Pulau Burung Landfill Site Research Articles

Humic acid recovery from stabilized leachate: Characterization and interference with chemical oxygen demand-colour removal.

Heterogeneous combinations of organic compounds (humic acid (HA) and fulvic acid) are the prime factor for the high concentration of colour and chemical oxygen demand (COD) in semi-aerobic stabilized landfill leachate. These organics are less biodegradable and cause a severe threat to environmental elements. Microfiltration and centrifugation processes were applied in this study to investigate the HA removal from stabilized leachate samples and its corresponding interference with COD and colour. The three-stage extraction process recovered a maximum of 1412 ± 2.5 mg/L (Pulau Burung landfill site (PBLS) leachate), 1510 ± 1.5 mg/L (Alor Pongsu landfill site (APLS leachate) at pH 1.5 and 1371 ± 2.5 mg/L (PBLS) and 1451 ± 1.5 mg/L (APLS) of HA (about 42% of the total COD concentration) at pH 2.5, which eventually indicates the process efficiency. Comparative characteristics analysis of recovered HA by scanning electron microscopy, energy-dispersive X-ray, X-ray photoelectron spectroscopy, and Fourier transform infrared significantly indicate the existence of identical elements in the recovered HA compared with the previous studies. The higher reduction (around 37%) in ultraviolet (UV) absorbance values (UV254 and UV280) in the final effluent indicates the elimination of aromaticity and conjugated double-bond compounds from leachate. Moreover, 36 and 39% COD and 39 and 44% colour removal exhibit substantial interference.

Isolation and Characterization of Lignocellulolytic Bacteria from Municipal Solid Waste Landfill for Identification of Potential Hydrolytic Enzyme

The utilization of lignocellulose biomass as an alternative source of renewable energy production via green technology is becoming important, and is in line with sustainable development goal initiatives. Lignocellulolytic bacteria, such as Bacillus spp., can break down biomass by producing hydrolytic enzymes, which are crucial in the successful conversion of biomass or lignocellulosic material into renewable energy. This information gave rise to this study, where municipal solid waste sediments of a sanitary municipal solid waste landfill were sampled and screened, and lignocellulolytic bacteria were isolated and characterized. Samples were taken from four different locations at the Pulau Burung landfill site in Malaysia. Lignin and starch were used as sources of carbon to identify potential bacteria that exhibit multi-enzymatic activity. The growth rate and doubling time of bacterial isolates in lignin and starch were taken as the criteria for selection. Eleven bacterial isolates were screened for cellulase activity using iodine and Congo red dyes. The cellulase activity of these isolates ranged from 0.8 to 1.7 U/mL. We carried out 16S rRNA gene sequencing to identify the phyla of the selected bacterial isolates. Phylogenetic analysis was also conducted based on the 16S rRNA sequences of the bacterial isolates and related Bacillus species, and a tree was generated using the Neighbor-Joining method. In this study, Bacillus proteolyticus, Bacillus Sanguinis, Bacillus spizizenii, Bacillus paramycoides, Bacillus paranthracis and Neobacillus fumarioli were identified as promising bacteria capable of expressing lignocellulolytic enzymes and degrading the lignocellulosic biomass present in municipal solid waste.

Performance of UV Reactor for Total Coliform Removal from High and Low Strength Landfill Leachates

The levels of bacteria in landfill leachate is recently determined by researchers, as they may affect human health through pathogenic bacteria contaminations in surface and groundwater. The current study evaluated the effectiveness of ultra violet (UV) oxidation process for total coliform bacteria removal landfill high and low strength leachates in Pulau Pinang, Malaysia. The UV oxidation was applied as follow; leachate sample from Pulau Burung Landfill Site (PBLS) which has low total coliform content (200 MPN/100 m/L) and high organics (COD 1400-1600 mg/L), while the other used leachate sample from Ampang Jajar Landfill Site (AJLS) with high initial total coliform (>24 x 104 MPN/100 mL) and low organics (COD 130-300 mg/L). The UV contact time was varied between 2 and 5 min at 75 x 103 (mW-s/cm2) UV dosage. Highest removal (99.2%) in terms of Most Probable Number (MPN) was obtained for Total coliform from leachate with high initial total coliform and lower organic content, while 94% removal was attained for leachate with low initial total coliform and high organics content. The study revealed that UV is an efficient process for the removal of microorganisms from leachate with low dissolved and suspended organic and inorganic contents.

