Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, 97187, Luleå, Sweden.
Department of Civil and Environmental Engineering, Norwegian University of Science and Technology, NO-7491, Trondheim, Norway.
Environ Sci Pollut Res Int. 2022 Sep;29(43):65452-65465. doi: 10.1007/s11356-022-20341-8. Epub 2022 Apr 29.
Diffuse pollution is recognised as a major challenge in achieving EU Water Framework Directive compliance, with urban runoff being a key pathway connecting various sources to receiving waters. Gully pots, as one of the ubiquitous urban drainage infrastructures, are placed at the inlets of piped drainage pipe network and actively drain runoff from urban catchment with suspended solids proportionally retained. The physiochemical properties of these retained solids reflect the activities within the catchment during the accumulation period. In this work, seven gully pots in two catchment types (highway and housing) in Luleå, Sweden were fully emptied and sediments analysed for total mass, particle size distribution and selected metal concentrations by six size fractions. The results of this sampling campaign are compared with the results of a 2005 study of the same gully pots to identify changes in the physicochemical properties of sediments over time and examine whether changes identified can be linked to changes in wider catchment management practices. The results highlight the potential impacts of winter road maintenance operations (e.g. up to a 15-fold higher solids loading rate in road catchment gully pots), reaching a normalised solids accumulation rate of 0.176-0.819 kg m year. An increase in tyre and road wear associated with winter road maintenance operations is also understood to contribute to the temporal increase of several metals including Cu, Zn, Co, Cr and V in the < 63-µm solids fraction in the road catchment gully pots. The concentrations of As and Pb decrease in all size fractions in both catchments, with the implementation of unleaded fuels (for Pb in housing catchment only), End-of-Life Vehicle Directive (Directive 2000/53/EC) (for Pb in both catchments), and strengthened industrial emission reduction measures suggested as possible drivers. The high contamination load for Zn, Cu, Cd and Pb in < 63-µm sediments from low-traffic housing catchment also emphasised the necessity of tracing and restricting non-traffic-related metal sources. Further seasonal monitoring of gully pot sediments is recommended to fully follow up the development of metals loading in both catchments.
弥散型污染被认为是实现欧盟水资源框架指令合规的主要挑战之一，而城市径流则是连接各种污染源和受纳水体的关键途径。雨水篦子作为一种普遍存在的城市排水基础设施，位于管道排水管网的入口处，可主动从城市集水区中排出径流，并按比例截留悬浮物。这些截留物的理化性质反映了在积累期内集水区内的活动。在这项工作中，瑞典吕勒奥的两个集水区（高速公路和住宅区）的七个雨水篦子被完全排空，并用六个粒径分级对沉积物进行总质量、粒径分布和选定金属浓度的分析。本次采样活动的结果与 2005 年对同一雨水篦子的研究结果进行了比较，以确定沉积物理化性质随时间的变化，并探讨所识别的变化是否与更广泛的集水区管理实践的变化有关。结果突出了冬季道路养护作业的潜在影响（例如，道路集水区雨水篦子中的固体负载率高达 15 倍），达到了 0.176-0.819 kg m year 的归一化固体积累率。与冬季道路养护作业相关的轮胎和道路磨损的增加，也被认为是导致包括 Cu、Zn、Co、Cr 和 V 在内的几种金属在道路集水区雨水篦子的<63 µm 固体部分的时间增加的原因。在两个集水区的所有粒径分级中，As 和 Pb 的浓度都有所下降，这可能与无铅燃料的实施（仅在住宅区集水区针对 Pb）、报废车辆指令（指令 2000/53/EC）（针对两个集水区的 Pb）以及强化工业减排措施有关。低交通量住宅区<63 µm 沉积物中 Zn、Cu、Cd 和 Pb 的高污染负荷也强调了追踪和限制非交通相关金属源的必要性。建议进一步进行季节性雨水篦子沉积物监测，以全面跟踪两个集水区中金属负荷的发展。
