scholarly journals Efficient removal of ammoniacal nitrogen from textile printing wastewater by electrooxidation considering the effects of NaCl and NaOCl addition

2021 ◽  
Author(s):  
Bengisu Cifcioglu-Gozuacik ◽  
Sinem Merve Ergenekon ◽  
Bahar Ozbey-Unal ◽  
Cigdem Balcik ◽  
Ahmet Karagunduz ◽  
...  
Keyword(s):  
Oxygen Demand ◽  
Operation Time ◽  
Operating Conditions ◽  
Ammoniacal Nitrogen ◽  
Efficient Removal ◽  
Applied Current ◽  
Solution Ph ◽  
Graphite Electrodes ◽  
Textile Printing ◽  
Removal Efficiencies

Abstract In this study, electrooxidation (EO) process using graphite electrodes as electrode pairs was used for the removal of chemical oxygen demand (COD), ammoniacal nitrogen (NH4+-N), and color from real textile printing wastewater. The effect of solution pH, sodium chloride (NaCl) dosage, sodium hypochlorite (NaOCl), which is the oldest and still most important chlorine-based bleach, dosage, and oxidation time were investigated on the removal efficiencies. Operating conditions of EO reactor were applied to current density 1 mA/cm2, distance between the electrodes: 2 cm, 150 min operation time, and stirring speed of 500 rpm. At optimum condition; pH 9.5, applied current desitiy 1 mA/cm2, NaCl dosage of 8 g/L, NaOCl dosage of 44.4 mg/L and 150 min electrooxidation time, the obtained removal efficiencies were 86.5% and 91.1% for COD and ammoniacal nitrogen, respectively. The efficiency was enhanced to 91.1% for ammoniacal nitrogen from 21.7% after applying EO combined with NaOCl addition compared to individual NaOCl addition.

scholarly journals Synthesis of Nd-doped ZSM-5 and its application to treating slightly polluted water

2017 ◽  
Vol 8 (1) ◽  
pp. 86-93
Author(s):  
Mang Lu ◽  
Lin He ◽  
Yue Cheng
Keyword(s):  
Contact Time ◽  
Oxygen Demand ◽  
Raw Material ◽  
Molar Ratio ◽  
Polluted Water ◽  
Solution Ph ◽  
Experimental Conditions ◽  
Factors Influencing ◽  
Orthogonal Experiments ◽  
Removal Efficiencies

Abstract In this study, ZSM-5 zeolite was synthesized using diatomaceous mud as the raw material, and then doped with different amounts of Nd2O3. The orthogonal experiments were performed to investigate the influence of Nd:Si molar ratio, zeolite dosage, contact time, solution pH and temperature on the removal of humic acid (HA). The removal of HA was comprehensively evaluated by chemical oxygen demand (COD), UV254 and UV410 of the solution. The results demonstrate that solution pH and zeolite dosage are the two most important factors influencing HA adsorption. The optimum experimental conditions were determined to be: 35 °C, Nd:Si molar ratio of 1:100, 2.0 g/L zeolite, pH 4 and 50 min contact time. Under these conditions, the removal efficiencies of UV254, UV410 and COD are 82.70%, 76.00% and 82.10%, respectively, corresponding to a comprehensive removal of 81.02%.

scholarly journals Performance of Earthworm-Enhanced Horizontal Sub-Surface Flow Filter and Constructed Wetland

Water ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1309 ◽  
Author(s):  
Rajendra Singh ◽  
Dafang Fu ◽  
Jing Jia ◽  
Jiaguo Wu
Keyword(s):  
Constructed Wetland ◽  
Low Impact Development ◽  
Oxygen Demand ◽  
Ammonium Nitrogen ◽  
Surface Flow ◽  
Water Levels ◽  
Operating Conditions ◽  
Experimental Conditions ◽  
Hydraulic Load ◽  
Removal Efficiencies

In this study, the performance of the horizontal sub-surface flow filter (HSSFF) and constructed wetland (HSSFCW) experimental units enhanced with earthworms was investigated for the treatment of construction camp sewage wastewater. All the experimental units (filter and constructed wetland) were filled with the same filler except Eisenia foetida earthworms and Lolium perenne Linn plants. The performance of the earthworm-enhanced filter (EEF) and the earthworm-enhanced constructed wetland (EECW) was compared to that of the blank filter (BF) units. The results revealed that the removal efficiencies for chemical oxygen demand (COD), ammonium-nitrogen (NH4+-N), total nitrogen (TN) and total phosphorus (TP) in EEF were higher than the BF unit. In order to optimize the operating conditions, the experiments were conducted in three different water levels. The results revealed that the removal efficiencies of EEF for these pollutants are the highest in experimental conditions no. 2 (water level ~30 cm; HRT ~3 days; hydraulic load ~4.05 cm/day; and Inflow discharge ~0.27 L/h). Compared to the EEF and BF units, the EECW has higher removal efficiency for COD and TN and has more stable performance than the filters. This work will aid the design and improvement of filters and CWs for treatment of effluent wastewater from construction camps. The selection of appropriate hydraulic parameters and experimental conditions could be very beneficial in achieving the goal of implantation of low impact development (LID).

