Anthraquinone (AQS)/polyaniline (PANI) modified carbon felt (CF) cathode for selective H2O2 generation and efficient pollutant removal in electro-Fenton

2022 ◽  
Vol 304 ◽  
pp. 114315
Author(s):  
Ying Gao ◽  
Weihuang Zhu ◽  
Yaqi Li ◽  
Qingyu Zhang ◽  
Haonan Chen ◽  
...  
Keyword(s):  
Pollutant Removal ◽  
Carbon Felt ◽  
H2o2 Generation

scholarly journals Combined Electro-Fenton and Anodic Oxidation Processes at a Sub-Stoichiometric Titanium Oxide (Ti4O7) Ceramic Electrode for the Degradation of Tetracycline in Water

Water ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 2772
Author(s):  
Busisiwe N. Zwane ◽  
Benjamin O. Orimolade ◽  
Babatunde A. Koiki ◽  
Nonhlangabezo Mabuba ◽  
Chaimaa Gomri ◽  
...  
Keyword(s):  
Titanium Oxide ◽  
Anodic Oxidation ◽  
Removal Efficiency ◽  
Degradation Products ◽  
Complete Removal ◽  
Pollutant Removal ◽  
Carbon Felt ◽  
Oxidation Processes ◽  
Electrochemical Advanced Oxidation Processes ◽  
Total Organic Carbon Removal

The mineralization of tetracycline by electrochemical advanced oxidation processes (EAOPs) as well as the study of the toxicity of its intermediates and degradation products are presented. Electro-Fenton (EF), anodic oxidation (AO), and electro-Fenton coupled with anodic oxidation (EF/AO) were used to degrade tetracycline on carbon felt (cathode) and a sub-stoichiometric titanium oxide (Ti4O7) layer deposited on Ti (anode). As compared to EF and AO, the coupled EF/AO system resulted in the highest pollutant removal efficiencies: total organic carbon removal was 69 ± 1% and 68 ± 1%, at 20 ppm and 50 ppm of initial concentration of tetracycline, respectively. The effect of electrolysis current on removal efficiency, mineralization current efficiency, energy consumption, and solution toxicity of tetracycline mineralization were investigated for 20 ppm and 50 ppm tetracycline. The EF/AO process using a Ti4O7 anode and CF cathode provides low energy and high removal efficiency of tetracycline caused by the production of hydroxyl radicals both at the surface of the non-active Ti4O7 electrode and in solution by the electro-Fenton process at the cathodic carbon felt. Complete removal of tetracycline was observed from HPLC data after 30 min at optimized conditions of 120 mA and 210 mA for 20 ppm and 50 ppm tetracycline concentrations. Degradation products were elucidated, and the toxicity of the products were measured with luminescence using Microtox® bacteria toxicity test.

The characteristics and mechanism of electrochemical peroxymonosulfate activation by Co-N@CF anode for pollutant removal

2021 ◽  
Author(s):  
Ping Lin ◽  
Weihuang Zhu ◽  
Ying Gao ◽  
Junli Li ◽  
Jiawu Liu ◽  
...  
Keyword(s):  
Influencing Factors ◽  
Pollutant Removal ◽  
Carbon Felt ◽  
Kinetic Characteristics

Herein, the carbon felt modified by N and Co (Co-N@CF) was prepared as the anode to effectively activate peroxymonosulfate (PMS) for tetracycline (TC) removal. The influencing factors, kinetic characteristics and...

Field-Scale Studies of Subsurface Flow Constructed Wetlands for Stormwater Quality Enhancement

1997 ◽  
Vol 32 (1) ◽  
pp. 101-118 ◽  
Author(s):  
Q.J. ROCHFORT ◽  
W.E. Watt ◽  
J. Marsalek ◽  
B.C. Anderson ◽  
A.A. Crowder
Keyword(s):  
Organic Carbon ◽  
Constructed Wetlands ◽  
Suspended Solids ◽  
Nutrient Loading ◽  
Subsurface Flow ◽  
Reaction Rates ◽  
Pollutant Removal ◽  
Order Kinetic ◽  
Dissolved Metals ◽  
Subsurface Flow Constructed Wetlands

