scholarly journals Removal of Cr (VI) by Biochar Derived from Six Kinds of Garden Wastes: Isotherms and Kinetics

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3243
Author(s):  
Qiao-Chu Zhang ◽  
Cheng-Chen Wang ◽  
Jin-Hua Cheng ◽  
Cheng-Liang Zhang ◽  
Jing-Jing Yao

Garden waste is one of the main components of urban solid waste which affects the urban environment. In this study, garden waste of Morus alba L. (SS), Ulmus pumila L. (BY), Salix matsudana Koidz (LS), Populus tomentosa (YS), Sophora japonica Linn (GH) and Platycladus orientalis (L.) Franco (CB) was pyrolyzed at 300 °C, 500 °C, 700 °C to obtain different types of biochar, coded as SSB300, SSB500, SSB700, BYB300, etc., which were tested for their Cr (VI) adsorption capacity. The results demonstrated that the removal efficiency of Cr by biochar pyrolyzed from multiple raw materials at different temperatures was variable, and the pH had a great influence on the adsorption capacity and removal efficiency. GHB700 had the best removal efficiency (89.44%) at a pH of 2 of the solution containing Cr (VI). The pseudo second-order kinetics model showed that Cr (VI) adsorption by biochar was chemisorption. The Langmuir model showed that the adsorption capacity of SSB300 was the largest (51.39 mg·g−1), BYB500 was 40.91 mg·g−1, GHB700, CBB700, LSB700, YSB700 were 36.85 mg·g−1, 36.54 mg·g−1, 34.53 mg·g−1 and 32.66 mg·g−1, respectively. This research, for the first time, used a variety of garden wastes to prepare biochar, and explored the corresponding raw material and pyrolysis temperature for the treatment of Cr (VI). It is hoped to provide a theoretical basis for the research and utilization of garden wastes and the production and application of biochar.

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 681
Author(s):  
Monika Sterczyńska ◽  
Marek Zdaniewicz ◽  
Katarzyna Wolny-Koładka

During the production of beer, and especially beer wort, the main wastes are spent grain and hot trub, i.e., the so-called “hot break.” Combined with yeast after fermentation, they represent the most valuable wastes. Hot trub is also one of the most valuable by-products. Studies on the chemical composition of these sediments and their rheological properties as waste products will contribute to their effective disposal and even further use as valuable pharmaceutical and cosmetic raw materials. So far, hot trub has been studied for morphology and particle distribution depending on the raw material composition and beer wort extract. However, there are no preliminary studies on the rheological properties of hot trub and hops. In particular, no attention has yet been paid to the dependence of these properties on the hop variety or different protein sources used. The aim of this study was to examine the effect of different hopping methods on hot trub viscosity and beer wort physicochemical parameters. Additionally, the hop solutions were measured at different temperatures. A microbiological analysis of hop sediments was also performed to determine the post-process survival of selected microorganisms in these wastes. For manufacturers of pumps used in the brewing industry, the most convenient material is that of the lowest viscosity. Low viscosity hot trub can be removed at lower velocities, which reduces costs and simplifies washing and transport. The sediments also had similar equilibrium viscosity values at high shear rates.


Author(s):  
Oleksiy Andryushayev ◽  
Olena Ruban ◽  
Yuliia Maslii ◽  
Inna Rusak

The aim. To determine the intensified method of extraction of phenolic compounds from Acorus calamus leaves and optimal conditions for the process. Materials and methods. In order to develop the optimal intensified method of extraction samples were prepared in different conditions of raw materials-extractant ratio, temperature, time and multiplicity. As a raw materials spectrophotometrically pre-standardized Acorus calamus leaves were used. The extraction was carried out in a hermetically sealed ultrasonic extraction reactor PEX 1 (REUS, Contes, France). As the criteria of extraction efficiency were indicators of dry residue and total amount of flavonoids determined using methods described in State Pharmacopoeia of Ukraine. The amount of flavonoids was determined spectrophotometrically on a certified device Specord 200 (Analytik Jena, Germany). Results. According to our research results it was found that ultrasonic action and addition of surfactant significantly improves the efficiency of the extraction process. The optimal conditions for the process were determined. Experimentally proved that the rational raw material-extractant ratio is 1:15. Comparative study of the extraction process with different temperatures showed that the highest amount of extractives is achieved at temperature 70 °C and 45 min of duration. The optimal extraction multiplicity is 3. Conclusions. As a result of the study, the intensified extraction method for Acorus calamus leaves – re-maceration with ultrasound – was established. The conducted researches allowed to develop the method of extraction, expedient in the conditions of the modern pharmaceutical industry.


