scholarly journals Sequential Treatment of Landfill Leachate By Advanced Oxidation Processes and Struvite Precipitation

Author(s):  
Sushma lavudya ◽  
maneesha vodnala ◽  
Bhagawan Dheeravath ◽  
kiran kumar Panga ◽  
Vijaya krishna saranga ◽  
...  

Abstract Landfill leachate contains organic, inorganic compounds, heavy metals, ammonia, and xenobiotic compounds which are considered unsafe for discharging into surface water which requires to be treated before its discharge into the water. In this paper, preliminary studies are reported on the application of Fenton, Struvite, and Electrooxidation processes for the removal of Chemical Oxygen Demand (COD) and ammonia from landfill leachate. Various operational parameters like pH, dosage, reaction time, and applied voltage were optimized in laboratory batch experiments and evaluated for removal of COD and ammonia. Results demonstrated that the Fenton process could effectively remove COD and ammonia by 75% and 23% respectively at 210 min for Fe+2:H2O2: 1:5 at a fixed pH 3. The Struvite process has been effective in the removal of ammonia by 74% at pH 9 with the dosage of Mg+2:PO43-:NH4+ at 1:1:1 ratio. Results from Electrooxidation for COD and ammonia were observed as 58.25% and 44% respectively at the applied voltage 8 V for a reaction time of 60 min. The efficiency of treatment processes was also evaluated in Sequential processes for COD and ammonia i.e., Sequence-I (Fenton-Electrooxidation-Struvite) and Sequence-II (Fenton-Struvite) at pre-optimized conditions. The sequential processes have been depicted, the removal efficiencies of COD and ammonia of 89% and 82% by Sequence-I; 76.77%, and 77% by Sequence-II respectively. The present study demonstrates that Fenton followed by Electrooxidation and Struvite is an effective treatment process that can enhance the treatment of landfill leachate.

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Edris Bazrafshan ◽  
Hossein Moein ◽  
Ferdos Kord Mostafapour ◽  
Shima Nakhaie

Dairy industry wastewater is characterized by high biochemical oxygen demand (BOD5), chemical oxygen demand (COD), and other pollution load. The purpose of this study was to investigate the effects of the operating parameters such as applied voltage, number of electrodes, and reaction time on a real dairy wastewater in the electrocoagulation process. For this purpose, aluminum electrodes were used in the presence of potassium chloride as electrolytes. It has been shown that the removal efficiency of COD, BOD5, and TSS increased with increasing the applied voltage and the reaction time. The results indicate that electrocoagulation is efficient and able to achieve 98.84% COD removal, 97.95% BOD5removal, 97.75% TSS removal, and >99.9% bacterial indicators at 60 V during 60 min. The experiments demonstrated the effectiveness of electrocoagulation techniques for the treatment of dairy wastewaters. Finally, the results demonstrated the technical feasibility of electrocoagulation process using aluminum electrodes as a reliable technique for removal of pollutants from dairy wastewaters.


2015 ◽  
Vol 73 (1) ◽  
pp. 102-112 ◽  
Author(s):  
Ahmed H. Hilles ◽  
Salem S. Abu Amr ◽  
Rim A. Hussein ◽  
Anwar I. Arafa ◽  
Olfat D. El-Sebaie

The objective of this study was to investigate the performance of employing H2O2 reagent in persulfate activation to treat stabilized landfill leachate. A central composite design (CCD) with response surface methodology (RSM) was applied to evaluate the relationships between operating variables, such as persulfate and H2O2 dosages, pH, and reaction time, to identify the optimum operating conditions. Quadratic models for the following two responses proved to be significant with very low probabilities (<0.0001): chemical oxygen demand (COD) and NH3-N removal. The obtained optimum conditions included a reaction time of 116 min, 4.97 g S2O82−, 7.29 g H2O2 dosage and pH 11. The experimental results were corresponding well with predicted models (COD and NH3-N removal rates of 81% and 83%, respectively). The results obtained in the stabilized leachate treatment were compared with those from other treatment processes, such as persulfate only and H2O2 only, to evaluate its effectiveness. The combined method (i.e., /S2O82−/H2O2) achieved higher removal efficiencies for COD and NH3-N compared with other studied applications.


Electrocoagulation (EC) process uses direct electric current source between metal electrode submerged in the effluent that results in electrode dissolution, with a suitable pH, metal ion can form a wide range of metal hydroxide and coagulated species that destabilized and dissolved contaminants absorbed. Electrocoagulation (EC) has been working for the percentage removal of BOD (Biochemical oxygen demand)/ chemical oxygen demand (COD) ratio, Color and COD on leachate in a batch Electrocoagulation reactor using stainless steel (SS) electrode. EC technology depends on so many factors such as electrode material, initial pH, applied voltage, inter-electrode distance, and electrolysis time. From the experimental work, results reveal that the maximum percentage of removal achieved were COD and Color 73.5% and 65.0% respectively and increasing BOD/COD ratio 0.11 to 0.62. The optimum inter-electrode distance 1cm with electrode surface area 35 cm2 and optimum electrolysis time of 120 min at optimum applied voltage 12V, stirring speed 250 rpm and pH 9.8. These results proved that the EC process is an appropriate and proficient approach for treating the landfill leachate.


