Anthropogenic rare earth elements in urban lakes: Their spatial distributions and tracing application

Anthropogenic Gadolinium Accumulation and Rare Earth Element Anomalies of the Typical Urban River, North China: Evidence from the Three-Dimensional Tracing System

“…Although limited large hospitals were found near the sampling points of the Chaobai River, the high level of anthropogenic Gd indicated that the Chaobai River could still be affected by medical wastewater. In general, patient excrement does not belong to medical waste, but it could flow into urban sewage treatment plants directly as domestic wastewater (i.e., residential sewage and hospital wastewater) . Because of the medical sewage input, wastewater released from sewage treatment plants may be a significant contributor of Gd anth in the world.…”

“…The potential origins of anthropogenic REEs could be revealed via the association with regional land use proportions . To assess the land use impact on REE concentrations in the Chaobai River, a 3 km buffer zone was established near 10 sampling sites (Figure ).…”

“…Within this context, changes in watershed land use have emerged as an important human-induced factor that exerts a substantial influence on the quality of the water environment within watersheds . Moreover, the uneven distribution of rare earth elements across varying land use types, coupled with the intensive human activities, acts as a catalyst for REE contamination in rivers . The examination of land use data within a watershed provides a promising way for accurately discerning the impact of anthropogenic factors on the concentration of REEs in urban water.…”

“…Since then, scientific works regarding anthropogenic REE anomalies in the water system have been identified in Europe, − North America, − and Asia. − For instance, Kulaksız and Bau reported the anthropogenic La and Sm anomalies because of effluent release in the Rhine River, which was attributed to the production of oil cracking catalysts. Liu et al also suggested that Sm and Gd were regarded as microcontaminants in the typical urban river of Wuhan due to the influence of wastewater treatment plants (WWTPs), factories, hospitals, and agricultural activities. ,, In addition, the apparently positive La anomaly was identified in Beijing’s rainwater. , The compounds of Gd and organic ligands have been applied in the medical field as the specific contrast agents of magnetic resonance imaging (MRI) since 1988 . With the development of medical analysis methods, numerous Gd compounds can be intravenously or orally administered for spinal, cranial, and abdominal MRI examinations .…”

Geochemical and Seasonal Characteristics of Dissolved Iron Isotopes in the Mun River, Northeast Thailand

“…Dissolved Fe in river water had different sources, mainly including rock weathering, anthropogenic sources (agriculture and industry activities) and other potential sources (groundwater and precipitation, etc.) [59,[62][63][64]. According to Han, Yang, Zeng and Zhao [40], the end-member of rock weathering had the highest Fe isotopes and a lower DFe/DAl ratio, the end-member of the anthropogenic source had a moderate Fe isotopes value (δ 56 Fe > 0) and the highest DFe/DAl ratio (anthropogenic input introduces extra Fe in river water) and the end-member of other potential sources had the lowest Fe isotopes value and a low DFe/DAl ratio (Chi River).…”