Department of Soil and Water Conservation and Organic Waste Management, Centro de Edafología y Biología Aplicada del Segura, CSIC, P.O. Box 164, 30100 Murcia, Spain.
J Environ Manage. 2011 Mar;92(3):733-41. doi: 10.1016/j.jenvman.2010.10.018. Epub 2010 Oct 29.
Reclamation of trace element polluted soils often requires the improvement of the soil quality by using appropriate organic amendments. Low quality compost from municipal solid waste has been tested for reclamation of soils, but these materials can provide high amounts of heavy metals. Therefore, a high-quality compost, with low levels of heavy metals, produced from the main by-product of the Spanish olive oil extraction industry ("alperujo") was evaluated for remediation of soils affected by a pyritic mine sludge. Two contaminated soils were selected from the same area: they were characterised by differing pH values (4.6 and 7.3) and total metal concentrations, which greatly affected the fractionation of the metals. Compost was applied to soil at two rates (equivalent to 48 and 72 Tm ha(-1)) and compared with an inorganic fertiliser treatment. Compost acted as an available nutrient source (C, N and P) and showed a low mineralisation rate, suggesting a slow release of nutrients and thus favouring long term soil fertility. In addition, the liming effect of the compost led to a significant reduction of toxicity for soil microorganisms in the acidic soil and immobilisation of soil heavy metals (especially Mn and Zn), resulting in a clear increase in both soil microbial biomass and nitrification. Such positive effects were clearly greater than those provoked by the mineral fertiliser even at the lowest compost application rate, which indicates that this type of compost can be very useful for bioremediation programmes (reclamation and revegetation of polluted soils) based on phytostabilisation strategies.
受污染土壤的修复通常需要通过使用适当的有机改良剂来改善土壤质量。已对城市固体废物的低质量堆肥进行了土壤修复测试，但这些材料可能会提供大量重金属。因此，评估了一种源自西班牙橄榄油提取工业主要副产物（“alperujo”）的高质量、低重金属含量的堆肥，以修复受硫化矿山污泥影响的土壤。从同一地区选择了两种受污染的土壤：它们的特征是 pH 值（4.6 和 7.3）和总金属浓度不同，这极大地影响了金属的分馏。将堆肥以两种用量（相当于 48 和 72 Tm ha(-1))施用于土壤，并与无机肥料处理进行了比较。堆肥充当了可用养分源（C、N 和 P），且矿化率较低，表明养分释放缓慢，从而有利于长期土壤肥力。此外，堆肥的石灰化作用导致酸性土壤中土壤微生物毒性显著降低，并使土壤重金属（尤其是 Mn 和 Zn）固定化，从而导致土壤微生物生物量和硝化作用明显增加。即使在最低的堆肥用量下，这种积极影响显然大于矿物肥料引起的影响，这表明这种类型的堆肥可非常有助于基于植物稳定化策略的生物修复计划（污染土壤的修复和再植被化）。
