scholarly journals Color ruler to confirm spectrophotometer results for nitro compound content in acidic wastewater from TNT processes

2021 ◽  
Author(s):  
Ahmed Mahjoub ◽  
Osman Eltayeb
Keyword(s):  
Nitro Compound ◽  
Colorimetric Analysis ◽  
High Concentration ◽  
Reference Procedure ◽  
Low Concentration ◽  
Single Beam ◽  
Sample Concentration ◽  
Acidic Wastewater ◽  
Analytical Reference

This study aimed to find an additional analytical reference procedure to verify the accuracy of single beam Spectrophotometer results that used to determine the concentration of nitro compound pollutants such as TNT, DNT, and MNT (Tri Nitro Toluene, Di Nitro toluene, and Mono Nitro Toluene respectively) in treated acidic wastewater generated from TNT manufacturing. This procedure was tested and confirmed to be a reference for a single-beam spectrophotometer. In this study 10 samples with known concentrations were taken and prepared for colorimetric analysis, the concentrations gradient from 10mg/L up to 60mg/L to make a ruler with gradient color, this ruler was suitable for high concentration samples but to specify the low concentration samples the procedure depended on adding a known concentration to the unknown concentration sample then this added concentration transferred the samples from unspecified color to specified color on the ruler consisted by known concentration mentioned above, the concentration of unknown concentration samples were specified by taking the concentration corresponding to the ruler color a subtracting the value of added concentration and the value of the remains was sample concentration. This study proved the reliability of this procedure to confirm single-beam spectrophotometer results, determining low concentration value of unknown concentration sample of TNT acidic wastewater, and then it can be used as a substituent of spectrophotometer in the event of malfunctions.

Study on Switch from High-concentration to Low-concentration Tacalcitol during Concomitant Use of Bath-PUVA Therapy

2007 ◽  
Vol 69 (6) ◽  
pp. 660-664
Author(s):  
Maki IWAKIRI ◽  
Noriko YASAKA ◽  
Kotaro ITO ◽  
Yuichi YOSHIDA ◽  
Yumiko KUBOTA ◽  
...  
Keyword(s):  
Puva Therapy ◽  
High Concentration ◽  
Low Concentration

ASSESSMENT OF HEAVY METAL CONCENTRATION IN COCONUT WATER

1970 ◽  
pp. 07-10
Author(s):  
MdDidarul Islam, Ashiqur Rahaman, Aboni Afrose
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Heavy Metal Concentration ◽  
Coconut Water ◽  
Toxic Heavy Metals ◽  
High Concentration ◽  
Toxic Heavy Metal ◽  
Low Concentration ◽  
Wet Ashing ◽  
Aas Method

This study was based on determining concentration of essential and toxic heavy metal in coconut water available at a local Hazaribagh area in Dhaka, Bangladesh. All essential minerals, if present in the drinking water at high concentration or very low concentration, it has negative actions. In this study, fifteen samples and eight heavy metals were analyzed by Atomic Absorption Spectroscopy (AAS) method which was followed by wet ashing digestion method. The concentration obtained in mg/l were in the range of 0.3 to 1.5, 7.77 to 21.2, 0 to 0.71, 0 to 0.9, 0 to 0.2, 0.9 to 17.3, 0.1 to 0.9, 0 to 0.9 and 0 to 0.7 for Fe, Ni, Cu, Cd, Cr, Zn, Pb and Se respectively. From this data it was concluded that any toxic heavy metals like Cd, Cr, Pb and Ni exceed their toxicity level and some essential nutrients were in low concentration in those samples. 

Assessment of micro and macro nutrients in poultry feeds available in Dhaka city, Bangladesh.

