scholarly journals Continuous Sorption of Remazol Brilliant Orange 3R Using Caulerpa scalpelliformis Biochar

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Gokulan Ravindiran ◽  
Pradeepkumar Sugumar ◽  
Elias G
Keyword(s):  
Water Quality ◽  
Mathematical Models ◽  
Flow Rate ◽  
Continuous Operation ◽  
Operating Conditions ◽  
Experimental Result ◽  
Industrial Activities ◽  
Dyeing Process ◽  
Textile Industries ◽  
Successive Removal

An ever increase in the utilization of water for domestic and industrial activities resulted in the depletion of fresh water. Water is being used in huge quantities for manufacturing and other activities. The toxic pollutants used in the industries get mixed with water and result in the degradation of water quality. Textile industries are considered as one of the major industries that release a huge quantity of wastewater. The dye used in the textile industries is not completely utilized in the dyeing process and gets mixed with water and reaches the environment. Caulerpa scalpelliformis, a novel sorbent, was used for the preparation of biochar and successive removal of dyes in a continuous operation. The operating conditions, namely, biochar bed depth, dye flow rate, and initial dye concentration, were investigated, and the experimental result was validated with the mathematical models.

scholarly journals Optimization of Working Conditions for Perovskite-Based Gas Sensor Devices by Multiregression Analysis

2019 ◽  
Vol 2019 ◽  
pp. 1-19 ◽  
Author(s):  
Fabio Zaza ◽  
Vanessa Pallozzi ◽  
Emanuele Serra
Keyword(s):  
Carbon Monoxide ◽  
Mathematical Models ◽  
Gas Sensor ◽  
Flow Rate ◽  
Gas Flow ◽  
Resource Depletion ◽  
Productive Efficiency ◽  
Operating Conditions ◽  
Gas Flow Rate ◽  
Sensor Devices

Environmental degradation and resource depletion drive scientific research priorities to develop technologies for sustainable productive systems. Among them, chemical sensing technology plays a key role for regulating energetic, ecological, and productive efficiency by monitoring and controlling the industrial processes. Semiconducting metal oxide sensors are particularly attractive technology because of their simplicity in function, small size, and projected low cost. The aim of this work is to synthesize Ti-substituted lanthanum ferrite perovskite, LaFe0.8Ti0.2O3, in order to develop a resistive sensor device for monitoring carbon monoxide. Since sensor performances are affected by experimental factors, such as temperature, target gas concentration, and gas flow rate, the aim of the authors was to define the optimum working condition by performing multiple regression analyses. The investigated ranges of operating conditions were temperature from 300 to 480°C, carbon monoxide concentration from 100 to 200 ppm, and inlet-gas flow rate from 40 to 100 cm3/min. The results confirm that the applied systematic analysis is a powerful method for studying the direct and indirect effects of every experimental factor on sensor performance and for computing mathematical models with predictive ability, that are useful tools for defining the optimum chemiresistors’ operating conditions. In addition, mathematical models are able to be used as multiple-factor surface calibration for restive gas sensor devices.

scholarly journals Mathematical modeling of supercritical CO2 extraction of valuable compounds from Eucheuma Cottonii and Gracilaria Sp

2018 ◽  
Vol 156 ◽  
pp. 02013 ◽  
Author(s):  
Dwila Nur Rizkiyah ◽  
Nazla ◽  
Farah Nadhifah ◽  
Siti Machmudah ◽  
Sugeng Winardi
Keyword(s):  
Flow Rate ◽  
Total Yield ◽  
Extraction Process ◽  
Extraction Yield ◽  
Operating Conditions ◽  
Experimental Result ◽  
Intact Cells ◽  
Best Fitting ◽  
Valuable Compounds ◽  
Eucheuma Cottonii