Performance of Ozone/ZrCl<sub>4</sub> Oxidation in Stabilized Landfill Leachate Treatment

Landfill leachate generation is one of the main problems from sanitary landfill. Chemical oxygen demand (COD), ammoniacal nitrogen (NH3-N), and color are among the most problematic parameters in stabilized leachate. In this regard, dedicated treatment facilities are required before leachate can be discharged into the environment. The performance of the combined ozonation (O3) and zirconium tetrachloride (ZrCl4) to treat two types of stabilized leachate was investigated during this study. Leachate samples were collected from an anaerobic stabilized leachate (Alor Pongsu Landfill Site, APLS) and semi-aerobic stabilized leachate (Pulau Burung Landfill Site, PBLS). Zirconium tetrachloride dosage was determined as 1 g/1 g (COD/ZrCl4 ratio) and then added to the leachate samples with 60 min ozonation at natural leachate pH (8). COD, color, and NH3-N were removed from the APLS sample at 33%, 70%, and 53% rates, respectively, whereas 48%, 75%, and 69%, respectively, from the PBLS samples. Ozone consumption was also calculated with the highest value (3.81 Kg O3/ Kg COD) reported in PBLS, whereas the lowest value (2.32 Kg O3/ Kg COD) was reported in APLS. Biodegradability of (BOD5/COD) was investigated and improved from 0.07 to 0.08 for the APLS samples and 0.05 to 0.11 for the PBLS samples after leachate oxidation. Results showed that the performance of O3/ZrCl4 oxidation is more efficient in treating semi-aerobic stabilized leachate than anaerobic stabilized leachate Moreover, the combined method proved to be more efficient in remediating leachate compared with ozone and zirconium treatment alone.

Extraction and application of starch-based coagulants from sago trunk for semi-aerobic landfill leachate treatment.

Malaysia is one of the highest starch producers. In this study, sago starch was utilized as a natural coagulant aid to reduce the dosage of aluminum-based coagulant in leachate treatment. The potential of native sago trunk starch (NSTS) and commercial sago starch (CSS) was evaluated as sole coagulant and coagulant aid in the presence of polyaluminum chloride (PACl) in the removal of color, suspended solids (SS), NH3-N, turbidity, chemical oxygen demand, organic UV254, Cd, and Ni. Leachate was sampled from Pulau Burung Landfill Site, one of the semi-aerobic landfills in Malaysia. The optimum dosage for PACl in the presence of NSTS or CSS as coagulant aid was reduced from 3100 to 2000 mg/L. In the presence of 2000 mg/L PACl with 6000 mg/L NSTS and 2000 mg/L PACl with 5000 mg/L CSS, the removal performance for color, SS, and turbidity are 94.7, 99.2, and 98.9%, respectively. Similar results were obtained with the use of 3100 mg/L PACl alone. Therefore, CSS and NSTS can be used as coagulant aid.