2017 ◽  
Vol 1 ◽  
pp. 264
Author(s):  
Md Didarul Islam ◽  
Ashiqur Rahaman ◽  
Fahmida Jannat
Keyword(s):  
Heavy Metals ◽  
Adverse Effect ◽  
The Other ◽  
Nutrient Level ◽  
Dhaka City ◽  
Toxic Heavy Metals ◽  
High Concentration ◽  
Low Concentration ◽  
Feed Formulation ◽  
Macro Nutrients

This study was based on to determine the concentration of macro and micro nutrients as well as toxic and nontoxic heavy metals present in the chicken feed available in Dhaka city of Bangladesh. All macro nutrients, if present in the feed at high concentration have some adverse effect, at the same time if this nutrient present in the feed at low concentration this have some adverse effect too. So that this nutrient level should be maintained at a marginal level. On the other side toxic heavy metals if present in the feed at very low concentration those can contaminate the total environment of the ecosystem. In this study six brand samples (starter, grower, finisher and layer) which was collected from different renowned chicken feed formulation industry in Bangladesh. Those samples were prepared for analysis by wet ashing and then metals were determined by Atomic Absorption Spectroscopy. It was found that 27.7 to 68.4, 57.3 to 121.9, 0.21 to 4.1, 0.32 to 2.1, 0.11 to 1.58, 0.28 to 2.11 and 0.28 to 1.78 for zinc, iron, copper, mercury, cadmium, nickel and cobalt respectively. It was found that essential macro and micro nutrients were present in the feed in low concentration on the other side mercury was present in high concentration in the feed samples.

scholarly journals Start-up Strategies for Anaerobic Ammonia Oxidation (Anammox) in In-Situ Nitrogen Removal from Polluted Groundwater in Rare Earth Mining Areas

2021 ◽  
Vol 13 (8) ◽  
pp. 4591
Author(s):  
Shuanglei Huang ◽  
Daishe Wu
Keyword(s):  
Rare Earth ◽  
Low Temperature ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Ex Situ ◽  
High Concentration ◽  
Low Concentration ◽  
Start Up ◽  
Anammox Activity

The tremendous input of ammonium and rare earth element (REE) ions released by the enormous consumption of (NH4)2SO4 in in situ leaching for ion-adsorption RE mining caused serious ground and surface water contamination. Anaerobic ammonium oxidation (anammox) was a sustainable in situ technology that can reduce this nitrogen pollution. In this research, in situ, semi in situ, and ex situ method of inoculation that included low-concentration (0.02 mg·L−1) and high-concentration (0.10 mg·L−1) lanthanum (La)(III) were adopted to explore effective start-up strategies for starting up anammox reactors seeded with activated sludge and anammox sludge. The reactors were refrigerated for 30 days at 4 °C to investigate the effects of La(III) during a period of low-temperature. The results showed that the in situ and semi in situ enrichment strategies with the addition of La(III) at a low-concentration La(III) addition (0.02 mg·L−1) reduced the length of time required to reactivate the sludge until it reached a state of stable anammox activity and high nitrogen removal efficiency by 60–71 days. The addition of La(III) promoted the formation of sludge floc with a compact structure that enabled it to resist the adverse effects of low temperature and so to maintain a high abundance of AnAOB and microbacterial community diversity of sludge during refrigeration period. The addition of La(III) at a high concentration caused the cellular percentage of AnAOB to decrease from 54.60 ± 6.19% to 17.35 ± 6.69% during the enrichment and reduced nitrogen removal efficiency to an unrecoverable level to post-refrigeration.

scholarly journals Phytoremediation Potential of Vetiver System Technology for Improving the Quality of Palm Oil Mill Effluent

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Negisa Darajeh ◽  
Azni Idris ◽  
Paul Truong ◽  
Astimar Abdul Aziz ◽  
Rosenani Abu Bakar ◽  
...  
Keyword(s):  
Palm Oil ◽  
Oxygen Demand ◽  
Raw Material ◽  
Biofuel Production ◽  
Palm Oil Mill Effluent ◽  
System Technology ◽  
High Concentration ◽  
Low Concentration ◽  
Control Sets ◽  
Palm Oil Mill

