ECOTOXICOLOGICAL ASSESSMENT OF COAL MINING WASTE

ABSTRACT The disposal of large amounts of coal mining waste chemically modifies the soil, and this may change the structure and activity of soil fauna. The objective of this investigation was to study the ecotoxicological effects of depositions of pyritic waste (coal plus pyrite) in two soils collected in Santa Catarina, Argissolo Vermelho-Amarelo (Ultisol) e Nitossolo Háplico (Hapludox), at the application rates of 0, 2.5, 5, 10, and 20 % of that residue. Survival and reproduction of Enchytraeus crypticus and germination of Avena sativa and Lotus corniculatus were tested. The pH value, regardless of the type of soil, decreased as the rate of pyritic waste increased. Pyritic waste at the lowest rate resulted in negative effects on E. crypticus, as shown by reduction in the adult survival rate and no reproduction. In survival and reproduction testing of enchytraeids, the value of LC50 (estimated concentration that can cause negative effects on the survival and germination of 50 % of a group of organisms) was below 4 %, and EC50 (negative effects on reproduction) was less than 2.5 % for both soils. Exposure of A. sativa to the two soils did not have a toxic effect, nor did exposure of L. corniculatus to Hapludox. However, in the Ultisol, contamination caused effects at the lowest rate for L. corniculatus. In the seed germination test, only L. corniculatus showed sensitivity in the Ultisol (LC50<4 %). High sensitivity to the application of pyritic residue adversely affects soil organisms, both in the short term and long term.

**摘要** 大量煤矿开采废弃物的处置会通过化学作用改变土壤性状，进而可能影响土壤动物的群落结构与活动功能。本研究旨在探究硫铁矿废弃物（煤与黄铁矿混合物）在采自圣卡塔琳娜州的两种供试土壤中的沉积生态毒理效应，供试土壤分别为红黄色老成土（Argissolo Vermelho-Amarelo，Ultisol）与暗色湿润老成土（Nitossolo Háplico，Hapludox），设置的废弃物施用量梯度为0、2.5%、5%、10%及20%（以残留比例计）。本试验分别检测了隐链蚓（Enchytraeus crypticus）的存活与繁殖情况，以及燕麦（Avena sativa）和百脉根（Lotus corniculatus）的种子萌发情况。无论供试土壤类型如何，土壤pH值均随硫铁矿废弃物施用量的增加而降低。施加最低剂量的硫铁矿废弃物时，隐链蚓的成虫存活率下降且无繁殖发生，表现出显著负面效应。在土壤动物存活与繁殖试验中，两种供试土壤的半数致死浓度（LC50，即可导致50%受试生物的存活与萌发产生负面效应的估算浓度）均低于4%，半数效应浓度（EC50，即对繁殖产生负面效应的浓度）均低于2.5%。燕麦暴露于两种供试土壤均未表现出毒性效应，百脉根暴露于暗色湿润老成土也未产生毒性反应。但在红黄色老成土中，施加最低剂量的废弃物便对百脉根产生了负面影响。在种子萌发试验中，仅红黄色老成土中的百脉根表现出敏感性（LC50<4%）。硫铁矿废弃物施加对土壤生物具有高毒性敏感性，该效应将在短期与长期尺度上对土壤生态系统造成不利影响。