Abstract

One strategy to re-use solid urban wastes is the production of energy by anaerobic digestion. This process also generates high volume of digestates, which are frequently disposal in landfills. The aim of this work is to assess anaerobic digestates as agricultural inputs. Three different biomethanation wastes from different plants were collected. Firstly, a complete physico-chemical characterization of the wastes was done according to the Spanish regulation, showing that the materials had the 90% of the particles below 25 mm, high values of pH, electric conductivity, organic matter, humic acids and soluble nutrients such as NO₃⁻, SO₄²⁻, Ca²⁺, Mg²⁺, PO₄³⁻ and K⁺. Total concentrations of heavy metals and microbiological parameters were below the threshold levels allowed for agricultural use. The wastes were then treated with a strong acid and a strong base having two different solutions (ATr and BTr, respectively) which were evaluated as biostimulants for tomato plants in hydroponic culture. Those liquid extracts, ATr and BTr, demonstrated their biostimulant ability towards root system of tomato enhancing the hair root density and plant biometric parameters including plants weight and chlorophyll content. This work demonstrates the re-use feasibility of treated digestates in agriculture as fertilizers and more over as feedstock for biostimulants production.

Graphic Abstract

中文翻译：

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经处理的城市垃圾消化物在刺激水培番茄生长上的新用途（茄属植物lycopersicon L.）

摘要

重用城市固体废物的一种策略是通过厌氧消化产生能量。此过程还会产生大量的消化物，这些消化物经常在垃圾填埋场处理。这项工作的目的是评估厌氧消化物作为农业投入物。收集了来自不同工厂的三种不同的生物甲烷化废物。首先，根据西班牙法规对废物进行了完整的理化表征，结果表明，这些材料中90％的颗粒低于25毫米，具有较高的pH值，电导率，有机质，腐殖酸和可溶性营养素如NO ₃ ^-，SO ₄ ^2-，钙²⁺，镁²⁺，PO ₄ ^3-和K⁺。重金属的总浓度和微生物学参数低于农业使用的阈值水平。然后将废料用具有两种不同溶液（分别为ATr和BTr）的强酸和强碱处理，这些溶液被评估为水耕法中番茄植株的生物刺激剂。这些液体提取物ATr和BTr证明了它们对番茄根系的生物刺激能力，可增强发根密度和植物生物特征参数，包括植物重量和叶绿素含量。这项工作证明了处理过的消化物在农业中作为肥料以及作为生物刺激剂生产原料的再利用的可行性。

图形摘要