Applicability of an electrochemical Fenton-type process to actual wastewater treatment

2015 ◽  
Vol 72 (6) ◽  
pp. 850-857 ◽  
Author(s):  
Naoyuki Kishimoto ◽  
Takuya Kitamura ◽  
Yu Nakamura
Keyword(s):  
Wastewater Treatment ◽  
Chemical Oxygen Demand ◽  
Municipal Wastewater ◽  
Oxygen Demand ◽  
Metal Scrap ◽  
Yellow Colour ◽  
Type Process ◽  
Automobile Factory ◽  
High Concentrations ◽  
Electrochemical Fenton

The applicability of an electrochemical Fenton-type process (EF-HOCl-ReFe) to the treatment of three actual wastewaters, namely wastewater from an automobile factory (automobile wastewater), metal scrap-cleansing wastewater, and municipal wastewater, is discussed in this research. The EF-HOCl-ReFe successfully removed the chemical oxygen demand (COD) from automobile wastewater pre-treated by a coagulation process without any inhibition. The apparent current efficiency reached 86%, 46% of which was ascribed to the electrochemical Fenton-type mechanism. The metal scrap-cleansing wastewater had a yellow colour and high concentrations of COD (6550 mg/L) and Cl− (1560 mM). The EF-HOCl-ReFe could achieve almost complete COD removal and decolourization after 48 h of treatment, although a temporary intensification of colour was observed before the decolourization. The EF-HOCl-ReFe was also effective in the removal of 1,4-dioxane from municipal wastewater pre-treated by activated sludge and coagulation processes, which were unable to remove 1,4-dioxane. The 1,4-dioxane removal efficiency after 30 min of treatment reached 68.5%. Thus, the EF-HOCl-ReFe was applicable to the treatment of these actual wastewaters.

scholarly journals Bio-tower Application for Wastewater Treatment

2020 ◽  
pp. 1-7
Author(s):  
Klaus Doelle ◽  
Yue Qin ◽  
Qian Wang
Keyword(s):  
Wastewater Treatment ◽  
Chemical Oxygen Demand ◽  
Total Phosphorus ◽  
Municipal Wastewater ◽  
Oxygen Demand ◽  
Growth Media ◽  
Performance Tests ◽  
Flow Rates ◽  
Batch Type ◽  
Phosphorus Reduction

The study tested the performance of a batch-type recirculating laboratory scale bio-tower for the treatment of municipal wastewater. Performance tests were done with a HACH DR-1900 spectrophotometer include chemical oxygen demand, total phosphorus and nitrogen ammonia. This study showed that the recirculated laboratory type bio-tower containing 0.276 ft3 (0.008 m3) of polypropylene growth media with a surface area of 6.624 ft2 (0.615 m2) can reduce the chemical oxygen demand between 70% to 87%. NH3-N reduction was found to be between 94% to 96%, and total phosphorus reduction was between 69% and 87% for flow rates of 0.6 l/min to 1.5 l/min.

scholarly journals Excessive greenhouse gas emissions from wastewater treatment plants by using the chemical oxygen demand standard

2021 ◽  
Author(s):  
Zongqing Lv ◽  
Xiaoyu Shan ◽  
Xilin Xiao ◽  
Ruanhong Cai ◽  
Yao Zhang ◽  
...  
Keyword(s):  
Organic Matter ◽  
Wastewater Treatment ◽  
Chemical Oxygen Demand ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Carbon Sink ◽  
Oxygen Demand ◽  
Organic Pollution ◽  
Municipal Wastewater Treatment ◽  
Recalcitrant Organic Matter

AbstractChemical oxygen demand (COD) is widely used as an organic pollution indicator in wastewater treatment plants. Large amounts of organic matter are removed during treatment processes to meet environmental standards, and consequently, substantial greenhouse gases (GHGs) such as methane (CH4) are released. However, the COD indicator covers a great amount of refractory organic matter that is not a pollutant and could be a potential carbon sink. Here, we collected and analysed COD data from 86 worldwide municipal wastewater treatment plants (WWTPs) and applied a model published by the Intergovernmental Panel on Climate Change to estimate the emission of CH4 due to recalcitrant organic compound processing in China’s municipal wastewater treatment systems Our results showed that the average contribution of refractory COD to total COD removal was 55% in 86 WWTPs. The amount of CH4 released from the treatment of recalcitrant organic matter in 2018 could have been as high as 38.22 million tons of carbon dioxide equivalent, which amounts to the annual carbon sequestered by China’s wetlands. This suggests that the use of COD as an indicator for organic pollution is undue and needs to be revised to reduce the emission of GHG. In fact, leaving nontoxic recalcitrant organic matter in the wastewater may create a significant carbon sink and will save energy during the treatment process, aiming at carbon neutrality in the wastewater treatment industry.

scholarly journals Precious Data from Tiny Samples: Revealing the Correlation Between Energy Content and the Chemical Oxygen Demand of Municipal Wastewater by Micro-Bomb Combustion Calorimetry

2021 ◽  
Vol 9 ◽  
Author(s):  
Benjamin Korth ◽  
Claudia Heber ◽  
Monika Normant-Saremba ◽  
Thomas Maskow ◽  
Falk Harnisch
Keyword(s):  
Wastewater Treatment ◽  
Chemical Oxygen Demand ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Energy Content ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Combustion Calorimetry ◽  
Energy Potential ◽  
Combustion Enthalpy

