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In Malaysia, there are some accumulation of sugar refinery byproducts with a lot of this material not being utilized in a productive manner, while, these byproducts had the great potential when mixed into agricultural soils as organic fertilizer with many of benefits that can improve soil health, and sustainable agronomic productivity. Pressmud or known as filter cake is a by-product of sugar industry and for every 100 tons of sugarcane crushed about 3 tons of pressmud cake is left behind as by-product. This studies carried out on this material have not properly summarized their characteristics properties that they can be used as aid for future works. Data from tests involving pressmud samples from Malayan Sugar Manufacturing (MSM) Prai Berhad, Penang which was part of a larger collection was analyzed. The physicochemical properties of pressmud characterization as well as leaching test were carried out. The physicochemical and engineering properties involved compaction behavior, permeability, cation exchange capacity (CEC), compressive stress test and its surface functional groups. The leaching test method included batch equilibrium test and column test. The optimum value of water content in pressmud was determined in the compaction test. It was found out that pressmud has higher optimum water content value was observed. The permeability test of pressmud gave value in ranges of 1.84 x 10-5 cm/s. The Cation Exchange Capacity (CEC) of pressmud indicated value in the range of 99 to 101 meq/100 g. The high cation exchange capacity indicated that pressmud was believed to be primarily responsible for sorption of metal ions. It can be concluded that pressmud having the capability to remove heavy metals through CEC process. Pressmud also showed higher compressive strength value. Batch equilibrium test glaringly showed that pressmud have the capability to remove from 53.6%-93.8% metal removed from metal solutions for Chromium (Cr), Copper (Cu), Manganese (Mn), Nickle (Ni), Lead (Pb) and Zinc (Zn). From the result of column test, pressmud alone was able to retain efficiently all the heavy metals as these metals did not reach 1 (relative concentration) until 10 pore volume (PV.) indicating that pressmud was a good mixture material as it can assist in adsorption of heavy metals. Based on the characterization study, removal efficiency and column test, pressmud has great potentiality to be used as an additional material in soil amendments to enhance soil fertility and strength ability.

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.

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 stabilised anaerobic landfill leachate (SAL) from Alor Pongsu, Perak. Hydroxyl radical (OH•) is an important oxidising 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 colour 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 oxidised 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.

The current study investigated the performance of combined ozonation and zirconium tetrachloride (ZrCl4) for an anaerobic stabilized landfill leachate treatment. The effectiveness of ZrCl4 dosage [COD0/ZrCl4 ratio (g/g)], pH variation, and reaction time during ozonation were evaluated to obtain the optimal operational conditions of ozone (O3)/ZrCl4 oxidation process. The maximum removal efficiencies for chemical oxygen demand (COD) and color were 88 and 100 %, respectively, at 1/2 g zirconium tetrachloride dosage (COD0/ZrCl4), pH 6, and 90 min reaction time, whereas 79 % removal for ammonia (NH3–N) was obtained at pH 11. Biodegradability (BOD5/COD) was improved from 0.07 to 0.09 and 0.34 after treatment with O3 alone and O3/ZrCl4, respectively. Treatments using ozonation alone and zirconium alone were performed and compared with the results obtained from the treatment with the new catalytic ozone method (O3/ZrCl4). The new oxidation method (i.e., O3/ZrCl4) obtained better removal efficiencies for organic substances and ammonia and this method reported better biodegradability ratio compared with other related processes. The O3/ZrCl4 process is also more efficient than O3/Fenton and O3/persulfate for stabilizing leachate treatment.

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.

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.

One of an anaerobic stabilized landfill leachate in Malaysia underwent ozonation process. The sample rich in chemical oxygen demand (COD) was collected from Alor Pongsu Landfill Site, Perak (APLS). This site has been operating since year 2000. The leachate also contains other pollutants that exceeded the standard discharge limit for wastewater effluents. The effectiveness of ozone (O3) dosage, pH variation, and reaction time during ozonation was evaluated to measure the performance of O3 and determine the maximum operational conditions for this treatment. The maximum removal efficiency for COD was 50% at an ozone dosage of 31 g/m3, natural of pH 8.5, and reaction time of 60 min. The biodegradability ratio (BOD5/COD) improved from 0.08 to 0.23 after treatment with O3. The ozonation method has enhanced the biodegradability ratio and resulted high percentage removal of COD. This improvement showed that oxidation has a great potential to remediate recalcitrant pollutant wastes, such as landfill leachate.

