Suchergebnisse

Cover -- Half Title -- Title Page -- Copyright Page -- Table of Contents -- About the book series -- Dedication -- Organizers -- Sponsors and Contributors -- Scientific Committee -- Foreword (Director General, Institute of Urban Environment, Chinese Academy of Sciences) -- Foreword (Vice President, China University of Geosciences, Beijing) -- Foreword (KTH Royal Institute of Technology) -- Foreword (Deputy Vice Chancellor, University of Southern Quensland) -- Foreword (Director, KWRWatercycle Research Institute) -- Foreword (Vice Chancellor and President, The University of Newcastle) -- Editors' foreword -- List of contributors -- Plenary presentations -- Sedimentological and hydro-biogeochemical processes controlling arsenic behavior in the Holocene and upper Pleistocene aquifers of the centralYangtze River Basin -- Groundwater Assessment Platform (GAP): A new GIS tool for risk forecasting and mitigation of geogenic groundwater contamination -- Arsenic biogeochemistry from paddy soil to rice -- Mechanism of As(III) S-adenosylmethionine methyltransferases and the consequences of human polymorphisms in hAS3MT -- Genetic susceptibility and alterations in relation to arsenic exposure, metabolism and toxicity -- Arsenic oral bioavailability in soils, housedust, and food: implications for human health -- Arsenic removal by iron-based nanomaterials -- Distribution of arsenic hazard in public water supplies in the United Kingdom - methods, implications for health risks and recommendations -- Section 1: Arsenic behaviour in changing environmental media -- 1.1 Sources, transport and fate of arsenic in changing groundwater systems -- AdvectAs challenge: multidisciplinary research on groundwater arsenic dissolution, transport, and retardation under advective flow conditions -- Arsenic in the Baltic Sea sediments - past, present, and future.

AbstractPetroleum hydrocarbon (PHC) contamination is a widespread and severe environmental issue affecting many countries' resource sectors. PHCs are mixtures of hydrocarbon compounds with varying molar masses that naturally attenuate at different rates. Lighter fractions attenuate first, followed by medium-molar-mass constituents, while larger molecules remain for longer periods. This results in significant regulatory challenges concerning residual hydrocarbons in long-term contaminated soils. This study examined the potential risks associated with residual PHC and its implications for risk-based management of heavily contaminated soils (23,000–26,000 mg PHC/kg). Ecotoxicological properties, such as seedling emergence and growth of two native plant species—small Flinders grass (Iseilema membranaceum) and ruby saltbush (Enchylaena tomentosa)—and earthworm survival tests in PHC-contaminated soils, were assessed. Additionally, the effects of aging on the attenuation of PHC in contaminated soils were evaluated. Toxicity responses of plant growth parameters were determined as no-observed-effect concentrations: 75%–100% for seedling emergence, < 25%–75% for plant shoot height, and 75%–100% for earthworm survival. After 42 weeks of aging, the total PHC levels in weathered soils decreased by 14% to 30% and by 67% in diesel-spiked soil due to natural attenuation. Dehydrogenase enzyme activity in soils increased during the initial aging period. Furthermore, a clear shift of bacterial communities was observed in the soils following aging, including enrichment of PHC-resistant and -utilizing bacteria—for example, Nocardia sp. This study underscores the potential of natural attenuation for eco-friendly and cost-effective soil management, underlining that its success depends on site-specific factors like water content and nutrient availability. Therefore, we recommend detailed soil assessments to evaluate these conditions prior to adopting a risk-based management approach.

Abstract
Background
When we paint our houses or offices, we might paint plastic, because most paints are generally formulated with polymer binders. After drying and curing, the binders fix the colourants on the painted surface as a film of plastic mixture, which is tested herein using Raman imaging to analyse and directly visualise the hybrid plastic-colourant (titanium dioxide or TiO2 nanoparticles).

Results
For the plastic mixture or hybrid, the co-existence and competition between the Raman signals of plastic and TiO2 complicate the individual analysis, which should be carefully extracted and separated in order to avoid the weak signal of plastic to be masked by that of TiO2. This is particularly important when considering the Raman activity of TiO2 is much stronger than that of plastic. Plastic is observed to coat the TiO2 nanoparticle surface, individually or as a bulk to embed the TiO2 nanoparticles as mixture or hybrid. Once branched, pended, scratched or aged, the paint can also be peeled off from the painted surface, including gyprock, wood and glass, releasing microplastics and nanoplastics (coating onto the individual TiO2 nanoparticle surface or embedding the TiO2 nanoparticles, or individually as particles) in potential.

Conclusions
Our test sends us a warning that we are surrounded by plastic items that might release microplastics and nanoplastics in potential, for which the risk assessment is needed. Overall, Raman imaging is a suitable approach to effectively characterise microplastics and nanoplastics, even from the mixture with the hybrid background and the complicated interference.

Graphical Abstract