scholarly journals Production of a bioflocculant by using activated sludge and its application in Pb(II) removal from aqueous solution

2020 ◽  
Vol 18 (1) ◽  
pp. 333-338 ◽  
Author(s):  
Zibo Yan ◽  
Li Peng ◽  
Miao Deng ◽  
Jinhui Lin
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Activated Sludge ◽  
Raw Materials ◽  
Fermentation Broth ◽  
Optimal Conditions ◽  
Protein Backbone ◽  
Pre Treatment

AbstractIn this study, the characteristics of a bioflocculant produced by using activated sludge as raw materials were investigated. The performance of this bioflocculant in the removal of Pb(II) from aqueous solution and the corresponding mechanisms were determined as well. After cultivating a bioflocculant-producing strain in an alkaline thermal pre-treatment sludge for 60 h, approximately 4.45 g of bioflocculant containing a protein backbone was harvested from 1 L of fermentation broth. This bioflocculant can remove 98.5% of Pb(II) from aqueous solutions under optimal conditions, which include a bioflocculant dosage of 6 mg/L and a CaCl2 concentration of 70 mg/L at a pH of 6.5.

Effect of Photodegradated Quinoline Aqueous Solutions on Enzyme Activities in Activated Sludge

2011 ◽  
Vol 374-377 ◽  
pp. 1025-1030
Author(s):  
Sui Yi Zhu ◽  
Ming Xin Huo ◽  
Kang Zhou ◽  
Jian Wang ◽  
Xia Yang
Keyword(s):  
Aqueous Solution ◽  
Enzyme Activity ◽  
Reaction Time ◽  
Aqueous Solutions ◽  
Activated Sludge ◽  
Enzyme Activities ◽  
Urease Activity ◽  
Glucose Medium ◽  
Pretreatment Time ◽  
Optimal Reaction

Synthesized wastewater containing quinoline photocatalytic oxidized at 0, 30 and 60 min respectively were applied in flask cultivation of activated sludge to evaluate the changes of activities of dehydrogenase, protease and urease in activated sludge with reference is glucose. The experiment results showed that quinoline aqueous solution after photodegradation of 60 min appeared to inconspicuous influence on the activities of dehydrogenase and protease, while after photodegradation of 0 min or 30 min the effluents presented obviously inhabitation. However, the urease activity cultured in all photodegradated quinoline solutions was higher than that in glucose medium due to the effect of C-N bond induction. Under the tested conditions, the optimal pretreatment time of photocatalysis system was observed at 60 minutes, which suggested that enzyme activity in activated sludge was benefited to investigate the biodegradability of wastewater for evaluating the optimal reaction time for photocatalytic pretreatment system.

scholarly journals STUDY OF VISCOSITY OF AQUEOUS SOLUTIONS OF NATURAL POLYSACCHARIDES

2016 ◽  
pp. 11-19 ◽  
Author(s):  
Lyudmila Asyakina ◽  
Lyudmila Asyakina ◽  
Lyubov Dyshlyuk ◽  
Lyubov Dyshlyuk
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Biodegradable Polymers ◽  
Raw Materials ◽  
Hydroxypropyl Methylcellulose ◽  
Methyl Cellulose ◽  
Preparation Temperature ◽  
Low Concentrations ◽  
Wide Range ◽  
Solution Preparation

One of the steps of synthesis of biodegradable polymers is preparation of an aqueous solution of raw materials. Formulation of biodegradable films with optimum characteristics requires to undertake a separate rheological study of each aqueous solution. An essential parameter in this step is a uniform thickness, which is achieved by means of specified viscosity parameters. Viscosity of solutions depends on many parameters, among which are composition and concentration of components in a solution, solution preparation temperature, pH of the finished medium, and presence of free ions. This article describes studies and results on study of viscosity parameters of aqueous solutions of natural polysaccharides: agar-agar, hydroxypropyl methyl cellulose and carrageenan. For aqueous solutions of carrageenan and hydroxypropyl methylcellulose, viscosity was measured at 25°C. In addition, viscosity parameters were measured for 1.5% hhydroxypropyl methylcellulose solutions at 40°C and 60°C. Depending on the gel formation temperature, viscosity of agar-agar solutions was measured at 50°C or 70°C. According to the results of experiments, it was found that viscosity of 1.0-1.5% hydroxypropyl methylcellulose aqueous solutions is in the range of 8.0-80.0 cP. Heating to 100°C at pH 6 results in irreversible destruction of hydroxypropylmethylcellulose molecules. Aqueous solutions of agar-agar are similar to hydroxypropyl methylcellulose solutions but agar-agar is able to gelate at sufficiently low concentrations (from 0.5%). Viscosity of 3.0- 5.0% carrageenan aqueous solutions varies within a wide range: 1.5-1400.0 cP. Thus, rheological properties allow to adjust viscosity of the process mixture in the production of biodegradable polymers in the desired range and in different directions.