Leachate is a critical problem of sanitary landfills because it contains high organic matter and hazardous compounds that can generate negative environmental effects. The high chemical oxygen demand (COD) and color of the leachate necessitates its treatment before it can be released to the water body. Thus, an investigation into the performance of advanced oxidation processes (AOPs) was conducted using a combination of ozone (O3) with zirconium tetrachloride (ZrCl4) as catalyst in stabilized landfill leachate treatment. Such leachate was collected from the Alor Pongsu Landfill site (APLS), Perak, Malaysia. COD and color parameter were used as indicators to examine the effect of O3/ZrCl4 dosage, pH, and contact time. The experiment was run under gas flow rate of 1,000 mL/min±10% and temperature below 15 °C. The maximum removal obtained for COD and color were 88% and 100%, respectively. This outcome was achieved at 27 g/m3 ozone dosage, pH 6, 90 min reaction time, and dosage ratio of 1:2 (COD g: ZrCl4 g). T...

The effectiveness of bentonite using chitosan as a coagulant for raw water treatment was assessed in this study. The possible link between Alzheimer's disease with conventional aluminium based coagulants, has become an issue in water treatment. A method for treating water, using a natural approach as an alternate to achieve enhanced coagulation, might help to reduce risk to health, and be more environmentally friendly. One method for removing turbidity from raw water is by the adding of a primary coagulant (e.g., a natural polymer of chitosan) and a coagulant aid (e.g., natural clay of bentonite) to the raw water. A series of batch coagulation tests were conducted by jar test to obtain the optimum dosage, pH, ratio of coagulant aid and primary coagulant, and the efficiency time for the jar test, by evaluating the standard parameters, such as turbidity, pH, colour, aluminium, and chlorine. In terms of these parameters, chitosan:bentonite showed the best result, with a ratio of 30:70 in an optimal concentration of 1,000 mg/l with 0.15 g chitosan plus 0.35 g bentonite. The coagulants performed with an optimal pH of 5, with 30 min of mixing time during flocculation. However, the optimal pH condition during the jar test showed an improvement in the water alkalinity results, from pH 5 to 6.8. Coagulation with bentonite-chitosan successfully removed the turbidity with a highest efficiency of 98%. After water treatment in the optimal condition, results showed a great water quality standard, with 1.38 NTU, 10 TCU, 0.01 mg/l amount of chlorine and aluminium, and a pH of 6.8. However, data only showed slight differences of efficiency, between natural and conventional coagulants. In terms of the sludge volume index (SVI), the ratio of alum to bentonite-chitosan was found to be 3:1 which indicated that less sludge was produced by the natural coagulant. In a cost comparison between these coagulants, based on a rough estimation, bentonite-chitosan is nearly 10 times more expensive than the alum coagulant. However, with mass production and commercial availability, in the long run the price of chitosan could be reduced tremendously.

The current study aimed to assess the performance of utilise Zirconium reagent during ozonation of anaerobic stabilised leachate. In this study, quadratic models using response surface methodology software was utilised to design the experiments and evaluate the interaction between experimental factors, such as zirconium tetrachloride, pH, and reaction time, at constant ozone dosage (27 g/m3). The performance of the new ozonation method was evaluated in terms of the removal of the chemical oxygen demand (COD), NH3-N and colour. The obtained quadratic models for colour, NH3-N and COD removal was considered significant (P < 0.0001). The optimal removal for of 100%, 90%, and 66% for colour, COD and NH3-N, was obtained at 38 min reaction time, ZrCl4 dosage (1/2(COD/ZrCl4 g/g) and pH 4.5, using 27g/m3 ozone dosage, respectively. The results obtained in this study were compared with zirconium only and ozone only, to evaluate its effectiveness. The performance of the new oxidation method (O3/ZrCl4) better than other related methods for the removal of colour, COD and NH3-N.

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.