A combined treatment of landfill leachate using calcium oxide, ferric chloride and clinoptilolite

2011 ◽  
Vol 46 (3) ◽  
pp. 323-328 ◽  
Author(s):  
Visnja Orescanin ◽  
Damir Ruk ◽  
Robert Kollar ◽  
Ivanka Lovrencic Mikelic ◽  
Karlo Nad ◽  
...  
2012 ◽  
Vol 63 (1) ◽  
pp. 21-26 ◽  
Author(s):  
Višnja Oreščanin ◽  
Robert Kollar ◽  
Karlo Nađ ◽  
Ivanka Mikelić ◽  
Nenad Mikulić

Boat Pressure Washing Wastewater Treatment with Calcium Oxide and/or Ferric ChlorideThe aim of this study was to investigate the efficiency of (1) chemical precipitation by calcium oxide, (2) coagulation/flocculation by ferric chloride (FC), and (3) the combination these two methods in reducing the toxicity of wastewater generated by boat pressure washing. All three methods gave satisfactory results in the removal of colour, turbidity, Cr, Fe, Cu, Zn, and Pb. The concentrations of heavy metals were lowered below national limits with 1 g of CaO, 2.54 mg of Fe3+ in the form of FeCl3x6H2O, and the combination of 0.25 g of CaO and 5.08 mg of Fe3+ per 50 mL of wastewater. Both CaO (1.50 g per 50 mL of wastewater) and FC proved efficient, but their combination yielded a significantly better performance: 99.41 %, 100.00 %, 97.87 %, 99.09 %, 99.90 %, 99.46 % and 98.33 % for colour, turbidity, Cr, Fe, Cu, Zn, and Pb respectively. For colour, Cr, Cu, Zn, and Pb removal efficiencies increased in the following order: FC<CaO<CaO+FC, while this order for turbidity and Fe was as follows: CaO<FC<CaO+FC. As expected, all three methods increased the concentration of total dissolved solids in the final effluent. Our results suggest that the combined treatment of marina wastewaters with calcium oxide followed by ferric chloride is efficient, cost-effective, and user-friendly.


1978 ◽  
Vol 5 (1) ◽  
pp. 83-97 ◽  
Author(s):  
Robert D. Cameron

The use of cheap, locally available peat as a treatment method for landfill leachate was investigated by passing leachate through plexiglass columns filled with an amorphous-granular peat. Preliminary adjustment of pH showed that reducing pH to 4.8 dramatically reduced adsorption. Increasing the pH to 8.4, metal removal was increased owing to filtration of precipitated metals. The best adsorption of metals occurred at the 'natural' pH of 7.1. Manganese was found to be the limiting pollutant. At the 0.05 mg/ℓ maximum acceptable manganese concentration 94% of the total metals were removed, requiring 159 kg of peat per 1000 ℓ of leachate.Resting the peat for 1 month did significantly increase removal capacity.Desorption of some contaminants occurred when water was percolated through the peat. The desorption test effluent was not toxic to fish although iron, lead and COD (chemical oxygen demand) exceeded acceptable values.Chemical pretreatment using lime and ferric chloride achieved significant iron, manganese and calcium removals. Chemical pretreatment followed by peat adsorption offered no advantage other than reducing toxicity to fish.Peat treatment alone was effective in reducing concentrations to a level that was non-toxic to fish.


Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 946
Author(s):  
Chunlian Wang ◽  
Xiaojie Sun ◽  
Huijun Shan ◽  
Hongxia Zhang ◽  
Beidou Xi

This study explored the performance of TiO2 nanoparticles in combination with aged waste reactors to treat landfill leachate. The optimum conditions for synthesis of TiO2 were determined by a series of characterizations and removal rates of methyl orange. The effect of the ultraviolet irradiation time, amount of the catalyst, and pH on the removal efficiency for the chemical oxygen demand (COD) and color in the leachate was explored to determine the optimal process conditions, which were 500 min, 4 g/L and 8.88, respectively. The removal rates for COD and chroma under three optimal conditions were obtained by the single factor control method: 89% and 70%; 95.56% and 70%; and 85% and 87.5%, respectively. Under optimal process conditions, the overall average removal rates for ammonium nitrogen (NH4+–N) and COD in the leachate for the combination of TiO2 nanoparticles and an aged waste reactor were 98.8% and 32.5%, respectively, and the nitrate (NO3−–N) and nitrite nitrogen (NO2–N) concentrations were maintained at 7–9 and 0.01–0.017 mg/L, respectively. TiO2 nanoparticles before and after the photocatalytic reaction were characterized by emission scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, and Fourier transform infrared spectrometry. In addition, TiO2 nanoparticles have excellent recyclability, showing the potential of the photocatalytic/biological combined treatment of landfill leachate. This simulation of photocatalysis-landfilling could be a baseline study for the implementation of technology at the pilot scale.


