Valorisation of waste galvanizing dross: Emphasis on recovery of zinc with zero effluent strategy.

Galvanizing dross-a waste product from steel industries but it can be a potential secondary resource for zinc through urban mining and recycling. In this concern, a novel and scalable recycling route with zero effluent strategy is developed for the recovery of zinc from galvanizing dross as high grade zinc salts along with value-added products through hydrometallurgical processing. In particular, as-such dross block was leached in 9% (v/v) sulphuric acid medium, wherein strong hydrogen gas effervescence results in alleviating the pulverization and stirring requirements; which are material and energy intensive. Leached zinc is purified and recovered as high purity ZnSO4.(H2O/7H2O) and Zn3(PO4)2.4H2O through controlled crystallization and phosphate precipitation respectively; which find application in fertilizers and anti-corrosive paints. Temperature difference method was opted for the crystallization of zinc sulfate salts, wherein 70 °C and 30 °C were found to be stability range of crystallization of ZnSO4.H2O and ZnSO4.7H2O respectively. ZnSO4-H2O phase diagram is developed using Factsage calculations to corroborate crystallization study. Moreover, exhaustive thermodynamic analysis of Zn2+-PO43--H2O system at 303 K on precipitation of zinc phosphate using di-ammonium hydrogen phosphate (80-240 g/L) is conducted and the results reveal that with increasing pH (3-6), intermediate hydrogen phosphate species (H3PO4, H2PO4- and H2PO42-) decompose to produce stable PO43- ions leading to zinc phosphate precipitation. Impurity like Iron and supernatant solution left after crystallization are recovered as hydrated iron-calcium sulfate mixture and ammonium sulfate salt respectively. This explored route is economical and easily adaptable with zero effluents, therefore, transcends serious challenges in terms of energy requirement, scale-up and effluent generation.

Hazardous waste to materials: recovery of molybdenum and vanadium from acidic leach liquor of spent hydroprocessing catalyst using alamine 308.

Recovery of valuable materials/metals from waste goes hand in hand with environmental protection. This paper deals with the development of a process for the recovery of metals such as Mo, V, Ni, Al from spent hydroprocessing catalyst which may otherwise cause a nuisance if dumped untreated. A detailed study on the separation of molybdenum and vanadium from the leach solution of spent hydroprocessing catalyst of composition: 27.15% MoO3, 1.7% V2O5, 3.75% NiO, 54.3% Al2O3, 2.3% SiO2 and 10.4% LOI is reported in this paper. The catalyst was subjected to roasting under oxidizing atmosphere at a temperature of about 550 °C and leaching in dilute sulphuric acid to dissolve molybdenum, vanadium, nickel and part of aluminium. Metals from the leach solution were separated by solvent extraction. Both molybdenum and vanadium were selectively extracted with a suitable organic solvent leaving nickel and dissolved aluminium in the raffinate. Various parameters such as initial pH of the aqueous feed, organic to aqueous ratio (O:A), solvent concentration etc. were optimized for the complete extraction and recovery of Mo and V. Molybdenum and vanadium from the loaded organic were stripped by ammonia solution. They were recovered as their corresponding ammonium salt by selective precipitation, and were further calcined to get the corresponding oxides in pure form.

Phosphonomethyl iminodiacetic acid functionalized metal organic framework supported PAN composite beads for selective removal of La(III) from wastewater: Adsorptive performance and column separation studies.

The rare earth elements being toxic in nature are being accumulated in water bodies as their industrial usage is growing exponentially, thus their efficient separation holds an immense significance. Herein, ligand functionalized metal organic framework (MOF), Phosphonomethyl iminodiacetic acid coordinated at Fe-BTC, was synthesized post-synthetically and incorporated subsequently in polyacrylonitrile polymer to prepare the composite beads via nonsolvent induced-phase-inversion technique for selective adsorption of La(III) from the wastewater in batch and dynamic column mode. XPS NMR, and FTIR were used to establish the interaction between functionalized ligand and unsaturated metal nodes of MOF. The adsorption capacity was 232.5 mg/g and 77.51 mg/g at 298 K of the functionalized MOF and composite beads respectively. Adsorption kinetics followed a pseudo-second order rate equation, and isotherm indicated the best fitting with Langmuir model. The dynamic behavior of the adsorption column packed with MOF/Polymer beads was fairly described by the Thomas model. The breakthrough time of 23.2 h could be attained with 12 cm of bed height and 10 ml/min of flow rate. These MOF/Polymer beads shown the selectivity of La over transitional metals were recycled over 5 times with about 15% loss of adsorption capacity. The findings provide suggestive insights of the potential use of functionalized MOF towards the separation of the rare earth element.

