Reduction of COD and Highly Coloured Mature Landfill Leachate by Tin Tetrachloride with Rubber Seed and Polyacrylamide

Tin tetrachloride (SnCl4) as a coagulant and rubber seed (Hevea brasiliensis) (RS), and polyacrylamide (PAM) as the coagulant aid were investigated in this work to treat matured and stabilised landfill leachate rich in COD and colour. A standard jar test was conducted at different pH values and dosages of coagulant/coagulant aid. When SnCl4 acted as the primary coagulant, the optimum conditions occurred at pH 8 and 10,000 mg/L dosages, with 97.3% and 81% reductions of colour and COD, respectively. Both RS and PAM were not effective when used alone. When RS was used as the coagulant aid, the dosage of SnCl4 was reduced to 8000 mg/L. The colour reduction was maintained at 97.6%, but the COD removal dropped to 43.1%. In comparison, when PAM was supplemented into 6000 mg/L SnCl4, the reduction in colour was maintained at 97.6%, and the COD removal was almost at par when SnCl4 was used alone. The addition of polymers as the coagulant aid helped in improving the sludge properties with a better settling rate (SSR) and larger flocs size. The decline of the SVI value indicates that less amount of sludge will be disposed of after the treatment. In addition, the rise of settling velocity (SSR) will reduce the size of the settling tank used in coagulation-flocculation treatment. Based on the results, it can be concluded that incorporation of coagulant aid into the treatment reduced the primary coagulant dosage without affecting the removal performances of pollutants.

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Tannin and chemical-based agents for coagulation and flocculation of landfill leachate

Periódico Eletrônico Fórum Ambiental da Alta Paulista ◽

10.17271/1980082717120212557 ◽

2021 ◽

Vol 17 (1) ◽

Author(s):

Bruno Rodrigues dos Santos ◽

Roselene Maria Schneider ◽

Adriana Garcia do Amaral ◽

Milene Carvalho Bongiovani ◽

Ednaldo Antonio de Andrade

Keyword(s):

Humic Substances ◽

Landfill Leachate ◽

Suspended Solids ◽

Post Treatment ◽

Natural Coagulant ◽

Ph Values ◽

Jar Test ◽

Stabilization Ponds ◽

Coagulation And Flocculation ◽

Coagulant Dosage

Effluents generated in landfills are difficult to treat and require different forms of treatment to reach the necessary polishing for disposal. Leachate is usually treated in stabilization ponds where pollutants are significantly removed, but it might not be enough for disposal. Thus, we aimed at evaluating the applicability of the natural coagulant Tanfloc SG and the chemical coagulant PAC, with the addition of the anionic flocculation auxiliary polymer (PA), in the coagulation / flocculation processes as a post-treatment of landfill effluents. The tests were carried out by means of a jar test, with coagulant dosage ranging from 0 - 1,250 mg.L-1 and pH values ranging from 5 - 9, in three decantation times. The results showed that both Tanfloc SG and PAC are efficient in clarifying the effluents, even though they act well in different dosage values of coagulants and pH. The polymer dosage did not generate significant improvements in the variations of the variables studied, however, in some experiments it was shown to expand removal range in regards to some variables. The PAC coagulant showed to be efficient in the removal of suspended solids, dissolved materials, colloidals and humic substances, and Tanfloc SG acted mainly in the removal of solids.