Extraction by using supercritical CO2 has been extensively developed to extract materials that are easily decomposed at high temperatures. Therefore, in this study extraction of valuable compounds (such as: carotenoids and fatty acids) from macroalgae of Eucheuma cottonii and Gracilaria sp was carried out experimentally with supercritical CO2 and mathematical model of Broken and Intact Cells (BIC) and Chrastil model. The result with BIC model is compared with the experimental result that has been done. Extraction was conducted at various pressures of 15, 20, and 25 MPa, temperature of 40, 60, and 80 ºC, CO2 flow rate of 6 mL/min, and ethanol concentrations for cosolvent of 5 %, 7.5%, and 10% CO2 flow rate. The content of extract was analyzed by using a Spectrophotometer UV - Vis and HPLC. The total yield of extract on Eucheuma cottonii was about 0.01623-0.03752 gr extract/gr sample at operating conditions 15 MPa pressure, temperature 60 ºC, and ethanol flow rate of 10%. The total yield of the extract on Gracilaria sp was 0.1982-0.4237 gr extract/gr samples, at operating conditions 15 MPa pressure, 60 ºC temperature, and ethanol flow rate 7.5% CO2 flow rate. The solubility of Eucheuma cottonii are greater than Gracilaria Sp with constant of Chrastil k, a, and b that are: 2,52; 0,911; and-27,66 at operating conditions. Broken and Intact Cells model could also describe well for extraction yield. The best fitting parameters in BIC model depends on condition at extraction process, such as : 0.45 – 0.46 for f, 0.5 - 0.75 for Xc, and 0.15 - 0.4 for K value..

scholarly journals Spatial-temporal Transformation of the Volga Reservoirs’ Soil Complex. Communication 7. Sediment Formation in the Highly Running Reservoirs of the Volga Cascade

2021 ◽  
pp. 29-46
Author(s):  
Keyword(s):  
Water Quality ◽  
Bottom Sediments ◽  
Flow Rate ◽  
Water Exchange ◽  
Operating Conditions ◽  
Coarse Grained ◽  
River Systems ◽  
Sediment Formation ◽  
Volga Reservoirs ◽  
Temporal Transformation

Large plain reservoirs are water bodies of a slow water exchange with Кw less than 10 year-1 contributing to multi-year (annual) flow regulation. All reservoirs of the Volga-Kama cascade belong to this type of reservoirs, except the Cheboksary and Saratov reservoirs with Кw about 20 year-1. Weekly and daily fluctuations of the runoff are observed in these reservoirs. This mode of operation of hydraulic constructions leads to an increase in the flow rate and fluctuations of the level, which determines the specific conditions for the formation and accumulation of bottom sediments characteristic of river systems. It is shown that the areas of coarse-grained sediments are 55 and 70%, respectively. The reservoirs under consideration are transit reservoirs for suspended substances and aerators for the oxidation of chemical pollutants and their neutralization, so they play a crucial role in the natural self-purification and management of natural water quality. Methods. The aim of the study is to characterize the spatial and temporal transformation of the lower layer of the ecosystem in reservoirs with high water exchange (by the example of the Cheboksary and Saratov reservoirs) and to identify its role in water self-purification taking into account biomarkers. It is known that river systems or systems similar to them are more efficient and are characterized as potentially saturated with food organic/mineral resources for hydrobionts. The assessment of water quality and bottom sediments of different hydro-morphometric characteristics, dynamics of water masses and operating conditions is presented using methods of bioassay and toxicology by the example of chironomid larvae and antioxidant defense system of benthic fish. Results. Based on the data of the integrated hydrobiological cruises during the growing season 2014–2020, it is difficult to say that the quality of water and bottom sediments, biotic and toxicological parameters depend on the flow rate, so further studies are required. The work is original, because there are no analogues in the world for monitoring of bottom sediments in reservoirs and quantitative assessment of sedimentation processes in space and time. The results of the biogeochemical analysis indicate, that in terms of the degree of deterioration of the eco/toxicological state, the Volga reservoirs are in a series: Volgograd = Saratov > Kuibyshev > Cheboksary > Gorky.