Interaction-induced partitioning and magnetization jumps in the mixed-spin oxide FeTiO3-Fe2O3.

In this study we report on jumps in the magnetic moment of the hemo-ilmenite solid solution (x)FeTiO(3)-(1-x)Fe(2)O(3) above Fe(III) percolation at low temperature (T<3 K). The first jumps appear at 2.5 K, one at each side of the magnetization loop, and their number increases with decreasing temperature and reaches 5 at T=0.5 K. The jumps occur after field reversal from a saturated state and are symmetrical in the trigger field and intensity with respect to the field axis. Moreover, an increase of the sample temperature by 2.8% at T=2.0 K indicates the energy released after the ignition of the magnetization jump, as the spin-currents generated by the event are dissipated in the lattice. The magnetization jumps are further investigated by Monte Carlo simulations, which show that these effects are a result of magnetic interaction-induced partitioning on a sublattice level.

Detecting hidden spatial and spatio-temporal structures in glasses and complex physical systems by multiresolution network clustering.

We elaborate on a general method that we recently introduced for characterizing the "natural" structures in complex physical systems via multi-scale network analysis. The method is based on "community detection" wherein interacting particles are partitioned into an "ideal gas" of optimally decoupled groups of particles. Specifically, we construct a set of network representations ("replicas") of the physical system based on interatomic potentials and apply a multiscale clustering ("multiresolution community detection") analysis using information-based correlations among the replicas. Replicas may i) be different representations of an identical static system, ii) embody dynamics by considering replicas to be time separated snapshots of the system (with a tunable time separation), or iii) encode general correlations when different replicas correspond to different representations of the entire history of the system as it evolves in space-time. Inputs for our method are the inter-particle potentials or experimentally measured two (or higher order) particle correlations. We apply our method to computer simulations of a binary Kob-Andersen Lennard-Jones system in a mixture ratio of A(80)B(20) , a ternary model system with components "A", "B", and "C" in ratios of A(88)B(7)C(5) (as in Al(88)Y(7)Fe(5) , and to atomic coordinates in a Zr(80)Pt(20) system as gleaned by reverse Monte Carlo analysis of experimentally determined structure factors. We identify the dominant structures (disjoint or overlapping) and general length scales by analyzing extrema of the information theory measures. We speculate on possible links between i) physical transitions or crossovers and ii) changes in structures found by this method as well as phase transitions associated with the computational complexity of the community detection problem. We also briefly consider continuum approaches and discuss rigidity and the shear penetration depth in amorphous systems; this latter length scale increases as the system becomes progressively rigid.

Studies on solvent extraction of iron(III) as a step for conversion of a waste effluent to a value added product.

Solvent extraction of iron(III) from actual sulphate waste pickle liquor was investigated using trialkylphosphine oxide diluted with kerosene. The waste pickle liquor was procured from a local company which deals with the manufacturing of pipes and tubes made of iron and steel. Various parameters were studied to optimise a suitable condition for the maximum extraction of iron. The composition of the aqueous feed used in the experiment was 60.88 g/L Fe(III), 53 g/L acid with traces of Cu, Ni and Co. An ambient extraction at 30 °C yielded acceptable kinetics and loading efficiency for 40% trialkylphosphine oxide with a saturated loading capacity of 51.85 g/L in four contacts at O/A ratio of 1/1 in a multiple contact mode. Iron from the loaded organic was stripped using various strippants such as distilled water, H(2)SO(4) and oxalic acid. Since only 32% of loaded Fe could be stripped with 2 M H(2)SO(4) in five contacts, further stripping was done with 5% oxalic acid which showed a very promising result. It was found that almost 100% of Fe(III) could be stripped out with 5% oxalic acid at O/A of 1/1 in five contacts.

Extractive removal of chromium (VI) from industrial waste solution.