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.


Author(s):  
Amin Mojiri ◽  
John L. Zhou ◽  
Harsha Ratnaweera ◽  
Akiyoshi Ohashi ◽  
Noriatsu Ozaki ◽  
...  

Abstract Landfill leachate is characterised by high chemical and biological oxygen demand and generally consists of undesirable substances such as organic and inorganic contaminants. Landfill leachate may differ depending on the content and age of landfill contents, the degradation procedure, climate and hydrological conditions. We aimed to explain the characteristics of landfill leachate and define the practicality of using different techniques for treating landfill leachate. Different treatments comprising biological methods (e.g. bioreactors, bioremediation and phytoremediation) and physicochemical approaches (e.g. advanced oxidation processes, adsorption, coagulation/flocculation and membrane filtration) were investigated in this study. Membrane bioreactors and integrated biological techniques, including integrated anaerobic ammonium oxidation and nitrification/denitrification processes, have demonstrated high performance in ammonia and nitrogen elimination, with a removal effectiveness of more than 90%. Moreover, improved elimination efficiency for suspended solids and turbidity has been achieved by coagulation/flocculation techniques. In addition, improved elimination of metals can be attained by combining different treatment techniques, with a removal effectiveness of 40–100%. Furthermore, combined treatment techniques for treating landfill leachate, owing to its high chemical oxygen demand and concentrations of ammonia and low biodegradability, have been reported with good performance. However, further study is necessary to enhance treatment methods to achieve maximum removal efficiency.


Author(s):  
Visnja Orescanin ◽  
Robert Kollar ◽  
Damir Ruk ◽  
Ivan Halkijevic ◽  
Marin Kuspilic

Water ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1849 ◽  
Author(s):  
Javier Tejera ◽  
Ruben Miranda ◽  
Daphne Hermosilla ◽  
Iñigo Urra ◽  
Carlos Negro ◽  
...  

This study focuses on the treatment of a mature landfill leachate by coagulation and photo-Fenton at different conditions. Optimal coagulation is carried out with ferric chloride in acid conditions; and with alum in near-neutral conditions, to minimize the use of sulphuric acid for pH adjustment (1 g/L vs. 7.2 g/L), the generation of sludge and the increase of conductivity in the final effluent. In both cases, a similar chemical oxygen demand (COD) removal is obtained, higher than 65%, which is high enough for a subsequent photo-Fenton treatment. However, the removal of absorbance at 254 nm (UV-254) was significantly higher with ferric chloride (83% vs. 55%), due to the important removal of humic acids at acid pH. The best results for coagulation are 2 g/L ferric chloride at initial pH = 5 and 5 g/L alum at initial pH = 7. After coagulation with ferric chloride, the final pH (2.8) is adequate for a homogeneous photo-Fenton using the remaining dissolved iron (250 mg/L). At these conditions, using a ratio H2O2/COD = 2.125 and 30 min contact time, the biodegradability increased from 0.03 to 0.51. On the other hand, the neutral pH after alum coagulation (6.7) allows the use of zero valent iron (ZVI) heterogeneous photo-Fenton. In this case, a final biodegradability of 0.32 was obtained, after 150 min, using the same H2O2/COD ratio. Both treatments achieved similar results, with a final COD, UV-254 and color removal greater than 90%. However, the economic assessment shows that the approach of ferric chloride + homogeneous photo-Fenton is much cheaper (6.4 €/m3 vs. 28.4 €/m3). Although the discharge limits are not achieved with the proposed combination of treatments, the significant increase of the pre-treated leachate biodegradability allows achieving the discharge limits after a conventional biological treatment such as sequencing batch reactor, which would slightly increase the total treatment cost.


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