scholarly journals A Comparative Study of Copper, Zinc and Aluminium as Electrodes in the Preparation of Starch-based Polyelectrolyte

Author(s):  
J. O. Jeje ◽  
K. T. Oladepo

Alum (Al2 (SO4)3. 18H2O) has been the coagulant mostly used in the water treatment process. Alum imported into the country gets stuck at the port because of the congestion of the port. When alum is used to coagulate water, it depresses the pH of the water, thus, requiring a pH booster. Because of the high dependence on alum, alternative coagulants produced with local raw materials will be of great advantage. A starch-based polyelectrolyte was prepared by dispersing 3 g of cassava starch and 10 g of heaping teaspoon of high-test granular calcium hypochlorite (commercially available as HTH) in 100 ml distilled water; making it up to a litre solution with hot distilled water (temperature 80ºC – 100ºC) and electrolysing by means of stabilized power supply using aluminium rods as electrodes to produce polyelectrolyte A. Copper rods and zinc rods were similarly used to polyelectrolyte B and polyelectrolyte C respectively. To test the effect(s) and interaction of the charging variables, i.e. separating distance, power supply and time of charging, a three-factor experiment (23 factorial designs) was carried out. The variables were operated at High Level (+) and Low Level (-). The analysis indicates that the power of charging has the most significant effect on the coagulation characteristics of the starch-based polyelectrolyte. Polyelectrolytes A and C were tested with raw water drawn from Opa dam and were found to be effective water coagulants. Polyelectrolyte B on the other hand, adds to the turbidity of the raw water with which it was tested. Polyelectrolyte A was found to be as effective as Alum at natural water condition (pH 7) causing better than 88% turbidity removal with the dosage of 65 mg/l.

2012 ◽  
Vol 209-211 ◽  
pp. 1892-1895
Author(s):  
Hong Zhuan Zhang ◽  
Zhen Jia Zhang ◽  
Cui Yi Zhang ◽  
Yang Lu

The comparative pilot experiments were conducted by using two medium-scale test equipments. All the raw water was taken from upstream of Huangpu River in Shanghai, China. The turbidity is studied for the output water of pre-ozonation process compared with that of pre-chlorination process. It was found that the effects of turbidity removal by pre-ozonation process were significantly better than that of pre-chlorination process in both the sedimentation tanks effluent and filters effluent.


2017 ◽  
Vol 43 (5) ◽  
pp. 2465
Author(s):  
P. Lampropoulou ◽  
Th. Tzevelekou ◽  
D. Papamantellos ◽  
V Stivanakis ◽  
S. Papaefthymiou

The need to restore the relationship of mankind with the environment led to the designation of measures, terms and processes worldwide for the prevention or reduction to the highest possible degree of the negative consequences to the environment ensuring a high level of protection of human health and the environment. It is general ascertainment that there is a big lack of objective information in Greece regarding the possibilities of modern science and technology for the treatment of Solid Industrial Wastes (SIW), Municipal Solid Wastes (MSW) and biological Sewage Treatment Plants (STP) products safely for the public health and the environment. In Greece the most significant sources of SIW are the big exploitations of “Mineral Ores”.On the contrary, the cement industries provide an important way out for the consumption of SIW like fly ash, red mud, et. A big percentage of the total amount of produced alloys of iron, copper, zinc and aluminium do not use “Mineral Resources” as raw materials but recycle scrap metals. At the end, the successful results of pyrometallurgical production of final products by SIW as well as the results of the production of new friendly to the environment and high technology refractory materials are given in this work.


Water ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 57 ◽  
Author(s):  
Abderrezzaq Benalia ◽  
Kerroum Derbal ◽  
Antonio Panico ◽  
Francesco Pirozzi

