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

2018 ◽  
Vol 250 ◽  
pp. 06007 ◽  
Author(s):  
Siti Nor Aishah Mohd-Salleh ◽  
Nur Shaylinda Mohd-Zin ◽  
Norzila Othman ◽  
Nur Syahirah Mohd-Amdan ◽  
Fitryaliah Mohd-Shahli

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.

Author(s):  
Hamidi Abdul Aziz ◽  
Nur Syahirah Rahmat ◽  
Motasem Y. D. Alazaiza

Chemical-based coagulants and flocculants are commonly used in the coagulation–flocculation process. However, the drawbacks of using these chemical materials have triggered researchers to find natural materials to substitute or reduce the number of chemical-based coagulants and flocculants. This study examines the potential application of Nephelium lappaceum seeds as a natural coagulant–coagulant aid with Tin (IV) chloride (SnCl4) in eliminating suspended solids (SS), colour, and chemical oxygen demand (COD) from landfill leachate. Results showed that the efficiency of Nephelium lappaceum was low when used as the main coagulant in the standard jar test. When SnCl4 was applied as a single coagulant, as much as 98.4% of SS, 96.8% of colour and 82.0% of COD was eliminated at an optimal dose of 10.5 g/L and pH 7. The higher removal efficiency of colour (88.8%) was obtained when 8.40 g/L of SnCl4 was applied with a support of 3 g/L of Nephelium lappaceum. When SnCl4 was utilised as a coagulant, and Nephelium lappaceum seed was used as a flocculant, the removal of pollutants generally improved. Overall, this research showed that Nephelium lappaceum seed is a viable natural alternative for treating landfill leachate as a coagulant aid.


Author(s):  
Bruno Rodrigues dos Santos ◽  
Roselene Maria Schneider ◽  
Adriana Garcia do Amaral ◽  
Milene Carvalho Bongiovani ◽  
Ednaldo Antonio de Andrade

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. 


2018 ◽  
Vol 67 ◽  
pp. 04004 ◽  
Author(s):  
Aditha Oktariany ◽  
Sutrasno Kartohardjono

Wastewater from tofu industry is one of water pollution sources that still require more effective treatment. This study aim to treat wastewater from tofu industry through a combination of coagulation-flocculation and ultrafiltration processes. Coagulation-flocculation is conducted prior to ultrafiltration process to minimize the effect of fouling on membrane and to improve the performance of ultrafiltration process. Poly aluminum chloride (PAC) was used as coagulant with doses of 100, 200, 300, 400 and 500 ppm. The wastewater feed have pH, total dissolved solid (TDS), total suspended solids (TSS), turbidity and chemical oxygen demand in the ranges of 3.8 - 4, 850 - 880 mg /L, 380 - 420 mg /L, 450-530 FAU and 5600 - 6600 mg /L, respectively. Experimental results showed that the effectiveness of coagulation increased with the addition of coagulant dose until the optimum dose is reached. After coagulation-flocculation process, COD, TSS, and turbidity decreased, whereas TDS increased. The optimum dose of the coagulationflocculation process was then used for a combination of coagulation-flocculation and ultrafiltration processes. The result of this combination process showed a decrease in COD, BOD, TSS, and turbidity.


2019 ◽  
Vol 6 (1) ◽  
pp. 41-48 ◽  
Author(s):  
Abdul Aziz Hamidi ◽  
Syed Zainal Sharifah Farah Fariza ◽  
Alazaiza Motasem Y.D

Landfill leachate is highly polluted and generated as a result of water infiltration through solid waste produced domestically and industrially. This study investigated the applicability of the response surface methodology (RSM) to optimize the removal performances of chemical oxygen demand (COD), color, and suspended solids (SS) from landfill leachate by coagulation process using Tin tetrachloride pentahydrate. The leachate samples were collected from Alor Pongsu Landfill (APLS) in Perak, Malaysia. Before starting the experiments, general characterization was carried out for raw leachate samples to investigate their physical and chemical properties. The effects of the dosage and pH of SnCl4 on the removal performances were evaluated as well. An ideal experimental design was performed based on the central composite design (CCD) by RSM. In addition, this RSM was used to evaluate the effects of process variables and their interaction toward the attainment of their optimum conditions. The statistical design of the experiments and data analysis was resolved using the Design-Expert software. Further, the range of coagulant dosage and pH was selected based on a batch study which was conducted at 13000 mg/L to 17000 mg/L of SnCl4 and pH ranged from 6 to 10. The results showed that the optimum pH and dosage of SnCl4 were 7.17 and 15 g/L, respectively, where the maximum removal efficiency was 67.7% for COD and 100% for color and SS. The results were in agreement with the experimental data with a maximum removal efficiency of 67.84 %, 98.6 %, and 99.3%, for COD, color, and SS, respectively. Overall, this study verified that the RSM method was viable for optimizing the operational condition of the coagulation-flocculation process.


