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The massive drawbacks of conventional wastewater treatment have led to a demand investigation about new advanced wastewater treatment technology. The issue can be addressed via advanced oxidation p...

To enhance dye removal and energy recovery efficiencies in single-pair electrode photocatalytic fuel cell (PFC-AC), dual cathodes PFC (PFC-ACC) and dual photoanodes PFC (PFC-AAC) were established. Results revealed that PFC-AAC yielded the highest decolorization rate (1.44 h

Photocatalytic fuel cell (PFC) is promising to own its synchronous degradation of organic pollutants with electricity generation under illumination of light. The oxidation and reduction process promote the conversion of chemical energy in the pollutants into electrical energy. In this study, PFC is driven by the electrode reactions between the zinc oxide loaded carbon plate (ZnO/C) photoanode and carbon plate cathode under irradiation of UVA light. The ZnO/C photoanode was successfully fabricated by using simple ultrasonication-annealed method and investigated by XRD, SEM and EDX. To investigate the capability of the PFC, reactive red 120 (RR120), congo red (CR) and acid orange 7 (AO7) are employed well compared among themselves. The results indicated that the molecular structure of azo dyes with different adsorption of light by dye itself, number of azo bonds and sulfonic groups can be the crucial factors of decolorization in the PFC. The photocatalytic fuel cell with AO7 as sacrificial agent was able to perform 82.43% of decolorization efficiency, a maximum short circuit current (JSC) of 0.0017 mA cm-2 and maximum power density (Pmax) of 0.0886 µW cm-2.

Photocatalytic fuel cell (PFC) is considered as a sustainable green technology which could degrade organic pollutant and generate electricity simultaneously. A synergistic double-sided ZnO/BaTiO3 loaded carbon plate heterojunction photoanode was fabricated in different ratios by using simple ultrasonication and mixed-annealed method. The double-sided design of photoanode allowed the lights irradiated at both sides of the photoanode. The ferroelectricity fabricated photoanode was applied in a membraneless PFC with platinum-loaded carbon as the cathode. Results revealed that the photoanode with 1:1 ratio of BaTiO3 and ZnO exhibited a superior photocatalytic activity among all the photoanodes prepared in this study. The heterojunction of this photoanode was able to achieve up to a removal efficiency of 93.67% with a maximum power density of 0.5284 μW cm−2 in 10 mg L−1 of Reactive Red 120 (RR120) without any supporting electrolyte. This photoanode was able to maintain at high performance after recycling 3 times. Overloading of ZnO above 50% on BaTiO3 could lead to deterioration of the performance of PFC due to the charge defects and light trapping ability. The interactions, interesting polarizations of the photocatalysts and proposed mechanism of the n-n type heterojunction in the photoanode of ZnO/BaTiO3 was also discussed.

A Successive Alkalinity Producing System (SAPS) was evaluated for the remediation of synthetic Acid Mine Drainage (AMD) by using an organic substrate of peat soil and limestone aggregate. The characterization of the AMD was conducted by the testing the AMD effluent originated from active mining site at Pengkalan Hulu, Perak, Malaysia. The characterization of the peat soil and limestone revealed stipulated composition, carbon content in the peat soil and particle size distribution of the limestone. Synthetic AMD was prepared incorporating iron sulphate (FeSO4) and sulphuric acid (H2SO4). The synthetic AMD was acidic (pH

A unidirectional flow solar photocatalytic fuel cell (PFC) was successfully developed for the first time to offer alternative for electricity generation and simultaneous wastewater treatment. This study was focused on the synthesis of α-, δ- and β-MnO