Palm oil mill effluent (POME), a pollutant produced by the palm oil industry, was treated by the Vetiver system technology (VST). This technology was applied for the first time to treat POME in order to decrease biochemical oxygen demand (BOD) and chemical oxygen demand (COD). In this study, two different concentrations of POME (low and high) were treated with Vetiver plants for 2 weeks. The results showed that Vetiver was able to reduce the BOD up to 90% in low concentration POME and 60% in high concentration POME, while control sets (without plant) only was able to reduce 15% of BOD. The COD reduction was 94% in low concentration POME and 39% in high concentration POME, while control just shows reduction of 12%. Morphologically, maximum root and shoot lengths were 70 cm, the number of tillers and leaves was 344 and 86, and biomass production was 4.1 kg m−2. These results showed that VST was effective in reducing BOD and COD in POME. The treatment in low concentration was superior to the high concentration. Furthermore, biomass of plant can be considered as a promising raw material for biofuel production while high amount of biomass was generated in low concentration of POME.

Kinetics of growth and multi substrate degradation by an indigenous mixed microbial culture isolated from a wastewater treatment plant in Guwahati, India

2008 ◽  
Vol 58 (5) ◽  
pp. 1101-1106
Author(s):  
Pichiah Saravanan ◽  
K. Pakshirajan ◽  
P. K. Saha
Keyword(s):  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Lag Phase ◽  
Microbial Culture ◽  
High Concentration ◽  
Mixed Microbial Culture ◽  
Phenol Biodegradation ◽  
Low Concentration ◽  
Culture Growth

An indigenous mixed culture of microorganisms, isolated from a sewage treatment plant, was investigated for its potential to simultaneously degrade phenol and m-cresol during its growth in batch shake flasks. 22 full factorial designs with the two substrates as the factors, at two different levels and two different initial concentration ranges, were employed to carry out the biodegradation experiments. For complete utilisation of phenol and m-cresol, the culture took a minimum duration of 21 hrs at their low concentration of 100 mg/L each, and a maximum duration of 187 hrs at high concentration of 600 mg/L each in the multisubstrate system. The biodegradation results also showed that the presence of phenol in low concentration range (100–300 mg/L did not inhibit m-cresol biodegradation; on the other hand, presence of m-cresol inhibited phenol biodegradation by the culture. Moreover, irrespective of the concentrations used, phenol was degraded preferentially and earlier than m-cresol. During the culture growth, a lag phase was observed above a combined concentration of 500 mg/L i.e., 200 mg/L m-cresol and 300 mg/L of phenol and above). Statistical analysis of the specific growth rate of the culture in the multisubstrate system was also performed in the form of ANOVA and Student ‘t’ test, which gave good interpretation in terms of main and interaction effects of the substrates.

Manufacturing and Measuring Mechanical Properties of Continuous Functionally Graded Beam

2021 ◽  
Vol 21 (2) ◽  
pp. 7-11
Author(s):  
Ahmed Mansoor Abbood ◽  
Haider K. Mehbes ◽  
Abdulkareem. F. Hasan
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Volume Fraction ◽  
Young's Modulus ◽  
Functionally Graded ◽  
High Concentration ◽  
Functionally Graded Beam ◽  
Low Concentration ◽  
Graded Material ◽  
Vertical Gravity

In this study, glass-filled epoxy functionally graded material (FGM) was prepared by adopting the hand lay-up method. The vertical gravity casting was used to produce a continuous variation in elastic properties. A 30 % volume fraction of glass ingredients that have mean diameter 90 μm was spread in epoxy resin (ρ = 1050 kg/m3). The mechanical properties of FGM were evaluated according to ASTM D638. Experimental results showed that a gradually relationship between Young’s modulus and volume fraction of glass particles, where the value of Young’s modulus at high concentration of glass particles was greater than that at low concentration, while the value of Poisson’s ratio at high concentration of glass particles was lower than that at low concentration. The manufacture of this FG beam is particularly important and useful in order to benefit from it in the field of various fracture tests under dynamic or cyclic loads.