Author(s):  
Amin Mojiri ◽  
Lou Ziyang ◽  
Wang Hui ◽  
Ali Gholami

Municipal solid waste has continued to be a major problem in many nations of the world. The primary methods of treating landfill leachate include physical-chemical and biological treatment processes. Pressure-driven membrane processes, such as microfiltration, ultrafiltration, nanofiltration, and reverse osmosis (RO), are among the utmost promising and capable ways for treating landfill leachate. The concentrated leachate created from pressure-driven membrane processes typically represents 13%–30% of total incoming landfill leachate. Concentrated leachate is a dark brown solution with high levels of pollutants. Treating concentrated leachate is extremely difficult, and thus, a combined treatment system is suggested. In the present study, concentrated landfill leachate was treated using a combined treatment technique that included electro-ozonation. The removal efficacies of chemical oxygen demand (COD), color, and nickel were monitored at original pH (7.3) as well as current and voltage of 4 A and 9 V, respectively.


2022 ◽  
Vol 961 (1) ◽  
pp. 012059
Author(s):  
Sara Mohannad Abd Al-Hamza ◽  
Hayder Mohammed Abd Al-Hamed

Abstract One of the most significant issues that people throughout the world will confront in the future years is a lack of clean and safe water. Anthropogenic activities, in particular, are polluting water systems. With rising population, urbanization, and climate change, water reuse has become a requirement in some areas of the globe, putting pressure on the development of effective water treatment methods for a range of contaminants. High biological oxygen demand (BOD), chemical oxygen demand (COD), oil-grease, and other pollutant loads define dairy sector effluent. Improved technology is required to address these issues. Electrocoagulation is a new type of therapy. It’s simple to use, ecologically friendly, and removes a wide range of contaminants from a variety of water types. The goal of this study was to see how operational factors such applied voltage, number of electrodes, distance between electrodes, electrode shape, and reaction time affected the electrocoagulation of actual dairy effluent. Aluminum and iron electrodes are used for this purpose. It was discovered that raising the applied voltage, reaction time, and decreasing the distance between electrodes improved COD, BOD, EC, TDS, color, and oil-grease removal efficiency. Moreover, switch between square, triangular electrodes and perforated cylindrical. The data show that electrocoagulation is effective at the maximum COD, BOD removal efficiency of first electrode at 20 holes of cylindrical shape is (88.03) %, (87.97) %, respectively. Second triangle shape is (100) %, (100) % respectively. Third square shape is (99.38) %, (99.42) % respectively. the maximum removal of TDS, EC efficiency of first electrode at 20 holes of cylindrical shape is (67.57) %, (62.34) %, respectively. Second triangle shape is (77.45) %, (67.68) % respectively. Third square shape is (81.96) %, (71.25) % respectively. The maximum color and oil-grease removal efficiency of first electrode at 20 holes of cylindrical shape is (100) %, (100) %, respectively. Second triangle shape is (100) %, (100) % respectively. Third square shape is (100) %, (100) % respectively. Electrocoagulation methods for the treatment of dairy wastewaters were shown to be successful in the research. Finally, the findings indicated that electrocoagulation is a technically feasible method for removing contaminants from dairy wastewaters.


The present research work mainly deals with the removal percentage of Color and Chemical Oxygen Demand (COD) on landfill leachate by using electrocoagulation (EC) process. An EC process was carried out with an aluminium electrode and it act as both anode and cathode. The study mainly targets the factors affecting on electrode material, electrolysis time, initial pH, applied voltage, inter-electrode distance. The experimental result reveals that there was raise in BOD/COD ratio from 0.11 to 0.66 and the maximum percentage removal achieved were COD and Color 78.4% and 77.0% respectively. The optimum inter-electrode distance 1cm with electrode surface area 35 cm2 and optimum electrolysis time of 90 min at optimum applied voltage 10V, stirring speed 250 rpm and pH is 9.3. These results showed that the EC process is appropriate and well-organized approach for the landfill leachate treatment.


