Multivariate analysis of biochar-derived carbonaceous nanomaterials for detection of heavy metal ions in aqueous systems

J Plácido; S Bustamante López; K E Meissner; D E Kelly; S L Kelly

doi:10.1016/j.scitotenv.2019.06.342

Multivariate analysis of biochar-derived carbonaceous nanomaterials for detection of heavy metal ions in aqueous systems

Sci Total Environ. 2019 Oct 20:688:751-761. doi: 10.1016/j.scitotenv.2019.06.342. Epub 2019 Jun 24.

Authors

J Plácido¹, S Bustamante López², K E Meissner³, D E Kelly⁴, S L Kelly⁵

Affiliations

¹ Institute of Life Science (ILS 1), Swansea University Medical School, Swansea University, Swansea SA2 8PP, Wales, UK. Electronic address: j.e.placidoescobar@swansea.ac.uk.
² Institute of Life Science (ILS 1), Swansea University Medical School, Swansea University, Swansea SA2 8PP, Wales, UK; Department of Physics, Centre for NanoHealth, Swansea University, Swansea SA2 8PP, Wales, UK.
³ Department of Physics, Centre for NanoHealth, Swansea University, Swansea SA2 8PP, Wales, UK.
⁴ Institute of Life Science (ILS 1), Swansea University Medical School, Swansea University, Swansea SA2 8PP, Wales, UK.
⁵ Institute of Life Science (ILS 1), Swansea University Medical School, Swansea University, Swansea SA2 8PP, Wales, UK. Electronic address: s.l.kelly@swansea.ac.uk.

PMID: 31255813
DOI: 10.1016/j.scitotenv.2019.06.342

Abstract

This article focuses on implementing multivariate analysis to evaluate biochar-derived carbonaceous nanomaterials (BCN) from three different feedstocks for the detection and differentiation of heavy metal ions in aqueous systems. The BCN were produced from dairy manure, rice straw and sorghum straw biochar using our NanoRefinery process. The NanoRefinery process transforms biochar into advanced nanomaterials using depolymerisation/chemical oxidation and purification of nanomaterials using solvent extraction. Dairy manure biochar-derived carbonaceous nanomaterials (DMB-CN), rice straw biochar-derived carbonaceous nanomaterials (RSB-CN) and sorghum straw biochar-derived carbonaceous nanomaterials (SSB-CN) were utilised as probes for the evaluation of their fluorescent properties and the detection of heavy metal ions. The BCN fluorescence quenching and fluorescence recovery was tested with lead (Pb²⁺), nickel (Ni²⁺), copper (Cu²⁺) and mercury (Hg²⁺). Principal component analysis (PCA) and discriminant analysis were used to differentiate among heavy metal ions in water samples. The BCN from different feedstocks had different characteristics and produced different interactions with heavy metal ions. DMB-CN had the highest quenching for Hg²⁺ and Ni²⁺ while SSB-CN and RSB-CN responded best to Cu²⁺ and Pb²⁺, respectively. The fluorescence quenching was modelled using linear and empirical functions. PCA and discriminant analysis used the quenching measurements to differentiate heavy metal ions in aqueous system. A key result was that the discriminant analysis had a 100% accuracy to detect Pb²⁺, 66% for Ni²⁺ and Cu²⁺, and 33% for Hg²⁺. This study has shown that biochar-derived carbonaceous nanomaterials could be used in heavy metal ions sensing applications. This is the first step in the development of a fast and accurate method for the detection of heavy metal ions in waters using environmentally friendly BCN.

Keywords: Biochar; Carbonaceous nanomaterials; Fluorescence sensors; Heavy metal ions; Multivariate analysis; Quenching.

MeSH terms

Charcoal / chemistry
Environmental Monitoring / methods*
Metals, Heavy / analysis*
Multivariate Analysis
Nanostructures / chemistry*
Water Pollutants, Chemical / analysis*

Substances

Metals, Heavy
Water Pollutants, Chemical
biochar
Charcoal