Search results for "remediation."
showing 10 items of 267 documents
Lead(II) ions adsorption onto amyloid particulates: An in depth study
2022
The production of new cost-effective biocompatible sorbent sustainable materials, with natural origins, able to remove heavy metals from water resources is nowadays highly desirable in order to reduce pollution and increase clean water availability. In this context, self-assembled protein materials with amyloid structures seem to have a great potential as natural platform for a broader development of highly-tunable structures. In this work we show how protein particulates, a generic form of protein aggregates, with spherical micro sized shape can be used as adsorbents of Pb2+ ions from aqueous solution. The effect of pH, ionic medium, ionic strength and temperature of the metal ion solution…
Ex situ conservation and exploitation of fungi in Italy
2011
Abstract The kingdom Fungi comprises one of the most diverse groups of living organisms. They are numerous, ubiquitous and undertake many roles both independently and in association with other organisms. Fungi display a wide diversity of forms also mirrored by functional diversity and play such a dominant role in human society that they are arguably biotechnologically the most important group of organisms. Ex situ conservation of fungi, not only guarantees correct management and conservation of biodiversity, but also its exploitation in different fields. This article describes the major biological resource centres dealing with fungi in Italy and gives several examples of fungal exploitation…
Laccase: A Review of Its Past and Its Future in Bioremediation
2011
Laccases are multicopper proteins that use molecular oxygen to oxidize a broad spectrum of organic compounds by a radical-catalyzed reaction mechanism. Many articles over the past 15 years have touted the diverse potential applications of laccase in various biotechnological processes. This review covers the natural roles of the enzyme, its structural properties, substrates, reaction mechanism, and inhibitors, as well as its applications regarding the detoxification and bioremediation of polluted wastewaters and soils. Other applications are briefly covered as well. The authors critically assess the advantages, shortcomings, and future needs relating to laccase availability, effectiveness, a…
Sorption of Pd(II) ion by calcium alginate gel beads at different chloride concentrations and pH. A kinetic and equilibrium study
2016
Abstract A kinetic and thermodynamic study on the sorption ability of calcium alginate gel beads towards Pd(II) ion was made in aqueous solution at different pH and chloride concentrations. The experimental conditions adopted in the sorption experiments were established on the basis of a speciation study on the Pd 2+ -AA system in which all the side reactions, such as the hydrolysis of Pd(II), the protonation of alginate and the interactions of the ligand and the metal ion with ions of ionic medium were taken into account. In the pH range 2–5 and at chloride concentration in the range 0 ⩽ C Cl - /mmol L −1 ⩽ 10 the gel beads showed good sorption ability towards Pd(II) ion as confirmed by k…
Removal of Cypermethrin from Water by Using Fucus Spiralis Marine Alga
2019
Alpha-cypermethrin is a synthetic pyrethroid that was extensively used for insect control, since the early 1980s. However, it is known that its presence in the environment has toxic effects on humans and aquatic life forms. For this reason, it is commendable for it to be removed completely from the contaminated environment. In this study, we evaluated the adsorption capacity of a marine alga for the removal of cypermethrin from water. The adsorption experiments were performed based on the batch equilibrium technique. The samples containing the pesticide were analyzed using gas chromatography with an electron capture detector, after liquid-liquid extraction in hexane. The results obtained fr…
Changing the ownership of ideas: Multimedial accomplishment of collaborative reflection in an organizational workshop
2022
Reflecting on work processes together with one's co-workers is becoming increasingly important in workplaces. This study examined collaborative reflection in the organizational context through analyzing a case of a complex workplace setting where an enterprise social media platform, talk-in-interaction, and handwriting were used to engage participants in the process of reflection. Drawing on the concept of remediation, the results show that collaborative reflection is interactionally accomplished through a multimedial activity chain, in which the ownership of presented ideas is transformed from individual ideas into shared views of the team. The study shows in detail how the process of coll…
Effects of activated carbon ageing in three PCB contaminated sediments: Sorption efficiency and secondary effects on Lumbriculus variegatus.
2015
The sorption efficiency and possible secondary effects of activated carbon (AC) (o 63-200 μm) was studied with Lumbriculus variegatus in three PCB contaminated sediments applying long AC-sediment contact time (3 years). AC amendment efficiently reduced PCB bioavailability as determined with both, L. variegatus bioaccumulation test and passive samplers. However, dose related secondary effects of AC on egestion rate and biomass were observed (applied doses 0.25% and 2.5% sediment dry weight). The sorption capacity and secondary effects remained similar when the experiments were repeated after three years of AC-sediment contact time. Further, transmission electron microscopy (TEM) samples reve…
Responses of Lumbriculus variegatus to Activated Carbon Amendments in Uncontaminated Sediments
2012
Activated carbon (AC) amendment is a recently developed sediment remediation method. The strong hydrophobic organic contaminant sorption efficiency of AC has been shown in several studies, but effects on benthic organisms require more investigation. The AC induced effects on egestion rate, growth and reproduction of Lumbriculus variegatus were studied by applying bituminous coal based AC in three different particle size fractions, namely <63 μm (90%, AC(p)), 63-200 μm (AC(m)) and 1000 μm (AC(g)), to natural uncontaminated (HS) and artificial sediment (AS). Egestion rate, growth and reproduction decreased with increasing AC concentration and finer AC particle fractions, effects being stronge…
Phosphonate degradation by Spirulina strains: cyanobacterial biofilters for the removal of anticorrosive polyphosphonates from wastewater
2011
The ability of Spirulina spp. to metabolize the recalcitrant xenobiotic Dequest 2054(®) [hexamethylenediamine-N,N,N',N'-tetrakis(methylphosphonic acid)], a CaSO(4) inhibitor used for boiler treatment and reverse osmosis desalination, was investigated. The compound served as sole source of phosphorus, but not of nitrogen, for cyanobacterial growth. In vivo utilization was followed by (31)P NMR analysis. The disappearance of the polyphosphonate proceeded only with actively dividing cells, and no release of inorganic phosphate was evident. However, no difference was found between P-starved and P-fed cultures. Maximal utilization reached 1.0 ± 0.2 mmoll(-1), corresponding to 0.56 ± 0.11 mmol g(…
A computer-based Pinyin intervention for disadvantaged children in China: Effects on Pinyin skills, phonological awareness, and character reading.
2019
Pinyin is an alphabetic script that denotes pronunciations of Chinese characters. Studies have shown that Pinyin instruction enhances both phonological awareness (e.g., Shu et al., Developmental Science, 2008, 11, 171-181) and character reading (e.g., Lin et al., Psychological Science, 2010, 21, 1117-1122) in Chinese children. In the present study, we provided a 3-week Pinyin intervention with a computer-based Pinyin GraphoGame to disadvantaged migrant children with poor Pinyin skills. A total of 252 first graders who were children of migrant workers in a large Chinese city were assessed to identify poor Pinyin readers. Fifty-six 7-year-old children with poor Pinyin skills were selected and…