Application of a Pilot-Scale Pulsed Electrocoagulation system to OCC-Based Paper Mill Effluent

TAPPI Journal ◽  
2009 ◽  
Vol 8 (3) ◽  
pp. 14-20 ◽  
Author(s):  
YUAN-SHING PERNG ◽  
EUGENE I-CHEN WANG ◽  
SHIH-TSUNG YU ◽  
AN-YI CHANG
Keyword(s):  
Water Quality ◽  
Quality Indicators ◽  
Paper Mill ◽  
Pilot Scale ◽  
Operating Conditions ◽  
Optimal Dosage ◽  
Water Quality Indicators ◽  
Paper Mill Effluent ◽  
Treated Effluent ◽  
True Color

Trends toward closure of white water recirculation loops in papermaking often lead to a need for system modifications. We conducted a pilot-scale study using pulsed electrocoagulation technology to treat the effluent of an old corrugated containerboard (OCC)-based paper mill in order to evaluate its treatment performance. The operating variables were a current density of 0–240 A/m2, a hydraulic retention time (HRT) of 8–16 min, and a coagulant (anionic polyacrylamide) dosage of 0–22 mg/L. Water quality indicators investigated were electrical con-ductivity, suspended solids (SS), chemical oxygen demand (COD), and true color. The results were encouraging. Under the operating conditions without coagulant addition, the highest removals for conductivity, SS, COD, and true color were 39.8%, 85.7%, 70.5%, and 97.1%, respectively (with an HRT of 16 min). The use of a coagulant enhanced the removal of both conductivity and COD. With an optimal dosage of 20 mg/L and a shortened HRT of 10 min, the highest removal achieved for the four water quality indicators were 37.7%, 88.7%, 74.2%, and 91.7%, respectively. The water qualities thus attained should be adequate to allow reuse of a substantial portion of the treated effluent as process water makeup in papermaking.

Stabilization of the Speed of the Hydraulic Motor Through Throttle Compensation for Volume Losses

2020 ◽  
Vol 26 (3) ◽  
pp. 126-130
Author(s):  
Krasimir Kalev
Keyword(s):  
Flow Rate ◽  
Hydraulic Drive ◽  
Pressure Change ◽  
Operating Conditions ◽  
Drive System ◽  
Inlet Pressure ◽  
Schematic Diagram ◽  
Hydraulic Characteristics ◽  
Hydraulic Motor ◽  
Flow Through

AbstractA schematic diagram of a hydraulic drive system is provided to stabilize the speed of the working body by compensating for volumetric losses in the hydraulic motor. The diagram shows the inclusion of an originally developed self-adjusting choke whose flow rate in the inlet pressure change range tends to reverse - with increasing pressure the flow through it decreases. Dependent on the hydraulic characteristics of the hydraulic motor and the specific operating conditions.

Radon removal by aeration: observations on testing, installation and maintenance of domestic treatment units

2009 ◽  
Vol 9 (4) ◽  
pp. 469-475
Author(s):  
T. Turtiainen
Keyword(s):  
Water Quality ◽  
Water Flow ◽  
Removal Efficiency ◽  
Flow Rate ◽  
Test Protocol ◽  
Household Water ◽  
Medium Flow ◽  
Removal Efficiencies ◽  
Frequent Sampling

Radon is one of the contaminants that sometimes impair the water quality of wells, especially those drilled in bedrock. Domestic radon removal units based on aeration have been commercially available for more than ten years. In order to determine how effectively these units remove radon a new test protocol applying frequent sampling while letting 100 litres of water flow, was developed. This way, removal efficiencies can be more accurately calculated and possible malfunctions detected. Seven models of domestic aerators designed for removing radon from household water were tested. The aerators were based on diffused bubble aeration, spray aeration or jet aeration. The average removal efficiencies for 100 litres with a medium flow rate were 86–100% except for a unit that circulated the aerated water back to the well that had removal efficiency of 80% at the maximum. By conducting a questionnaire study usual problems related to the aeration units were localized and recommendations on maintenance and installation are given accordingly.

