Search results for "WASTE"
showing 10 items of 2580 documents
FeOOH and Mn8O10Cl3modified zeolites for As(V) removal in aqueous medium
2017
BACKGROUND Arsenic in drinking water poses serious potential health risks in more than 30 countries with total affected population of around 100 million people. The present study is devoted to the development of innovative sorbents based on zeolite materials for As(V) sorption by modifying raw materials with iron oxyhydroxide and manganese oxychloride. Natural clinoptilolite and synthetic zeolite A were modified in order to obtain improved sorption of As(V). Sorption properties of newly developed sorbents were studied. Zeolites containing natural clinoptilolite are chosen due to relatively low cost and their broad use in industrial production as well as characteristic large surface area. RE…
Anodic abatement of organic pollutants in water in micro reactors
2010
The electrochemical oxidation of oxalic acid (OA) was performed in a micro flow cell equipped with a boron doped diamond (BDD) anode. This preliminary study demonstrates that a flow cell with a micrometric distance between the cathode and the anode can be used to perform the electrochemical treatment of waters contaminated by organic pollutants in the absence of added supporting electrolytes with high abatements. The effect of the distance between the cathode and the anode, the flow rate and the current density on the abatement of oxalic acid and on the current efficiency was in particular studied.
Self-Sustaining Supramolecular Ionic Liquid Gels for Dye Adsorption
2018
Water contamination is one of the main problems of modern society, and scientific research is continuously involved in identifying solutions able to preserve this valuable source. In this context, we characterized novel ionogels formed by organic salts with different anions. In particular, they show self-strengthening behavior, a quite unusual property for supramolecular gels, and they also exhibit a good load-bearing capacity. These ionogels are able to remove cationic dyes from wastewater. Thanks to their properties, they can be used in different apparatuses like dialysis membranes and as loading in adsorption columns. In the latter case over 95% removal is achieved in less than 10 min. I…
Consequences of 3,4-dichloroaniline to guppy populations (Poecilia reticulata): computer simulation and experimental validation
1993
Abstract In order to evaluate the effects of 3,4-dichloroaniline (3,4-DCA), which were detected in a life-cycle test with guppies, on the population level, laboratory guppy populations were examined with regard to regulative parameters. Among the endpoints investigated in life-cycle tests, fecundity was shown to be a sensitive parameter. In laboratory guppy populations, however, intraspecific predation on newborn was the main regulator. Based on these data, a computer simulation programme was used to predict the consequences of 3,4-DCA to guppy populations. A population exposure experiment was conducted to validate the simulation results. The effects detected in the life-cycle test (LOEC: 2…
Dendrochemical assessment of mercury releases from a pond and dredged-sediment landfill impacted by a chlor-alkali plant.
2016
International audience; Although current Hg emissions from industrial activities may be accurately monitored, evidence of past releases to the atmosphere must rely on one or more environmental proxies. We used Hg concentrations in tree cores collected from poplars and willows to investigate the historical changes of Hg emissions from a dredged sediment landfill and compared them to a nearby control location. Our results demonstrated the potential value of using dendrochemistry to record historical Hg emissions from past industrial activities.
Ecotoxicity assessment of boreal lake sediments affected by metal mining: Sediment quality triad approach complemented with metal bioavailability and…
2019
Highlights • Ecological risk assessment of metal-contaminated boreal lakes and sediments. • Sediment Quality Triad complemented with bioavailability and body residue studies. • Toxicity studies for natural sediments with several organisms and endpoints • Adverse effects observed. High variation on results between different methods. • Standard toxicity tests not suitable for testing, too low pH hampers the results. There are several methods for studying metal-contaminated freshwater sediments, but more information is needed on which methods to include in ecological risk assessment. In this study, we compliment the traditional Sediment Quality Triad (SQT) approach – including information on c…
Preliminary insights about the treatment of contaminated marine sediments by means of bioslurry reactor: Process evaluation and microbiological chara…
2022
Abstract Contaminated marine sediments represent a critical threat towards human health and ecosystems, since they constitute a potential reservoir of toxic compounds release. In the present study, a bioslurry reactor was studied for the treatment of real marine sediments contaminated by petroleum hydrocarbons. The experimental campaign was divided in two periods: in the first period, microcosm trials were carried out to achieve useful indicators for biological hydrocarbon removal from sediments. The microcosm trials highlighted that the inoculum of halotolerant allochthonous bacteria provided the highest performance followed by autochthonous biomass. Based on the achieved results, in the s…
Hydrocarbons removal from real marine sediments: Analysis of degradation pathways and microbial community development during bioslurry treatment
2022
In this study, real marine sediments polluted by petroleum compounds were treated by means of a bioslurry pilot scale reactor. The treatment performance was evaluated by measuring the removal of total petroleum hydrocarbon (TPH), coupled to further analyses required to understand the mechanisms involved in the biodegradation process. The maximum TPH-removal efficiency reached 86 % at the end of experiments. Moreover, high throughput 16S RNA gene sequencing was used to describe the microbiome composition in sediment prior to, and after, bioslurry treatment, in order to identify the taxa mostly entailed in the TPH removal process. The raw sediment was mostly colonized by members of Sulfurimon…
Ecotoxicity assessment of natural attenuation effects at a historical dumping site in the western Baltic Sea.
2005
During the late 1950s and early 1960s of the past century, industrial waste material highly enriched in various contaminants (heavy metals, PAHs) was dumped in the inner Mecklenburg Bay, western Baltic Sea. Large-scale shifts in the spatial distribution of heavy metals in surface sediments were mapped by geochemical monitoring in the mid-1980s and 12 years later in 1997. A further study in 2001 was designed to investigate the small-scale spatial distribution of contaminants inside, on top of, and around the historical dumping ground and to examine possible effects to benthic organisms (Arctica islandica, microbiological toxicity tests). The site is located within an area characterized by a …
Ecotoxicity of sediments in rivers: Invertebrate community, toxicity bioassays and the toxic unit approach as complementary assessment tools
2015
The determination of the real toxicity of sediments in aquatic ecosystems is challenging and necessary for an appropriate risk assessment. Different approaches have been developed and applied over the last several decades. Currently, the joint implementation of chemical, ecological and toxicological tools is recommended for an appropriate and successful toxicity risk assessment. We chose the combination of the toxic unit approach with acute pore water tests (Vibrio fischeri, Pseudokirchneriella subcapitata and Daphnia magna) and whole-sediment exposure tests (V. fischeri, Chironomus riparius), together with invertebrate community composition (multivariate analyses) to detect short and long-…