scholarly journals Combining Coagulation and Electrocoagulation with UVA-LED Photo-Fenton to Improve the Efficiency and Reduce the Cost of Mature Landfill Leachate Treatment

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6425
Author(s):  
Javier Tejera ◽  
Daphne Hermosilla ◽  
Antonio Gascó ◽  
Carlos Negro ◽  
Ángeles Blanco

This study focused on the reduction of the treatment cost of mature landfill leachate (LL) by enhancing the coagulation pre-treatment before a UVA-LED photo-Fenton process. A more efficient advanced coagulation pretreatment was designed by combining conventional coagulation (CC) and electro-coagulation (EC). Regardless of the order in which the two coagulations were applied, the combination achieved more than 73% color removal, 80% COD removal, and 27% SUVA removal. However, the coagulation order had a great influence on both final pH and total dissolved iron, which were key parameters for the UVA-LED photo-Fenton post-treatment. CC (pH = 5; 2 g L−1 of FeCl36H2O) followed by EC (pH = 5; 10 mA cm−2) resulted in a pH of 6.4 and 100 mg L−1 of dissolved iron, whereas EC (pH = 4; 10 mA cm−2) followed by CC (pH = 6; 1 g L−1 FeCl36H2O) led to a final pH of 3.4 and 210 mg L−1 dissolved iron. This last combination was therefore considered better for the posterior photo-Fenton treatment. Results at the best cost-efficient [H2O2]:COD ratio of 1.063 showed a high treatment efficiency, namely the removal of 99% of the color, 89% of the COD, and 60% of the SUVA. Conductivity was reduced by 17%, and biodegradability increased to BOD5:COD = 0.40. With this proposed treatment, a final COD of only 453 mg O2 L−1 was obtained at a treatment cost of EUR 3.42 kg COD−1.

2011 ◽  
Vol 46 (1) ◽  
pp. 148-153 ◽  
Author(s):  
Susana Cortez ◽  
Pilar Teixeira ◽  
Rosário Oliveira ◽  
Manuel Mota

Author(s):  
Siti Nor Farhana Zakaria

Landfill leachate is a hazardous pollutant generated from a landfill site. Discharge of landfill leachate has caused a major contamination to the environment and detrimental to human health. This chapter introduces an alternative method to treat recalcitrant pollutant in leachate by using ozonation with catalyst. The production of hydroxyl radical in ozonation was not enough to oxidize complex molecular structure in the leachate. Theoretically, the addition of catalyst enhances the capacity of radical and accelerates the chemical reaction. The effectiveness of ozonation with Fenton (O3/Fenton), hydrogen peroxide (O3/H2O2), and zirconium tetrachloride (O3/ZrCl4) in removing pollutant such as chemical oxygen demand (COD), color, and improvement of biodegradability by using this process were also discussed in this chapter. Comparison in term of treatment cost and benefits of the application of chemical as catalyst are briefly elaborated at the end of this chapter.


2020 ◽  
pp. 204-220
Author(s):  
Zawawi Daud ◽  
Halizah Awang

In this chapter, the performance of combined treatment of municipal landfill leachate is reviewed. Although individual physico-chemical treatments are suitable for the removal of heavy metals and hydrolyzation of some organic compounds, a combination of two physico-chemical treatments or physico-chemical and biological is required for optimum treatment of stabilized landfill leachate. A combination of two physico-chemical treatments can give optimum results in removal of recalcitrant organic compounds from stabilized leachate, as reflected by a significant decrease of the COD values after treatment. On the other hand, a combination of physico-chemical and biological treatments is required to achieve effective removal of NH3-N and COD with a substantial amount of biodegradable organic matter. In many cases, physico-chemical treatments are suitable for pre-treatment of stabilized leachate. The objective of this paper is to highlight various types of integrated leachate treatments as it has been difficult to get optimum efficiency from single approached treatment.


2006 ◽  
Vol 1 (3) ◽  
Author(s):  
A. Vilar ◽  
S. Gil ◽  
M. A. Aparicio ◽  
C. Kennes ◽  
M. C. Veiga

The optimization of leachate treatment was investigated as well as the configuration of a biological-ozonation process. The leachate used for the experiments was diluted to 1/5 with tap water and treated anaerobically. The anaerobic effluent and the raw leachate were treated with ozone in order to increase their biodegradability getting the minimum organic matter removal. Both were submitted to the ozonation process, applying a constant ozone dose and varying the contact time. The ozonation of raw leachate produced a decrease of COD and BOD5 concentrations as well as BOD5/COD ratios, applying an ozone dose of 38.72 mg/L·min and contact times between 15 and 60 minutes. Ozonation as a pre-treatment process to the biological system did not improve the biodegradability of the raw leachate. The anaerobic effluent from the reactor fed with leachate diluted to 1/5, was subjected to an ozone dose of 34.99 mg/L·min and applying different contact times. BODf values increased from 74.75 up to 1220 mg/L and BODf/COD ratios reached values higher than 1. Then, the application of ozone to the anaerobic effluent led to the improvement of the biodegradability of the leachate as well as the BODf/COD ratio for all the contact times used.


