The aim of this study was to evaluate the use of drinking-water treatment residuals (DWTR) in the amendment of a soil affected by mining activities (Aljustrel mine, Portuguese sector of the Iberian Pyrite Belt), considering the effects on its chemical, biochemical and ecotoxicological characteristics. The DWTR had neutral characteristics (pH 6.7) and an organic matter (OM) content of 575 g kg⁻¹ dry matter (DM), which makes them a potential amendment for the remediation of mine degraded soils, as they may correct soil acidity and reduce the extractable metal fraction. An incubation assay, with soil and DWTR, with or without lime, was carried out to test the doses to be used in the assisted-phytostabilization experiment. Based on the results obtained, the doses of DWTR used were the equivalent to 48, 96, and 144 t DM ha⁻¹, with and without lime application (CaCO₃ 11 t DM ha⁻¹). Agrostis tenuis Sibth was used as the test plant. Some amendments doses were able to improve soil characteristics (pH and OM content), to decrease metal extractability by 0.01 M CaCl₂ (especially for Cu and Zn), and to allow plant growth, that did not occur in the non-amended soil. Copper, Pb and Zn concentrations in the plant material were lower than the maximum tolerable level for cattle feed, used as an indicator of risk of entry of those metals into the human food chain. The simultaneous application of DWTR (96 and 144 t ha⁻¹), with lime, allowed a reduction in the mine soil ecotoxicity, as evaluated by some lethal and sub-lethal bioassays, including luminescence inhibition of Vibrio fischeri, Daphnia magna acute immobilization test, mortality of Thamnocephalus platyurus, and 72-h growth inhibition of the green microalgae Pseudokirchneriella subcapitata. However, DWTR were unable to increase soil microbial activity, evaluated by dehydrogenase activity, an important soil-health indicator. Also, OM content and N_Kjeldahl, concentrations increased slightly but remained low or very low (P and K extractable concentrations were not affected). In general, the bioassays highlighted a decrease in soil ecotoxicity with the presence of lime and DWTR (144 t DM ha⁻¹). In conclusion, DWTR are recommended to amend acidic soils, with high concentrations of trace elements, but an additional application of organic or mineral fertilizers should be considered.

这项研究的目的是评估饮用水处理残留物（DWTR）在受采矿活动影响的土壤（Aljustrel矿，伊比利亚黄铁矿带的葡萄牙部门）的改良中的使用，并考虑对其化学，生化的影响和生态毒理学特征。DWTR具有中性特征（pH 6.7）和有机物（OM）含量为575 g kg ^-1干物质（DM），这使它们成为补救矿山退化土壤的潜在改良剂，因为它们可以纠正土壤酸度并减少可提取的金属含量。在有或没有石灰的情况下，进行了含有土壤和DWTR的孵化试验，以测试辅助植物稳定实验所用的剂量。根据获得的结果，在使用和不使用石灰的情况下（CaCO ₃ 11 t DM ha ^-1），所用DWTR的剂量相当于48、96和144 t DM ha ^-1。Agrostis tenuis Sibth被用作测试植物。一些修正剂量能够改善土壤特性（pH和OM含量），使金属提取能力降低0.01 M CaCl _2。（特别是对于铜和锌而言），并且为了允许植物生长，在未改良的土壤中不会发生这种情况。植物材料中的铜，铅和锌的浓度低于牛饲料的最大容许水平，用作表明这些金属进入人类食物链的风险指标。DWTR（96和144 t ha ^-1）与石灰的同时施用，降低了矿山土壤的生态毒性，这已通过一些致死和亚致死生物测定法评估，包括对费氏弧菌的发光抑制，大型蚤（Daphnia magna）的急性固定试验藻，扁叶鼠的死亡率和绿色微藻Pseudokirchneriella subcapitata的72小时生长抑制。然而，通过重要的土壤健康指标脱氢酶活性评估，DWTR无法增加土壤微生物活性。同样，OM含量和N _Kjeldahl浓度略有增加，但仍然很低或非常低（P和K的可提取浓度未受影响）。通常，生物测定法强调了石灰和DWTR（144 t DM ha ^-1）的存在对土壤生态毒性的降低。总之，建议使用DWTR修正微量元素含量高的酸性土壤，但应考虑额外使用有机或矿物肥料。