2019 ◽  
Vol 80 (3) ◽  
pp. 458-465 ◽  
Author(s):  
Ahmed Samir Naje ◽  
Mohammed A. Ajeel ◽  
Isam Mohamad Ali ◽  
Hussein A. M. Al-Zubaidi ◽  
Peter Adeniyi Alaba

Abstract In this work, landfill leachate treatment by electrocoagulation process with a novel rotating anode reactor was studied. The influence of rotating anode speed on the removal efficiency of chemical oxygen demand (COD), total dissolved solids (TDS), and total suspended solids (TSS) of raw landfill leachate was investigated. The influence of operating parameters like leachate pH, leachate temperature, current, and inter-distance between the cathode rings and anode impellers on the electrocoagulation performance were also investigated. The results revealed the optimum rotating speed is 150 rpm and increasing the rotating speed above this value led to reducing process performance. The leachate electrocoagulation treatment process favors the neutral medium and the treatment performance increases with increasing current intensity. Furthermore, the electrocoagulation treatment performance improves with increasing leachate temperature. However, the performance reduces with increasing inter-electrode distance.


2014 ◽  
Vol 67 (4) ◽  
Author(s):  
Nor Azimah Ahmad ◽  
Mohd Ariffin Abu Hassan ◽  
Zainura Zainon Noor ◽  
Abdullahi Mohammed Evuti ◽  
Jibrin Mohammed Danlami

Optimum pH and coagulant dosage for chemical precipitation in wastewater treatment plants is conventionally obtained through repeated jar test. In this research, optimization of the performance of polyacrylamide in the treatment of industrial wastewater was carried out using response surface methodology. The individual linear and quadratic effect of coagulant dosage and pH on the degree of removals of nickel, total suspended solids, Chemical Oxygen Demand and turbidity were investigated. The optimum pH and polyacrylamide dosage were found to be 10.5 and 1.6 ml/L respectively and the optimum percentage nickel removal was 96.9%. The model used in predicting the precipitation process gave a good fit with the experimental variables and hence the suitability of response surface methodology for the optimization of polyacrylamide performance.


2013 ◽  
Vol 5 (4) ◽  
pp. 356-362 ◽  
Author(s):  
Irina Kačinskaja ◽  
Kristina Bazienė ◽  
Saulius Vasarevičius

Currently, depositing municipal waste in landfills is the dominating method in Lithuania. A large amount of landfill leachate is the main environmental problem. Municipal waste landfill leachate is characterized by high biochemical oxygen demand (BOD) containing a number of heavy metals and concentration of organic compounds. The colmatation of landfill leachate collection systems is another burning problem that occurs due to certain characteristics of leachate such as suspended solids, an increase in calcium and magnesium concentrations and vital activity of microorganisms. Therefore, it is necessary to examine conditions affecting these parameters. The paper presents and analyses the characteristics of experimental data, assesses the factors having the greatest influence on recent development and introduces the measures that should be taken into account so that to the ensure optimal operation of the systems for collecting municipal waste landfill leachate. Article in Lithuanian. Santrauka Pagrindinis atliekų tvarkymo būdas Lietuvoje yra jų deponavimas sąvartynuose. Viena iš svarbiausių aplinkosauginių problemų – dideli susidarantys sąvartyno filtrato kiekiai. Komunalinių atliekų sąvartynų filtratui būdinga didelis biocheminio deguonies suvartojimas (BDS), filtrate taip pat nemažà sunkiųjų metalų bei organinių junginių koncentracija. Svarbu išskirti ir tokią problemą kaip sąvartyno filtrato surinkimo sistemų kolmatacija, pasireiškianti dėl tam tikrų filtrato savybių: skendinčiųjų medžiagų, kalcio ir magnio koncentracijų padidėjimo ir mikroorganizmų gyvybinės veiklos. Būtina įvertinti sąlygas, turinčias įtakos šių parametrų kitimui. Pateikti minėtų savybių eksperimentinių tyrimų duomenys ir analizė. Įvertinta, kokie veiksniai turi didžiausią įtaką filtrato parametrų kitimui, pavyzdžiui, tai, jog bendrasis kietumas (kalcis ir magnis) lemia pH didėjimą, t. y. terpės šarmėjimą. Be to, išanalizuota, kokių priemonių reikėtų imtis optimaliam komunalinių atliekų sąvartyno filtrato surinkimo sistemų veikimui užtikrinti.