2020 ◽  
Vol 15 (4) ◽  
pp. 174-185
Author(s):  
Elif Yılmaz ◽  
Sevda Altaş ◽  
Nildeniz Adman

Metalized yarns are produced by cutting the films in different thicknesses, metalized with aluminum on one or both sides, in a rectangular form in the desired dimensions and wrapping them on bobbins under a certain tension. Textile products made of these yarns are exposed to repetitive washings like most textile products; metal surfaces of metalized yarns are abraded over time, their bright appearance decreases or disappears. It is undesirable because it affects the lifetime of the final product. In the study, laminated films were produced by the lamination technique using different raw materials to produce metalized yarns with the improved fastness and mechanical properties. Laminated films were subjected to repetitive washings at different temperatures, and the effects of washings on the surface appearance of the films, lamination strength, and optical density properties were examined. As a result of the study, it was determined that repetitive washings reduce the lamination strength, the gloss property is affected by raw material type, the sample type, washing temperature, and the number of washing cycles affect the optical density.


2011 ◽  
Vol 287-290 ◽  
pp. 1521-1525
Author(s):  
Kui Xian Wei ◽  
Wen Hui Ma ◽  
Yang Zhou ◽  
Ke Qiang Xie ◽  
Bin Yang ◽  
...  

Vacuum evaporation is usually utilized to remove volatile impurities in metallurgical grade silicon to prepare solar grade silicon by metallurgical routes. Especially phosphorus needs to be removed by vacuum evaporation. And the removal efficiency of impurities strongly influenced the quality and performance of products. In this paper, the removal efficiency of impurities is studied by using different raw material. The results indicated that the content of impurities in raw material had deep effect on the removal efficiency of vacuum evaporation. The high quality product can be obtained by vacuum evaporation only once from raw materials with the lower content of impurities whereas it is not for high content of impurities in raw material. This is due to the vapor-liquid equilibrium in the vacuum furnace. The impurities can be removed effectively by vacuum evaporation many times.


2018 ◽  
Vol 3 ◽  
pp. 56-64
Author(s):  
Iryna Tsykhanovska ◽  
Victoria Evlash ◽  
Alexandr Alexandrov ◽  
Tetiana Lazareva ◽  
Tetiana Yevlash

