Enhanced Selective Removal of Cd(II) by an Amino-Functional Water-Retaining Agent Incorporating Nano Hydrous Manganese Oxide

2020 ◽  
Vol 20 (9) ◽  
pp. 5906-5915
Author(s):  
Liang Peng ◽  
Siyan Zhou ◽  
Huijuan Song ◽  
Yahui Yang ◽  
Ming Lei ◽  
...  

An amino-functionalized water-retaining agent (PPM40-NH2) and a water-retaining agent lacking functionalization (PPM40) were prepared to investigate their selective Cd(II) removal properties. The affinity for Cd(II) was increased after introducing the amino functional group. The SFCd/Ca of PPM40-NH2 was 3–7 fold higher than that of PPM40 although the CCa was 100–1000 times higher than that of CCd. The chelating effect of –COOH and –NH2 in PPM40-NH2 corresponded well with the selective adsorption of Cd(II), as confirmed by simulations. A seed germination experiment demonstrated that PPM40-NH2 could act as a filter of heavy metals to supply “clean” water for the roots of the pakchoi plant. The leaching experiment indicated that PPM40-NH2 is an efficient in situ fixation agent for the remediation of agricultural soil contaminated with Cd(II) in the presence of high concentrations of Ca(II) salts.

2013 ◽  
Vol 58 (1) ◽  
pp. 283-290 ◽  
Author(s):  
Y. Nishizaki ◽  
H. Miyamae ◽  
S. Ichikawa ◽  
K. Izumiya ◽  
T. Takano ◽  
...  

Our effort for decontamination of radioactive cesium scattered widely by nuclear accident in March 2011 in Fukushima, Japan has been described. Radioactive cesium scattered widely in Japan has been accumulating in arc or plasma molten-solidified ash in waste incinerating facilities up to 90,000 Bq/kg of the radioactive waste. Water rinsing of the ash resulted in dissolution of cesium ions together with high concentrations of potassium and sodium ions. Although potassium inhibits the adsorption of cesium on zeolite, we succeeded to precipitate cesium by in-situ formation of ferric ferrocyanide and iron rust in the radioactive filtrate after rinsing of the radioactive ash with water. Because the regulation of no preservation of any kind of cyanide substances, cesium was separated from the precipitate consisting of cesium-captured ferric ferrocyanide and ferric hydroxide in diluted NaOH solution and subsequent filtration gave rise to the potassium-free radioactive filtrate. Cesium was captured by zeolite from the potassium-free radioactive filtrate. The amount of this final radioactive waste of zeolite was significantly lower than that of the arc-molten-solidified ash.


2021 ◽  
Vol 9 (3) ◽  
pp. 336
Author(s):  
Stephanie K. Moore ◽  
John B. Mickett ◽  
Gregory J. Doucette ◽  
Nicolaus G. Adams ◽  
Christina M. Mikulski ◽  
...  

Efforts to identify in situ the mechanisms underpinning the response of harmful algae to climate change demand frequent observations in dynamic and often difficult to access marine and freshwater environments. Increasingly, resource managers and researchers are looking to fill this data gap using unmanned systems. In this study we integrated the Environmental Sample Processor (ESP) into an autonomous platform to provide near real-time surveillance of harmful algae and the toxin domoic acid on the Washington State continental shelf over a three-year period (2016–2018). The ESP mooring design accommodated the necessary subsystems to sustain ESP operations, supporting deployment durations of up to 7.5 weeks. The combination of ESP observations and a suite of contextual measurements from the ESP mooring and a nearby surface buoy permitted an investigation into toxic Pseudo-nitzschia spp. bloom dynamics. Preliminary findings suggest a connection between bloom formation and nutrient availability that is modulated by wind-forced coastal-trapped waves. In addition, high concentrations of Pseudo-nitzschia spp. and elevated levels of domoic acid observed at the ESP mooring location were not necessarily associated with the advection of water from known bloom initiation sites. Such insights, made possible by this autonomous technology, enable the formulation of testable hypotheses on climate-driven changes in HAB dynamics that can be investigated during future deployments.


Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 330
Author(s):  
Hengli Xiang ◽  
Genkuan Ren ◽  
Yanjun Zhong ◽  
Dehua Xu ◽  
Zhiye Zhang ◽  
...  

