Anjali Jayakumar

2023

1. Nature-Based Solution to Eliminate Cyanotoxins in Water Using Biologically Enhanced Biochar

   Jane Moore, Anjali Jayakumar, Sylvia Soldatou, and 3 more authors

   Environmental Science & Technology, Oct 2023

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   Climate change and high eutrophication levels of freshwater sources are increasing the occurrence and intensity of toxic cyanobacterial blooms in drinking water supplies. Conventional water treatment struggles to eliminate cyanobacteria/cyanotoxins, and expensive tertiary treatments are needed. To address this, we have designed a sustainable, nature-based solution using biochar derived from waste coconut shells. This biochar provides a low-cost porous support for immobilizing microbial communities, forming biologically enhanced biochar (BEB). Highly toxic microcystin-LR (MC-LR) was used to influence microbial colonization of the biochar by the natural lake-water microbiome. Over 11 months, BEBs were exposed to microcystins, cyanobacterial extracts, and live cyanobacterial cells, always resulting in rapid elimination of toxins and even a 1.6–1.9 log reduction in cyanobacterial cell numbers. After 48 h of incubation with our BEBs, the MC-LR concentrations dropped below the detection limit of 0.1 ng/mL. The accelerated degradation of cyanotoxins was attributed to enhanced species diversity and microcystin-degrading microbes colonizing the biochar. To ensure scalability, we evaluated BEBs produced through batch-scale and continuous-scale pyrolysis, while also guaranteeing safety by maintaining toxic impurities in biochar within acceptable limits and monitoring degradation byproducts. This study serves as a proof-of-concept for a sustainable, scalable, and safe nature-based solution for combating toxic algal blooms.

   @article{doi:10.1021/acs.est.3c05298,
     author = {Moore, Jane and Jayakumar, Anjali and Soldatou, Sylvia and Mašek, Ondřej and Lawton, Linda A and Edwards, Christine},
     title = {Nature-Based Solution to Eliminate Cyanotoxins in Water Using Biologically Enhanced Biochar},
     journal = {Environmental Science \& Technology},
     volume = {0},
     number = {0},
     pages = {null},
     month = oct,
     year = {2023},
     doi = {10.1021/acs.est.3c05298},
     https://doi.org/10.1021/acs.est.3c05298
     },
     eprint = { 
     https://doi.org/10.1021/acs.est.3c05298
     },
   }

2. Unlocking the Power of Woody and Non-Woody Biochar: Maximising Supercapacitor Performance Through Feedstock and Activation Treatment Selection

   Jiacheng Sun, Anjali Jayakumar, Carlos Díaz-Maroto, and 3 more authors

   Aug 2023

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   This study investigates the influence of feedstocks and activation methods on the electrochemical properties of activated biochars, which are promising electrode materials for energy storage devices. Two categories of lignocellulosic biomasses (woody and non-woody) and three activation methods (CO2, steam, and KOH) were used to produce biochars, and the physicochemical and electrochemical properties were evaluated. The results showed that biochars derived from non-woody had higher specific capacitance than woody biochars, despite lower electrical conductivity and porosity. Chemical activation was found to increase volatile matter and porosity of the biochar material, resulting in improved electrochemical performance compared to physical activation. However, chemical activation can cause low electrical conductivity. KOH activated Miscanthus straw pellet biochar exhibited best specific capacitance of 468 F g-1. The study highlights the importance of carefully selecting the feedstocks and activation methods to optimise the electrochemical properties of biochar for potential commercial use as a sustainable supercapacitor material.

   @misc{sun_unlocking_2023,
     address = {Rochester, NY},
     type = {{SSRN} {Scholarly} {Paper}},
     title = {Unlocking the {Power} of {Woody} and {Non}-{Woody} {Biochar}: {Maximising} {Supercapacitor} {Performance} {Through} {Feedstock} and {Activation} {Treatment} {Selection}},
     shorttitle = {Unlocking the {Power} of {Woody} and {Non}-{Woody} {Biochar}},
     doi = {10.2139/ssrn.4556356},
     language = {en},
     urldate = {2023-09-05},
     author = {Sun, Jiacheng and Jayakumar, Anjali and Díaz-Maroto, Carlos and Moreno, Inés and Fermoso, Javier and Mašek, Ondřej},
     month = aug,
     year = {2023},
     keywords = {Agriculture waste, Biochar, Supercapacitor, Activation, Carbon material},
   }

2021

1. New directions and challenges in engineering biologically-enhanced biochar for biological water treatment

   Anjali Jayakumar, Christian Wurzer, Sylvia Soldatou, and 3 more authors

   Science of The Total Environment, Aug 2021

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   Cost-effective, efficient, and sustainable water treatment solutions utilising existing materials and technology will make it easier for low and middle-income countries to adopt them, improving public health. The ability of biochar to mediate and support microbial degradation of contaminants, combined with its carbon-sequestration potential, has attracted attention in recent years. Biochar is a possible candidate for use in cost-effective and sustainable biological water treatment, especially in agrarian economies with easy access to abundant biomass in the form of crop residues and organic wastes. This review evaluates the scope, potential benefits (economic and environmental) and challenges of sustainable biological water treatment using ‘Biologically-Enhanced Biochar’ or BEB. We discuss the various processes occurring in BEB systems and demonstrate the urgent need to investigate microbial degradation mechanisms. We highlight the need to correlate biochar properties to biofilm development, which can eventually determine process efficiency. We also demonstrate the various opportunities in adopting BEB as a cheaper and more viable alternative in Low and Middle Income Countries and compare it to the current benchmark, ‘Biological Activated Carbon’. We focus on the recent advances in the areas of data science, mathematical modelling and molecular biology to systematically and sustainably design BEB filters, unlike the largely empirical design approaches seen in water treatment. ‘Sequential biochar systems’ are introduced as specially designed end-of-life techniques to lower the environmental impact of BEB filters and examples of their integration into biological water treatment that can fulfil zero waste criteria for BEBs are given.

   @article{JAYAKUMAR2021148977,
     title = {New directions and challenges in engineering biologically-enhanced biochar for biological water treatment},
     journal = {Science of The Total Environment},
     volume = {796},
     pages = {148977},
     year = {2021},
     issn = {0048-9697},
     doi = {10.1016/j.scitotenv.2021.148977},
     author = {Jayakumar, Anjali and Wurzer, Christian and Soldatou, Sylvia and Edwards, Christine and Lawton, Linda A. and Mašek, Ondřej},
     keywords = {Biologically-enhanced biochar, Biological water treatment, Biochar-microbial interactions, Sequential biochar systems}
   }