Abstract Two subsurface flow constructed wetlands were tested for pollutant removal performance in conjunction with an on-line stormwater detention pond, in Kingston Township, Ontario. The 4.9 m2 wetland cells were filled with 9 mm limestone gravel, and planted with cattail, common reed and spike rush. Changes in nutrient (total organic carbon, PO43- and NH4+), suspended solids and metal (Cu, Pb, Zn) concentrations were used to assess performance. Contaminant removal occurred through a combination of physical, chemical and biological means. As with any biological system, variation in performance of stormwater wetlands can be expected to occur as a result of fluctuations in contaminant loading, contact time and ambient environmental conditions. Storm pond effluent was delivered in continuous flow through the wetlands (during baseflow and event conditions), with a detention time of 1 to 3 days. The wetlands were able to maintain removal rates of up to 39% for orthophosphate even during the more severe conditions of fall dieback. Average removal of suspended solids (46%) and dissolved metals (Cu 50%) remained similar throughout all tests. Organic carbon was reduced by less than 10% during these tests. Low nutrient levels in the pond effluent were supplemented by spiking with sources of carbon, nitrogen and phosphorus during pulsed loading conditions. Daily sampling produced a time series, which illustrated the rates of decline in concentration of nutrients. First order kinetic assimilation rates ranged from 1.7 d-1 for NH4002B to 0.12 d-1 for organic carbon, which were noticeably lower when compared with municipal and industrial wastewater treatment rates. Three methods of sizing stormwater wetlands (impervious surface area, volumetric load and kinetic reaction rates) were compared using the same design storm and data from this study. From this comparison it was seen that the kinetic sizing approach proved to be the most versatile, and allowed for adaptation to northern climatic conditions and anticipated nutrient loading.

Performance and Modelling of a Highway Wet Detention Pond Designed for Cold Climate

2009 ◽  
Vol 44 (3) ◽  
pp. 253-262 ◽  
Author(s):  
Jes Vollertsen ◽  
Svein Ole Åstebøl ◽  
Jan Emil Coward ◽  
Tor Fageraas ◽  
Asbjørn Haaning Nielsen ◽  
...  
Keyword(s):  
Rate Constants ◽  
Pond Water ◽  
Pollutant Removal ◽  
Cold Climate ◽  
Traffic Load ◽  
Substantial Part ◽  
First Order ◽  
Detention Pond ◽  
Time Of Year ◽  
Wet Detention Pond

Abstract A wet detention pond in Norway has been monitored for 12 months. The pond receives runoff from a highway with a traffic load of 42,000 average daily traffic. Hydraulic conditions in terms of inflow, outflow, and pond water level were recorded every minute. Water quality was monitored by volume proportional inlet and outlet samples. During most of the year, excellent pollutant removal was achieved; however, during two snowmelt events the pollutant removal was poor or even negative. The two snowmelt events accounted for one third of the annual water load and for a substantial part of the annual pollutant discharge. The performance of the pond was analyzed using a dynamic model and pollutant removal was simulated by first-order kinetics. Good agreement between measurement and simulation could be achieved only when choosing different first-order rate constants for different parts of the year. However, no relation between the rate constants obtained and the time of year could be identified, and neither did the rate constants for different pollutants correlate. The study indicates that even detailed measurements of pollutant input and output allow only average performance to be simulated and are insufficient for simulating event-based variability in pond performance.

scholarly journals Selenium in wastewater can be adsorbed by modified natural zeolite and reused in vegetable growth

2021 ◽  
Vol 104 (2) ◽  
pp. 003685042110198
Author(s):  
Xiao Zhang ◽  
Xinyuan Li ◽  
Zihao Jin ◽  
Sadam Hussain Tumrani ◽  
Xiaodong Ji
Keyword(s):  
Aqueous Solution ◽  
Ph Value ◽  
Soil Improvement ◽  
Pollutant Removal ◽  
Maximum Adsorption Capacity ◽  
Selenium Content ◽  
Water Release ◽  
Soil Release ◽  
Release Ratio ◽  
Water Pollutant

Modified natural zeolites (MNZ) are widely used in pollutant removal, but how to address these MNZ that have adsorbed pollutants must be considered. Selenium is an essential trace element for metabolism and is also a water pollutant. Selenium is adsorbed in the water by MNZ in this study first. Then the Brassica chinensis L. was planted in the soil which contains the MNZ loaded with selenium (MNZ-Se) to explore selenium uptake. MNZ-Se release tests in water and soil were also considered. The results showed the following: (1) The maximum adsorption capacity of MNZ for selenium is 46.90 mg/g. (2) Water release experiments of MNZ-Se showed that regardless of how the pH of the aqueous solution changes, the trend of the release of selenium from MNZ-Se in aqueous solution is not affected and first decreases before stabilizing. (3) Soil release experiments of MNZ-Se showed that the selenium content in the soil increased and reached the concentration in the standard of selenium-rich soil. Addition amount and soil pH value will affect the release ratio. The release ratio of MNZ-Se in the water was higher than that in the soil. (4) With an increase in the soil MNZ-Se content, the selenium content in the soil and B. c increases. Above all, MZN can be a good medium for water pollutant removal and soil improvement.

