The linear range is wide（1 ng-600μg）and the detection limit is low（0.21 ng）in the square-wave anodic stripping voltammetry.（3）A novel CaAl layered bihydroxide modified porous biochar composite（CaAl-LDH-BC）is used for the removal of trace Cd²⁺.CaAl-LDH-BC showed strong adsorption capacity for Cd²⁺in water samples,with the maximum adsorption capacity up to 195.06 mg,and reached the adsorption equilibrium within 20 min.This efficient adsorption performance is mainly due to the porosity of biochar and the strong adsorption capacity of Cd²⁺when CaAl-LDH is adsorbed on CaAl-LDH-BC surface.The study material has realized the efficient removal of Cd²⁺,which provides a new enlightenment for the functionalization of biochar materials and the environmental field.