Pollutants of emerging concern originating from reclaimed wastewater: plant uptake, translocation and transformation - PECtake

由于中东等半干旱和干旱地区淡水短缺，经处理的城市污水（TWW）越来越多地用于作物灌溉。在以色列和约旦，大约85%的TWW用于作物灌溉;这包括大约50%的灌溉用水总量。过去几年的调查表明，在农业中使用TWW会将新出现的污染物（PEC）引入农业生态系统，这些PEC可能会被植物吸收。这些化合物包括药物、个人护理产品、家用化学品等。也就是说，在蒸渗仪研究以及常规田间试验中，已经证明了某些难降解的非离子药物从用于灌溉的TWW中可测量地吸收到植物中，并出现在可食用部分中。本项目重点关注以下问题：对于TWW的哪种PEC，土壤或根区不是有效的过滤器？PEC的物理化学性质如何影响植物的吸收和转运？在多大程度上，PEC进入农业植物到达其可食用部分？PEC在植物中的转化程度如何，转化为哪些产品？如果不考虑转化产品，植物吸收和人类接触的PEC被低估了？灌溉对农田地下水水质有何影响？农产品中的多氯联苯对人类接触的影响如何？该项目将通过在温室、蒸渗仪和采用TWW灌溉的田间进行协调研究来解决这些问题。将主要研究对以色列和约旦生产重要的叶菜和根菜。为了量化水、土壤和植物材料中的PEC以及识别转化产物，将使用最新的质谱仪器，包括通过液相色谱-高分辨率质谱法（LC-HRMS）进行筛选。考虑到使用荃湾污水厂作灌溉用途是无可避免的，该财团最终会利用其研究的科学结果，评估现时采用是否可以继续用TWW灌溉食用植物，或者是否应该给出建议，以避免污染物、土壤和作物的某些关键组合。

Due to the shortage of fresh water in semiarid and arid zones such as the Middle-East, treated municipal wastewater (TWW) is increasingly used for crop irrigation. In Israel and Jordan about 85% of the TWW is used for crop irrigation; this comprises about 50% of the total irrigation water. Investigations of the last years have outlined that the use of TWW in agriculture introduces pollutants of emerging concern (PEC) into the agro-ecosystem and that these PEC may be taken up by the plants. Among these compounds are pharmaceuticals, personal care products, household chemicals and others. Namely for some poorly degradable non-ionic pharmaceuticals measurable uptake from TWW used for irrigation into plants and occurrence in edible parts has been proven, in lysimeter studies as well as on regular field sites. This project focusses on the following issues:For which PEC from TWW is the soil or the root zone not an effective filter? How do physico-chemical properties of PEC affect plant uptake and translocation in plants? To which extent do PEC entering the agricultural plants reach its edible parts? To which extent are PEC transformed in the plants and to which products? For which PEC is plant uptake and human exposure underestimated if transformation products are not considered? What is the effect of irrigation on groundwater quality underneath the agricultural fields? What is the contribution of PEC in agricultural produce to the exposure to humans?The project will tackle these issues with coordinated studies in greenhouse, in lysimeters and on field sites where irrigation with TWW is practiced. Leafy and root vegetables of importance for production in Israel and Jordan will be primarily investigated. For the quantification of PEC in water, soil and plant material as well as for the identification of transformation products most recent mass spectrometric instrumentation will be used, including screening by liquid chromatography-high resolution-mass spectrometry (LC-HRMS).Considering that the use of TWW for irrigation purposes is inevitable the consortium will eventually use the scientific results of its studies to assess whether the present practice of irrigation of edible plants with TWW can be continued or whether recommendations should be given to avoid certain critical combinations of pollutants, soils and crops.