Oxidation of p-Cresol was investigated by using ozonation process. The aim of this research is to assess the effectiveness of ozonation on oxidation of micropollutant such as p-Cresol. Ozonation performance was evaluated based on p-Cresol concentration reduction and chemical oxidation demand (COD) reduction. It was found ozonation at pH11 achieved the highest p-Cresol degradation, with 95.8% of p-Cresol reduced and 96.0% of COD reduced, for an initial 50 mgL-1 of p-Cresol. The degradation of p-Cresol could be expressed by second-order of kinetic model. The second-order rate constant k increases as the initial pH increased, but decreases with the increasing of initial p-Cresol concentrations. Besides, the absorption spectra of p-Cresol over ozonation time were analyzed by spectrophotometry. The evolution of absorption spectra of p-Cresol degradation suggests that the oxidation of p-Cresol follows three stages mechanisms with cycloaddition as the first step to produce aromatic intermediates followed by ring-opening reactions, degradation of the intermediates, and subsequently achieved mineralization.

The concentrations of supporting electrolyte and external resistance (Rext) played crucial roles to improve photocatalytic fuel cell (PFC) efficiency. Herein, the significant influence of Na2SO4 concentration (0.05–0.20 M) and the Rext (100, 280, 500, 1000 and 10,000 Ω) on the power production and dye decolorization in PFC were addressed. Analysis of variance (ANOVA) revealed that the further increment of 0.10 M of Na2SO4 concentration only enhanced maximum power density (Pmax) but had no significant effect on the dye decolorization (P > 0.05). Conversely, the result showed distinct differences in PFC performances under different Rext (P

A novel sustainable hybrid system of photocatalytic fuel cell (PFC) and Fenton process is an alternative wastewater treatment technology for energy-saving and efficient treatment of organic pollutants. The electrons generated from PFC photoanode are used to produce H2O2 in the Fenton reactor and react with the in situ generation of Fe2+ from sacrificial iron for hydroxyl radical formation. In this study, the effect of different initial Amaranth dye concentrations on degradation and electricity generation were investigated. ZnO/Zn photoanode was prepared by anodizing method and characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). Results revealed that the maximum power density (9.53 mW/m2) and current density (0.0178 mA/m2) were achieved at 10 mg/L of Amaranth. The correlation between dye degradation, voltage output, and kinetic photocatalytic degradation were also investigated and discussed.

A novel hybrid system composed of a photocatalytic fuel cell (PFC) and Fenton reactor was developed with the aim to degrade the azo dye Reactive Black 5 (RB5) and generate electricity. Compared to previously established system of bioelectro-Fenton system, microbial fuel cell (MFC) system has significant challenge in the development and operation system. Therefore, PFC is used instead of MFC to generate electrons for the Fenton system. The effect of azo dye (RB5) on each PFC and Fenton reactor was investigated. The experimental results showed that maximum power output was achieved in the absence of dye in the Fenton reactor of this hybrid system. Furthermore, higher degradation efficiency of RB5 could also be observed in the PFC reactor in this hybrid system.