scholarly journals Mathematical planning of experiments to optimize the extraction of extractive substances from needles of Pinus sylvestris

2021 ◽  
pp. 221-237
Author(s):  
Н.Н. Никонова ◽  
Т.В. Хуршкайнен ◽  
А.В. Кучин
Keyword(s):  
Aqueous Solution ◽  
Pinus Sylvestris ◽  
Raw Materials ◽  
Biologically Active ◽  
Raw Material ◽  
Optimal Conditions ◽  
Traditional Methods ◽  
Emulsion Method ◽  
Extractive Substances

Представленная работа посвящена определению оптимальных условий выделения суммы экстрактивных веществ из древесной зелени сосны методом эмульсионной экстракции. Экологически безопасный эмульсионный метод экстракции растительного сырья в водно-щелочной среде не уступает традиционным методам извлечения низкомолекулярных компонентов и позволяет эффективно выделять как гидрофильные, так и гидрофобные соединения. Объектом данного исследования являются отходы лесозаготовок - древесная зелень сосны обыкновенной - источник природных биологически активных веществ, имеющих практическое применение. Определение оптимальных условий экстракции ДЗ сосны эмульсионным способом в данном исследовании было проведено методом поверхности отклика с использованием ротатабельного композиционного униформ-плана второго порядка, который включал 13 экспериментальных опытов со всеми возможными комбинациями уровней двух изучаемых факторов: концентрации водного раствора NaOH и гидромодуля : отношения объема щелочного раствора к массе сырья. Анализ результатов исследований показал, что в заданном интервале варьирования факторов наибольшее влияние на выход экстрактивных веществ оказывает гидромодуль, при увеличении которого до 10:1 выход увеличивается, далее устанавливается равновесная концентрация в системе «сырье – экстрагент». Установлены оптимальные условия эмульсионной экстракции древесной зелени сосны: концентрация водного раствора NaOH - 5%, гидромодуль - 10:1. В оптимальных условиях выход экстрактивных веществ составил 9,84% от массы сухого сырья, что сопоставимо с результатами, полученными традиционными методами экстракции сырья органическими растворителями. The presented work is devoted to the determination of the optimal conditions for the isolation of the sum of extractives from wood greenery (WG) of Pinus sylvestris by the method of emulsion extraction. The environmentally friendly emulsion method for the extraction of plant raw materials in an aqueous-alkaline medium is not inferior to the traditional methods of extracting low molecular weight components and makes it possible to effectively isolate both hydrophilic and hydrophobic compounds. The object of this study is logging waste – woody greenery of Pinus sylvestris – a source of natural biologically active substances that have practical application. The determination of the optimal conditions for the extraction of WG pine by the emulsion method in this study was carried out by the response surface method using a rotatable compositional uniform plan of the second order, which included 13 experiments with all possible combinations of the levels of two studied factors: the concentration of an aqueous solution of NaOH and the hydromodule – ratio of the volume of water-alkaline solution to the mass of raw materials. Analysis of the research results showed that in a given range of variation of factors, the greatest influence on the yield of extractive substances is exerted by the hydromodule, with an increase of which to 10: 1, the yield increases, then an equilibrium concentration is established in the "raw material – extractant" system. The optimal conditions for emulsion extraction of WG pine were established: concentration of an aqueous solution of NaOH – 5%, hydromodule 10:1. Under optimal conditions, the yield of extractive substances was 9,84% of the weight of the dry raw material, which is comparable with the results obtained by traditional methods of raw material extraction with organic solvents.

scholarly journals Removal of Reactive Blue 19 Dye Using a Combined Sonochemical and Modified Pistachio Shell Adsorption Processes from Aqueous Solutions

2018 ◽  
Author(s):  
Somayeh Rahdar ◽  
Leila Shikh ◽  
Shahin Ahmadi
Keyword(s):  
Aqueous Solution ◽  
Experimental Study ◽  
Aqueous Solutions ◽  
Polluted Water ◽  
Optimal Conditions ◽  
Combined Process ◽  
Pistachio Shell ◽  
Reactive Blue 19 ◽  
Adsorption Processes ◽  
Sonochemical Oxidation

Background and purpose: Reactive Blue 19(RB19) dye is one of the major dangers to human health and environment. Hence, the removal of these compounds from polluted water has been considered. This study was an attempt to investigate the removal of RB19 dye from aqueous solution in the presence of modified pistachio shell.Materials and Methods: In this experimental study, the treatability of water polluted with RB19dye was investigated by using sonochemical oxidation in a reactor. The sample with the desired concentrations of dye (10-80 mg/L) at pH 2-11 was prepared, then the required concentrations of MPS (0.1– 1.2 g/L) was flowed into the reactor intermittently.Results: The results of the current study showed that 40.26% of the dye was removed in the presence of MPS after 20 min at pH 2, MPS dose 0.7 g/L, and concentration of 20 mg/L.Conclusion: The findings showed that the combined process of ultrasonic and adsorption in the presence of MPS at optimal conditions of operation can be used as an acceptable option in the removal of dye from waters.

