Sustainable approaches to minimize arsenic in drinking water and rice in Vietnam

受砷污染的地下水被用作饮用水和水稻种植的灌溉水，对数千万人构成重大威胁，特别是在南亚和东南亚。该项目的主要目标是减少两个最重要的接触源，即水和大米中的有毒砷（As），并确定i）如何有效地从饮用水中去除As，以及ii）如何在湿耕中减少大米的As吸收。在第一个子项目中，我们将确定在何种条件下饮用水过滤器在越南有效地去除砷，多久的过滤器可以使用，以及是否有毒的硝酸盐水平形成的过滤器。我们将在过滤器中开发一个视觉指示器，使广大人群能够在不需要复杂的分析或教育的情况下确定过滤器的功效何时因As饱和而失效并需要更换。我们还将研究如何在没有未来风险的情况下处理已加载的使用过的过滤材料。在第二个子项目中，我们将调查是否刺激水稻土中的硝酸盐还原，铁氧化细菌减少水稻吸收作为作为一个后果，作为结合形成的矿物。我们将确定如何定义的硝酸盐添加可以帮助同时最大限度地减少水稻的吸收和温室气体N2O的排放，在微生物硝酸盐还原过程中形成的。该项目将为生活在受砷影响国家的人们提供切实可行的解决方案，以减少他们对砷和硝酸盐的接触，并改善他们的健康和生活状况。

Arsenic-contaminated groundwater is a major threat to tens of millions of people, in particular in South and South-East Asia, via its use as drinking water and irrigation water for rice cultivation. The main goals of this project are to decrease toxic arsenic (As) in the two most important sources of exposure, i.e. water and rice, and to determine i) how As can be removed efficiently from drinking water and ii) how As uptake by rice can be diminished in wet cultivation. In the first subproject, we will determine under which conditions drinking water filters in Vietnam efficiently remove As, how long the filters can be used, and whether toxic-levels of nitrate are formed in the filters. We will develop a visual indicator in the filter that allows the broad population to determine, without a need for sophisticated analytics or education, when the efficacy of the filters fails, due to saturation with As, and need replacement. We will also investigate how the As-loaded, used filter material can be disposed of without future risk. In the second subproject we will investigate whether the stimulation of nitrate-reducing, iron-oxidizing bacteria in paddy soil decreases As uptake by rice as a consequence of As-binding to the formed minerals. We will determine how defined nitrate addition can help to simultaneously minimize As uptake into the rice and the emission of the greenhouse gas N2O that is formed during microbial nitrate reduction. This project will provide practical solutions for people living in As-affected countries to reduce their exposure to As and nitrate, and to improve their health and living situation.