scholarly journals Removal of PAHs from leachate using a combination of chemical precipitation and Fenton and ozone oxidation

2018 ◽  
Vol 78 (5) ◽  
pp. 1064-1070 ◽  
Author(s):  
H. Ates ◽  
M. E. Argun
Keyword(s):  
Statistical Significance ◽  
Oxygen Demand ◽  
Chemical Precipitation ◽  
Operating Conditions ◽  
Program Optimization ◽  
Ozone Oxidation ◽  
Treatment Processes ◽  
Micropollutant Removal ◽  
Polycyclic Aromatic ◽  
Removal Efficiencies

Abstract In this study, six emerging pollutants, belonging to the polycyclic aromatic hydrocarbons (PAHs) group, found in landfill leachate were investigated for their removal by sequential treatment processes including chemical precipitation (CP), Fenton oxidation (FO) and ozone oxidation (OO). Each treatment process was run under different conditions using an experimental design program. Optimization of both CP and FO processes was designed based on the measured values of the residual chemical oxygen demand (COD) of the samples analyzed. The analysis of variance test was applied to the obtained results for determination of statistical significance of the model. Removal efficiencies of micropollutants were determined in the optimal conditions both for CP and FO processes. Samples obtained after these processes were treated with different pH and ozonation times for observing the performances of ozonation on micropollutant removal under different operating conditions. In this study, the removal of acenaphthylene, acenaphthene, fluorene, phenanthrene, fluoranthene and pyrene micropollutants was investigated. The values obtained for PAHs in leachate were determined to be above 10 ppb. In the CP process, the removal efficiencies for PAHs were ranged between 6% and 40% except for pyrene. Removal efficiencies of all micropollutants with FO were over 70% except for fluorene (55%). The removal efficiencies of the investigated micropollutants were 80–100% as a result of consecutive treatment processes including CP, FO and OO respectively.

scholarly journals Optimization of electrocoagulation process to treat biologically pretreated bagasse effluent

2014 ◽  
Vol 79 (5) ◽  
pp. 613-626 ◽  
Author(s):  
K. Thirugnanasambandham ◽  
V. Sivakumar ◽  
Maran Prakash
Keyword(s):  
Response Surface ◽  
Three Dimensional ◽  
Oxygen Demand ◽  
Electrical Energy ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Applied Current ◽  
Initial Ph ◽  
Electrocoagulation Process ◽  
Pretreated Bagasse

The main objective of the present study was to investigate the efficiency of electrocoagulation process as a post-treatment to treat biologically pretreated bagasse effluent using iron electrodes. The removal of chemical oxygen demand (COD) and total suspended solids (TSS) were studied under different operating conditions such as amount of dilution, initial pH, applied current and electrolyte dose by using response surface methodology (RSM) coupled with four-factor three-level Box-Behnken experimental design (BBD). The experimental results were analyzed by Pareto analysis of variance (ANOVA) and second order polynomial mathematical models were developed with high correlation of efficiency (R2) for COD, TSS removal and electrical energy consumption (EEC). The individual and combined effect of variables on responses was studied using three dimensional response surface plots. Under the optimum operating conditions, such as amount of dilution at 30 %, initial pH of 6.5, applied current of 8 mA cm-2 and electrolyte dose of 740 mg l-1 shows the higher removal efficiency of COD (98 %) and TSS (93 %) with EEC of 2.40 Wh, which were confirmed by validation experiments.

scholarly journals Effective removal of chemical oxygen demand and phosphates from aqueous medium using entrapped activated carbon in alginate

2018 ◽  
Vol 3 (5) ◽  
pp. 227-236
Author(s):  
Soha A Abd El-Gawad ◽  
Hossam M Abd ElAziz
Keyword(s):  
Activated Carbon ◽  
Oxygen Demand ◽  
Operating Parameter ◽  
Freundlich Isotherm ◽  
Operating Conditions ◽  
Phosphate Removal ◽  
Efficient Removal ◽  
Stirring Rate ◽  
Effective Removal ◽  
Adsorption Data

The aim of this study is to decrease different wastewater contaminants using entrapped activated carbon in alginate polymer (AG-AC) by adsorption. Different phosphate concentrations were prepared in the laboratory. The effect of the operating parameter was studied by external factors (e.g., contact time, pH, concentrations, adsorbent dose, and stirring rate). The results were analyzed according to the Freundlich and Langmuir adsorption isotherm. The adsorption data are more appropriate by the Freundlich isotherm. Efficient removal percentages for COD (500 mg\L) at pH 3 using dose 30g of the adsorbent for 60min with a fixed stirring rate at 100rpm were about (79%). Efficient removal percentages for phosphates (5mg\L) at pH 4 using dose 30g of the adsorbent for 45min with a fixed stirring rate at 100rpm were about (89%). The best-operating conditions have been determined to increase phosphate removal efficiency.

