Landfill leachate is well known as a hazardous byproduct from dumpling sites that has a negative impact on the environment and human life. Therefore, an effective treatment is imperative to overcome this issue. This research study investigates the effectiveness of zirconium tetrachloride (ZrCl
Landfill leachate can threaten the environment and human life. Therefore, this study aims to investigate the efficiency of ozone (O3 ), O3 with zirconium tetrachloride (O3 /ZrCl4 ), and O3 with tin tetrachloride (O3 /SnCl4 ) in remediating the stabilized anaerobic landfill leachate (SAL) from Alor Pongsu, Perak. Hydroxyl radical (OH•) is an important oxidizing agent in the ozonation process. Its presence was tested using tert-butyl alcohol. Results showed that using ZrCl4 and SnCl4 in ozonation boosted the generation of hydroxyl radical, thereby enhancing the oxidation process and pollutant removal inside the sample. The O3 /ZrCl4 mix at chemical oxygen demand (COD) to ZrCl4 ratio of 1:1.5, pH 8-9, and 90-min reaction time resulted in the highest reduction rates of COD and color at 91.9% and 99.6%, respectively. All results demonstrated that the optimum performance occurred at alkaline conditions (pH > 8), proving that OH radicals primarily oxidized the pollutants through an indirect reaction pathway. The biodegradability (biochemical oxygen demand/COD) ratio was also considerably improved from 0.02 (raw) to 0.37 using O3 /ZrCl4 , compared with using O3 alone and using O3 /SnCl4 , which only recorded 0.23 and 0.28, respectively, after the treatment. The study demonstrated that O3 /ZrCl4 was the most efficient combination. PRACTITIONER POINTS: The O3 /ZrCl4 recorded the highest COD and color removals. The O3 /ZrCl4 combination also recorded higher OH• concentrations. The biodegradability of leachate (BOD5 /COD ratio) improved from 0.02 to 0.37.
Landfill leachate generation is one of the main problems from sanitary landfill. Chemical oxygen demand (COD), ammoniacal nitrogen (NH 3 -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 (O 3 ) and zirconium tetrachloride (ZrCl 4 ) 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/ZrCl 4 ratio) and then added to the leachate samples with 60 min ozonation at natural leachate pH (8). COD, color, and NH 3 -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 O 3 / Kg COD) reported in PBLS, whereas the lowest value (2.32 Kg O 3 / Kg COD) was reported in APLS. Biodegradability of (BOD 5 /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/ZrCl 4 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.
Municipal solid waste landfills are major sources of environmental pollution. This study evaluated heavy metal concentrations in soils around Pulau Burung Landfill, Penang, Malaysia, to determine the pollution potential of a landfill. Soil samples were collected at depths of 0–20 cm (top), 20–40 cm (center) and 40–60 cm (bottom) around the landfill and at a control site and characterized for various properties and concentrations of Lead (Pb) and Zinc (Zn). Samples of daily soil cover, collected from the same sites where soil samples were collected, were also analyzed for several of heavy metals analysis. The soils were silty sand, mostly acidic (4.45) with low organic matter content (0.41%) and cation exchange capacity (3.15-3.19 meq/100 g). Other basic physico-chemical and adsorption properties were conducted on soil indicated that soil alone is not effective to be used in the landfill to support the pollutant for a long time. Heavy metals concentrations (as background data) in the soils followed the order Iron (Fe) > Zinc (Zn) > Manganese (Mn) > Lead (Pb) > Arsenic (As) > Chromium (Cr) > Cadmium (Cd) > Copper (Cu) > Nickle (Ni) with samples from around the landfill having higher concentrations especially Iron, (Fe) and Zinc, (Zn). For soil profile contribution, heavy metal enrichment was highest at a depth of 40–60 cm. In short, soil alone cannot retain and minimize the migration of heavy metals in landfill based on the results of this study including removal efficiency test. Monitoring of environments around active landfills needs to be ongoing to mitigate negative impacts on humans and the environment.
Abstract Pressmud is one of the most abundant wastes produced by the sugarcane industry. However, it has received far too little attention as a reactive material for pollutant removal, although its beneficial effect on soil fertility and crop productivity is well established. This paper investigates the potential of pressmud to minimize heavy metal migration while boosting soil fertility and productivity. Firstly, the adsorbent was characterized by Fourier Transform Infrared Spectroscopy (FTIR) and Field-Emission Scanning Electron Microscopy (FESEM) analyses, which showed the presence of functional groups such as carbonyl, hydroxyl, and silica capable of adsorbing metal ions. The cation exchange capacity (CEC) of pressmud is very high, ranging between 44.9 and 45.2 meq/100 g. Along with removal efficiency testing and evaluating breakthrough curves, characterization and adsorption analyses (batch equilibrium and column test) were carried out. The pressmud reveals promising adsorption characteristics, including a high organic content (17.62%) and the presence of carbon, which significantly affects its excellent removal effectiveness. Based on the removal efficiency test, pressmud successfully removes metal ions at the highest value, such as zinc (Zn), at 99.7%. Meanwhile, its breakthrough curve reveals that it efficiently retained all heavy metals, as these metals do not reach 1 to 10 pore volumes (p.v.), indicating that pressmud is a good material for heavy metal adsorption and soil productivity. This possible use establishes a new cyclical flow for the material and contributes to its minimization and reuse, adhering to circular economy ideas. However, pressmud must be disposed of properly to avoid adverse effects on humans and the environment.
