Abstract Phosphate limitation has been suggested as a preventive method against biofilms. P-limited feed water was studied as a preventive strategy against biofouling in cooling towers (CTs). Three pilot-scale open recirculating CTs were operated in parallel for five weeks. RO permeate was fed to the CTs (1) without supplementation (reference), (2) with supplementation by biodegradable carbon (P-limited) and (3) with supplementation of all nutrients (non-P-limited). The P-limited water contained ≤10 µg PO4 l−1. Investigating the CT-basins and coupons showed that P-limited water (1) did not prevent biofilm formation and (2) resulted in a higher volume of organic matter per unit of active biomass compared with the other CTs. Exposure to external conditions and cycle of concentration were likely factors that allowed a P concentration sufficient to cause extensive biofouling despite being the limiting compound. In conclusion, phosphate limitation in cooling water is not a suitable strategy for CT biofouling control. Graphical Abstract

中文翻译：

---

磷酸盐可用性对冷却塔中生物膜形成的影响

摘要 磷酸盐限制已被建议作为一种针对生物膜的预防方法。研究了限磷给水作为防止冷却塔 (CT) 中生物污垢的预防策略。三台中试规模的开放式循环 CT 并行运行了五周。RO 渗透物被送入 CTs (1) 不添加（参考），（2）添加生物可降解碳（P 限制）和（3）添加所有营养素（非 P 限制）。限磷水含有≤10 µg PO4 l−1。对 CT 盆和试样的研究表明，与其他 CT 相比，限磷水 (1) 不会阻止生物膜形成，并且 (2) 导致每单位活性生物质的有机物体积更高。尽管是限制性化合物，但暴露于外部条件和浓度循环可能是允许 P 浓度足以引起广泛生物污垢的因素。总之，冷却水中的磷酸盐限制不是 CT 生物污垢控制的合适策略。图形概要