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The paper evaluates the toxicity of spent acid pickling liquor (SAPL) formed in the production of titanium products during its etching with a mixture of hydrofluoric and hydrochloric acids. The SAPL contained TiF₃, HF and HCl in the amounts of 21,9 g/l, 1,7 g/l and 6,2 g/l, respectively. To determine the toxicity of SAPL, a phytotesting method was used. As a phytoecological indicator, cress of Zabava variety was used. The experiment was carried out according to the procedure for determining the toxicity of drinking, ground, surface and sewage water; the toxicity of chemical solutions by measuring the germination index, average length and average dry weight of seed germs of cress (Lepidium sativum). The toxicity of the SAPL was determined before and after neutralizing with alkali. It has been shown that SAPL has an acute toxic effect both before and after its neutralization by alkali. To determine a safe dilution rate, the influence of SAPL dilution on seed germination, average length and average dry weight of the seedlings was studied. It was found that the seedlings average length-dilution rate equations most reliably describe the experimental findings. The safe dilution rate calculated from these relations is 669,2 for non-neutralized SAPL and 382,5 for alkaline neutralized SAPL.

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.