Department of Aquatic Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Droevendaalsesteeg 10, 6708 PB, Wageningen, The Netherlands.
Department of Aquatic Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Droevendaalsesteeg 10, 6708 PB, Wageningen, The Netherlands.
Water Res. 2024 Aug 15;260:121875. doi: 10.1016/j.watres.2024.121875. Epub 2024 Jun 3.
Global surface waters are in a bad ecological and chemical state, which has detrimental effects on entire ecosystems. To prevent further deterioration of ecosystems and ecosystem services, it is vital to minimize environmental pollution and come up with ways to keep surface water healthy and clean. Recently, photogranules have emerged as a promising platform for wastewater treatment to remove organic matter and nutrients with reduced or eliminated mechanical aeration, while also facilitating CO capture and production of various bioproducts. Photogranules are microbial aggregates of microalgae, cyanobacteria, and other non-phototrophic organisms that form dense spheroidic granules. Photogranules settle fast and can be easily retained in the treatment system, which allows increased amounts of water and wastewater to be treated. So far, photogranules have only been tested on various "high-strength" wastewaters but they might be an excellent choice for treatment of large volumes of polluted surface water as well. Here, we propose and tested for the first time photogranules on their effectiveness to remove nutrients from polluted surface water at unprecedented low concentrations (3.2 mg/L of nitrogen and 0.12 mg/L of phosphorous) and low hydraulic retention time (HRT = 1.5 h). Photogranules can successfully remove nitrogen (<0.6 mg/L, ∼80 % removal) and phosphorous (<0.01 mg/L, 90-95 % removal) to low levels in sequencing batch operation even without the need for pH control. Subjecting photogranules to surface water treatment conditions drastically changed their morphology. While, under "high-strength" conditions the photogranules were spherical, dense and defined, under polluted surface water conditions photogranules increased their surface area by forming fingers. However, this did not compromise their excellent settling properties. Finally, we discuss the future perspectives of photogranular technology for surface water treatment.
全球地表水的生态和化学状况都很差，这对整个生态系统造成了有害影响。为了防止生态系统和生态系统服务进一步恶化，必须最大限度地减少环境污染，并找到保持地表水健康和清洁的方法。最近，光颗粒作为一种很有前途的废水处理平台出现，可以在减少或消除机械曝气的情况下去除有机物和营养物质，同时促进 CO2 的捕获和各种生物制品的生产。光颗粒是微藻、蓝藻和其他非光合生物的微生物聚集体，形成致密的球形颗粒。光颗粒沉降速度快，容易在处理系统中保留，从而可以处理更多的水量和废水。到目前为止，光颗粒仅在各种“高强度”废水中进行了测试，但它们也可能是处理大量受污染地表水的绝佳选择。在这里，我们首次提出并测试了光颗粒在前所未有的低浓度（氮 3.2mg/L，磷 0.12mg/L）和低水力停留时间（HRT=1.5h）下从受污染地表水中去除营养物质的有效性。即使不需要 pH 控制，光颗粒也可以成功地去除氮（<0.6mg/L，约 80%的去除率）和磷（<0.01mg/L，90-95%的去除率），达到低水平。在序批式运行中，光颗粒处理地表水的条件会极大地改变它们的形态。虽然在“高强度”条件下，光颗粒是球形的、致密的和有定义的，但在受污染的地表水条件下，光颗粒通过形成指状物增加了它们的表面积。然而，这并没有影响它们卓越的沉降性能。最后，我们讨论了光颗粒技术用于地表水处理的未来展望。
