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Explora: Environment
and Resource Environmental contamination of titanium

coughing, and breathing difficulty, while dermal contact may cause irritation. To
control the main anthropogenic input sources of Ti in the environment, it is critical
to develop affordable technologies for Ti removal during wastewater treatment. This
comprehensive review examines the presence, sources, biogeochemical behavior,
and potential risks of Ti in the environment and provides an in-depth outline of
the network visualization bibliography to graphically represent the relationships
between key publications, research areas, and authors. Additionally, future research
priorities are suggested for the sustainable management of Ti contamination.

Keywords: Titanium dioxide; Carcinogen; Biogeochemistry; Human health; Remediation

1. Introduction of the most important Ti compounds, accounting for the
largest application of the metal. Based on the United States
Titanium (Ti) is the ninth-most abundant element in Geological Survey (USGS) statistics, there are more than
nature (0.63% w/w) and is present in most igneous rocks 2.00 billion metric tons of Ti ore in the world, including
and their associated sediments, although it is primarily 0.70 billion metric tons of ilmenite and 0.049 billion metric
found bound to other elements in the Earth’s crust. The 13-15
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main mineral sources of Ti are anatase, rutile, and brookite, tons of rutile.
each contains approximately 95% Ti dioxide (TiO ), as Larger-particle TiO , or bulk TiO₂ (>200 nm), is
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well as ilmenite (FeTiO ) and titanite (CaTiSiO ), which frequently utilized as a pigment in paints and coatings.
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contain 40 – 65% TiO . The countries with the largest TiO₂ nanoparticles (NPs), or nano-TiO₂, are much smaller,
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reserves of ilmenite and/or rutile are China, Australia, typically <100 nm. Natural nanoscale Ti (20 – 300 nm) can
India, South Africa, Brazil, Madagascar, Norway, Canada, be found in a variety of ores and minerals.TiO is primarily
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and Mozambique (Table S1). available in two sizes, i.e., micrometer (250 – 400 nm)
Two major processing technologies, the sulfate and and nanometer (<250 nm) ranges. 12-14 Due to differences
chloride processes, are used to produce industrial pure in surface area-to-volume ratios, these various size ranges
TiO for use in pigments or to produce Ti metal from have distinct physical characteristics. In the food industry,
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enriched raw materials, including ilmenite and rutile. In micrometer-sized TiO particles are frequently employed
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the sulfate process, ground ilmenite ore or high-TiO slag as a food coloring agent to enhance texture, avoid caking,
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is treated with sulfuric acid, while in the chloride process, and brighten or whiten food products due to their low
Ti-enriched materials are converted into Ti chlorides using toxicity compared to pigmentary and nano-TiO . 13-15 For
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hydrochloric acid at high temperature. As the chloride applications as a pigment material, TiO particle sizes of
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process produces high-quality TiO pigments with 250 nm were found ideal. 16,17 TiO nanomaterials are the
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fewer waste products, this approach has largely replaced second-most produced nanomaterial worldwide. These
the sulfate strategy. This shift from sulfate to chloride materials are bright white pigments that have many
processing in TiO pigment production has resulted applications, such as white paints, sunscreens, infrared
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in increasing demand for high-grade Ti raw materials, reflectors, self-cleaning glass, and food additives. Ti
including rutile and Ti-enriched slag. 8 metal alloys are in demand due to their high strength-to-
weight ratio and corrosion resistance. Although there are
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The significance of Ti in various industries, such as different Ti- and TiO -containing compounds—such as
aerospace and biomedical applications, has been extensively total Ti, soluble ionic Ti, insoluble minerals, TiNPs, TiO
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discussed. 9-11 Ti is light yet strong and corrosion-resistant. NPs—the present review will focus primarily on TiO given
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These unique properties enabled its wide application in its widespread use/applications. A detailed discussion
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the building and sporting goods industries, as well as in of the applications of TiO as food additives has been
implants in a number of medical procedures. Furthermore, 2 18
due to its strong resistance to salinity, Ti is used in offshore provided elsewhere by the authors.
rigs, propellers and rigging of ships, and desalination units. The chemistry of Ti is similar to that of silicon and
Ti is capable of osseointegration, indicating that it is readily zirconium. The Ti element does not exist alone in
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accepted by bone, and is nonreactive; thus, it is widely used nature, as it is mostly chemically bound with oxygen or
in medical applications, including hip and knee joints, iron, and chemical processing is applied to synthesize
bone screws and plates, and dental implants. TiO is one a low-density, high-strength metal. 3,14 Ti has three
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Volume 2 Issue 3 (2025) 2 doi: 10.36922/EER025130027