The Application of Phytotesting Method to Assess the Toxicity of Titanium Etching Effluents

Abstract:

The article evaluates the toxicity of the spent acid etching solution (SAES) formed in production of titanium products when etched with a mixture of hydrofluoric and hydrochloric acids. The SAES contained TiF₃, HF and HCl in the amount of 21.9 g/l, 1.7 g/l and 6.2 g/l, respectively. To determine the toxicity of SAES the phytotesting method was used. As a phytoecological indicator, a cress of Zabava variety was used. The experiment was carried out according to the method for determining the toxicity of drinking, ground, surface and sewage water, chemical solutions by measuring the germination index, average length and average dry weight of seedlings of cress seeds (Lepidium sativum). The SAES toxicity was determined before its neutralization with alkali and after neutralization with alkali. It is shown that SAES has an acute toxic effect both before neutralization and after neutralization with alkali. To determine the safe dilution factor, the effect of SAES dilution on seed germination, average length and average dry weight of seedlings was investigated. It was found that “seedlings average length – dilution factor” equations most reliably describe the experimental data. The safe dilution factor calculated from these dependencies is 669.2 for non-neutralized SAES and 382.5 for neutralized SAES.

• Periodical: Key Engineering Materials (Volume 769)
• Pages: 161-165
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.769.161
• Online since: April 2018
• Authors: Nikolay Alekseevich Bykovsky*, Timur Z. Zabirov, Inna V. Ovsyannikova, Nadezhda Nikolaevna Fanakova
• Keywords: Average Dry Weight of Seedlings, Average Length of Seedlings, Correlation Coefficients, Cress, Etching, Neutralization, Phytotesting, Production of Titanium Products, Regression Equations, Safe Dilution Factor, Seed Germination, Spent Acid Etching Solution, Toxicity

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