College of Geography and Environmental Science, Hainan Normal University, Haikou, Hainan, China E-mail:
Analysis and Testing Center, Capital Normal University, Beijing, China.
Water Sci Technol. 2020 Dec;82(11):2503-2512. doi: 10.2166/wst.2020.522.
Palladium (Pd), in platinum group elements (PGEs), is widely used as a catalyst in vehicle exhaust catalytic converters (VECs). The cumulative level of Pd in the environment is growing rapidly, and the potential threat to human health is increasing. In this paper, the mangrove wetland in Dongzhai Harbor, Hainan Province, China, was taken as the research area for the collection of water samples. The particulate Pd was determined by microwave digestion and inductively coupled plasma-mass spectrometry (ICP-MS). The particulate Pd showed a decreasing trend from the estuary to offshore. The land origin of Pd in the mangrove wetland was explained. The Pd concentrations in the suspended state were lower in the wet season than in the dry season. Tide had an obvious influence on particulate Pd. The concentrations of particulate Pd at spring tide were higher than those at neap tide. The concentrations of particulate Pd at ebb tide were higher than those at flood tide. The rainfall intensity also had a strong influence on the particulate Pd. The particulate Pd increased after moderate and light rain but decreased after heavy rain. The pH, redox potential(Eh), and Cl had little effect on particulate Pd in the water environment. This study is helpful for understanding the environmental geochemical characteristics of Pd in mangrove wetlands and provides a theoretical basis for the study of Pd in urban coastal mangrove environment.
钯（Pd）是铂族元素（PGEs）中的一种，广泛用作汽车尾气催化转化器（VECs）中的催化剂。环境中钯的累积水平正在迅速增长，对人类健康的潜在威胁也在增加。本文以中国海南省东寨港红树林湿地为研究区域，采集水样。采用微波消解和电感耦合等离子体质谱（ICP-MS）法测定了颗粒态钯。颗粒态钯呈现出从河口向近海逐渐减少的趋势。解释了红树林湿地中颗粒态钯的陆源成因。在雨季，悬浮态钯的浓度低于旱季。潮流对颗粒态钯有明显的影响。大潮时的颗粒态钯浓度高于小潮时的浓度。落潮时的颗粒态钯浓度高于涨潮时的浓度。降雨强度也对颗粒态钯有强烈的影响。中雨和小雨过后，颗粒态钯增加，大雨过后，颗粒态钯减少。pH 值、氧化还原电位（Eh）和 Cl 在水环境中对颗粒态钯的影响较小。本研究有助于了解红树林湿地中钯的环境地球化学特征，为城市滨海红树林环境中钯的研究提供了理论依据。