Measuring 81 characterization parameters from different tropical landfill leachates and potential treatment techniques

<div> <p>Raw municipal landfill leachate is extremely polluted wastewater and it regards as one of the drawbacks of the sanitary landfill treatment method. If the untreated landfill leachate is discharged to the natural environment, a great problem for the environment can be created, particularly for the water resources. To assess fresh leachate; collection, analyzing for various parameters, and comparing with the standards are essential. Thus, this study was purposed to examine the characteristics of different landfill leachate samples collected from three tropical landfill sites. The results of the formed leachate at the anaerobic Kulim Sanitary Landfill, semi-aerobic Pulau Burung Landfill Site, and anaerobic Kuala Sepetang landfill leachate in the northern region of Malaysia have been analyzed for 27 parameters and compared. The studied parameters in the present study were  phenols, zeta potential, oxidation-reduction potential (ORP), chemical oxygen demand (COD), biochemical oxygen demand (BOD<sub>5</sub>),  heavy metals, nitrogen compounds, salinity, electrical conductivity etc. For checking the risks of the leachate on the environment, the obtained results were compared with the Malaysia Standards. In addition, the leachate treatment opportunities upon the characterization are highlighted in this study. The effectiveness of various applications in treating leachate collected from municipal landfill was presented and discussed. It could be concluded that the knowledge of leachate quality is particularly significant in choosing an appropriate treatment techniques</p> </div> <p> </p>

Variability in the Concentration of Indicator Bacteria in Landfill Leachate – A Comparative Study

Leachate collected from the collection ponds of four landfill sites was investigated and compared for total coliforms and E. coli concentration as representatives of fecal pollution. Concentration of total coliforms and E. coli was comparable for leachate obtained from Kulim Landfill Site (KLS) and Ampang Landfill Site (ALS) with little variations. However, the level of indicator bacteria was significantly lower for Kuala Sepetang Landfill Site (KSLS), whereas Pulau Burung Landfill Site (PBLS) had the lowest concentration for both total coliforms and E. coli. Considering the landfills are currently operational, with the exception of ALS, the presence of indicator bacteria implies their inactivation prior to discharge. High concentration of indicator bacteria in ALS is attributed to the run-off entering the leachate pond. Greater concentration of ammonia and salinity level were partly responsible for lower concentration of indicator bacteria in leachate from KSLS and PBLS, indicating that salinty and ammonia could significantly affect the survival of indicator bacteria.

Initial Characterization of Semi-aerobic Landfill Leachate Based On Its Biodegradation

The characterization of landfill leachate has been well established. However, its biodegradation properties have not been well reported. Therefore, this research was undertaken to investigate the biodegradability of semi-aerobic sanitary landfill and the ratio of the biological oxygen demand (BOD) to chemical oxygen demand (COD) BOD5/COD, COD fraction on leachate from Pulau Burung landfill Site (PBLS). These parameters are important as they may provide appropriate and suitable treatment for this kind of leachate. In this research, leachate from two different ponds were studied i.e., the raw leachate from leachate collection pond and the leachate effluents of the treatment plant'. Five different measurement points were tested for each pond to understand the characterization for leachate. The soluble and particulate organic compound was separated by filtration using a 0.45μm pore size membrane filter. The results indicated that leachate in PBLS has low BOD5/COD ratio. The total COD (TCOD) ranged from 2040mg/L to 3160mg/L. The Biodegradable COD (BCOD), unbiodegradable COD (UBOD), soluble biodegradable (RBCOD), particlulate biodegradable (SBCOD), particulate inert (UPCOD), and soluble inert (USCOD) ranged from 53%-67%, 33%-47%, 38%-46%, 9%-25%, 12%-26%, and 18%-25%. This indicates, the leachate in Pulau Burung Landfill Site have different of COD fraction behavior compare with domestic wastewater. In which, leachate have low SBCOD, but relatively high in others COD fraction compare with domestic wastewater.

