scholarly journals Investigation of the effect of magnetic field on the chemical oxygen demand removal of wastewater

Author(s):  
Anup Jagadeesh

This study investigated the effect of magnetic field on the biological treatment of wastewater at varied liquid volumetric flow rates. Wastewater quality is measured by Chemical Oxygen Demand (COD) which quantifies the amount of oxygen required to chemically oxidize organic compounds present in the water. The results obtained from the present study show that at the flow rate of 6.7 x 10⁻⁵ m³s⁻¹ there was a significant effect on the COD removal. At lower flow rates the magnetic field had more time to act on the microorganisms which in-turn increased the COD removal rate. However at flow rates 3.3 x 10⁻⁴ to 1.2 x 10⁻⁴ m³s⁻¹ the effect of the applied magnetic field on the COD removal decreased slightly.

2021 ◽  
Author(s):  
Anup Jagadeesh

This study investigated the effect of magnetic field on the biological treatment of wastewater at varied liquid volumetric flow rates. Wastewater quality is measured by Chemical Oxygen Demand (COD) which quantifies the amount of oxygen required to chemically oxidize organic compounds present in the water. The results obtained from the present study show that at the flow rate of 6.7 x 10⁻⁵ m³s⁻¹ there was a significant effect on the COD removal. At lower flow rates the magnetic field had more time to act on the microorganisms which in-turn increased the COD removal rate. However at flow rates 3.3 x 10⁻⁴ to 1.2 x 10⁻⁴ m³s⁻¹ the effect of the applied magnetic field on the COD removal decreased slightly.


2013 ◽  
Vol 448-453 ◽  
pp. 532-535
Author(s):  
Bin Liu ◽  
Xu Ya Peng ◽  
Hua Zhao ◽  
Qi Tian

The biodegradability of aged landfill leachate is low, and the treatment effects of common processes are very poor. This paper explored the effects of the Ultrasound/Ultraviolet - Aged Refuse Bioreactor combined process on aged landfill leachate. The main results were as follows: 1The optimum power of ultrasound was 100 W, and the optimum wavelength of ultraviolet was 254 nm. The removal rate of COD was 27.33% and the value of BOD/COD ratio was increased from 0.1 to 0.35 after the treatment of Ultrasound/Ultraviolet process. Therefore, the biodegradability of the leachate was improved, which might meet the demand of subsequent biological treatment. 2The COD removal rates of the two-stage series aged refuse bioreactor were both kept above 50% during the experiment and this process had a strong capacity of resistance to impact load. 3The COD removal rate of the combined process was over 80% as a whole without any pretreatment, and it has positive significance for the treatment of aged leachate.


2013 ◽  
Vol 68 (1) ◽  
pp. 257-260 ◽  
Author(s):  
Yujie Feng ◽  
Junfeng Liu ◽  
Limin Zhu ◽  
Jinzhi Wei

The clomazone herbicide wastewater was treated using a combined technology composed of electrochemical catalytic oxidation and biological contact degradation. A new type of electrochemical reactor was fabricated and a Ti/SnO2 electrode was chosen as the anode in electrochemical-oxidation reactor and stainless steel as the cathode. Ceramic rings loaded with SnO2 were used as three-dimensional electrodes forming a packed bed. The operation parameters that might influence the degradation of organic contaminants in the clomazone wastewater were optimized. When the cell voltage was set at 30 V and the volume of particle electrodes was designed as two-thirds of the volume of the total reactor bed, the chemical oxygen demand (COD) removal rate could reach 82% after 120 min electrolysis, and the ratio of biochemical oxygen demand (BOD)/COD of wastewater increased from 0.12 to 0.38. After 12 h degradation with biological contact oxidation, the total COD removal rate of the combined technology reached 95%, and effluent COD was below 120 mg/L. The results demonstrated that this electrocatalytic oxidation method can be used as a pretreatment for refractory organic wastewater before biological treatment.


Archaea ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Shuo Wang ◽  
Jianzheng Li ◽  
Guochen Zheng ◽  
Guocheng Du ◽  
Ji Li

Hydrogen-producing acetogens (HPA) have a transitional role in anaerobic wastewater treatment. Thus, bioaugmentation with HPA cultures can enhance the chemical oxygen demand (COD) removal efficiency and CH4yield of anaerobic wastewater treatment. Cultures with high degradation capacities for propionic acid and butyric acid were obtained through continuous subculture in enrichment medium and were designated as Z08 and Z12. Bioaugmentation with Z08 and Z12 increased CH4production by glucose removal to 1.58. Bioaugmentation with Z08 and Z12 increased the COD removal rate in molasses wastewater from 71.60% to 85.84%. The specific H2and CH4yields from COD removal increased by factors of 1.54 and 1.63, respectively. Results show that bioaugmentation with HPA-dominated cultures can improve CH4production from COD removal. Furthermore, hydrogen-producing acetogenesis was identified as the rate-limiting step in anaerobic wastewater treatment.


