Herein, ternary composites from polypyrrole (PPy), Mnsub.0.8Znsub.0.2Fesub.2Osub.4 (MZF), and graphite oxide (GO) were prepared to remove acid red dye (AR1) from wastewater. MZF was synthesized using ...spent Zn-C batteries, acid leaching, and sucrose auto-combustion processes; GO was prepared via oxidation and exfoliation of graphite. The composites were prepared by adding MZF and GO during the in-situ polymerization of pyrrole. Different PPy/MZF/GO (PMG) composites were prepared by changing the weight ratios of the PPy, MZF, and GO. We investigated the prepared composites' structural, magnetic, and electrical/dielectric properties. We evaluated different experimental conditions' influences on dye removal performance, such as pH, dosage, dye concentration, temperature, and contact time. XRD, FT-IR, and magnetic properties indicated that PPy completely coated the other contents. The electrical/dielectric properties improved while increasing the GO ratio. The PMG at GO content 50 wt.% (PMG50) showed the most efficient ratio for better removing AR1 from wastewater.
In the present study, a simple, economic and environmentally friend method was utilized for the production of multi-walled carbon nanotubes (MWCNTs) decorated with Mn sub(0.8)Zn sub(0.2)Fe sub(2)O ...sub(4) nanoparticles, synthesized via recycling process of Zn-C battery. The chemical composition and structure of the MWCNTs/Mn sub(0.8)Zn sub(0.2)Fe sub(2)O sub(4) composite were confirmed by X-ray diffraction and Fourier transform infrared measurements. The morphology as well as the decoration process was characterized using transmission electron microscopy. The results showed that the MWCNTs are homogeneously decorated with cubic loosely agglomerated ferrite particles having mean crystallite size of 20 nm. An appropriate decoration mechanism was suggested and discussed. The hysteresis measurements exhibited reasonable magnetic characteristics for the obtained composite which facilitate its separation from their dispersed solution using normal magnet. Surface area measurement indicates relatively large specific surface enhances its use in adsorption process. The adsorption capacity of the entire composite was investigated using crystal violet dye. The effect of composite mass, contact time, solution pH and solution temperature on the adsorption process was investigated. The adsorption process was found to follow a pseudo-second-order model. The calculated adsorption thermodynamic parameters ( Delta G, Delta H and Delta S) suggested the spontaneity of the thermodynamically favorable adsorption process.
The paper deals with the conventional physical, chemical and biological unit processes that are widely applied in the Middle East for treating feedwater to reverse osmosis (RO) systems which produce ...potable water from brackish groundwater and saline seawater. Depending on the quality of intake water, membrane process, posttreatment and desired quality of product water, a pretreatment system was designed. Such a system usually comprises a train of unit processes based on technical and cost considerations. Proper decision for selecting unit processes involves a thorough evaluation of available alternatives. Results of previous experiences and present guidelines and schemes that are developed combining unit processes for pretreatment of RO feed are reviewed. Through the process, the combination of pretreatment units is made in such a way so that the quality of feedwater is improved at a minimal cost for pretreatment and with minimal adverse effects on succeeding processes: membranes, storage and supply systems. Conceptual layouts of several such systems of alternatives are presented along with comparative data on expected system performance and cost.
In the present study, Mn sub(0.8)Zn sub(0.2)Fe sub(2)O sub(4) nanoparticles, synthesized from spent Zn-C batteries extract, were successfully used for decoration of multi-walled carbon nanotubes ...(MWCNTs). This MWCNTs/Mn sub(0.8)Zn sub(0.2)Fe sub(2)O sub(4) magnetic nano-composites were prepared by the addition of MWCNTs during the preparation of the entire ferrite using sucrose combustion method. The effect of MWCNTs content (0-70%) on the structural, morphological and magnetic properties of entire ferrite was investigated and discussed. The results showed that high purity Mn sub(0.8)Zn sub(0.2)Fe sub(2)O sub(4) nano-crystallites were completely decorated on the sidewalls of the MWCNTs up to 30% content and the decoration behavior, shape and density are dependent on the composition. The saturation magnetization was observed to decrease with increasing MWCNTs content while coercivity showed a particle size dependent behavior. The composition with 70% MWCNTs was examined as adsorbent for methylene blue dye (MB) from aqueous media based on its relatively high surface area and the capability of removing the nano-composite after adsorption process using normal magnet. The nano-composite showed a very high adsorption capacity and the kinetic as well as the thermodynamics of adsorption/removal process were investigated and discussed. Repeated testing showed the applicability of the nano-composite for the removal of MB from aqueous solution frequently with acceptable efficiencies.