2018 ◽  
Author(s):  
sinardi ◽  
Prayatni Soewondo ◽  
Suprihanto Notodarmojo

Green mussels (Mytilus virdis linnaeus) shell is one of the marine resources that can be used as raw material chitosan. Coagulant can remove turbidity through coagulation and flocculation process using coagulant. Biopolymers from natural coagulant safer and environmentally friendly so can subtitute synthetic coagulant. The use of chitosan as a coagulant in this study used synthetic turbid water using distilled water, suspended solids representing kaolin and humic acids which represents organic matter. Chitosan was used with variations in pH and coagulant dosage. Chitosan remove turbidity optimum at pH 7 at a dose of 300 mg/L of 95.15%.


2021 ◽  
Vol 1195 (1) ◽  
pp. 012035
Author(s):  
R L Chu ◽  
S Vasanthi ◽  
S Anurita

Abstract In the present study, fenugreek and aloe vera were investigated for the removal of turbidity (TUR), total suspended solids (TSS) and chemical oxygen demand (COD) from POME by using a central composite design (CCD) in the Design Expert software. The effects of three factors such as pH, coagulant dosage and flocculant dosage were analysed using jar test experiment and optimised using response surface methodology (RSM). The optimum results obtained from process optimisation analysis were pH 4, 24.13 g of coagulant dosage and 20 ml of flocculant dosage that are sufficient to remove 82.78 % of TUR, 83.40 % of TSS and 32.95 % of COD. The maximum error between the optimised values and the experimental values (82.78 % for TUR, 83.08 % for TSS and 33.76 % for COD) were below 4 %, indicating that satisfactory agreement was achieved. This showed that modelling and optimisation of the coagulation-flocculation process can be achieved by RSM approach. From analytical studies, it was found that the interactions between coagulant-flocculant and colloidal particles involve the mechanisms of charge neutralisation, adsorption and bridging, due to the active components such as amine (N-H) and hydroxyl (O-H) groups contained in the fenugreek and aloe vera.


2017 ◽  
Vol 8 (2) ◽  
pp. 234-243 ◽  
Author(s):  
Mohini Verma ◽  
R. Naresh Kumar

Abstract Landfill leachate and municipal wastewater at various ratios (1:20, 1:10, 1:7 and 1:5) were subjected to coagulation and electrocoagulation (EC). Alum was used in conventional coagulation at pH 6 and aluminum plate as electrode was used in EC at a current density of 386 A/m2 with 5 cm inter electrode spacing. Treatment efficiency was assessed from removal of chemical oxygen demand (COD), total suspended solids (TSS), turbidity, ammonia, nitrate and phosphate. At 1:5 ratio of landfill leachate to municipal wastewater, highest COD removal was with 3.8 g/L alum whereas highest turbidity removal was with 3.3 g/L alum during coagulation. EC exhibited almost similar removal efficiency for all the parameters at different ratios tested except for COD which was considerably higher at 1:20 ratio. Aluminum consumption from electrode was 0.7 g/L following EC as compared to 3.8 g/L alum used in coagulation. The amount of sludge produced was found to be higher with EC as compared to coagulation which could be due to the fact that the electrochemical method was performed for a longer duration than conventional coagulation. For minimal sludge generation, EC reaction time should be ∼30 min. Further studies with EC process on costing and sludge generation will help to advance the technology for wastewater treatment.


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