2021 ◽  
Author(s):  
M.ADNAN A. Khan

Simulated wastewater samples containing antifreeze were treated biologically using a packed column as an aerator. The objective of this project is to determine the rate of biological degradation of ethylene glycol at different air flow rates, liquid flow rates, and varied seeding rates at different time intervals, to achieve the highest removal rate of the BOD. The biological oxygen demand (BOD) of the wastewater was measured. Under a liquid flowrate of 5.5 kg m̃²s̃¹ the BOD removal increased when the air flowrate was increased from 0.0069 to 0.0414 kg m̃²s̃¹. However, further increases of the air flowrate beyond 0.0138 kg m̃²s̃¹ did not affect the BOD removal rate significantly. On the other hand, with a constant air flowrate when the liquid flowrate was increased from 5.5 to 11, 16.5, and 27.5 kg m̃²s̃¹, the percent BOD removal appeared to decrease slightly. It was also found that the increase in amount of seeding has no significant effect on BOD removal. The averaged BOD removal of about 90% was obtained after 72 hours of the wastewater treatment.


2001 ◽  
Vol 43 (11) ◽  
pp. 51-58 ◽  
Author(s):  
P. C. Male ◽  
W. A. Pretoruis

Wastewater high in phenolic content (948 mg/l) and dissolved solids (5.4 g/l) had to be treated to remove most of the organic material and toxic compounds. A laboratory scale High Pressure (3 bar) Bioreactor (HPB) was developed and operated to treat the wastewater using a ceramic ultra filtration membrane as biomass separator. The performance of the system was compared to a normal activated sludge plant (ASP) using sludge settling for separation. The HPB was more stable than the ASP, which twice became unstable with a resulting biomass loss. Both reactors removed 90% of the chemical oxygen demand (COD) loading, reducing the phenol concentration below 20 mg/l. The maximum COD removal rate of the HPB was 28 kg/m3.d compared to 15 kg/m3.d of the ASP, while the HPB achieved 16-32 times better oxygen transfer than the ASP. It was concluded that the HPB was the preferred treatment system compared to the ASP, when treating high strength inhibitory wastewaters, due to its stable operating performance and high COD removal rate.


1993 ◽  
Vol 28 (3) ◽  
pp. 597-620 ◽  
Author(s):  
Catherine N. Mulligan ◽  
Bechara F. Safi ◽  
Jacques Meunier ◽  
Jean Chebib

Abstract The SNC multiplate reactor (1,200 L) has been developed and tested to determine chemical oxygen demand (COD) removal, nutrient requirement, and gas production from the anaerobic treatment of effluents generated at the Agropur (Notre Dame-du-Bon-Conseil, Quebec) and Nutrinor cheese dairies (Chambord, Quebec). At the Agropur plant, wastewater (3,000 mg/L COD) was treated the best at a retention time of 12 h. Using this retention time, effluents containing whey with organic loads of 10.2 to 41.6 kg COD/m3/day could be treated at a 84% COD removal rate. When the reactor was subjected to shock by increasing the organic load suddenly from 8.9 to 31 kg COD/m3/day, the total COD removal decreased to 72% and then returned to 86% after 7 days. Hydrology tests indicated that the reactor functions as a series of completely mixed stirred tanks. At Nutrinor, using a 12-h retention time and diluted whey permeate (20,000 mg/L COD), total COD removal was 86% and gas production was 12.0 m3/m3/day for a loading of 36.5 kg COD/m3/day. Nutrient supplementation was not required. For experiments performed with different proportions of wastewater (2,000 mg/L COD) to whey permeate (70,000 mg/L COD) results of 89% total and 93% soluble COD removal with a gas production of 11 m3/m3/day for a loading of 25 kg COD/m3/day were obtained. Retention times were varied from 18 to 60 h to correspond to initial CODs of 20,000 to 70,000 mg/L. In conclusion, this reactor functions in a superior manner to other published anaerobic treatment systems.


2013 ◽  
Vol 750-752 ◽  
pp. 1381-1384 ◽  
Author(s):  
Xi Wang ◽  
Hua Zhao

Biological treatment is one of the considerable choices for removing of organic pollutants present in petrochemical wastewaters. In this study, BS5, the isolate with the highest COD removal rate, was identified asBacillus flexus, based on 16S rDNA sequences. Subsequently, the optimized COD removal conditions of BS5 were investigated. It was indicated that the optimal conditions were 35°C, pH 7.5. Under such circumstance, the removal rate of COD can reach 81.04%. The isolation ofBacillus flexusstrain BS5 provided an alternative for the bioremediation of alkaline wastewater. Lastly, the study showed that consecutive disposal process may help to reducing COD of wastewater effectively.


2011 ◽  
Vol 255-260 ◽  
pp. 2962-2966
Author(s):  
Rong Gui Fan ◽  
Chun E Li ◽  
Yong Xin Bai ◽  
Da Qing Huang ◽  
Liao Wei Fang ◽  
...  

The electrochemical oxidation of wastewater from DDNP production was investigated using a boron-doped diamond (BDD) thin film electrode. The effects of operating factors such as cell voltage, interelectrode distance and additive NaCl have been studied. This study showed that the chemical oxygen demand (COD) reduction is most influenced by the applied cell voltage. Higher current densities resulting from higher cell voltages increase the formation of oxidative reagents resulting in an increased COD removal rate. The maximum COD removal was 57% after 210 min, with an energy consumption of 14.90 KWh·kg-1 COD when cell voltage was 12V, interelectrode distance was 3cm and additive NaCl concentration was 1g·L-1. The use of BDD thin film electrode for the treatment of DDNP production wastewater appears commercially feasible.


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