2013 ◽  
Vol 295-298 ◽  
pp. 1472-1477
Author(s):  
Tao Yu ◽  
Tao Huang ◽  
Yin Xi Pan ◽  
Lin Hai Yang

The technology used the coagulation-sedimentation + electro-oxidation joint reactor has been studied to treat landfill leachate. First adding FeCl30.4g/L into all leachate for coagulation and sedimentation, its CODcr elimination rate can achieve 35%, but does have no effect on ammonia nitrogen. Then using electro-oxidation reactor to deal with effluent water, the reaction order of electro-oxidation reactor is first-level, as the reaction conditions are 20mA/cm2 of electric current density, 140min of reaction time, the leachate CODcr elimination rate can reach to above 90%, the ammonia nitrogen elimination rate meets to 98% around. Using coagulation-sedimentation + electro coagulation joint reactor to treat landfill leachate can get stable effluent water quality with good treatment effect, has very high elimination efficiency of CODcr and ammonia nitrogen. It is a suitable treatment technology for landfill leachate.


1996 ◽  
Vol 34 (9) ◽  
pp. 33-40 ◽  
Author(s):  
J. Fettig ◽  
H. Stapel ◽  
C. Steinert ◽  
M. Geiger

Landfill leachate pretreated in an aerobic biological stage was studied with respect to the adsorption behaviour of its organic components with and without preoxidation by different amounts of ozone. Isotherm data evaluated by adsorption analysis showed that the fractions of non-adsorbable and weakly adsorbable species had been increased after preoxidation. As a result, the carbon capacity in a fixed-bed adsorption process was expected to be significantly lower for preoxidized leachate. This conclusion was confirmed by data from column experiments. The breakthrough curves under operating conditions typical for leachate treatment could be predicted quite well by the homogeneous surface diffusion model when no preoxidation was applied. After preozonation about 40% of the remaining organic substances were biodegradable. Data evaluation revealed that biodegradation took place inside the activated carbon beds. Therefore the total removal of ozonated leachate in activated carbon columns will be higher than the removal due to adsorption processes. An economic analysis must show in any practical case whether a combination of preoxidation and adsorption will be more cost-efficient than either of the single processes. The modelling technique applied in this study can be a useful tool for that purpose.


2019 ◽  
Vol 118 ◽  
pp. 04017
Author(s):  
Yuan-Yuan Zhao ◽  
You-Ze Xu ◽  
Shuang Zhou ◽  
Jiao-Mei Liu ◽  
Yingxiang Cheng ◽  
...  

In order to verify the feasibility of Fe/C microelectrolysis-Fenton oxidation for mature landfill leachate treatment in industrial application, this study conducted the treatment processes at full-scale by physicochemical and spectral characterization. The full-scale studies showed that 48.17% of the dissolved organic carbon (DOC) and 42.27% of the dissolved organic nitrogen (DON) were removed by the microelectrolysis-Fenton oxidation process, respectively. Spectra analysis further suggested that the mature leachate was mainly composed of tryptophan-like and fulvic-like compounds. The combination of microelectrolysis and Fenton oxidation efficiently decomposed the aromatic C=C into carboxyl-C and decreased the molecular size of DOC, resulting in a dramatic reduce (97.1%-98.3%) of the fluorescence intensity. The DON removal by microelectrolysis-Fenton oxidation likely associated with the NH2-decomposition of tryptophan-like and aromatic compounds into NO3-N. The tryptophan-like compounds may play a dominant role in Ba binding, while Pb and Cd were likely bound to both the tryptophan-like and fulvic-like compounds. Above 60% of the heavy metals were removed in the microelectrolysis-Fenton oxidation section. Results above confirmed the effectiveness of Fe/C microelectrolysis-Fenton oxidation for mature landfill leachate treatment in industrial application.


Author(s):  
Zawawi Daud ◽  
Halizah Awang

In this chapter, the performance of combined treatment of municipal landfill leachate is reviewed. Although individual physico-chemical treatments are suitable for the removal of heavy metals and hydrolyzation of some organic compounds, a combination of two physico-chemical treatments or physico-chemical and biological is required for optimum treatment of stabilized landfill leachate. A combination of two physico-chemical treatments can give optimum results in removal of recalcitrant organic compounds from stabilized leachate, as reflected by a significant decrease of the COD values after treatment. On the other hand, a combination of physico-chemical and biological treatments is required to achieve effective removal of NH3-N and COD with a substantial amount of biodegradable organic matter. In many cases, physico-chemical treatments are suitable for pre-treatment of stabilized leachate. The objective of this paper is to highlight various types of integrated leachate treatments as it has been difficult to get optimum efficiency from single approached treatment.


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