Leachate Characterization and Phytoremediation Using Water Hyacinth (Eichorrnia crassipes) in Pulau Burung, Malaysia

ABSTRACT Leachate from Pulau Burung landfill site was analyzed and treated using phytoremediation technique while water hyacinth (Eichhornia crassipes) was used as the phytoremediator. Some parameters analyzed included ammonia nitrogen (NH3-N), nitrate, nitrite, total Kjeldahl nitrogen (TKN), phosphate, and zinc. The range of values of nutrients such as the pH, ammonia nitrogen, TKN, phosphate and zinc during leachate characterization were 8.72 and 8.58, 1810 and 1070 mg/L, 1183 and 1120 mg/L, 46.4 and 31.2 mg/L, 11.1 and 5.4 mg/L, respectively. After phytoremediation, significant reduction was noticed in all the nutrients and zinc. Nitrite, phosphate and zinc values were between 91.9% and 98.2%, 4.4 to 0.6 mg/L and 1.1 and 0.1 mg/L, respectively. Statistical analyses showed significant differences between the planted and unplanted systems (p ≤ .05). It was established that Eichhornia crassipes had the capacity to remove nutrients and heavy metals from leachate, which requires treatment to minimize pollutants to an acceptable level before discharging into water courses.

The Effectiveness of Silica Sand in Semi-Aerobic Stabilized Landfill Leachate Treatment

This study examines the suitability of natural silica sand as a low-cost adsorbent for the removal of ammoniacal nitrogen and heavy metals, particularly iron and zinc, from semi-aerobic stabilized landfill leachate. Leachate samples were collected from the Pulau Burung landfill site (PBLS) in Penang, Malaysia. The above-mentioned contaminants are highlighted in this study because of their unsafe concentrations at PBLS. The effects of shaking time, settling time, and silica sand dosage on the study parameter removal efficiencies were investigated to predict the performance of the process. The adsorptions of ammoniacal nitrogen, iron, and zinc were judiciously described by Langmuir and Freundlich isotherm models. The optimum removal efficiencies of ammoniacal nitrogen, iron, and zinc obtained were 51%, 44.4%, and 39.2%, respectively, with a shaking time of 90 min, a settling time of 60 min, and with a dosage of 60 g (0.5 kg/L) of silica sand. Based on the coefficient of determination (R2) values obtained from Langmuir and Freundlich isotherm models, ammoniacal nitrogen, iron, and zinc adsorption were better fitted to the Freundlich model.

Leachate characterization in semi-aerobic and anaerobic sanitary landfills: A comparative study

This study analyzes and compares the results of leachate composition at the semi-aerobic Pulau Burung Landfill Site (PBLS) (unaerated pond and intermittently aerated pond) and the anaerobic Kulim Sanitary Landfill in the northern region of Malaysia. The raw samples were collected and analyzed for twenty parameters. The average values of the parameters such as phenols (1.2, 6.7, and 2.6 mg/L), total nitrogen (448, 1200, and 300 mg/L N-TN), ammonia-N (542, 1568, and 538 mg/L NH 3-N), nitrite (91, 49, and 52 mg/L NO 2 −-N), total phosphorus (21, 17, and 19 mg/L), BOD 5 (83, 243, and 326 mg/L), COD (935, 2345, and 1892 mg/L), BOD 5/COD (0.096,0.1124,0.205%), pH (8.20, 8.28, and 7.76), turbidity (1546, 180, and 1936 Formazin attenuation units (FAU)), and color (3334, 3347, and 4041 Pt Co) for leachate at the semi-aerobic PBLS (unaerated and intermittently aerated) and the anaerobic Kulim Sanitary Landfill were recorded, respectively. The obtained results were compared with previously published data and data from the Malaysia Environmental Quality Act 1974. The results indicated that Pulau Burung leachate was more stabilized compared with Kulim leachate. Furthermore, the aeration process in PBLS has a considerable effect on reducing the concentration of several pollutants. The studied leachate requires treatment to minimize the pollutants to an acceptable level prior to discharge into water courses.