scholarly journals Activation of Peroxymonosulfate Using Secondary Pyrolysis Oil-Based Drilling Cuttings Ash for Pollutant Removal

ACS Omega ◽  
2021 ◽  
Author(s):  
Yuqing Zhao ◽  
Hang Yang ◽  
Jianfa Sun ◽  
Yi Zhang ◽  
Shibin Xia
Keyword(s):  
Pollutant Removal ◽  
Pyrolysis Oil

scholarly journals Inorganic Nitrogen Production and Removal along the Sediment Gradient of a Stormwater Infiltration Basin

Water ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 320
Author(s):  
Qianyao Si ◽  
Mary G. Lusk ◽  
Patrick W. Inglett
Keyword(s):  
Removal Efficiency ◽  
N Mineralization ◽  
Inorganic Nitrogen ◽  
Dry Season ◽  
Pollutant Removal ◽  
Net N Mineralization ◽  
Wet Season ◽  
Inorganic N ◽  
N Removal ◽  
Stormwater Infiltration

Stormwater infiltration basins (SIBs) are vegetated depressions that collect stormwater and allow it to infiltrate to underlying groundwater. Their pollutant removal efficiency is affected by the properties of the soils in which they are constructed. We assessed the soil nitrogen (N) cycle processes that produce and remove inorganic N in two urban SIBs, with the goal of further understanding the mechanisms that control N removal efficiency. We measured net N mineralization, nitrification, and potential denitrification in wet and dry seasons along a sedimentation gradient in two SIBs in the subtropical Tampa, Florida urban area. Net N mineralization was higher in the wet season than in the dry season; however, nitrification was higher in the dry season, providing a pool of highly mobile nitrate that would be susceptible to leaching during periodic dry season storms or with the onset of the following wet season. Denitrification decreased along the sediment gradient from the runoff inlet zone (up to 5.2 μg N/g h) to the outermost zone (up to 3.5 μg N/g h), providing significant spatial variation in inorganic N removal for the SIBs. Sediment accumulating around the inflow areas likely provided a carbon source, as well as maintained stable anaerobic conditions, which would enhance N removal.

scholarly journals Treatment of Combined Dairy and Domestic Wastewater with Constructed Wetland System in Sicily (Italy). Pollutant Removal Efficiency and Effect of Vegetation

Water ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1086
Author(s):  
Mario Licata ◽  
Roberto Ruggeri ◽  
Nicolò Iacuzzi ◽  
Giuseppe Virga ◽  
Davide Farruggia ◽  
...  
Keyword(s):  
Plant Growth ◽  
Organic Compounds ◽  
Removal Efficiency ◽  
Constructed Wetland ◽  
Organic Pollutant ◽  
Dairy Farm ◽  
Domestic Wastewater ◽  
Pollutant Removal ◽  
Dairy Wastewater ◽  
Giant Reed

Dairy wastewater (DWW) contains large amounts of mineral and organic compounds, which can accumulate in soil and water causing serious environmental pollution. A constructed wetland (CW) is a sustainable technology for the treatment of DWW in small-medium sized farms. This paper reports a two-year study on the performance of a pilot-scale horizontal subsurface flow system for DWW treatment in Sicily (Italy). The CW system covered a total surface area of 100 m2 and treated approximately 6 m3 per day of wastewater produced by a small dairy farm, subsequent to biological treatment. Removal efficiency (RE) of the system was calculated. The biomass production of two emergent macrophytes was determined and the effect of plant growth on organic pollutant RE was recorded. All DWW parameters showed significant differences between inlet and outlet. For BOD5 and COD, RE values were 76.00% and 62.00%, respectively. RE for total nitrogen (50.70%) was lower than that of organic compounds. RE levels of microbiological parameters were found to be higher than 80.00%. Giant reed produced greater biomass than umbrella sedge. A seasonal variation in RE of organic pollutants was recorded due to plant growth rate Our findings highlight the efficient use of a CW system for DWW treatment in dairy-cattle farms.

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