Extractive removal of Cr (VI) was carried out from chloride solutions using cyanex 923 mixed with kerosene. The efficiency of this extractant was studied under various experimental conditions, such as concentration of different mineral acids in the aqueous phase, concentration of cyanex 923 and Cr (VI) present in the initial aqueous feed, temperature and time of extraction, organic to aqueous (O/A) phase ratio. Percentage Cr (VI) extraction decreases with the increase in temperature at varying concentration of cyanex 923. The interference of the impurities usually associated with Cr (VI) such as Cr (III), Cu, Ni, Fe (II), Zn, Chloride and sulphate, etc., were examined under the optimized conditions and only Zn was found to interfere. Under the optimum experimental conditions 98.6-99.9% of Cr (VI) was extracted in 3-5 min at O/A of 2 with the initial feed concentration of 1g/L of Cr (VI). The extracted Cr (VI) was quantitatively stripped with 1M NaOH and the organic phase obtained after the stripping of Cr (VI) was washed with dilute HCl solution to neutralize any NaOH trapped/adhered to the solvent and then with distilled water. This regenerated solvent was reused in succeeding extraction of chromium (VI). Finally a few experiments were performed with the synthetic effluent from an electroplating industry.

Process integration for material synthesis from a deactivated catalyst: Studies on the interaction of metal ions between two immiscible phases.

Present investigation deals with the treatment of deactivated Co-Mn bromide catalyst for the recovery of Co and Mn as Co metal powder and chemical manganese dioxide by an integrated process comprising of a selective metal ion transfer from an aqueous solution containing a mixture of metal ions with a saponified solution of di-2ethyl-hexyl phosphoric acid, followed by selective scrubbing and metal stripping. The pure metal solutions so obtained were subjected to precipitation and hydrothermal treatment to obtain a desired material. The deactivated catalyst was leached by H2SO4 in presence of H2O2 followed by removing Fe, Si etc. The purified leach liquor of composition: 6.9g/L Co, 9.4g/L Mn was used for detail study to optimize the best conditions for the separation of Co from Mn. Experimental observations show that the extraction of both increased with increasing equilibrium pH and the concentration of the organic, with a separation factor of about 10, at equilibrium pH of 3. A quantitative extraction of Mn was possible with 20% D2EHPA in three stage counter-current extraction. After Co scrubbing, Mn was stripped with dilute H2SO4 and high pure spherical shaped CMD was produced. Co in the raffinate was recovered as powder by hydrothermal H2- reduction.

Variation in Adherence Measures to Imatinib Therapy.

PURPOSE: The introduction of tyrosine kinase inhibitors has transformed the care of patients with chronic myeloid leukemia, with survival approaching that of healthy individuals. Current-day challenges in chronic myeloid leukemia care include adherence to tyrosine kinase inhibitor therapy. We studied adherence from resource-constrained settings and tried to analyze the factors responsible for nonadherence in these individuals. We also correlated adherence to current molecular status. PATIENTS AND METHODS: This was a single-center, cross-sectional, observational study from north India. It consisted of a questionnaire-based survey in which a one-to-one interview technique was used by trained nursing staff administering the Modified Morisky Adherence Scale (MMAS-9) questionnaire. Adherence was also measured on the basis of physician's assessment. JMP 13.0.0 was used for statistical analysis. RESULTS: A total of 333 patients with a median age of 42 years were included in the study. The median BCR-ABL/ABL ratio (IS) was 0.175 (0.0 to 98.0). The mean MMAS-9 score was 11 ± 2. Adherence was seen in 54.95% on the basis of MMAS-9, whereas physician's assessment reported adherence in 90.39% of patients. Using the χ2 test, no relationship was found between the two assessment techniques. There was a significant relationship between major molecular response status and adherence by physician's assessment and MMAS-9 ( P < .001). Bivariate analysis by logistic fit showed a good relation between the MMAS-9 score and the BCR-ABL/ABL ratio (IS), χ2 (1,220) = 135.45 ( P < .001). On multivariate analysis, enrolment in the Novartis Oncology Access program (a patient assistance program) was significantly associated with adherence ( P = .012). CONCLUSION: This study highlights the lack of adherence in real-world settings and the various factors responsible. Such studies are important from a public health services perspective in various settings around the world because they may lead to corrective action being taken at the institutional level.

Kinetic and isotherm studies of cadmium adsorption on manganese nodule residue.

