scholarly journals Electrolysis-assisted UV/sulfite oxidation for water treatment with automatic adjustments of solution pH and dissolved oxygen

2021 ◽  
Vol 403 ◽  
pp. 126278 ◽  
Author(s):  
Long Chen ◽  
Yunfei Xue ◽  
Tao Luo ◽  
Feng Wu ◽  
Akram N. Alshawabkeh
Keyword(s):  
Water Treatment ◽  
Dissolved Oxygen ◽  
Solution Ph ◽  
Sulfite Oxidation

Proportional Control of Dissolved Oxygen Concentration of Sewage Water Treatment in Oil Field

2013 ◽  
Vol 421 ◽  
pp. 798-802
Author(s):  
Chao Xie
Keyword(s):  
Water Treatment ◽  
Dissolved Oxygen ◽  
Activated Sludge ◽  
Design Procedure ◽  
Sewage Water ◽  
Oil Field ◽  
Dissolved Oxygen Concentration ◽  
Proportional Control ◽  
Simulation Results ◽  
Sewage Water Treatment

Activated sludge method is mainly used to sewage water treatment of water injection system in oil field, dissolved oxygen of sewage pond plays a important role in the sewage water treatment process. The proportional control algorithm of dissolved oxygen concentration is developed based on a first time delay model, and the parameter values of the controller is determined by using stability margins design approach. Simulation results are provided to illustrate the design procedure and the effectiveness of the proposed methods. When applying to the wastewater treatment system based on activated sludge, this method can achieve a satisfied treating performance with robustness. Simulation results are given to demonstrate the design procedure and the effectiveness of the proposed methods.

UV Photolytic Mechanism ofN-Nitrosodimethylamine in Water:  Roles of Dissolved Oxygen and Solution pH

2005 ◽  
Vol 39 (24) ◽  
pp. 9702-9709 ◽  
Author(s):  
Changha Lee ◽  
Wonyong Choi ◽  
Jeyong Yoon
Keyword(s):  
Dissolved Oxygen ◽  
Solution Ph

Diagnosis for Water and Steam Quality Problem in Taishan Ultra-Supercritical Power Plant

2014 ◽  
Vol 1044-1045 ◽  
pp. 291-294
Author(s):  
Mao Dong Li ◽  
Chen Lin Dai ◽  
Jun Ming Zhao ◽  
Yu Hui Du ◽  
Lin Yang ◽  
...  
Keyword(s):  
Water Treatment ◽  
Power Plant ◽  
Dissolved Oxygen ◽  
Working Condition ◽  
Iron Deposit ◽  
Feed Water ◽  
Steam Quality ◽  
Control Effect ◽  
Boiler Water ◽  
Quality Problem

Water and steam quality during operation must be strictly controlled for ultra-supercritical unit. Changes of indicators in water and steam are supervised, water and steam quality and working condition of boiler water, as well as supervision of water and steam quality are reviewed in this paper. Risks of corrosion and scaling in Taishan power plant is assessed. As a result, control effect of TOC is remarkable in Taishan power plant, content of Cl- and SO42- can satisfy the control standard, that is , risk of corrosion and scaling is low. Dissolved oxygen is significantly exceeded in the condensate polishing desalination device , and there has risk of iron deposit. To convert the feed water treatment from AVT(All Volatile Treatment) to OT(Oxygenated Treatment) can solve the problems above .

scholarly journals Paraquat dichloride adsorption from aqueous solution using Carbonized Bambara Groundnut (Vigna subterranean) Shells

2020 ◽  
Vol 12 (1) ◽  
pp. 167-177
Author(s):  
Ayuba Abdullahi Muhammad ◽  
Nyijime Thomas Aondofa
Keyword(s):  
Aqueous Solution ◽  
Water Treatment ◽  
Contact Time ◽  
Adsorption Process ◽  
Bambara Groundnut ◽  
Experimental Result ◽  
Isotherm Model ◽  
Batch Adsorption ◽  
Solution Ph ◽  
Adsorbent Dosage

