Blind inlets are implemented to promote obstruction-free surface drainage of field depressions as an alternative to tile risers for the removal of sediment and particulate phosphorus (P) through an aggregate bed. However, conventional limestone used in blind inlets does not remove dissolved P, which is a stronger eutrophication agent than particulate P. Steel slag has been suggested as an alternative to limestone in blind inlets for removing dissolved P. The objectives of this study were to construct a blind inlet with steel slag and evaluate its ability to remove dissolved P, nitrogen (N), and herbicides. A blind inlet was constructed with steel slag in late 2015; data from only 2018 are reported due to inflow sampling issues. The blind inlet removed at least 45% of the dissolved P load and was still effective after three years. The dissolved P removal efficiency was greater with higher inflow P concentrations. More than 70% of glyphosate and its metabolite, and dicamba were removed. Total N was removed in the form of organic N and ammonium, although N cycling processes within the blind inlet appeared to produce nitrate. Higher dissolved atrazine and organic carbon loads were measured in outflow than inflow, likely due to the deposition of sediment-bound particulate forms not measured in inflow, which then solubilized with time. At a cost similar to local aggregate, steel slag in blind inlets represents a simple update for improving dissolved P removal.

中文翻译：

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利用盲孔钢渣去除溶解磷

实施盲入口以促进田间洼地的无障碍地表排水，作为瓷砖立管的替代方案，用于通过骨料床去除沉积物和颗粒磷 (P)。然而，盲孔中使用的常规石灰石不能去除溶解的 P，这是一种比颗粒 P 更强的富营养化剂。有人建议钢渣作为盲孔中石灰石的替代品，以去除溶解的 P。本研究的目的是构建钢渣的盲孔，并评估其去除溶解的 P、氮 (N) 和除草剂的能力。2015年底用钢渣建造了一个盲水口；由于流入采样问题，仅报告了 2018 年的数据。盲孔去除了至少 45% 的溶解磷负荷，三年后仍然有效。流入的 P 浓度越高，溶解的 P 去除效率越高。超过 70% 的草甘膦及其代谢物和麦草畏被去除。总氮以有机氮和铵的形式被去除，尽管盲入口内的氮循环过程似乎会产生硝酸盐。在流出中测量到的溶解莠去津和有机碳负荷高于流入，这可能是由于流入中未测量到的沉积物结合颗粒形式的沉积，然后随着时间的推移而溶解。以与当地骨料相似的成本，盲孔中的钢渣代表了一种提高溶解磷去除率的简单更新。尽管盲入口内的氮循环过程似乎会产生硝酸盐。在流出中测量到的溶解莠去津和有机碳负荷高于流入，这可能是由于流入中未测量到的沉积物结合颗粒形式的沉积，然后随着时间的推移而溶解。以与当地骨料相似的成本，盲孔中的钢渣代表了一种提高溶解磷去除率的简单更新。尽管盲入口内的氮循环过程似乎会产生硝酸盐。在流出中测量到的溶解莠去津和有机碳负荷高于流入，这可能是由于流入中未测量到的沉积物结合颗粒形式的沉积，然后随着时间的推移而溶解。以与当地骨料相似的成本，盲孔中的钢渣代表了一种提高溶解磷去除率的简单更新。