The adsorption equilibrium and kinetics studies of cadmium (Cd) ions from aqueous solutions on manganese nodule residue were carried out by considering the influence of various parameters, such as contact time, solution pH and initial metal concentration in solution, temperature and adsorbent quantity. The adsorption of Cd increased with an increase in the concentrations of this metal in solution. Presence of manganese and iron content in manganese nodule residue (MNR) played a significant role in Cd(II) ions removal. The linear forms of the Langmuir and Freundlich equations were utilized for experiments with metal concentrations of 200 mg/L for Cd(II) as functions of solution pH (2.0-6.0). First-order rate equation and pseudo second-order rate equations were applied to study adsorption kinetics. Mass transfer study was also done to know the reaction rate. Thermodynamic parameters, such as standard Gibb's free energy (deltaG(o)), standard enthalpy (deltaH(o)) and standard entropy (deltaS(o)), were also evaluated by Van't Hoff equation. Thus, adsorption of Cd on this adsorbent was found to be spontaneous and exothermic thermodynamically. The adsorption capacity for Cd was found to be 19.8 mg/g of MNR. Under the optimised conditions, cadmium level was brought down from 100 mg/L to Cd less than detection limits and from 200 to 2 mg/L. Thus, the wastewater after cadmium removal could be safely disposed off on to land or sewage. Finally, the metal loaded adsorbent was subjected to desorption using different mineral acids and leaching by using toxicity characteristic leaching procedure (TCLP), synthetic precipitation leaching procedure (SPLP) tests for its further treatment or its safe disposal.

Separation and recovery of lead from a mixture of some heavy metals using Amberlite IRC 718 chelating resin.

A weakly acidic ion exchanger resin containing the iminodiacetate group has been used to separate and recover metal ion from their mixtures. Batch and column methods were applied for the separation studies. Previous study on the kinetics and thermodynamics shows that the selectivity of this resin for transition metals was quite high as compared to that of alkaline earth metals. The efficiency of this resin in different experimental conditions was established and because of the large difference in the distribution coefficient values separation of the metal ions from their mixture was performed.

Profile of pancreatic tumors at a tertiary care center.

BACKGROUND: Pancreas, a relatively inaccessible organ, poses diagnostic difficulties with overlapping presentation among benign and malignant tumors. In the present study, pancreatic aspirates obtained by computed tomography (CT) guided procedures were used for cytodiagnosis. Our study aims at correlating clinical, cytological, biochemical, and histopathological results in obtaining a final diagnosis. METHODOLOGY: A retrospective study of 2 years was done which included 32 cases of pancreatic tumors at a tertiary care center. Patient data were retrieved and analyzed. RESULTS: Twenty-seven of the 32 (84.37%) cases were malignant tumors. Age distribution in malignant tumors was predominantly seen in the fourth to eighth decade, whereas in benign, it ranged in the second to third decade. Thirteen out of the 32 (40.62%) cases reported were females, with male:female ratio of 1.46:1. The most common presenting symptom was abdominal pain followed by jaundice and vomiting. Three of the 32 cases had visceral metastasis at the time of diagnosis. CT-guided aspirates in most cases yielded diagnostic material. Cytological and histopathological results concurred except for three cases. Cancer Antigen 19-9 was worked up for 14 of 27 malignant cases, 11 of which showed grossly elevated values (700-7000), and three cases showed mildly elevated values (100-300). Three of the four benign cases worked up for CA 19-9 showed normal values. CONCLUSIONS: Among the mass forming lesions in pancreas, malignancy was more common compared to benign tumors. A multidisciplinary approach in the assessment and diagnosis of pancreatic tumors yields accurate results in spite of the limitations faced in obtaining adequate samples by needle aspirates.

Systematic studies on adsorption of lead on sea nodule residues.

Lead adsorption from aqueous solutions was studied with the aim of detoxifying industrial effluents before their safe disposal onto land or into river waters. Sea nodule residue (SNR), a waste material containing oxides and oxyhydroxides of manganese, iron, silicon, etc., was used as an effective adsorbent for lead in this study. The effect of various parameters such as contact time, initial lead concentration, pulp density, particle size of the adsorbent, pH, and temperature was studied to optimize the conditions for maximum adsorption. Adsorption followed first-order kinetics and 99% of lead adsorption was achieved at a solid:liquid ratio of 1:330, in the pH range 5.5-6.0 at a particle size of -150 microm in 8 h for solution containing 200 ppm lead. The adsorption capacity was found to be 99.0 mg of lead per gram of SNR and the adsorption isotherms followed the Langmuir and Freundlich adsorption models. The mechanism of adsorption of lead onto the sea nodule residue was also investigated. It was possible to reduce the lead level from 25-200 ppm to acceptable levels (0.1 ppm) by adsorption over this solid waste.