Carbonized Bambara GroundNut Shell (CBGNS) was used as adsorbent for the adsorption of paraquat dichloride (PQ) from aqueous solution. The prepared adsorbent was characterized using scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy methods. Several parameters that might affect the adsorption process including pH, contact time, adsorbent dosage, temperature and initial concentration were investigated and optimized using batch adsorption technique. Results of the study revealed that maximum removal efficiency (98%) was achieved using 0.05g adsorbent dosage, solution pH of 5 and 60 min of contact time. The equilibrium experimental result revealed that Langmuir model best described the adsorption process with R2 value of 0.956.The heat of adsorption process was estimated from Temkin Isotherm model to be 19.99J/mol and the mean free energy was estimated from Duninin-Radushkevich (DRK) isotherm model to be 0.289KJ/mol indicating chemisorptions process. The kinetic and thermodynamic studies revealed that the adsorption processes followed pseudo-second-order kinetics with R2 value of 0.999 and the value of ∆G (- 27.74 kJ mol-1), ∆H (13.145 kJ mol-1) indicate the spontaneous and endothermic nature of PQ adsorption on CBGNS. The results suggested that CBGNS had the potential to become a promising material for PQ contaminated water treatment. Keywords: Adsorption, Paraquat dichloride, Carbonized Bambara Ground nut shell, Water treatment.

scholarly journals Removal of radio N-nitrosodimethylamine (NDMA) from drinking water by coagulation and Powdered Activated Carbon (PAC) adsorption

2009 ◽  
Vol 2 (1) ◽  
pp. 79-100 ◽  
Author(s):  
J. Chung ◽  
Y. Yoon ◽  
M. Kim ◽  
S.-B. Lee ◽  
H.-J. Kim ◽  
...  
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
Water Treatment ◽  
Background Electrolyte ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Powdered Activated Carbon ◽  
Individual Treatment ◽  
Solution Ph ◽  
Treatment Processes

Abstract. The presence of N-nitrosodimethylamine (NDMA) in drinking water supplies has raised concern over its removal by common drinking water treatment processes. A simple detection method based on scintillation spectroscopy has been used to quantify the concentration of 14C-labeled NDMA at various ratios of sample to scintillation liquid. Without sample pretreatment, the method detection limits are 0.91, 0.98, 1.23, and 1.45 ng/L of NDMA at scintillation intensity ratios of 10:10, 5:15, 15:5, and 2.5:17.5 (sample: scintillation liquid), respectively. The scintillation intensity in all cases is linear (R2>0.99) and is in the range of 0 to 100 ng/L of NDMA. In addition, because scintillation intensity is independent of solution pH, conductivity, and background electrolyte ion types, a separate calibration curve is unnecessary for NDMA samples at different solution conditions. Bench-scale experiments were performed to simulate individual treatment processes, which include coagulation and adsorption by powdered activated carbon (PAC), as used in a drinking water treatment plant, and biosorption, a technique used in biological treatment of waste water. The commonly used coagulation process for particulate control and biosorption is ineffective for removing NDMA (<10% by coagulation and <20% by biosorption). However, high doses of PAC may be applied to remove NDMA.

scholarly journals Removal of Manganese(II) from Acid Mine Wastewater: A Review of the Challenges and Opportunities with Special Emphasis on Mn-Oxidizing Bacteria and Microalgae

Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2493 ◽  
Author(s):  
Yongchao Li ◽  
Zheng Xu ◽  
Hongqing Ma ◽  
Andrew S. Hursthouse
Keyword(s):  
Dissolved Oxygen ◽  
Mine Drainage ◽  
Enzymatic Catalysis ◽  
Microbial Oxidation ◽  
Solution Ph ◽  
Chemical Reagents ◽  
Synergistic Interactions ◽  
Challenges And Opportunities ◽  
Mine Wastewater ◽  
Neutral Conditions

Many global mining activities release large amounts of acidic mine drainage with high levels of manganese (Mn) having potentially detrimental effects on the environment. This review provides a comprehensive assessment of the main implications and challenges of Mn(II) removal from mine drainage. We first present the sources of contamination from mineral processing, as well as the adverse effects of Mn on mining ecosystems. Then the comparison of several techniques to remove Mn(II) from wastewater, as well as an assessment of the challenges associated with precipitation, adsorption, and oxidation/filtration are provided. We also critically analyze remediation options with special emphasis on Mn-oxidizing bacteria (MnOB) and microalgae. Recent literature demonstrates that MnOB can efficiently oxidize dissolved Mn(II) to Mn(III, IV) through enzymatic catalysis. Microalgae can also accelerate Mn(II) oxidation through indirect oxidation by increasing solution pH and dissolved oxygen production during its growth. Microbial oxidation and the removal of Mn(II) have been effective in treating artificial wastewater and groundwater under neutral conditions with adequate oxygen. Compared to physicochemical techniques, the bioremediation of manganese mine drainage without the addition of chemical reagents is relatively inexpensive. However, wastewater from manganese mines is acidic and has low-levels of dissolved oxygen, which inhibit the oxidizing ability of MnOB. We propose an alternative treatment for manganese mine drainage that focuses on the synergistic interactions of Mn in wastewater with co-immobilized MnOB/microalgae.

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