In this study, the use of acorn leaves as a natural coagulant to reduce raw water turbidity and globally improve drinking water quality was investigated. The raw water was collected from a drinking water treatment plant located in Mila (Algeria) with an initial turbidity of 13.0 ± 0.1 NTU. To obtain acorn leaf powder as a coagulant, the acorn leaves were previously cleaned, washed with tap water, dried, ground and then finely sieved. To improve the coagulant activity and, consequently, the turbidity removal efficiency, the fine powder was also preliminarily treated with different solvents, as follows, in order to extract the coagulant agent: (i) distilled water; (ii) solutions of NaCl (0.25; 0.5 and 1 M); (iii) solutions of NaOH (0.025; 0.05 and 0.1 M); and (iv) solutions of HCl (0.025; 0.05 and 0.1 M). Standard Jar Test assays were conducted to evaluate the performance of the coagulant in the different considered operational conditions. Results of the study indicated that at low turbidity (e.g., 13.0 ± 0.1 NTU), the raw acorn leaf powder and those treated with distilled water (DW) were able to decrease the turbidity to 3.69 ± 0.06 and 1.97 ± 0.03 NTU, respectively. The use of sodium chloride solution (AC-NaCl) at 0.5 M resulted in a high turbidity removal efficiency (91.07%) compared to solutions with different concentrations (0.25 and 1 M). Concerning solutions of sodium hydroxide (AC-NaOH) and hydrogen chloride (AC-HCl), the lowest final turbidities of 1.83 ± 0.13 and 0.92 ± 0.02 NTU were obtained when the concentrations of the solutions were set at 0.05 and 0.1 M, respectively. Finally, in this study, other water quality parameters, such as total alkalinity hardness, pH, electrical conductivity and organic matters content, were measured to assess the coagulant performance on drinking water treatment.


2013 ◽  
Vol 594-595 ◽  
pp. 226-230 ◽  
Author(s):  
Muhammad Ridwan Fahmi ◽  
Nasrul Hamidin ◽  
Che Zulzikrami Azner Abidin ◽  
M. Ali Umi Fazara ◽  
M.D. Irfan Hatim

The objective of this study is to evaluate the performance of turbidity removal in water by using Okra (Abelmoschus esculentus) as natural coagulant. The coagulation active agent in various Okra sections was extracted with distilled water and NaCl 1.0 M solutions. Synthetic water containing kaolin with turbidity of 55 NTU was used as water source in this study. The result shows that Okra seed that extracted both with distilled water and NaCl 1.0 N solution has the potential advantage as natural coagulant for turbidity removal in comparison with other sections of the plant. However, the seed is not economically feasible to be used as coagulant. The dried Okras leaf that commonly considered as waste material could be proposed as an alternative coagulant in water treatment process, due to its similarity in coagulation behaviour with Okras seed. FTIR analysis on leaf shows that chemical functional groups in protein were significantly removed after extraction with distilled water and NaCl 1.0 N solution. The result indicated a strong correlation between the protein content and turbidity removal efficiency, which eventually suggest that the protein in Okra could potentially be an active agent in coagulation process.


Author(s):  
H.A. Cohen ◽  
W. Chiu ◽  
J. Hosoda

GP 32 (molecular weight 35000) is a T4 bacteriophage protein that destabilizes the DNA helix. The fragment GP32*I (77% of the total weight), which destabilizes helices better than does the parent molecule, crystallizes as platelets thin enough for electron diffraction and electron imaging. In this paper we discuss the structure of this protein as revealed in images reconstructed from stained and unstained crystals.Crystals were prepared as previously described. Crystals for electron microscopy were pelleted from the buffer suspension, washed in distilled water, and resuspended in 1% glucose. Two lambda droplets were placed on grids over freshly evaporated carbon, allowed to sit for five minutes, and then were drained. Stained crystals were prepared the same way, except that prior to draining the droplet, two lambda of aqueous 1% uranyl acetate solution were applied for 20 seconds. Micrographs were produced using less than 2 e/Å2 for unstained crystals or less than 8 e/Å2 for stained crystals.


Author(s):  
Travis Eiles ◽  
Patrick Pardy

Abstract This paper demonstrates a breakthrough method of visible laser probing (VLP), including an optimized 577 nm laser microscope, visible-sensitive detector, and an ultimate-resolution gallium phosphide-based solid immersion lens on the 10 nm node, showing a 110 nm resolution. This is 2x better than what is achieved with the standard suite of probing systems using typical infrared (IR) wavelengths today. Since VLP provides a spot diameter reduction of 0.5x over IR methods, it is reasonable, based simply on geometry, to project that VLP using the 577 nm laser will meet the industry needs for laser probing for both the 10 nm and 7 nm process nodes. Based on its high level of optimization, including high resolution and specialized solid immersion lens, it is highly likely that this VLP technology will be one of the last optically-based fault isolation methods successfully used.


