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Studies assessing chromium phytoextration from natural waters rarely consider potential implications of chromium speciation in the presence of ubiquitous humic substances. Therefore, the present study investigated the influence of environmentally relevant concentration of humic acid (TOC = 10 mg L(-1)) on chromium speciation (Cr = 0.15 mg L(-1)) and consequently on phytoextraction by aquatic macrophyte duckweed Lemna minor. In absence of humic acid, only hexavalent chromium was present in water samples and easily taken up by L. minor. Chromium uptake resulted in a significant reduction of growth rate by 22% and decrease of chlorophyll a and chlorophyll b contents by 48% and 43%, respectively. On the other hand, presence of humic acid significantly reduced chromium bioavailability (57% Cr uptake decrease) and consequently it did not cause any measurable effect to duckweed. Such effect was related to abiotic reduction of hexavalent chromium species to trivalent. Hence, findings of our study suggest that presence of humic acid and chromium speciation cannot be neglected during phytoextraction studies.
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http://dx.doi.org/10.1016/j.chemosphere.2015.12.090 | DOI Listing |
Bioresour Technol
September 2025
College of Engineering, Huazhong Agricultural University, Wuhan 430070, China. Electronic address:
In response to the challenges of nutrient limitations and low efficiency in synthesizing artificial humic acid (AHA) during the resource utilization of agricultural wastes, this study innovatively developed a process that integrates biogas slurry (BS) impregnation pretreatment with hydrothermal humification (HTH). Using steam-exploded corn straw (SES) as the raw material, the impregnation parameters were optimized (40 °C, liquid-to-solid ratio of 15:1, 18 h, 3 cycles), achieving an AHA yield of 40.61 %, which was over 15 % higher than that of the untreated group.
View Article and Find Full Text PDFSci Total Environ
September 2025
Sichuan Academy of Eco-Environmental Sciences, Chengdu 610041, China.
This study investigates the bioavailability of humic nitrogen (humic-N) to algae through controlled bioassay experiments. Algae were able to utilize dissolved organic nitrogen (DON) from both humic acid (HA) and fulvic acid (FA), with bacterial co-culture enhancing uptake. Bioavailable nitrogen (BAN) from HA accounted for ~20 % of total nitrogen, whereas FA reached ~45 %, with bacterial presence further increasing FA utilization by about 6-7 %.
View Article and Find Full Text PDFWater Res
September 2025
Advanced Institute of Natural Sciences, Beijing Normal University, Zhuhai 519087, China. Electronic address:
Plantation forest areas are rapidly expanding worldwide. Forests at different stand ages exhibit distinct patterns in litterfall input, soil microbial diversity, and enzyme activity, all of which potentially affect the properties of dissolved organic matter (DOM). DOM is an important precursor of disinfection byproducts (DBPs).
View Article and Find Full Text PDFAquat Toxicol
September 2025
State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510655, China. Electronic address:
Microplastics (MPs) have emerged as ubiquitous environmental contaminants, while thallium (Tl), a highly toxic metalloid, is gaining attention as a novel pollutant due to its increasing release from electronic waste and mining activities. These pollutants frequently coexist in aquatic environments; however, their combined effects at environmentally relevant concentrations remain poorly understood. In this study, the adsorption behavior and joint neurotoxicity of polystyrene (PS) microplastics and Tl were systematically evaluated using Caenorhabditis elegans as a model organism.
View Article and Find Full Text PDFJ Environ Manage
September 2025
Key Lab of Basin Water Resource and Eco-Environmental Science in Hubei Province, Basin Water Environmental Research Department, Changjiang River Scientific Research Institute, No.23 Huangpu Road, Wuhan, 430010, PR China; Innovation Team for Basin Water Environmental Protection and Governance of Chan
Small cascade dams drive spatial divergence in the composition of dissolved organic matter (DOM) in local sediments. Taking Xixi River in the southeast of China, a representative small cascade-dammed watershed, as an example, this study explored the spatial variations of DOM components and its interactions with microbial communities under the influence of cascade dams. Results revealed that DOM composition differed significantly, i.
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