scholarly journals Chemical–Electrochemical Process Concept for Lead Recovery from Waste Cathode Ray Tube Glass

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1546
Author(s):  
Árpád Imre-Lucaci ◽  
Melinda Fogarasi ◽  
Florica Imre-Lucaci ◽  
Szabolcs Fogarasi
Keyword(s):  
Flow Rate ◽  
Current Density ◽  
Complete Recovery ◽  
Electrochemical Process ◽  
Operating Conditions ◽  
General Effect ◽  
Optimal Operating ◽  
Recirculation Flow ◽  
Lead Recovery ◽  
Cathode Ray Tube

This paper presents a novel approach for the recovery of lead from waste cathode-ray tube (CRT) glass by applying a combined chemical-electrochemical process which allows the simultaneous recovery of Pb from waste CRT glass and electrochemical regeneration of the leaching agent. The optimal operating conditions were identified based on the influence of leaching agent concentration, recirculation flow rate and current density on the main technical performance indicators. The experimental results demonstrate that the process is the most efficient at 0.6 M acetic acid concentration, flow rate of 45 mL/min and current density of 4 mA/cm2. The mass balance data corresponding to the recycling of 10 kg/h waste CRT glass in the identified optimal operating conditions was used for the environmental assessment of the process. The General Effect Indices (GEIs), obtained through the Biwer Heinzle method for the input and output streams of the process, indicate that the developed recovery process not only achieve a complete recovery of lead but it is eco-friendly as well.

Photo-degradation of butyl parahydroxybenzoate by using TiO2-supported catalyst

2013 ◽  
Vol 67 (10) ◽  
pp. 2141-2147 ◽  
Author(s):  
Patrick Atheba ◽  
Patrick Drogui ◽  
Brahima Seyhi ◽  
Didier Robert
Keyword(s):  
Flow Rate ◽  
Photocatalytic Oxidation ◽  
Supported Catalyst ◽  
Operating Conditions ◽  
Treatment Efficiency ◽  
Optimal Operating ◽  
Photo Degradation ◽  
Photochemical Process ◽  
Recirculation Flow ◽  
High Treatment

The present work evaluates the potential of the photocatalysis (PC) process for the degradation of butylparaben (BPB). Relatively high treatment efficiency was achieved by comparison to photochemical process. Prior to photocatalytic degradation, adsorption (AD) of BPB occurred on the titanium dioxide (TiO2)-supported catalyst. AD was described by Langmuir isotherm (KL = 0.085 L g−1, qm = 4.77 mg g−1). The influence of angle of inclination of the reactor, pH, recirculation flow rate and initial concentration of BPB were investigated. The PC process applied under optimal operating conditions (recirculation flow rate of 0.15 L min−1, angle of inclination of 15°, pH = 7 and 5 mg L−1 of BPB) is able to oxidize 84.9–96.6% of BPB and to ensure around 38.7% of mineralization. The Langmuir–Hinshelwood kinetic model described well the photocatalytic oxidation of BPB (k = 7.02 mg L−1 h−1, K = 0.364 L mg−1).

Flow Features Analysis of Throttle Notches of Proportional Direct Valve

2011 ◽  
Vol 189-193 ◽  
pp. 2285-2288
Author(s):  
Wen Hua Jia ◽  
Chen Bo Yin ◽  
Guo Jin Jiang
Keyword(s):  
Fluid Flow ◽  
Dynamic Behavior ◽  
Flow Rate ◽  
Discharge Coefficient ◽  
3D Models ◽  
Operating Conditions ◽  
Flow Models ◽  
Flow Features ◽  
Rate Discharge ◽  
Spool Valve

Flow features, specially, flow rate, discharge coefficient and efflux angle under different operating conditions are numerically simulated, and the effects of shapes and the number of notches on them are analyzed. To simulate flow features, 3D models are developed as commercially available fluid flow models. Most construction machineries in different conditions require different actions. Thus, in order to be capable of different actions and exhibit good dynamic behavior, flow features should be achieved in designing an optimized proportional directional spool valve.

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