Today in Ukraine the share of low-quality bakery products is near 20–25 %, because they often don’t correspond to quality standards and sanitary norms, because of being produced of flour with low bakery properties. That is why new raw material sources, functional ingredients and so on are searched for in bread technologies. For using new raw material and food supplement types, it is necessary to know their functional-technological properties (FTP) that allows to prognosticate the behavior of powder-like raw materials and food supplements in food masses at technological processing and storage of ready products. The water-retaining capacity (WRC) is one of main functional-technological parameters of carbohydrate-containing raw materials, because it favors the outcome, structural-mechanical properties and quality characteristics of ready products. The authors introduced “Magnetofood” polyfunctional food supplement for increasing WRC of rye-wheat dough. For grounding the mechanism of forming supramolecular groups in carbohydrate food systems: Magnetofood-polysacharide-water, there was studied the influence of “Magnetofood” food supplement on processes of hydration, swelling and water-retention by rye-wheat starch and rye-wheat flour. It was established, that introduction of “Magnetofood” food supplement in rye-wheat starch and flour in amounts: 0,10; 0,15; 0,20 % to the mass of starch or flour increases swelling and water-retaining capacity (WRC) of starch and flour: swelling in 1,3–1,5 and 1,5–2,25 times, respectively; WRC in 1,10–1,15 and 1,1–1,3 times, respectively. The rational dose of “Magnetofood” food supplement – 0,15 % to the mass of dry raw material was experimentally set. There was studied the influence of “Magnetofood” food supplement on rheological properties of water suspensions of rye-wheat starch and flour at different temperatures and different speeds of shift. It was established, that adding “Magnetofood” in amount 0,15 % favors increasing the effective viscosity of suspensions of experimental samples of starch and flour at temperatures: (23±2) ºС and (40±2) ºС comparing with control samples in average by 29,0 % – for starch and by 22,0 % – for flour at 23 °С and by 16,0 % – for starch and by 10,0 % – for flour at 40 °С. There was studied the dynamics of changing viscosity of colloid solutions of starch and flour, enriched with “Magnetofood” in amount 0,15 % to the mass of dry raw material in the keeping process at different temperatures and shift speed 9 s-1. There was established the increase of viscosity of suspensions of rye-wheat starch and flour in the process of infusion (especially at adding “Magnetofood”) that is connected with continuing hydration and swelling process. It was demonstrated, that the temperature increase of the colloid system from (23±20) ° С to (40±2) °С favors the increase of its viscosity – both at the initial moment and in infusion process during 30 min in average by 20,0–25,0 % at the expanse of the aforesaid processes. Moreover, adding “Magnetofood” accelerates and intensifies the processes of swelling and hydration of experimental samples of rye-wheat starch and flour comparing with control ones. The received experimental data may be used at elaborating the technology of rye-wheat bread, enriched with “Magnetofood” food supplement; and also at elaborating innovative technologies of carbohydrate food systems. The results of this study may be used at elaborating recipes and technologies of carbohydrate-containing food products for increasing their viscosity, water-retaining and stabilizing capacities.


2003 ◽  
Vol 47 (1) ◽  
pp. 83-87
Author(s):  
C. Hung-Lung ◽  
T.-C. Chen ◽  
M.-C. Tsai ◽  
Y.-L. Chen

This study selected biosolids from a petrochemical wastewater treatment plant as the raw material. The sludge was immersed in 0 to 5 mol l-1 of ZnCl2 solutions and pyrolyzed at different temperatures. When the sludge was pyrolyzed for 30 min at temperatures of 400, 500, 600, and 700°C, the corresponding surface area of the biosolid adsorbent was 46, 401, 921, and 727 m2/g, respectively. Pore size analysis indicated that the mesopore (20 to 500 Å) contributed more than the macropore and micropore in the sludge pyrolytic residue. When the benzene influent concentration was 800 ppmv, the adsorption capacity ranged from 59 to 164 mg/g for different biosolid adsorbents. A larger BET surface area and smaller average pore diameter yielded a larger benzene adsorption capacity.


1970 ◽  
Vol 2 (2) ◽  
pp. 8-15
Author(s):  
Heyam Saad Ali ◽  
Junaid Aslam ◽  
Bazigah Rasool ◽  
Saeed Ahemad Khan ◽  
Alaa Agondi