Influence of Operating Conditions on the Persulfate Oxidation of Textile Waste Water at Ambient Temperature

2015 ◽  
Vol 802 ◽  
pp. 454-459 ◽  
Author(s):  
Fagbenro Oluwakemi Kehinde ◽  
Hamidi Abdul Aziz
Keyword(s):  
Contact Time ◽  
Suspended Solids ◽  
Oxygen Demand ◽  
Textile Wastewater ◽  
Operating Conditions ◽  
Molar Ratio ◽  
Solution Ph ◽  
Persulfate Oxidation ◽  
Ambient Temperatures ◽  
Textile Waste Water

At the ambient temperatures, the influence of operating conditions on persulfate (S2O8) oxidation of real textile wastewater was investigated for the removal of color, suspended solids (SS) and chemical oxygen demand (COD). The effects of oxidant dosage, initial solution pH and contact time were studied in a series of batch experiments using persulfate (PS) oxidant as sodium persulfate. Oxidant dose was defined by an oxidant/contaminant (PS/COD) molar ratio, varied from 1/1-10/1. Although parameter removals increased with the oxidant dose, especially for color and SS, a PS/COD molar ratio of 4/1 (6720mg/L) was adopted in a bid to use fewer chemicals. The pH was varied from 2-11, with pH of between 2 and 3 being the optimum. At 360minutes contact time, the removals of color, SS and COD were 84%; 71% and 32% respectively. Although relatively effective, especially for color removal, results show that the reactions might have been inhibited at ambient temperatures as shown by the particularly low removal of COD.

Behaviour of Alkylphenol Polyethoxylate Surfactants and of Nitrilotriacetate in Sewage Treatment

1987 ◽  
Vol 19 (3-4) ◽  
pp. 449-460 ◽  
Author(s):  
W. Giger ◽  
M. Ahel ◽  
M. Koch ◽  
H. U. Laubscher ◽  
C. Schaffner ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Sewage Treatment ◽  
Operating Conditions ◽  
Municipal Sewage ◽  
Sludge Treatment ◽  
Loading Rates ◽  
Treatment Conditions ◽  
Physico Chemical ◽  
Treated Sewage ◽  
Removal Efficiencies

Effluents and sludges from several municipal sewage treatment plants in Switzerland were analyzed for nonylphenol polyethoxylates (NPnEO, n=3-20), nonylphenol mono- and diethoxylate (NPlEO, NP2EO), corresponding nonylphenoxy carboxylic acids (NP1EC, NP2EC) and nonylphenol (NP). These chemicals derive from nonionic surfactants of the NPnEO-type, and specific analitical techniques were used to study their behaviour during mechanical-biological sewage and subsequent sludge treatment. The parent NPnEO-surfactants, with concentrations in raw and mechanically treated sewage from 400-2200 mg/m3, were relatively efficiently removed by the activated sludge treatment. The abundances of the different metabolites varied depending on treatment conditions. The refractory nature of NPl/2EO, NP and NPl/2EC was recognized. Both biotransformations and physico-chemical processes determine the behaviour and fate of nonylphenolic substances in sewage treatment. Nitrilotriacetate (NTA) was found in primary effluents at concentrations between 430 and 1390 mg/m3. The various treatment plants showed different removal efficiencies for NTA depending on the operating conditions. Activated sludge treatment with low sludge loading rates and nitrifying conditions removed NTA with efficiencies between 95 and 99%. High sludge loading caused a decrease in NTA removal efficiencies from 70% to 39%.

Validation of On-line Respiration Meter and its Applications by Computer Simulation

1992 ◽  
Vol 26 (5-6) ◽  
pp. 1355-1363 ◽  
Author(s):  
C-W. Kim ◽  
H. Spanjers ◽  
A. Klapwijk
Keyword(s):  
Steady State ◽  
Activated Sludge ◽  
Respiration Rate ◽  
Oxygen Demand ◽  
Operating Conditions ◽  
Mass Balances ◽  
Short Term ◽  
Respiration Rates ◽  
On Line ◽  
Made In

