Soil and Water Management and Conservation Postgraduate Programme, Faculty of Agronomy, Federal University of Pelotas, Capão do Leão, RS, Brazil.
Brazilian Agricultural Research Corporation (EMBRAPA), Pelotas, RS, Brazil.
J Environ Manage. 2020 Dec 1;275:111203. doi: 10.1016/j.jenvman.2020.111203. Epub 2020 Aug 20.
Agricultural use is the main way of recycling sewage sludge. Besides providing nutrients and organic matter to crops and soils, it is an important alternative for recycling this residue. However, problems during the sewage treatment process may generate sludge batches with an acidic pH. Thus, it is essential to understand the consequences of using such sludge on soils and plants, and to explore ways to overcome this limitation. The objective of this study was to evaluate addition rates of anaerobic sewage sludge (ASS) with acidic compositions on the soil fertility and performance of lettuce plants. Additionally, a methodology for pH correction of ASS with acidic pH is proposed. An agronomic experiment was conducted in a greenhouse using seven addition rates of ASS (0.0, 0.25, 0.5, 1, 2, 4 and 8 g kg in dry basis), treated with an additional step of disinfection (solarization), and applied in an Albaqualf soil cultivated with lettuce (Lactuca sativa). Soil and leaf chemical composition, as well as chlorophyll index and the dry matter of lettuce leaves were evaluated. Failures during the acidogenesis phase of the anaerobic digestion process were probably the cause of ASS acidification. Although this ASS increased soil fertility indicators and plant dry matter, it significantly reduced soil pH, thereby requiring a complementary assay to correct its pH up to 6.0, which was achieved through liming. Anaerobic sewage sludges with an acidic pH can be effectively used in agriculture after being dried and disinfected through solarization, followed by pH correction, avoiding negative impacts on soil chemical attributes and plant response.
农业用途是回收污水污泥的主要方式。除了为作物和土壤提供养分和有机物外，它还是回收这种残留物的重要替代方法。然而，污水处理过程中的问题可能会导致产生 pH 值呈酸性的污泥批次。因此，了解使用这种污泥对土壤和植物的影响，并探索克服这种限制的方法是至关重要的。本研究的目的是评估具有酸性成分的厌氧污水污泥（ASS）的添加率对生菜植物的土壤肥力和性能的影响。此外，还提出了一种用于校正酸性 pH 值 ASS 的方法。在温室中进行了一项农业试验，使用了七种 ASS 添加率（以干基计为 0.0、0.25、0.5、1、2、4 和 8 g kg），经过额外的消毒（太阳化）处理，并应用于用生菜（生菜）种植的 Albaqualf 土壤中。评估了土壤和叶片的化学成分、叶绿素指数以及生菜叶片的干物质。厌氧消化过程中酸生成阶段的失败可能是 ASS 酸化的原因。尽管这种 ASS 增加了土壤肥力指标和植物干物质，但它显著降低了土壤 pH 值，因此需要进行补充试验来将其 pH 值校正至 6.0，这可以通过石灰处理来实现。经过干燥和太阳化消毒以及 pH 值校正后，具有酸性 pH 值的厌氧污水污泥可以有效地用于农业，避免对土壤化学特性和植物反应产生负面影响。
