Millions of tonnes of plastic litter end up annually in the environment causing damage to the ecosystem. There are currently no standards regulating the amount of microplastic in wastewater, and the question is, should there be? Answering this question requires an understanding of damages microplastic causes to the environment and its removal potential from wastewater. This paper examines the cost-effectiveness of three wastewater treatment (activated sludge, rapid sand filtering and membrane bioreactor) and two sludge management technologies (anaerobic digestion and incineration), in terms of their microplastic removal capacity regarding aquatic and terrestrial ecosystems. We find removing microplastic from wastewater technically feasible and cost-effective. Membrane bioreactor with sludge incineration preventing removed microlitter from accumulating in soils is the most cost-effective option. This gives grounds for extending government regulation to microplastics in wastewater treatment plants. Policy targeting companies using microplastics in their products is, however, necessary to solve the problem ultimately.

每年有数百万吨塑料垃圾最终进入环境，对生态系统造成破坏。目前还没有规范废水中微塑料含量的标准，问题是，应该有吗？回答这个问题需要了解微塑料对环境的损害及其从废水中去除的潜力。本文研究了三种废水处理（活性污泥、快速砂滤和膜生物反应器）和两种污泥管理技术（厌氧消化和焚烧）在水生和陆地生态系统中微塑料去除能力方面的成本效益。我们发现从废水中去除微塑料在技术上可行且具有成本效益。带有污泥焚烧功能的膜生物反应器可防止去除的微量垃圾在土壤中积累，是最具成本效益的选择。这为将政府监管扩展到废水处理厂中的微塑料提供了依据。然而，政策针对在其产品中使用微塑料的公司是最终解决问题的必要条件。