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Colour and COD removal from mature landfill leachate using electro-persulphate oxidation process

Materials Today Proceedings ◽

10.1016/j.matpr.2020.01.193 ◽

2020 ◽

Vol 31 ◽

pp. 69-74 ◽

Cited By ~ 1

Author(s):

Soh Wai Onn ◽

Mohammed J.K. Bashir ◽

Sumathi Sethupathi ◽

Salem S. Abu Amr ◽

Tan Tai Nguyen

Keyword(s):

Landfill Leachate ◽

Oxidation Process ◽

Cod Removal ◽

Mature Landfill Leachate ◽

Persulphate Oxidation

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Dosage and pH optimization on stabilized landfill leachate via coagulation-flocculation process

MATEC Web of Conferences ◽

10.1051/matecconf/201825006007 ◽

2018 ◽

Vol 250 ◽

pp. 06007 ◽

Cited By ~ 1

Author(s):

Siti Nor Aishah Mohd-Salleh ◽

Nur Shaylinda Mohd-Zin ◽

Norzila Othman ◽

Nur Syahirah Mohd-Amdan ◽

Fitryaliah Mohd-Shahli

Keyword(s):

Landfill Leachate ◽

Suspended Solids ◽

Oxygen Demand ◽

Primary Treatment ◽

Toxicological Effects ◽

Jar Test ◽

Coagulant Dosage ◽

Conventional Optimization ◽

Ph Optimization ◽

Flocculation Process

Treatment on the generated landfill leachate is crucial as it can cause serious toxicological effects and environmental hazards, particularly when the unfavorable contaminants are left accumulated for a long period of time. The purpose of this study was to determine the optimum coagulant dosage of polyaluminium chloride (PAC) in selected dosage ranges (2250-4500 mg/L) and to analyse the ideal pH of leachate sample (pH 3-10). PAC was tested on stabilized leachate taken from Simpang Renggam Landfill Site (SRLS), by investigating the percentage removals of five significant parameters, which were suspended solids, chemical oxygen demand (COD), ammonia, and heavy metals (iron (Fe) and chromium (Cr)). The removal efficiency was determined by a series of experiments using jar test. From the obtained results, it was found that 3750 mg/L and pH 7 were the optimum conditions for PAC dosage and sample pH, respectively. The conventional optimization test showed satisfactory results for suspended solids, COD, Fe, and Cr at 95%, 53%, 97%, and 79% respectively, but had low removal on ammonia at 18%. It can be concluded that the coagulation-flocculation process has the potential to be applied as a primary treatment for stabilized landfill leachate in Malaysia.

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OPTIMIZATION CONDITIONS AND APPLICATION OF MOVING BED BIOFILM REACTOR FOR MATURE LANDFILL LEACHATE TREATMENT

Environmental Engineering and Management Journal ◽

10.30638/eemj.2016.010 ◽

2016 ◽

Vol 15 (1) ◽

pp. 81-91

Author(s):

Wei Li ◽

Min Liu ◽

Lei Liu ◽

Yao-wen Guo ◽

Yang-shuo Shen

Keyword(s):

Landfill Leachate ◽

Biofilm Reactor ◽

Moving Bed Biofilm Reactor ◽

Leachate Treatment ◽

Moving Bed ◽

Mature Landfill Leachate

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UVA-LED Technology’s Treatment Efficiency and Cost in a Competitive Trial Applied to the Photo-Fenton Treatment of Landfill Leachate

Processes ◽

10.3390/pr9061026 ◽

2021 ◽

Vol 9 (6) ◽

pp. 1026

Author(s):

Javier Tejera ◽

Antonio Gascó ◽

Daphne Hermosilla ◽

Víctor Alonso-Gomez ◽

Carlos Negro ◽

...

Keyword(s):