Wastewater treatment plants (WWTP) are aimed to be transformed from sinks into sources of energy and material. For fostering corresponding engineering efforts and economic assessments, comprehensive knowledge of the energy content of wastewater is required. We show in this proof-of-concept study that these data can be gathered by combining micro-bomb combustion calorimetry with freeze-drying. Thereby, the methodology for measuring the combustion enthalpy (ΔcH) of wastewater is significantly improved by decreasing the time demand for the drying process as only tiny amounts of samples are required. Here, the effluent of the primary clarifier of a wastewater treatment plant treating low-strength municipal wastewater was sampled on a weekly basis for 1 year, yielding 53 composite samples that were analyzed for ΔcH and standard wastewater parameters. A robust correlation between the chemical oxygen demand (COD) and ΔcH of −14.9 ± 3.5 kJ gCOD−1 (r = 0.51) was determined, verifying previous results obtained with more laborious and time-demanding methodologies. The global chemical energy potential of the sampled WWTP is presumably higher as the first treatment steps and losses during sample preparation reduced the amount of energy-rich compounds. A stronger correlation was observed between ΔcH and the biochemical oxygen demand (BOD5, r = 0.64), suggesting its usage for predicting the potential of wastewater as feedstock for biotechnological applications. This demonstrates that micro-bomb combustion calorimetry can be applied for deriving precious information on the energy content of wastewater from simple COD measurements.

Metro-environmental data approach for the prediction of chemical oxygen demand in new Nicosia wastewater treatment plant

2021 ◽  
Vol 221 ◽  
pp. 31-40
Author(s):  
A.S. Mubarak ◽  
Parvaneh Esmaili ◽  
Z.S. Ameen ◽  
R.A. Abdulkadir ◽  
M.S. Gaya ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Chemical Oxygen Demand ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Environmental Data

scholarly journals Municipal Wastewater Treatment Using a Packed Bio-tower Approach

2020 ◽  
pp. 42-50
Author(s):  
Klaus Doelle ◽  
Qian Wang
Keyword(s):  
Wastewater Treatment ◽  
Flow Rate ◽  
Municipal Wastewater ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Continuous Operation ◽  
Growth Media ◽  
Municipal Wastewater Treatment ◽  
Bacteria Growth ◽  
Tower System

The study tested a designed and built pilot scale packed bio-tower system under continuous operation using pre-clarified municipal wastewater. Performance was evaluated by measuring the removal of chemical oxygen demand and nitrogen ammonia. The pilot scale packed bio-tower system had a diameter of 1209 mm (4 ft.) and a height of 3,962 mm (13 ft.) and contained Bentwood CF-1900 bacteria growth media with a surface area of 6,028.80 ft² (560.09 m²). The municipal residential sewage was fed into a 1,481 l (375 gal.) recirculation reservoir at a temperature of 15°C (59.0°F) and a flow rate between 7,571 l/d (2000 gal/d) and 90,850 l/d (24,000 gal/d) and recirculated through the bio-tower with a fixed recirculation rate of 75.7 l/min (20 gal/min). The influent COD value reduction achieved is between 63.4% and 84.8%, whereas the COD influent value varied between 87 mg/l and 140 mg/l. The influent NH3-N reduction achieved was between 99.8% and 91.8% whereas the influent NH3-N value was between 28.8 mg/l and 18.6 mg/l  at a flow rate between 7571 l/d (2000 gal/d) and 90,850 l/d (24,000 gal/d).

scholarly journals Wastewater treatment in flow photobioreactors continuous illuminated by artificial and solar light

2020 ◽  
Vol 9 (6) ◽  
pp. e183963748
Author(s):  
Rafael Souza Leopoldino Nascimento ◽  
Ludymyla Marcelle Lima Silva ◽  
Lucas Periard ◽  
Anibal da Fonseca Santiago
Keyword(s):  
Organic Matter ◽  
Wastewater Treatment ◽  
Chemical Oxygen Demand ◽  
Continuous Flow ◽  
Suspended Solids ◽  
Oxygen Demand ◽  
Total Suspended Solids ◽  
Operational Stability ◽  
Artificial Light ◽  
Light Emitting

The technology of microalgae photobioreactors and illuminated by LEDs has been widely studied for the treatment of wastewater. However, sunlight is a free resource and should be taken advantage of. But the question remains whether photobioreactors illuminated by natural (sunlight) light in combination with artificial light can have greater operational stability or greater performance when compared to systems illuminated only by artificial light. In this context, continuous flow photobioreactors illuminated by Light Emitting Diodes (LEDs) combined, or not, with sunlight were operated and had their performance evaluated. The variables analyzed were pH, OD, chemical oxygen demand (COD), chlorophyll - a and total suspended solids. The photobioreactors were effective for removing organic matter, with 75 ± 15% in the photobioreactor illuminated by LED and 65 ± 10% in the photobioreactor illuminated by sunlight and LED. The results showed that the use of combined lighting favors the production of dissolved oxygen and ensures greater operational stability in the removal of carbonaceous organic matter.

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