A generalized settling approach in the numerical modeling of sedimentation tanks

1998 ◽  
Vol 38 (3) ◽  
pp. 95-102 ◽  
Author(s):  
G. Mazzolani ◽  
F. Pirozzi ◽  
G. d'Antonoi
Keyword(s):  
Transport Model ◽  
Numerical Models ◽  
Removal Rate ◽  
Total Concentration ◽  
Suspended Solid ◽  
Primary Concern ◽  
High Concentration ◽  
Hindered Settling ◽  
Low Concentration ◽  
Solid Distribution

Numerical models for the prediction of turbulent flow field and suspended solid distribution in sedimentation tanks are characterized by refined modeling of hydrodynamics, but apparently weak modeling of settling properties of suspensions. It is known that sedimentation tanks typically treat highly heterodisperse suspensions, whose concentrations range from relatively high to low values. However, settling is modeled either by considering one or more particle classes of different settling velocity, without accounting for hindered settling conditions, or by treating the suspension as monodisperse, even in regions of low concentration. A new generalized settling model is proposed to account for both discrete settling conditions in low concentration regions of the tanks and hindered settling conditions in high concentration regions. Settling velocities of heterodisperse suspensions are then determined as a function of particle velocities in isolation and their total concentration. The settling model is used in the framework of a transport model for the simulation of hydrodynamics and solid distribution in a rectangular sedimentation tank. Results show that solid distribution is mainly affected by particle interactions in the inlet region and by settling properties of individual particles in the outlet region. Comparison of the proposed settling model with other settling models suggests that a generalized approach of the modeling of settling properties of suspensions is a primary concern to obtain reliable predictions of the removal rate.

scholarly journals Improvement on filterability in the aerobic treatment of carboxymethyl cellulose (CMC) wastewater

2014 ◽  
Vol 20 (4) ◽  
pp. 491-501
Author(s):  
Pei Qing ◽  
Chen Hui ◽  
Zhou Ming ◽  
Lu Qin ◽  
Ma Qiang
Keyword(s):  
Sodium Chloride ◽  
Membrane Fouling ◽  
Aerobic Treatment ◽  
Treatment Efficiency ◽  
High Concentration ◽  
Low Concentration ◽  
Chemically Modified ◽  
Natural Cellulose ◽  
Salinity Shock ◽  
Filtration Flux

CMC is chemically modified from natural cellulose and widely applied in various industries. CMC wastewater consists mainly of sodium glycolate, sodium chloride and water. With extremely high COD and salinity, high concentration CMC wastewater can?t be biologically treated, but with COD and salinity around 15000 mg/L and 30000 mg/L respectively, low concentration CMC wastewater can be aerobically treated. In a CMC factory, the treatment of low concentration wastewater with aerobic MBR was successful except for one serious problem: poor filterability. Two trial solutions: adding micronutrients and applying MBBR were expected to improve the filterability. In the experiment, adding micronutrients was achieved by mixing filtered natural water into the wastewater, rather than dosing chemicals into it. The treatment efficiency of both solutions was close, but adding micronutrients showed distinguished performance in improving filterability, which includes higher filtration flux and slighter membrane fouling. Adding micronutrients also effectively improved the filterability under severe salinity shock.

Experimental Study of CO2 Sequestration Using Glycinate-TEA

2014 ◽  
Vol 522-524 ◽  
pp. 396-400 ◽  
Author(s):  
Wei Feng Zhang ◽  
Jian Hui Shu
Keyword(s):  
Experimental Study ◽  
Absorption Capacity ◽  
High Concentration ◽  
Low Concentration

The experimental study on the mechanism of CO2 absorption and desorption was tested by two kinds of glycinate (SG and PG) with TEA. The absorption and regeneration of CO2 by mixed absorption liquid were tested and compared with each other. The results showed that a low concentration of TEA in the SG and PG increased CO2 absorption capacity of mixed absorption solution. Addin more TEA on PG or SG lowered CO2 absorption capacity of mixed absorption solution. Desorption of PG didnt change with TEA. The low concentration of TEA had a role in promoting the desorption of mixed absorption solution (SG+TEA), and the high concentration of TEA inhibited the desorption of mixed absorption solution (SG+TEA).

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