The present study was undertaken to assess and evaluate the effect of two parameters on tablet formulation of Ciprofloxacin: a) particle size of raw material and b) storage conditions of both raw material and finished product. The raw materials were two commercial products, coarse (RM1) and fine (RM2) and locally produced granular form (RM3) prepared from RM2. Three tablet formulations were prepared from the raw materials and designated as F1, F2 and F3. The formulation F1 were prepared from RM1, F2 from RM2 by slugging and F3 from RM3 by direct compression. The raw materials and finished products were then subjected to assessment of the different parameters at the time of production and after storage for three month. The particle size distribution for the raw materials was found to be < 100, 100 – 250 and > 250 μm for RM2, RM1 and RM3, respectively. The moisture uptake at 25°C and 4°C under 75% RH was found to be the highest for the fine powder raw material (RM2), however, the developed granular form RM3 showed the least uptake. Moreover, F2 did not attain 80% dissolution after storage of 3 month. The F1 and F3 formulation passed the dissolution test after storage of 3 month, hence, F3 showed the highest value of dissolution (82%) in 30 minutes. The physicochemical properties of raw materials, storage conditions, and manufacturing techniques were found to exert a great influence over the dissolution behavior of Ciprofloxacin tablet formulations.  Key words: Ciprofloxacin tablets; dissolution behavior; physicochemical properties; storage conditionsDOI: 10.3329/sjps.v2i2.5819Stamford Journal of Pharmaceutical Sciences Vol.2(2) 2009: 8-15


2005 ◽  
Vol 237-240 ◽  
pp. 1121-1128
Author(s):  
Alexander Eder ◽  
Rudolf Königshofer ◽  
Walter Lengauer

A general trend in the field of hardmetals is to achieve a refinement of the microstructures, usually by using sub-micron powders as raw materials. In this study, an alternative route to produce fine structures within the fcc hard phase (W,Ti)(C,N) is investigated: nitrogen indiffusion into (W,Ti)C leads to precipitation of tungsten-rich phases. The mechanism of precipitation (lamella- and labyrinth-like structures with a size of 100-400nm) is thought do be discontinuous segregation on the one hand and spinodal decomposition on the other hand. Hot-pressed (W,Ti)(C,N) samples of different compositions were annealed at different temperatures and C activities in high-pressure N2 atmosphere. The composition and resulting structures of the precipitates were correlated with composition of the (W,Ti)(C,N) phase as well as with annealing conditions. An outlook of a possible application of the observed phenomena to powder particles is given to achieve micron-sized particles of this hard phase with nanometer-sized structures as a raw material for fine-grained hardmetals.


2015 ◽  
Vol 1117 ◽  
pp. 152-155
Author(s):  
Liga Grase ◽  
Gundars Mezinskis ◽  
Inta Vitina

A variety of industrial minerals, such as kaolinite, feldspars, and etc., have been used as solid raw materials in the geopolymerization technology. The illite-containing raw material in this study was obtained by the use of sedimentation method. Clay and dust fractions was subjected to the treatment with NaOH alkaline solution and afterwards treated at different temperatures. Results obtained by X-ray diffraction, Scanning electron microscopy, nitrogen adsorption method confirmed the usability of Liepas deposit homogenized gray and red clays for possible realization of geopolymer method.


2021 ◽  
Vol 13 (6) ◽  
pp. 3050
Author(s):  
Mariana Mariana ◽  
Farid Mulana ◽  
Lisa Juniar ◽  
Dinda Fathira ◽  
Risna Safitri ◽  
...  

This study reports the development of bio-based adsorbent by utilizing coffee endocarp (CE) waste as a raw material for lead (Pb) removal from liquid wastewater. The effect of NaOH and HCl as activation precursors on the characteristics and performance of the resulting adsorbents was investigated. The prepared adsorbents were characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray fluorescence (XRF) and Surface Area Analyzer (SAA). The characterization results confirm the positive role of the activation by either NaOH or HCl in enhancing the surface properties of the resulting adsorbents. The chemical activations removed most of impurities leading to smoother surface, pore size enlargement and enhanced surface area to pore volume ratio, which result in an enhanced adsorption capacity and Pb removal efficiency. The raw adsorbent shows 57.7% of Pb removal efficiency and sorption capacity of 174.4 mg/g. On the other hand, after the chemical treatment using HCl and NaOH, the Pb removal efficiencies increased up to 63.9% and 89.86%, with adsorption capacity of 193 and 271.58 mg/g, respectively. Though both activated sorbents demonstrate better adsorption performance compared to the non-activated CE, overall results reveal that the NaOH-activated sorbent offers better characteristic and performance than the HCl-activated sorbent.


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