The Toxic Effect Of Inorganic Salts On The Germination Of Cabbage Seeds

The study on the pollution of inorganic compounds is an indispensable part to the modern environmental science. Evaluating the toxicity of inorganic compounds is an important aspect to the research on the pollution of inorganic compounds, which affects the migration and transformation of inorganic compounds in the environment. The research on the toxicity of the heavy metals is much more than that of common inorganic compounds.In this dissertation, the toxic effects of more than seventy species of inorganic compounds on huaxing early V Chinese cabbage were assessed, based on seed germination. The toxicity sequence was obtained by comparing the toxicity of different elements in the same main group; represented by chlorine and sulfur, the toxicity of elements in different valence conditions were also investigated; the toxicity variation of lithium chloride, copper chloride and lead nitrate at different pH was evaluated. The main results and conclusions obtained are as follows:(1) The toxicity effects GC50 of more than seventy species of inorganic compounds were obtained on the basis of seed germination. The toxicity of the chlorides of elements inâ… A,â…¡A andâ…¡B were compared. The toxicity decreased first and then increased inâ… A andâ…¡A, and the GC50 were similar inâ…¡A compared with that inâ… A; but the trend ofâ…¡B was opposite to the I A andâ…¡A:It increased first and then decreased, and the GC50 values ofâ…¡B were bigger than that ofâ… A and â…¡A.(2) Represented by chlorine and sulfur, the toxicity of elements in different valence conditions were investigated:the toxicity of chlorine increased first and then decreased with the variation of valence, the toxicity of +2 valence was the maximum; but the trend of sulfur was opposite to that of chlorine:It decreased first and then increased, the toxicity of intermediate valence was the minimum.(3) The toxicity effects GC50 varies with the pH values. The toxicity variation of lithium chloride, copper chloride and lead nitrate at different pH was evaluated. The toxicity of copper chloride and lead nitrate increased in the acidic condition (pH<5), compared with the neutral condition; lead ion and copper ion would form precipitation with hydroxyl ion, the concentration of the heavy metal ions were consequently decreased. The seed germination was derived from the joint effect of the residual heavy metal ions and hydrogen or hydroxide ions. The toxicity of lithium chloride changes greatly with the pH:The toxicity of lithium chloride increased first and then decreased and increased again, and the minimum was in neutral solution. The toxicity increased in the acidic and alkaline conditions, and the values in the acidic conditions were much bigger than that in the alkaline conditions.