2016 ◽  
Vol 18 (2) ◽  
pp. 360-370

<div> <p>The main objective of this study was to investigate the differences between the main pollutants in young and intermediate age landfill leachate in terms of molecular weight distribution (MWD). Parameters of chemical oxygen demand (COD), five day - biochemical oxygen demand (BOD<sub>5</sub>), ultraviolet-visible spectrophotometry (UV-VIS spectrum), total kjehldahl nitrogen (TKN), ammonia nitrogen (NH<sub>4</sub>-N) and colour were fractioned by membranes with the nominal pore size of 1&micro;m, 0.05 &micro;m, 100 kDa, 50 kDa, 10 kDa, 1 kDa and 0.5 kDa. According to the MWD results appropriate treatment technology could be choosen easily. According to the MWD results the ratio of soluble fractions (&lt; 0.5 kDa) to total COD was 34% in young leachate (YL), whereas low molecular weight (MW) fractions were dominant in intermediate leachate (IL) having this ratio of 71%. Presence of lower MW compounds in IL was also confirmed with UV-VIS absorbance spectra and its spectrum was higher than the YL. According to the specific ultraviolet absorption (SUVA) values, the organic contents of all of these processes were hydrophilic. TKN and NH<sub>4</sub>-N analysis showed that in IL all the nitrogen present is in ammoniacal form, instead in YL there is still the presence of organic nitrogen. Furthermore more than half of the TKN was less than 0.5 kDa while 6 % and 16 % TKN found in wastewater from IL and YL was higher than 1 &micro;m respectively. The observations of this study may provide useful criteria to choose a suitable landfill leachate treatment processes.</p> </div> <p>&nbsp;</p>


2010 ◽  
Vol 2010 ◽  
pp. 1-10 ◽  
Author(s):  
Wei Li ◽  
Qixing Zhou ◽  
Tao Hua

In most countries, sanitary landfill is nowadays the most common way to eliminate municipal solid wastes (MSWs). However, sanitary landfill generates large quantity of heavily polluted leachate, which can induce ecological risk and potential hazards towards public health and ecosystems. The application of advanced oxidation processes (AOPs) including ozone-based oxidation, Fenton oxidation, electrochemical oxidation, and other AOPs to treatment of landfill leachate was reviewed. The treatment efficiency in term of chemical oxygen demand (COD) of various AOPs was presented. Advantages and drawbacks of various AOPs were discussed. Among the AOPs reviewed, Fenton process should be the best choice, not only because it can achieve about 49~89% of COD removal with COD ranging from 837 to 8894 mg/L, but also because the process is cost-effective and simple in technological aspect, there is no mass transfer limitation (homogeneous nature) and both iron and hydrogen peroxide are nontoxic.


2017 ◽  
Vol 8 (1) ◽  
pp. 1061-1070
Author(s):  
B.F.A Basnayake

A laboratory scale Leachate Treatment Bioreactor (LTB) was needed to determine the optimum design and operational parameters because of poor performance of a full scale unit. In order to increase the lifespan of LTB, coconut comb and rubber tyres were included in the partially decomposed Municipal Solid Waste (MSW) as biofilter material inside the reactor. A composite liner of clay and waste polythene was used to mineralize excess inorganic compounds. The parameter reductions were from 26,000 mg/L to 6,832 mg/L of Total Solids (TS), 6,230 mg/L to 2,930 mg/L of Total Disolved Solids (TDS), 12,000 mg/L to 1182.6 mg/L of Volatile Solids (VS), 14,000 mg/L to 4,410 mg/L of Total Fixed Solids (TFS) and 29,700 mg/L to 3,000 mg/L of Biochemical Oxygen Demand (BOD). The kinetic analysis using the logistic growth equation showed cyclic events and the application of separating the growth and decay of microbes based on the Total Fixed Solids (TFS) gave a mineralization rate of 1.83 x 102 kg /m3 of leachate/m height of LTB /day for up scaling.


2010 ◽  
Vol 13 (3) ◽  
pp. 92-102
Author(s):  
Trung Duc Le

The industrial production of ethanol by fermentation using molasses as main material that generates large quantity of wastewater. This wastewater contains high levels of colour and chemical oxygen demand (COD), that may causes serious environmental pollution. Most available treatment processes in Vietnam rely on biological methods, which often fail to treat waste water up to discharge standard. As always, it was reported that quality of treated wastewater could not meet Vietnameses discharge standard. So, it is necessary to improve the treatment efficiency of whole technological process and therefore, supplemental physico-chemical treatment step before biodegradation stage should be the appropriate choice. This study was carried out to assess the effect of coagulation process on decolourization and COD removal in molasses-based ethanol production wastewater using inorganic coaglutant under laboratory conditions. The experimental results showed that the reductions of COD and colour with the utilization of Al2(SO4)3 at pH 9.5 were 83% and 70%, respectively. Mixture FeSO4 – Al2(SO4)3 at pH 8.5 reduced 82% of colour and 70% of COD. With the addition of Polyacrylamide (PAM), the reduction efficiencies of colour, COD and turbidity by FeSO4 – Al2(SO4)3 were 87%, 73.1% and 94.1% correspondingly. It was indicated that PAM significantly reduced the turbidity of wastewater, however it virtually did not increase the efficiencies of colour and COD reduction. Furthermore, the coagulation processes using PAM usually produces a mount of sludge which is hard to be deposited.


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