Abstract
Background
D-lactic acidosis (D-LA) is an uncommon complication in children with Short Bowel Syndrome (SBS). The clinical presentation is characterized by episodes of neurological ...manifestations and severe metabolic acidosis. Diagnosis of D-LA is made by a combination of clinical assessment and biochemical measurement of D-lactic acid.
Aims
This review of two cases aims to describe our recent experience in the management of DLA, and to review recent literature on the management of D-LA in patients with SBS.
Methods
A literature search was performed using PubMed, and Google Scholar databases using the terms, “D-lactic acidosis”, “short bowel syndrome”, and “lactic acidosis in short bowel syndrome”.
Results
Case 1: A 4 year old male with SBS secondary to midgut volvulus at 5 months of age (27 cm of proximal jejunum, 3 cm of terminal ileum with intact ileocecal valve remaining) presented in July, 2018 with acute ataxia, slurred speech and altered mental status. Laboratory tests revealed a high anion gap metabolic acidosis with D-lactate level 8.89 mmol/L. The patient improved with fluid resuscitation, bicarbonate administration and cessation of oral feeds. He was discharged on oral Metronidazole for 14 days and bicarbonate 3/4 teaspoon three times a day.
Case 2: A 12 year old male presented to the Emergency Department with episodes of frequent diarrhea, lethargy, dizziness and behavioral changes. He had a relevant past medical history of SBS secondary to congenital gastroschisis with jejunal and colonic atresia, and subsequent right hemicolectomy secondary to midgut volvulus. Investigations revealed metabolic acidosis with a D-lactate level of 4.26 mmol/L. He was managed with intravenous fluid, bicarbonate therapy and discharged on cycling antibiotics (Metronidazole) with rapid resolution of symptoms and normalization of acidosis and D-lactate levels. He presented again in August 2018 with recurrent neurological symptoms and D-lactate 7.48 mmol/L. His recurrent symptoms were felt to be likely due to small intestinal bacterial overgrowth (SIBO), given his elevated D-lactate levels and response to antibiotic therapy.
Conclusions
D-lactic acidosis is a rare but serious complication of short bowel syndrome (SBS). Investigations for SIBO and empiric treatment with long-term, cycling antibiotics may be considered in patients who have repeated episodes of D-LA. Intestinal microbiota composition in children with SBS is an important factor influencing the clinical outcome. Further studies will be required to verify the incidence of D-LA in settings with chronic antibiotic use, and assessing the role of probiotics or fecal microbiota transplant in its management.
Funding Agencies
None
Cement bypass dust (CBPD) or cement kiln dust is a by-product of the manufacture of portland cement. It is generated during the calcining process in the kiln. Lime (CaO) constitutes more than 60% of ...CBPD composition. Other compounds include SiO2, Al2O3, Fe2O3, K2O, Na2O, Cl-, etc. Oman Cement Company generates about 25,000-30,000 t of CBPD every year. Some CBPD is recycled back again with the clinker. However, most of the material is disposed of on-site without any further reuse or reclamation. As such, research was carried out to investigate potential reuses of CBPD in the Sultanate of Oman. This paper will present the results of a study that investigated the use of CBPD as a filler in asphalt paving mixtures. Initially, the effect of adding either lime or CBPD (0, 3, 5, 7, 10, and 15%) on binder properties (penetration, ductility, and softening point) was investigated. Then three different asphalt concrete mixtures were prepared using lime (control), and 5 and 13% CBPD substitution for lime or fine aggregate. The mixtures were subjected to Marshall testing. Results indicate that the substitution of 5% CBPD for lime will essentially produce the same optimum asphalt binder content as the control mixture (4.5%, by weight of aggregate) without any negative effect on asphalt concrete properties (stability, flow, voids in total mix, voids in mineral aggregate, and voids filled with asphalt). However, the use of 13% CBPD for lime and fine aggregate will require a higher optimum asphalt binder content of 5.7%, by weight of aggregate. This will produce an uneconomical mix. Thus, 5% CBPD substitution for lime or cement would be the optimum used in asphalt paving mixtures.
PDF
