The comprehensive review article published in the Journal of the Iranian Chemical Society by Marcelo van Petten Rocha, Rafael Cesar Russo Chagas, Alice Laura Silva Melo, Luiz Felipe Elver, and Tiago Silveira Gontijo maps out the global scientific production regarding carbonaceous materials used for wastewater remediation. The rapid global expansion of the modern textile industry and associated sectors has generated significant environmental imbalances due to the massive consumption and subsequent disposal of synthetic colorants. These industrial dyes are utilized intensely across diverse international sectors, including cosmetic formulation, plastics manufacturing, pharmaceutical production, leather tanning, and commercial paper printing. When spent industrial fluids enter aquatic ecosystems, they increase the visible coloration and turbidity of natural streams, alter baseline chemical neutrality, block crucial sunlight, and severely disrupt vital plant photosynthesis. For human populations exposed to this water contamination, the synthetic compounds spark dangerous health complications ranging from immediate skin irritations, severe nausea, and intense headaches to chronic dizziness, stomach pain, and elevated heart rates. Consequently, identifying highly efficient, low-cost alternative filtration media has become an urgent public health priority.

The compiled data shows an overwhelming accumulation of scientific interest over the past two decades, characterized by an average annual literature growth rate of thirty-two point thirty-three percent. While the absolute timeline evaluated spans twenty years, the actual volume of academic production is heavily concentrated in recent periods. Specifically, seventy-nine percent of all evaluated peer-reviewed articles and academic reviews were published during the final five years of the tracking period, resulting in seven hundred ninety-two independent scientific documents. This massive spike in global publication volume reflects a direct response from international research institutions attempting to replace expensive conventional treatments, such as commercial activated carbonActivated carbon is a form of carbon that has been processed to create a vast network of tiny pores, increasing its surface area significantly. This extensive surface area makes activated carbon exceptionally effective at trapping and holding impurities, like a molecular sponge. It is commonly More, which often produce highly toxic residual sludges. By utilizing discarded agricultural wastes and raw biomassBiomass is a complex biological organic or non-organic solid product derived from living or recently living organism and available naturally. Various types of wastes such as animal manure, waste paper, sludge and many industrial wastes are also treated as biomass because like natural biomass these More to produce highly porous charcoal and biochar, researchers are developing competitive, simple, and biodegradable alternatives that exhibit extreme flexibility and excellent separation capacity for large-scale water treatment systems.

The international mapping data also highlights a clear shift in scientific direction and material engineering over time. Early scientific endeavors primarily focused on standard charcoal materials, which rely almost exclusively on basic physical adsorption driven by pore microstructure, raw surface area, and simple porosityPorosity of biochar is a key factor in its effectiveness as a soil amendment and its ability to retain water and nutrients. Biochar’s porosity is influenced by feedstock type and pyrolysis temperature, and it plays a crucial role in microbial activity and overall soil health. Biochar More. In contrast, contemporary investigations emphasize chemically engineered biochar variants characterized by tunable surface chemistry, functionalization, magnetic properties, and the integration of advanced nanocomposites. This transition indicates that modern adsorption relies heavily on targeted structure-property optimization, where chemically modified surfaces employ complexation, advanced electrostatic interactions, and high anion and cation exchange capacities to isolate complex organic molecules. This evolution reflects the alignment of biochar with sustainable circular bioeconomy frameworks.

Geographically, the scientific literature exhibits a strong structural centralization within key Asian academic centers. China leads global research output with one thousand thirty-two independent scientific records, followed directly by India with four hundred seventy-five records. Over eighty percent of the Chinese research consists of individual domestic publications, demonstrating a robust focus supported by coordinated national research initiatives and localized environmental pressures. Beyond Asia, countries like Malaysia, Egypt, and Saudi Arabia also contribute significantly to the literature. From an editorial standpoint, the publishing landscape is heavily consolidated, with a single dominant publisher, Elsevier, controlling forty-four percent of the total output with four hundred thirty-three published documents. This high centralization underscores a critical imbalance in global knowledge creation. While leading countries maintain powerful internal networks, underdeveloped regions in Africa and Latin America suffer from limited funding and minimal participation, creating a noticeable gap in adapting these low-cost filtration technologies to unique regional wastewater crises.

Source: van Petten Rocha, M., Russo Chagas, R. C., Silva Melo, A. L., Elver, L. F., & Silveira Gontijo, T. (2026). A two-decade comprehensive bibliometric analysis of charcoal and biochar as adsorbents for dye removal (2003-2023). Journal of the Iranian Chemical Society, 23, 165.