Comparison study of ammonia and COD adsorption on zeolite, activated carbon and composite materials in landfill leachate treatment

Chemical oxygen demand (COD) and ammoniacal nitrogen have always been the crucially problematic parameters in landfill leachate treatment. This study was conducted to investigate the adsorption properties of ammoniacal nitrogen and COD in semi-aerobic leachate from the Pulau Burung landfill site on zeolite, activated carbon and a new composite media in terms of adsorption isotherm and kinetic. The results show that all adsorbents fitted well with both Langmuir and Freundlich isotherms (R 2 > 0.9) for ammonia adsorption. A comparison study indicated that the adsorption capacity of composite adsorbent towards ammoniacal nitrogen was higher than zeolite and activated carbon and comparable to activated carbon for COD. Findings from a kinetic study indicated that the adsorption of ammonia on new composite adsorbent and zeolite follow almost all kinetic models such as pseudo-first-order, pseudo-second-order, Elovich and intra-particle diffusion model, although pseudo-second-order was the most dominant. COD adsorption fitted well with the pseudo-second-order kinetic model, while activated carbon obeys the pseudo-first-order and intra-particle models.

Influence of Fenton reagent oxidation on mineralization and decolorization of municipal landfill leachate

This study evaluated the effectiveness of Fenton's technique for the treatment of semi-aerobic landfill leachate collected from Pulau Burung Landfill Site (PBLS), Penang, Malaysia. The Fe2 + or Fe3 + as catalyst and H2O2 as oxidizing agent are commonly used for the classical Fenton's reaction. In present study, the effect of operating conditions such as pH, reaction time, molar ratio, agitation rate, feeding mode and Fenton reagent concentrations which are important parameters that affect the removal efficiencies of Fenton method were investigated. Under the most favorable conditions, the highest removals of 58.1 and 78.3% were observed for COD and color, respectively. In general, the best operating conditions were pH = 3, Fe = 560 mg L−1, H2O2 = 1020 mg L−1, H2O2/Fe2 + molar ratio = 3, agitation rate = 400 rpm and reaction time = 120 minutes. The results highlighted that stepwise addition of Fenton's reagent was more effective than adding the entire volume in a single step. Excessive hydrogen peroxide and iron have shown scavenging effects on hydroxyl radicals and reduced degradation of refractory organics in the landfill leachate.

Application of the central composite design for condition optimization for semi-aerobic landfill leachate treatment using electrochemical oxidation

In the present study, Electrochemical Oxidation was used to remove COD and color from semi-aerobic landfill leachate collected from Pulau Burung Landfill Site (PBLS), Penang, Malaysia. Experiments were conducted in a batch laboratory-scale system in the presence of NaCl as electrolyte and aluminum electrodes. Central composite design (CCD) under Response surface methodology (RSM) was applied to optimize the electrochemical oxidation process conditions using chemical oxygen demand (COD) and color removals as responses, and the electrolyte concentrations, current density and reaction time as control factors. Analysis of variance (ANOVA) showed good coefficient of determination (R(2)) values of >0.98, thus ensuring satisfactory fitting of the second-order regression model with the experimental data. In un-optimized condition, maximum removals for COD (48.77%) and color (58.21%) were achieved at current density 80 mA/cm(2), electrolyte concentration 3,000 mg/L and reaction time 240 min. While after optimization at current density 75 mA/cm(2), electrolyte concentration 2,000 mg/L and reaction time 218 min a maximum of 49.33 and 59.24% removals were observed for COD and color respectively.

Variability of Parameters Involved in Leachate Pollution Index and Determination of LPI from Four Landfills in Malaysia

Landfill sites are potential sources of human and environmental hazards. Leachate produced form these waste dumping sites is heterogeneous and exhibits huge temporal and seasonal variations. Leachate pollution index (LPI) provides an overall pollution potential of a landfill site. The parameters required to calculate LPI from a landfill site are discussed in terms of their variations over time, and their significance has been highlighted in the context of LPI. The LPI values of two semiaerobic and two anaerobic landfill sites in Malaysia have been calculated in this study. Pulau Burung Landfill Site (PBLS) was found to have the highest LPI score while Ampang Jajar Landfill Site (AJLS) showed the lowest LPI as compared to other landfills. It is concluded that LPI value can be used as a tool to assess the leachate pollution potential from landfill sites particularly at places where there is a high risk of leachate migration and pollution of groundwater.