Fe3O4@C nanoparticles were prepared by an in situ, solid-phase reaction, without any precursor, using FeSO4, FeS2, and PVP K30 as raw materials. The nanoparticles were utilized to decolorize high concentrations methylene blue (MB). The results indicated that the maximum adsorption capacity of the Fe3O4@C nanoparticles was 18.52 mg/g, and that the adsorption process was exothermic. Additionally, by employing H2O2 as the initiator of a Fenton-like reaction, the removal efficiency of 100 mg/L MB reached ~99% with Fe3O4@C nanoparticles, while that of MB was only ~34% using pure Fe3O4 nanoparticles. The mechanism of H2O2 activated on the Fe3O4@C nanoparticles and the possible degradation pathways of MB are discussed. The Fe3O4@C nanoparticles retained high catalytic activity after five usage cycles. This work describes a facile method for producing Fe3O4@C nanoparticles with excellent catalytic reactivity, and therefore, represents a promising approach for the industrial production of Fe3O4@C nanoparticles for the treatment of high concentrations of dyes in wastewater.


1991 ◽  
Vol 69 (11) ◽  
pp. 1705-1712 ◽  
Author(s):  
Noburu Konno ◽  
K. J. Kako

Hydrogen peroxide (H2O2) and hypochlorite (HOCl) cause a variety of cellular dysfunctions. In this study we examined the effects of these agents on the electrical potential gradient across the inner membrane of mitochondria in situ in isolated rat heart myocytes. Myocytes were prepared by collagenase digestion and incubated in the presence of H2O2 or HOCl. Transmembrane electrical gradients were measured by distribution of [3H]triphenylmethylphosphonium+, a lipophilic cation. The particulate fraction was separated from the cytosolic compartment first by permeabilization using digitonin, followed by rapid centrifugal sedimentation through a bromododecane layer. We found that the mitochondrial membrane potential (161 ± 7 mV, negative inside) was relatively well maintained under oxidant stress, i.e., the potential was decreased only at high concentrations of HOCl and H2O2 and gradually with time. The membrane potential of isolated rat heart mitochondria was affected similarly by H2O2 and HOCl in a concentration- and time-dependent manner. High concentrations of oxidants also reduced the cellular ATP level but did not significantly change the matrix volume. When the extra-mitochondrial free calcium concentration was increased in permeabilized myocytes, the transmembrane potential was decreased proportionally, and this decrease was potentiated further by H2O2. These results support the view that heart mitochondria are equipped with well-developed defense mechanisms against oxidants, but the action of H2O2 on the transmembrane electrical gradient is exacerbated by an increase in cytosolic calcium. Keywords: ATP, calcium, cardiomyocyte, cell defense, mitochondrial membrane potential, oxidant, triphenylmethylphosphonium.


2003 ◽  
Vol 56 (9) ◽  
pp. 903 ◽  
Author(s):  
Gavin E. Collis ◽  
Dieter Wege

Addition of 2-diazopropane to 1,4-naphthoquinone at low temperature, followed by in situ enolization and acetylation or silylation gave 3,3-dimethyl-1H-benz[f]indazol-4,9-diyl diacetate and 3,3-dimethyl-9-(t-butyl-dimethylsilyloxy)-1H-benz[f]indazol-4-ol, respectively. Functional group manipulation of the latter compound provided a number of other 4,9-disubstituted 3,3-dimethyl-3H-benz[f]indazoles. Irradiation of the diacetate led to clean extrusion of nitrogen to give the naphtho[b]cycloproparene and an alkene. Attempts to elaborate the cycloproparene into the derived cyclopropanaphthoquinone were unsuccessful. Of the other 4,9-disubstituted 3,3-dimethyl-3H-benz[f]indazoles examined, only the compound possessing an acetoxy group at C9 was photoactive, and afforded the expected cycloproparene and alkene. Compounds bearing a hydroxy or alkoxy group at C9 were photochemically inert.


Synthesis ◽  
2021 ◽  
Author(s):  
Santanu Ghora ◽  
Chinnabattigalla Sreenivasulu ◽  
Gedu Satyanarayana

AbstractAn efficient, one-pot, domino synthesis of quinolines via the coupling of iodoanilines with allylic alcohols facilitated by palladium catalysis is described. The overall synthetic process involves an intermolecular Heck coupling between 2-iodoanilines and allylic alcohols, intramolecular condensation of in situ generated ketones with an internal amine functional group, and a dehydrogenation sequence. Notably, this protocol occurs in water as a green solvent. Significantly, the method exhibits broad substrate scope and is applied for the synthesis of deuterated quinolines through a deuterium-exchange process.


