Zhejiang Provincial Key Laboratory of Agricultural Resource and Environment, Zhejiang University, Hangzhou, 310058, China.
College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China.
Environ Sci Pollut Res Int. 2018 Sep;25(26):25726-25733. doi: 10.1007/s11356-017-9509-0. Epub 2017 Jun 21.
The production of biochar is a safe and beneficial disposal way for wastewater sludge. The biochar produced from wastewater sludge can be used as soil amendments for improving soil properties and for increasing crop yield. This work investigated the influences of wastewater sludge biochar (WSB) on the pH, exchangeable acidity, and physical properties of strongly acidic Ultisols with contrasting texture (clayey soil and sandy loam). Two soils were mixed with WSB at the rate of 0, 10, 20, and 40 g biochar kg soil and incubated for 240 days at 75% field water capacity. Incubation experimental results indicated that WSB significantly increased soil pH and exchangeable Ca and Mg contents, and decreased soil exchangeable H and Al, compared with the control. The application of WSB enhanced the formation of 5-2-mm macroaggregate, and decreased the content of <0.25-mm microaggregate. WSB application significantly increased aggregate stability of soils, determined by mean weight diameter (MWD) of aggregate. WSB increased the field water capacity and available water content (AWC) of sandy loam while WSB was not found to increase significantly water-holding capacity and AWC of clayey soil. WSB significantly reduced plastic index and tensile strength (TS) of clayey soil and did not alter the TS of sandy loam. Overall results suggest that WSB is a suitable amendment for strongly acidic Ultisols with poor physical properties. However, the soil texture affected greatly the improvement effect of WSB on poor physical properties in soils.
生物炭的生产是一种安全且有益的废水污泥处理方式。由废水污泥生产的生物炭可用作土壤改良剂，以改善土壤性质和提高作物产量。本研究调查了废水污泥生物炭（WSB）对具有不同质地（粘性土和砂壤土）的强酸性赤红壤 pH 值、可交换性酸度和物理性质的影响。将两种土壤与 WSB 以 0、10、20 和 40 g 生物炭 kg-1 土壤的比例混合，并在 75%田间持水量下培养 240 天。培养实验结果表明，与对照相比，WSB 显著提高了土壤 pH 值和可交换钙、镁含量，降低了土壤可交换氢和铝含量。WSB 的应用增加了 5-2mm 大团聚体的形成，降低了<0.25mm 微团聚体的含量。WSB 显著增加了土壤团聚体的稳定性，这可以通过团聚体的平均重量直径（MWD）来确定。WSB 增加了砂壤土的田间持水量和有效含水量（AWC），但对粘性土的持水能力和 AWC 没有显著影响。WSB 显著降低了粘性土的塑性指数和拉伸强度（TS），但对砂壤土的 TS 没有影响。总体结果表明，WSB 是一种适合强酸性赤红壤的改良剂，但其物理性质较差。然而，土壤质地对 WSB 改善土壤物理性质的效果有很大影响。