Landfill leachate is a hazardous pollutant generated from a landfill site. Discharge of landfill leachate has caused a major contamination to the environment and detrimental to human health. This chapter introduces an alternative method to treat recalcitrant pollutant in leachate by using ozonation with catalyst. The production of hydroxyl radical in ozonation was not enough to oxidize complex molecular structure in the leachate. Theoretically, the addition of catalyst enhances the capacity of radical and accelerates the chemical reaction. The effectiveness of ozonation with Fenton (O3/Fenton), hydrogen peroxide (O3/H2O2), and zirconium tetrachloride (O3/ZrCl4) in removing pollutant such as chemical oxygen demand (COD), color, and improvement of biodegradability by using this process were also discussed in this chapter. Comparison in term of treatment cost and benefits of the application of chemical as catalyst are briefly elaborated at the end of this chapter.
ABSTRACT Solid waste can be effectively managed through disposal in engineered landfills, which are specifically designed facilities. The application of daily soil cover at these landfills is vital for mitigating leachate generation and protecting groundwater from contamination. This study aims to investigate whether a mixture of laterite soil (LS), peat soil (PS), and rice husk (RH) can reduce the migration of heavy metals within a landfill setting. Heavy metal pollution poses a significant environmental challenge in Malaysia, specifically the five metals focused on in this research: Cd, Cr, Cu, Ni, and Zn. The study evaluates the adsorption capacity of the soil mixture for these metal ions by utilizing laboratory analyses of key parameters such as pH and cation exchange capacity (CEC). To assess the effectiveness of the soil mixture, various combinations were tested, highlighting a blend of 50% LS, 40% PS, and 10% RH as the most effective. An equilibrium study was conducted, wherein metal ion solutions were prepared, allowing the soil mixtures to interact with these solutions until a state of equilibrium was achieved. Subsequently, batch adsorption experiments were performed to measure the mixtures’ ability to adsorb the metal ions, with ongoing assessment of pH and CEC. The results indicate that the selected mixture can significantly reduce metal ion concentrations, demonstrating its potential as a viable daily cover for landfills. Ultimately, this research provides valuable insights into strategies for minimizing heavy metal migration in landfills and safeguarding groundwater resources.
Peat is a problematic soil, and it is a common problem faced by engineers in construction. The characteristics that have been noted before are high moisture content, poor shear strength, great compressibility, and long-term settlement. For this research study, it focuses on stabilizing peat soil using EPP and CaO. There are three main tests that were conducted in this research study: index properties testing, compaction testing, and For Index Properties testing, five (5) experiments were conducted to study the index properties of disturbed peat soil, which are moisture content, fiber content, liquid limit, organic content, pH, and specific gravity. Next, for the Compaction Test, using a 4.5 kg rammer, define the optimum mixture of stabilizer that is mixed with different volumes of 5%, 10%, 15%, and 20% of stabilizer. In this study, the expected result is to inspire an in-depth study of the use of EPP material and chemical CaO as peat soil stabilizers for better utilization of problematic soil. The main finding was that the mixture with the exact amount of moisture, EPP, and CaO helped stabilize the soil and cure peat soil. Thus, this study confirms the idea of treating peat with EPP and CaO, enhancing the properties of peat soil, and sustaining the settlement over loading for a period of time accordingly. 20% mix of EPP and CaO produces the highest dry density, showing that dry density increases linearly with the amount of mixture to stabilize peat. The crystallization process between peat and EPP was pronouncedly observed where smaller particles identified as EPP filled the gaps in between the pores identified from SEM. The silicon (Si content developed from each spectrum ranged from 14.4% to 17.7%. The EDX results show significant results where mineral crystallization occurred in the coagulation process. Doi: 10.28991/CEJ-2023-09-07-011 Full Text: PDF
This research was conducted essentially to treat fresh peat water using a series of adsorbents. Initially, the characterization of peat water was determined and five parameters, including pH, colour, COD, turbidity, and iron ion exhibited values that exceeded the water standard limit. There were two factors influencing the adsorption capacity such as pH, and adsorbent dosages that were observed in the batch study. The results obtained indicated that the majority of the adsorbents were very efficient in removing colour, COD, turbidity at pH range 2-4 and Fe at pH range 6-8. The optimum dosage of cationic surfactant modified zeolite (CSMZ) was found around 2 g while granular activated carbon (GAC) was exhibited at 2.5 g. In column study, serial sequence of CSMZ, GAC, and limestone showed that the optimal reduction on the 48 hours treatment were found pH = 7.78, colour = 12 TCU, turbidity = 0.23 NTU, COD = 0 mg/L, and Fe= 0.11 mg/L. Freundlich isotherm model was obtained for the best description on the adsorption mechanisms of all adsorbents.
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