Reactive Green (RG19) is one of azo dye that potentially hazardous towards human due to highly recalcitrant to degrade and still lack of effective treatments. This study introduced a significant study since numerous conventional treatment processes were not capable of removing that azo dye in fast and efficient process. Therefore, increase strong potential of sulfate and hydroxyl radical resulting in an improvement towards Advanced Oxidation Processes (AOPs) which is ozonation process has been proposed to degrade RG19 dye efficiently. Ozonation (O3) and Ozone/Persulfate (O3/S2O82-) processes were tested either can be a standalone process or need a better combination of a catalyst which is sodium persulfate (Na2S2O8). The efficiency of dye degradation as follows: colour removal, chemical oxygen demand (COD) and the presence of organic molecules. The efficiency colour removal with O3 reached 75% while (O3/S2O82-) reached 85% at similar reaction time. Also, the average rate of efficiency COD removal (O3/S2O82-) yielded the highest 27.82% whereas O3 reached only 10%. After that, the effects of operational conditions had been investigated in (O3/S2O82-) process including the fixed initial concentration of the dyes, initial pH of the RG19 (2-6), Na2S2O8 concentration (25-65 mM) and contact time (3-25 min) on the colour and COD removal efficiency. Central composite design (CCD) has been applied to achieve the optimization of (O3/S2O82-) was resulting (Colour removal; R2 = 0.900, COD removal; R2 = 0.508). Hence, the optimum conditions of the process at (pH 8, 40 mM, 14 min) and can be shown specifically by mathematical modelling equation also based on interactive effect by 3D contour plot. This overall result indicates that (O3/S2O82-) process enhances a synergistic effect that could be observed in structural changes of dye molecule along RG19 degradation.Reactive Green (RG19) is one of azo dye that potentially hazardous towards human due to highly recalcitrant to degrade and still lack of effective treatments. This study introduced a significant study since numerous conventional treatment processes were not capable of removing that azo dye in fast and efficient process. Therefore, increase strong potential of sulfate and hydroxyl radical resulting in an improvement towards Advanced Oxidation Processes (AOPs) which is ozonation process has been proposed to degrade RG19 dye efficiently. Ozonation (O3) and Ozone/Persulfate (O3/S2O82-) processes were tested either can be a standalone process or need a better combination of a catalyst which is sodium persulfate (Na2S2O8). The efficiency of dye degradation as follows: colour removal, chemical oxygen demand (COD) and the presence of organic molecules. The efficiency colour removal with O3 reached 75% while (O3/S2O82-) reached 85% at similar reaction time. Also, the average rate of efficiency COD removal (O3/S2O8...

There are approximately 450 water treatment plants in Malaysia which produce potable water to consumers. During coagulation process, huge volume of sludge was produced particularly when turbid water was treated. The main objective of this work is to study the physical and mechanical properties of clay sludge brick. In this research, the sludge from the water treatment plant was used as clay replacement material in brick production. Several design mixtures of sludge and clay with different moisture content were used to prepare the brick. These bricks were fired at two different temperature (500°C and 900°C) before being tested for its physical and mechanical properties. Result shows that the presence of sludge in brick would increase the water absorption capacity of the brick. The water absorption was increased from 5.5% to 51% when the 60% (w/w) of sludge was incorporated into the mix. In term of burning temperature, higher temperature would improve the physical and mechanical properties of the brick. Based on the results, sludge from the water treatment plant shows huge potential as clay replacement in brick making process. Recycling the sludge from water treatment plants could solve the sludge disposal problem face by most of the plant operators.

In the recent decades, Malaysia has been known as the one of the palm oil producers and exporters. The increasing of the production and demand of palm oil tends to increase the Palm Oil Mill Effluent (POME). Undeniably, the conventional biological treatment has been implemented to reduce the organic matters but insufficient to satisfy the discharge standard by the local authority. Consequently, the biological treated POME has to be treated further to meet the stringent discharge standard. Hence, an advanced oxidation processes (AOPs), electro-oxidation process (EOP) has been applied to treat further the biologically treated POME. There are two stages in this study, EOP carried on with catalyst and electrode (Al and Fe). Therefore, the performance of EOP is evaluated by investigating the removal efficiency on the organic parameters like COD, colour, suspended solid and NH3-N. The operational parameters are the pH adjustment (pH 3, 5, 7 and 9), contact time ranging from 0 to 60 min and the dosage of catalyst (H2O2 and TiO2). The highest degradation of the parameters was obtained under the most acidic solution pH 3, with addition of TiO2 by using Al electrode. The percentages of removal are 96.58 % of colour, 98.74 % of SS and 84.85 % of COD.

Textile and cosmetics industries are among the industries which produce huge volume of dyes wastewater. Photocatalysis is of the methods that effectively treating dye wastewater. Semiconductor such as zinc oxide (ZnO) is one of the photocatalyst which is widely used in photocatalysis treatment method. In this research, removal of chemical oxygen demand (COD) and colour from Methylene Blue (MB) solution using ZnO were compared with ZnO doped with Fe. In addition, ultrasonic cavitation was also applied during the preparation of the catalyst. The catalysts were successfully synthesized through sol-gel method. By comparing all catalysts, sonocatalyst ZnO doped Fe produced the highest efficiency for colour removal. During the experiments, the colour removal from MB solution with 10 ppm and 30 ppm concentration were 99.65% and 51.3% respectively. This study concluded that the presence of ultrasonic cavitation during the catalyst preparation did change the physical and chemical characteristics of ZnO doped Fe. As a result, the catalyst worked better during the treatment system to remove colour from MB solution.

