[Ecological toxicity of aluminum-based coagulant on representative corps in neutral environment]

By the terrestrial ecotoxicological methods of seed germination and root elongation, and with aluminum-based coagulant AlCl3 which was widely used in wastewater- and water treatment as an example, this work studied the toxicological effects of aluminum-based coagulants on representative crops, including radish Raphanus sativus, cabbage Brassica chinensis and wheat Triticum aestivum, over a range of exposure concentrations under the neutral condition (pH= 7.0), with contrast to an acid condition (pH= 4.00). The results indicated that there was a significantly positive correlation between the concentration of AlCl3 and the inhibitory rate of root elongation and seed germination either under pH 7.0 or 4.0 (P < 0.01). Cabbage and wheat was more susceptive to AlCl3 toxicity under acid than under neutral condition, while radish was in adverse. The minimum inhibitory concentration of AlCl3 (< 2.0 mg x L(-1)) was lower under neutral than under acid condition.