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1.
Environ Sci Technol ; 52(14): 7849-7858, 2018 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-29900735

RESUMO

In field applications, mostly in porous media, transport of stabilized nano zerovalent iron particles (nZVI) has never exceeded a few meters in range. In the present study, the transport of Carbo-Iron Colloids (CIC), a composite material of activated carbon as a carrier for nZVI stabilized by carboxymethyl cellulose (CMC), was tested under field conditions. The field site lies within a fractured chalk aquitard characterized by moderately saline (∼13 mS) groundwater. A forced gradient tracer test was conducted where one borehole was pumped at a rate of 8 L/min and CMC-stabilized CIC was introduced at an injection borehole 47 m up-gradient. Two CIC-CMC field applications were conducted: one used high 100% wt CMC (40 g/L) and a second used lower 9% wt loading (∼2.7 g/L). Iodide was injected as a conservative tracer with the CIC-CMC in both cases. The ratio between the CIC-CMC and iodide recovery was 76% and 45% in the high and low CMC loading experiments, respectively. During the low CMC loading experiment, the pumping rate was increased, leading to an additional CIC recovery of 2.5%. The results demonstrate the potentially high mobility of nZVI in fractured environments and the possibility for transport manipulation through the adjustment of stabilizer concentration and transport velocity.


Assuntos
Água Subterrânea , Nanopartículas Metálicas , Carbono , Carboximetilcelulose Sódica , Ferro
2.
Water Res ; 129: 375-383, 2018 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-29174827

RESUMO

The transport of nano scale iron particles (NIP) in fractures is of concern for remediation of both fractured aquifers and porous aquifers when hydro-fracking and flow in preferential pathways takes place. In this study the transport of various NIP in a natural discrete fractured chalk core was investigated and their mass recoveries calculated. Four different types of NIP were tested and characterized in two ionic strength (IS) solutions at a particle concentration of 100-200 mg/l. The effect of IS, stability (sedimentation rate), particle size, solution viscosity and stabilizer were studied. NIP stability ranged from 1 to 100% following 120 min of stability tests and recoveries ranged from about 6 to 69%. The stabilizer type and concentration were shown to have significant role in NIP recoveries, especially at increased IS. It was evident that gravitational stability is the most crucial factor dominating transport of NIP. Accordingly, stability tests were shown to be a reliable indicator of NIP mobility. The high recoveries of some NIP tested, combined with the lack of clogging effect illustrates the enhanced mobility of NIP in fractures. The wide range of recoveries indicates NIP transport manipulation potential in such media. We therefore suggest that application of NIP in contaminated fractures has considerable potential as a remediation measure. In order to achieve NIP distribution in the aquifer while avoiding leakage to the environment, NIP stabilizer concentration should be adjusted according to the site-specific hydrogeochemical properties of the contaminated media.


Assuntos
Recuperação e Remediação Ambiental , Água Subterrânea , Ferro , Nanopartículas Metálicas , Tamanho da Partícula , Porosidade , Viscosidade , Movimentos da Água
3.
Harefuah ; 153(11): 652-3, 687, 2014 Nov.
Artigo em Hebraico | MEDLINE | ID: mdl-25563025

RESUMO

This editorial is in response to Bar-Sela, Bentur, Schultz and Corn's article entitled "Spiritual care in hospitals and other healthcare settings in Israel--a profession in the making", published in Harefuah in May 2014. The integration of spiritual support into hospitals marks an interesting trend in light of the current emphases in the Israeli medical system on technological advancement, financial feasibility and quantifiable quality measures. This step is evidence of the importance still attached by policy and decisionmakers to those human aspects of illness and disease, which are difficult to define and measure. "Spiritual Support" is an ancient profession based on the principle, whereby support of the spirit is considered a basic human right, in recognition of the spirit as a source of strength during times of crisis and distress. This service was introduced into the Chaim Sheba Medical Center six years ago for patients with untreatable illnesses, and through identification of commonality between their coping features and those of rehabilitation patients. It was later expanded into the orthopedic and neurological rehabilitation departments. The service is provided on an individual level for the patients and in a group formal for their caregivers. Spiritual support as an integral part of the multi-disciplinary care further ratifies the holistic approach in medical practice, as an everlasting value transcending periodical trends. The conclusion drawn is that technological advancement, the scientific approach, physical-medical treatment, emotional therapy and spiritual support can and should exist side by side to improve the welfare and coping abilities of patients dealing with adverse medical conditions.


Assuntos
Atenção à Saúde/organização & administração , Terapias Espirituais/métodos , Espiritualidade , Adaptação Psicológica , Cuidadores/psicologia , Hospitais , Humanos , Israel , Assistência ao Paciente/métodos
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