Author(s):  
Oksana Bitlian ◽  
Oksana Kravchenko ◽  
Tetiana Kodak ◽  
Andrii Onyshchenko ◽  
Tetiana Konks

The analysis of literature sources shows that the type and material from which the packaging is made has an important place in the system of factors which influence on the storage of feed products and also prevents reducing the quality of raw materials and finished products. Therefore, the purpose of our research is the technological justification of changing the quality indexes of premix samples with salts of trace elements of different chemical nature in the process of storage. For the solution of the tasks, common zootechnical and statistical methods of the research were used. The use of premixes in feeding pigs is based on the fact that they should be used taking into account the biogeochemical properties of the region for which they are calculated. Foods depending on regional properties have a special biochemical composition and excess or lack of individual substances should be offset by the composition of premix. Ignoring this provision necessarily leads to the inappropriate use of BAR, the misbalance of the diet in relation to the physiological needs and inefficiency of the industry. In turn, it requires the purchase and conservation of products for the period of use. Various chemical structures and structures of BAR during the storage process react differently and change qualitative indexes, which leads to a decrease in the productive activity of active substances. It was determined that the humidity of premixes varied within the limits of 12.0-13.0 %, which exceeded the normative, but was not critical, the highest acidity had premix with sulfuric acid salts (6.9 units), the least - premix with lysates (5.7 unit). According to the results of the study, positive qualitative responses were found for the presence of vitamins A, D and B2, macro- and micronutrients: potassium, magnesium, copper, zinc, cobalt, iodine. The above facts of changes in the properties of premixes in the process of storage must be taken into account when providing technological bases for feeding pigs in order to obtain high gains and the quality of manufactured products. Key words: premix, micro-and macro elements, combined fodders, fodder mixes, chelating compounds, feeding, using, pigs' livestock.


2014 ◽  
Vol 07 (06) ◽  
pp. 1450035
Author(s):  
Lihui Yin ◽  
Xuebo Zhang ◽  
Xiaodong Li ◽  
Shaohong Jin

Samples of preparations contaminated by diethylene glycol (DEG), diethylene glycol raw materials and laboratory prepared solutions were measured to get NIR spectra. Then the identification models were developed using the collected spectra and the spectra of distilled water, propylene glycol and the preparations without diethylene glycol. Besides, the quantification model was also established for determining the concentration of diethylene glycol in the preparations. Validation results show the identification and quantification models have ideal prediction performance. The emergency NIR models are rapid, easy to use and accurate, and can be implemented for identifying diethylene glycol raw material, screening the preparations contaminated by diethylene glycol in the markets and analyzing the concentrations of DEG.


2013 ◽  
Vol 641-642 ◽  
pp. 574-577 ◽  
Author(s):  
Ying Tao Li ◽  
Ling Zhou ◽  
Mao Jiang ◽  
Yu Zhang ◽  
Jun Shao

In this paper, the mechanical property experiments of concrete based on the seawater and sea sand have been carried in different raw materials preparation and different conservation environments. The results show that the early strength and late strength of concrete based on seawater and sea sand are better than concrete based on freshwater and sand. There is no significant strength decreased for concrete based on seawater and sea sand under accelerated alternating wet and dry conditions. For concrete based on seawater and sea sand mixed with admixture, the downward trend of late strength is significantly delayed, the late strength of concrete based on the seawater and sea sand mixed with slag gets the most obvious growth trend, while the late strength of seawater and sea sand concrete mixed with fly ash gets the largest increment.


2015 ◽  
Vol 114 (6) ◽  
pp. 3351-3358 ◽  
Author(s):  
Stefania de Vito ◽  
Marine Lunven ◽  
Clémence Bourlon ◽  
Christophe Duret ◽  
Patrick Cavanagh ◽  
...  

When we look at bars flashed against a moving background, we see them displaced in the direction of the upcoming motion (flash-grab illusion). It is still debated whether these motion-induced position shifts are low-level, reflexive consequences of stimulus motion or high-level compensation engaged only when the stimulus is tracked with attention. To investigate whether attention is a causal factor for this striking illusory position shift, we evaluated the flash-grab illusion in six patients with damaged attentional networks in the right hemisphere and signs of left visual neglect and six age-matched controls. With stimuli in the top, right, and bottom visual fields, neglect patients experienced the same amount of illusion as controls. However, patients showed no significant shift when the test was presented in their left hemifield, despite having equally precise judgments. Thus, paradoxically, neglect patients perceived the position of the flash more veridically in their neglected hemifield. These results suggest that impaired attentional processes can reduce the interaction between a moving background and a superimposed stationary flash, and indicate that attention is a critical factor in generating the illusory motion-induced shifts of location.


Sign in / Sign up

Export Citation Format

Share Document