Landfill Leachate ◽

Mercury Vapor ◽

Cod Removal ◽

Treatment Efficiency ◽

Alternative Source ◽

Effluent Quality ◽

Radiation Sources ◽

Initial Ph ◽

Pre Treatment ◽

Set Up

The objective of this trial was to assess the application of UVA-LED technology as an alternative source of irradiation for photo-Fenton processes, aiming to reduce treatment costs and provide a feasible treatment for landfill leachate. An optimized combination of coagulation with ferric chloride followed by photo-Fenton treatment of landfill leachate was optimized. Three different radiation sources were tested, namely, two conventional high-pressure mercury-vapor immersion lamps (100 W and 450 W) and a custom-designed 8 W 365 nm UVA-LED lamp. The proposed treatment combination resulted in very efficient degradation of landfill leachate (COD removal = 90%). The coagulation pre-treatment removed about 70% of the COD and provided the necessary amount of iron for the subsequent photo-Fenton treatment, and it further favored this process by acidifying the solution to an optimum initial pH of 2.8. The 90% removal of color improved the penetration of radiation into the medium and by extension improved treatment efficiency. The faster the Fenton reactions were, as determined by the stoichiometric optimum set-up reaction condition of [H2O2]0/COD0 = 2.125, the better were the treatment results in terms of COD removal and biodegradability enhancement because the chances to scavenge oxidant agents were limited. The 100 W lamp was the least efficient one in terms of final effluent quality and operational cost figures. UVA-LED technology, assessed as the application of an 8 W 365 nm lamp, provided competitive results in terms of COD removal, biodegradability enhancement, and operational costs (35–55%) when compared to the performance of the 450 W conventional lamp.

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Mature landfill leachate treatment by denitrification and ozonation

Process Biochemistry ◽

10.1016/j.procbio.2010.07.033 ◽

2011 ◽

Vol 46 (1) ◽

pp. 148-153 ◽

Cited By ~ 22

Author(s):

Susana Cortez ◽

Pilar Teixeira ◽

Rosário Oliveira ◽

Manuel Mota

Keyword(s):

Landfill Leachate ◽

Leachate Treatment ◽

Mature Landfill Leachate

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Enhancing Nitrogen Removal In Mature Landfill Leachate by Mixed Microalgae Through Elimination of Inhibiting Factors

SSRN Electronic Journal ◽

10.2139/ssrn.3995999 ◽

2021 ◽

Author(s):

Zhangbao Wang ◽

Zhensheng Xiong ◽

Liming Yang ◽

Ling Lai ◽

Hongyan Xiao ◽

...

Keyword(s):

Nitrogen Removal ◽

Landfill Leachate ◽

Inhibiting Factors ◽

Mature Landfill Leachate

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Arsenic removal by ferric-chloride coagulation – effect of phosphate, bicarbonate and silicate

Water Science & Technology ◽

10.2166/wst.2011.419 ◽

2011 ◽

Vol 64 (5) ◽

pp. 1046-1055 ◽

Cited By ~ 11

Author(s):

Dóra Laky ◽

István Licskó

Keyword(s):

Adverse Effect ◽

Arsenic Removal ◽

Linear Regression Analysis ◽

Arsenic Concentration ◽

Ferric Hydroxide ◽

Multiple Linear Regression Analysis ◽

Ph Values ◽

Robust Model ◽

Coagulant Dosage ◽

Negative Effect

Jar tests with synthetic water were carried out in order to investigate the effect of phosphate, bicarbonate and silicate on arsenic removal efficiency by in-situ formed ferric hydroxide. Above 12 mg C/L inorganic carbon concentration, the adverse effect of bicarbonate was definite, and resulted in higher remaining arsenic concentration. At all pH values (7.5–7.8) and coagulant dosages (0.84–3.00 mg/L Fe) tested, the negative effect of phosphate on arsenic removal was also evident. In the presence of silicate small ferric-hydroxide colloids were formed, which were able to go through the 0.45 μm pore-size membrane. Compared to silicate-free systems, 2.5–3.5 times higher coagulant dose was needed to achieve the target arsenic concentration in the presence of 14–23 mg/L Si. At higher pH values the adverse effect of silicate was even more significant. All data were merged and multiple linear regression analysis was carried out in order to build up a robust model to predict the residual arsenic concentration if the raw water contains 50–60 μg/L initial arsenic concentration. The estimation was based on the following variables: PO4-P concentration, final pH, Si concentration, Fe(III) dose. The most important influencing factors proved to be the silicate concentration and applied coagulant dosage.

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