2018 ◽  
Vol 10 (2) ◽  
pp. 175-178
Author(s):  
Christian Romeo Bravo Aguilar ◽  
Franklin Xavier Bravo Aguilar ◽  
Adriana Abigail Guzmán Villa

BACKGROUND: The epiphysiolysis of the femoral head is the displacement of the epiphysis with respect to the metaphysis, in anterosuperior direction; it is etiology is unknown, frequent in adolescents, peripubertal period, and with high body mass index, average age between 12 and 18 years. It is incidence is variable, 0.2 (Japan) to 10 (United States) per 100 000 inhabitants. It is characterized by progressive pain in the hip, with irradiation to the groin or knee, is associated with lameness; with the early detection, an adequate treatment can be established, the most accepted one is the in situ fixation with central screws. CASE REPORT: A 14-year-old female patient with no pathological history attended the Children's Orthopedic Service due to the chronic lancinating pain of the right hip, which increases with walking, it is diagnosed by clinical examination and complementary exams of femoral head epiphysiolysis. Surgical dislocation of the hip and anatomical open reduction with placement of spongy screws was performed. EVOLUTION: On the third day of surgery, hospital discharge is decided; walking with crutches and without support during a postoperative month. The osteosynthesis remained for a year with monthly controls and corresponding physiotherapy; it has been evidenced favorable evolution; hip mobility arches preserved, normal ambulation, without complications CONCLUSIONS: The initial treatment of a patient with epiphysiolysis of stable femoral head depends on the evolution time and is done by fixing with screws or needles with of anatomical dislocation of the hip and osteoplasty of femoral neck remodeling. Most patients do not develop necrosis or chondro- lysis and long-term results with in situ fixation are usually excellent, unlike patients with late diagnosis.


Author(s):  
I.M. Zazirnyi ◽  
O.O. Kostrub

Summary. Femoral neck fractures are a commonly encountered injury in orthopedic practice and result in significant morbidity and mortality. It is essential that surgeons are able to recognize specific fracture patterns and patient characteristics that indicate the use of particular implants and methods to effectively manage these injuries. The use of the Garden and Pauwels classification systems has remained the practical mainstay of femoral neck fracture characterization that help choosing appropriate treatment. Operative options include in situ fixation, closed or open reduction and internal fixation, hemiarthroplasty, and total hip arthroplasty. Recent reports demonstrate diversity among orthopedic surgeons in regard to the optimal treatment of femoral neck fractures and changing trends in their management.


1986 ◽  
Vol 109 (2) ◽  
pp. 279-285 ◽  
Author(s):  
J. P. Hinson ◽  
G. P. Vinson ◽  
B. J. Whitehouse ◽  
G. M. Price

ABSTRACT Using the in-situ, isolated, perfused rat adrenal system, the actions of adrenal stimulants on steroidogenesis and perfusion medium flow rates (under constant perfusion pump conditions) have been studied. In a series of 100 experiments, initial rates of corticosterone output and flow rates were found to be positively correlated, although there was no such relationship between initial rates of aldosterone output and flow rates. Furthermore, in stable perfusion conditions, bolus injections of ACTH increased both flow rate and steroid output in a dose-related manner. In individual experiments there was a clear correlation between corticosterone and flow, but the association between aldosterone secretion rate and flow was less evident. It is possible that this discrepancy arises because of temporal differences in the responses of these two steroids. Flow was also stimulated by dibutyryl cyclic AMP (dbcAMP), with correlations with steroid output similar to ACTH, but the specific zona glomerulosa stimulants angiotensin II amide and potassium ions had, if anything, inhibitory effects on flow, but only at high concentrations. The data suggest that ACTH and dbcAMP evoke specific responses in the adrenal vasculature, resulting in relatively decreased intraglandular vascular resistance. They furthermore suggest that the secretory functions of the inner adrenocortical zones are subject to the additional control of vascular elements in the intact gland. J. Endocr. (1986) 109, 279–285


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