An on-line respiration meter is presented to monitor three types of respiration rates of activated sludge and to calculate effluent and influent short term biochemical oxygen demand (BODst) in the continuous activated sludge process. This work is to verify if the calculated BODst is reliable and the assumptions made in the course of developing the proposed procedure were acceptable. A mathematical model and a dynamic simulation program are written for an activated sludge model plant along with the respiration meter based on mass balances of BODst and DO. The simulation results show that the three types of respiration rate reach steady state within 15 minutes under reasonable operating conditions. As long as the respiration rate reaches steady state the proposed procedure calculates the respiration rate that is equal to the simulated. Under constant and dynamic BODst loading, the proposed procedure is capable of calculating the effluent and influent BODst with reasonable accuracy.

scholarly journals Treatment of fish processing industry wastewater using hydrodynamic cavitational reactor with biodegradability improvement

2019 ◽  
Vol 80 (12) ◽  
pp. 2310-2319 ◽  
Author(s):  
Prashant Dhanke ◽  
Sameer Wagh ◽  
Abhijeet Patil
Keyword(s):  
Organic Matter ◽  
New Technology ◽  
Oxygen Demand ◽  
Operating Conditions ◽  
Hydrodynamic Cavitation ◽  
Inlet Pressure ◽  
Fish Processing ◽  
Processing Industry ◽  
Cavitation Effect ◽  
Processing Plants

Abstract Water generated from the fish processing industry is contaminated with organic matter. This organic matter present in wastewater increases the biochemical oxygen demand (BOD) and chemical oxygen demand (COD). A new technology, hydrodynamic cavitation (HC) is used to deal with this wastewater produced in fish processing plants. The orifice plate is used in the HC reactor to generate a cavitation effect. The intensification of this technique was carried out with the help of hydrogen peroxide (H2O2) and TiO2. The treatment of this wastewater is reported in terms of percent degradation in BOD and COD and in biodegradability index (BI). Operating parameters like inlet pressure, pH, operating temperature and H2O2 doses were used to find the optimum condition. 15 g/L of H2O2 gave 69.5% reduction of COD in the 120 min of treatment that also increases BI value to 0.93 at inlet pressure 8 bar, Plate-5, temperature (30 °C), and pH 4. In the ultrasonic cavitation (UC) reactor, COD reduction is 68.7% without TiO2 and with TiO2 it is 71.2%. Also, this HC and UC reactor reduced CFU count to a great extent at the same operating conditions.

scholarly journals Effective Chromium Adsorption From Aqueous Solutions and Tannery Wastewater Using Bimetallic Fe/Cu Nanoparticles: Response Surface Methodology and Artificial Neural Network

2021 ◽  
Vol 14 ◽  
pp. 117862212110281
Author(s):  
Ahmed S. Mahmoud ◽  
Nouran Y. Mohamed ◽  
Mohamed K. Mostafa ◽  
Mohamed S. Mahmoud
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Industrial Effluent ◽  
Oxygen Demand ◽  
Operating Conditions ◽  
Tannery Wastewater ◽  
P Value ◽  
Cu Nanoparticles ◽  
Artificial Neural ◽  
Cr Removal

Tannery industrial effluent is one of the most difficult wastewater types since it contains a huge concentration of organic, oil, and chrome (Cr). This study successfully prepared and applied bimetallic Fe/Cu nanoparticles (Fe/Cu NPs) for chrome removal. In the beginning, the Fe/Cu NPs was equilibrated by pure aqueous chrome solution at different operating conditions (lab scale), then the nanomaterial was applied in semi full scale. The operating conditions indicated that Fe/Cu NPs was able to adsorb 68% and 33% of Cr for initial concentrations of 1 and 9 mg/L, respectively. The removal occurred at pH 3 using 0.6 g/L Fe/Cu dose, stirring rate 200 r/min, contact time 20 min, and constant temperature 20 ± 2ºC. Adsorption isotherm proved that the Khan model is the most appropriate model for Cr removal using Fe/Cu NPs with the minimum error sum of 0.199. According to khan, the maximum uptakes was 20.5 mg/g Cr. Kinetic results proved that Pseudo Second Order mechanism with the least possible error of 0.098 indicated that the adsorption mechanism is chemisorption. Response surface methodology (RSM) equation was developed with a significant p-value = 0 to label the relations between Cr removal and different experimental parameters. Artificial neural networks (ANNs) were performed with a structure of 5-4-1 and the achieved results indicated that the effect of the dose is the most dominated variable for Cr removal. Application of Fe/Cu NPs in real tannery wastewater showed its ability to degrade and disinfect organic and biological contaminants in addition to chrome adsorption. The reduction in chemical oxygen demand (COD), biological oxygen demand (BOD), total suspended solids (TSS), total phosphorus (TP), total nitrogen (TN), Cr, hydrogen sulfide (H2S), and oil reached 61.5%, 49.5%, 44.8%, 100%, 38.9%, 96.3%, 88.7%, and 29.4%, respectively.

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