Pursuing the circular economy driving scientists to explore additional environmental friendly application of lightweight aggregates (LWAs) derived from the dredged harbor sediment. We herein demonstrated the surface engineering of LWAs for the green fertilizer application by hydrothermally depositing iron species (Fe@LWAs) to increase the chemical reactivity. The obtained Fe@LWAs were first applied to adsorb nutrients ( and ). Desorption of the adsorbed nutrients was then utilized as the replacement of commercial chemical fertilizer to cultivate mung bean sprouts to further biofix environmental . Experimental results showed that the deposited iron species was the dominant component regulating the chemical behaviors of Fe@LWAs and adsorbed played an important role for Fe@LWAs to adsorb . With the coexistence of and , the adsorption capacities of Fe@LWAs were 0.220 mg-/g and 0.486 mg-/g. The growth rate of mung bean sprouts using nutrient loaded Fe@LWAs was similar to those cultivated using commercial chemical fertilizer. Despite the nutrient recovery and mung bean cultivation decreasing the carbon footprint of the Fe@LWAs, the preparation of LWAs by high temperature sintering and the following hydrothermal surface modification consumed intensive energy. Consequently, the green fertilizer application of Fe@LWAs requires at least 594 cycles of nutrient recovery and mung bean cultivation to reach negative carbon emissions. Importantly, the cultivated mung bean sprouts could return to the soil to effectively secure the biofixed , which could contribute additional environmental implications by increasing the organic content in the soil at the same time.

中文翻译：

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疏浚港口沉积物轻骨料表面工程绿色肥料利用


追求循环经济促使科学家探索从疏浚港口沉积物中提取的轻质骨料 (LWA) 的其他环保应用。我们在此展示了通过水热沉积铁物质（Fe@LWA）来提高化学反应性的用于绿色肥料应用的LWA表面工程。获得的 Fe@LWAs 首先用于吸附营养物质（和）。吸附的养分解吸后可替代商业化肥，用于培育绿豆芽，进一步生物修复环境。实验结果表明，沉积的铁物种是调节Fe@LWAs化学行为的主导成分，吸附对Fe@LWAs的吸附起着重要作用。当 和 共存时，Fe@LWAs 的吸附容量分别为 0.220mg-/g 和 0.486mg-/g。使用营养负载Fe@LWAs 的绿豆芽的生长速度与使用商业化肥栽培的绿豆芽的生长速度相似。尽管养分回收和绿豆种植减少了Fe@LWAs的碳足迹，但通过高温烧结制备LWAs和随后的水热表面改性消耗了大量能量。因此，Fe@LWAs的绿色肥料施用需要至少594个养分回收和绿豆种植循环才能达到负碳排放。重要的是，栽培的绿豆芽可以返回土壤以有效地固定生物固定物，同时增加土壤中的有机物含量，从而产生额外的环境影响。