Application of combined filtration and coagulation for semi-aerobic leachate treatment

The landfill leachate was taken from the Pulau Burung Landfill Site (PBLS), Malaysia. Filtration by limestone-zeolite (15 : 25) and limestone-GAC (15 : 25) with filtration rate = 0.01 m3/m2.minute showed that 70% and 85% of colour and 42% and 70% COD were removed, respectively. Maximum colour removal (93% and 92%) and COD removal (56% and 46%) were achieved by the addition of 2000 mg/L PAC and 9000 mg/L alum respectively. Filtration by limestone-zeolite (15 : 25) and limestone-GAC (15 : 25) followed by coagulation at optimum dosage of 800 mg/L PAC, was efficient to reduce colour (98% and 99%) and COD (70% and 86%) respectively.

Application of response surface methodology (RSM) to optimize coagulation–flocculation treatment of leachate using poly-aluminum chloride (PAC) and alum

Coagulation–flocculation is a relatively simple physical–chemical technique in treatment of old and stabilized leachate which has been practiced using a variety of conventional coagulants. Polymeric forms of metal coagulants which are increasingly applied in water treatment are not well documented in leachate treatment. In this research, capability of poly-aluminum chloride (PAC) in the treatment of stabilized leachate from Pulau Burung Landfill Site (PBLS), Penang, Malaysia was studied. The removal efficiencies for chemical oxygen demand (COD), turbidity, color and total suspended solid (TSS) obtained using PAC were compared with those obtained using alum as a conventional coagulant. Central composite design (CCD) and response surface method (RSM) were applied to optimize the operating variables viz. coagulant dosage and pH. Quadratic models developed for the four responses (COD, turbidity, color and TSS) studied indicated the optimum conditions to be PAC dosage of 2 g/L at pH 7.5 and alum dosage of 9.5 g/L at pH 7. The experimental data and model predictions agreed well. COD, turbidity, color and TSS removal efficiencies of 43.1, 94.0, 90.7, and 92.2% for PAC, and 62.8, 88.4, 86.4, and 90.1% for alum were demonstrated.

Physico-chemical removal of iron from semi-aerobic landfill leachate by limestone filter

Limestone has been proven effective in removing metals from water and wastewater. A literature review indicated that limestone is capable of removing heavy metals such as Cu, Zn, Cd, Pb, Ni, Cr, Fe and Mn are through a batch process or by filtration technique. The removal capability is reported at up to 90%. However, to date most of the studies have been focused on synthetic wastewater. The present study attempts to investigate the suitability of limestone to attenuate total iron (Fe) from semi aerobic leachate at Pulau Burung Landfill Site in Penang, Malaysia. Iron was found in significant quantities at the landfill site. The study also aims to establish the Fe isotherm and breakthrough time of the proposed limestone filter for post-treatment to the migrating landfill leachate before its release to the environment. The Fe isotherms were established using a batch equilibrium test, while the breakthrough characteristics were determined using continuous flow permeating through a limestone column. The latter was used in order to simulate the continuous flow of leachate that would occur in the proposed limestone filter. The limestone media used in the experiment contain more than 90% CaCO 3 with particle sizes ranging from 2 to 4 mm. Four filter columns (each 150 mm in diameter and 1000 mm depth) were installed at the landfill site. Metal loadings were kept below 0.5 kg /m 3 day and the experiment was run continuously for 30 days. Initial results indicated that 90% of Fe can be removed from the leachate based on retention time of 57.8 min and surface loading of 12.2 m 3/m 2 day. For the batch study on the Fe isotherm, the results indicated that limestone is potentially useful as an alternative leachate treatment system at a relatively low cost.