Van 't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, NL-1098 XH, Amsterdam, The Netherlands.
Water Res. 2018 Apr 15;133:19-26. doi: 10.1016/j.watres.2018.01.017. Epub 2018 Jan 10.
Struvite precipitation is a well-documented method for recovering up to 98% of phosphorus from urine, which is one of the main nutrients in fertilizers besides nitrogen and potassium. Shortcomings of this process, however, are the low nitrogen recovery ratio and the possible uptake of pharmaceuticals from urine. In this work, the NH adsorbent materials biochar and zeolite are coupled with struvite precipitation to increase the N-recovery of struvite from 5.7% to 9.8%. Since nitrogen is one of the main nutrients in fertilisers, this increase is of significance for its potential commercial use. In addition, urine is spiked with pharmaceuticals to measure the consequential uptake in struvite-based fertilisers and crops afterwards. Five fertilisers are prepared by nutrient recovery from spiked urine using: (1) struvite crystallisation, (2) struvite crystallisation combined with N adsorption on zeolite, (3) struvite crystallisation combined with N adsorption on biochar, (4) N adsorption on zeolite without struvite crystallisation, and (5) N adsorption on biochar without struvite crystallisation. The fertiliser with the highest purity product and the lowest uptake of pharmaceuticals was struvite combined with zeolite. Next, the contaminated struvite-sorbent fertilisers are tested in a crop trial in which the bioaccumulation of pharmaceuticals in edible plant tissue (tomatoes) is measured. This bioaccumulation in tomato fruit biomass from each of the spiked fertilisers in the crop trial was found to be lower than 0.0003% in all cases, far below the acceptable daily intake (ADI) levels (750 kg of dry tomatoes should be consumed per day to reach the ADI limit). Consequently, the subsequent risk to human health from tomato fruit grown using urine derived struvite-sorbent fertilisers is found to be insignificant.
鸟粪石沉淀是一种从尿液中回收高达 98%磷的方法，而磷是除氮、钾之外的肥料的主要营养元素之一。然而，该过程存在氮回收率低以及尿液中药物可能被吸收等缺点。在这项工作中，NH 吸附材料生物炭和沸石与鸟粪石沉淀相结合，将鸟粪石中磷的氮回收率从 5.7%提高到 9.8%。由于氮是肥料的主要营养元素之一，因此这一提高对其潜在的商业用途具有重要意义。此外，尿液中添加了药物，以测量随后在基于鸟粪石的肥料和作物中的吸收情况。通过从添加药物的尿液中回收养分制备了五种肥料：（1）鸟粪石结晶；（2）与沸石上的氮吸附相结合的鸟粪石结晶；（3）与生物炭上的氮吸附相结合的鸟粪石结晶；（4）无鸟粪石结晶的沸石上的氮吸附；（5）无鸟粪石结晶的生物炭上的氮吸附。具有最高纯度产品和最低药物吸收的肥料是与沸石结合的鸟粪石。接下来，在作物试验中测试了受污染的鸟粪石-吸附剂肥料，其中测量了可食用植物组织（西红柿）中药物的生物积累情况。在作物试验中，从每种添加肥料中获得的受污染的鸟粪石-吸附剂肥料在番茄果实生物量中的生物积累均低于所有情况下的 0.0003%，远低于可接受的日摄入量（ADI）水平（每天应消耗 750 公斤干番茄才能达到 ADI 限值）。因此，从使用尿液衍生的鸟粪石-吸附剂肥料种植的番茄果实中对人类健康的后续风险被认为是微不足道的。