Infrared Spectroscopy of Aqueous Antibiotic Solutions

1984 ◽  
Vol 38 (1) ◽  
pp. 32-35 ◽  
Author(s):  
James S. Wong ◽  
Alan J. Rein ◽  
Donald Wilks ◽  
Paul Wilks
Keyword(s):  
Aqueous Solution ◽  
Infrared Spectroscopy ◽  
Aqueous Solutions ◽  
Fermentation Broth ◽  
Analytical Sensitivity ◽  
Beta Lactam ◽  
Lactam Carbonyl ◽  
Ft Ir ◽  
Internal Reflectance ◽  
Ft Ir Spectroscopy

Infrared spectra of aqueous antibiotic solutions were obtained using a new Liquid Analyzer accessory in a Fourier transform infrared (FT-IR) spectrometer. Based on a cylindrical internal reflectance element, the Liquid Analyzer accessory provides a sufficiently short (∼0.015 mm) effective pathlength for infrared spectroscopy of aqueous solutions from 3200 to 800 cm−1, Spectra of aqueous solutions of penicillin VK, sodium oxacillin and sodium methicillin are shown. By measuring the absorbante of the beta-lactam carbonyl band, FT-IR spectroscopy with the accessory exhibits analytical sensitivity to less than 0.1% concentration by weight of antibiotic both in aqueous solution and in an actual fermentation broth.

PEMANFAATAN LIMBAH KULIT DURIAN (Durio zibethinus) DAN KULIT CEMPEDAK (Artocarpus integer) SEBAGAI EDIBLE FILM

2014 ◽  
Vol 6 (1) ◽  
pp. 27 ◽  
Author(s):  
Desi Mustika Amaliyah
Keyword(s):  
Tensile Strength ◽  
Food Packaging ◽  
Raw Materials ◽  
Edible Films ◽  
Edible Film ◽  
Durio Zibethinus ◽  
Yield Result ◽  
Pre Treatment

Durian (Durio zibethinus) and cempedak (Artocarpus integer) peels waste are not used by the society. The research aim is to extract pectin from durian and cempedak peels and to formulate the pectin into edible films for food packaging. The research stages were first pre-treatment of durian and cempedak peels, pectin extraction, pectin drying, and  pectin application as edible films with concentration of 0%, 5%, and 15%. Based on this research it was concluded that pectin can be extracted from durian and cempedak peels with yield result of 27.97 % and 55.58 %, respectively. Edible film obtained has  similar characteristics between raw materials cempedak and durian peels. The higher concentration of cempedak peel  pectin increased the thickness, but decreased the tensile strength and elongation at a concentration of 15%. While in edible films from durian peel pectin, the higher concentration of pectin decreased the thickness of edible film on pectin concentration of 15%, lowered tensile strength and raised the edible film elongation.Keywords: waste, durian, cempedak, pectin extraction, edible film

BIOSORPTION OF ZINC FROM AQUEOUS SOLUTIONS USING DRIED ACTIVATED SLUDGE

2012 ◽  
Vol 11 (4) ◽  
pp. 857-865 ◽  
Author(s):  
Ghasem Najafpour Darzi ◽  
Reza Katal ◽  
Hossein Zare ◽  
Hooman Taher Rahmati
Keyword(s):  
Aqueous Solutions ◽  
Activated Sludge

Effect of thermal history of aqueous solutions of KCl on the metastable zone width

1984 ◽  
Vol 49 (3) ◽  
pp. 559-569 ◽  
Author(s):  
Jaroslav Nývlt
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Thermal History ◽  
Equilibrium Solubility ◽  
Metastable Zone Width ◽  
Zone Width ◽  
Preceding Experiment ◽  
History Of ◽  
Metastable Zone ◽  
The Given

The metastable zone width of an aqueous solution of KCI was measured as a function of the time and temperature of overheating above the equilibrium solubility temperature. It has been found that when the experiments follow close upon one another, the parameters of the preceding experiment affect the results of the experiment to follow.The results are interpreted in terms of hypotheses advanced in the literature to account for the effect of thermal history of solution. The plausibility and applicability of these hypotheses are assessed for the given cause of aqueous solution of a well soluble electrolyte.

scholarly journals I. Thermo-electric behaviour of aqueous solutions with mercurial electrodes

1879 ◽  
Vol 29 (196-199) ◽  
pp. 472-482 ◽  
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Internal Diameter ◽  
Thermo Electric ◽  
Thin Glass ◽  
Mercury Surface

In order to investigate this subject, I devised and constructed the following apparatus :—A and B are two thin glass basins, 81 millims. internal diameter (= 5,153 sq. millims. of mercury surface), and 6·0 centims. deep; each containing a layer of mercury about 1·0 centim. deep, covered by a layer, about 3 centims. deep, of the aqueous solution to be examined.

Sign in / Sign up

Export Citation Format

Share Document