The present study investigates the impact of high biodegradable COD fraction in poultry processing wastewater on the performance of lab-scale SBR. The SBR’s reactor was operated under 3 phases with different airflow rates namely 2.5 L/min, 5.0L/min, and 7.0L/min; and each phase would have a constant 21days of Sludge Retention Time (SRT). The sample of poultry processing wastewater consists of 84.06% of biodegradable components and 15.94% of the non-biodegradable component. It was observed that high readily biodegradable soluble COD (rbsCOD) had caused a rapid bacteria’s metabolism to consume nutrient as fast as possible which consequently tuned the COD removal efficiency from 85.0% to 92.9% and increased the SVI from 51.66 mL/g to 66.96mL/g (2nd phase) and 110.1 mL/g (3rd Phase). The removal efficiency of Ammonia Nitrogen and Total Suspended Solid was observed in the range from 69.3% to 81.2%, and 61.8% to 81.7% respectively. The fluctuation of the biodegradable COD component in poultry processing wastewater was observed to affect the oxygen demand, where the oxygen transfer efficiency dropped from 3.82% to 0.63% as the airflow rate increase from 2.5L/min to 7.0L/min along with the increase of biodegradable COD fraction. Hence, this experiment provides a clear perspective of poultry processing wastewater behavior to SBR performance.

A unidirectional flow solar photocatalytic fuel cell (PFC) was successfully developed for the first time to offer alternative for electricity generation and simultaneous wastewater treatment. This study was focused on the synthesis of α-, δ- and β-MnO2 by wet chemical hydrothermal method for application as the cathodic catalyst in PFC. The crystallographic evolution was performed by varying the ratios of KMnO4 to MnSO4. The mechanism of the PFC with the MnO2/C as cathode was also discussed. Results showed that the catalytic activity of MnO2/C cathode was mainly predominated by their crystallographic structures which included Mn–O bond strength and tunnel size, following order of α- > δ- > β-MnO2/C. Interestingly, it was discovered that the specific surface areas (SBET) of different crystal phases did not give an impact on the PFC performance. However, the Pmax could be significantly influenced by the micropore surface area (Smicro) in the comparison among α-MnO2. Furthermore, the morphological transformation carried out by altering the hydrothermal duration demonstrated that the nanowire α-M3(24 h)/C with 1:1 ratio of KMnO4 and MnSO4 yielded excellent PFC performance with a Pmax of 2.8680 μW cm−2 and the lowest Rint of 700 Ω.

Manual monitoring of the eutrophication status of water bodies such as a dam is a challenging task. Hence, drone technology can be used in assisting the monitoring work of any water bodies. This study was conducted to develop UAV-based remote sensing to derive indicators in lake water bodies. Four sampling points were chosen for testing where the Normalized Difference Vegetation Index (NDVI) and Normalized Difference Turbidity Index (NDTI) were assessed. DJI Phantom 4 Pro drone was used for the aerial data acquisition. Ex-situ data were also acquired, such as nitrate concentration (N) and phosphate concentration (P). The hyperspectral UAV images were ortho-rectified and geo-referenced in Agisoft PhotoScan software and NDVI value estimation in ArcGIS. Results show the correlation between NDVI values and N and P concentration with coefficients values of 0.7079 for P concentration and 0.7004 for N concentration, respectively. This study confirmed the applicability of remote sensing for water resource management using UAVs, characterized as a quick and easy methodology.

In this paper, a respond surface methodology (RSM) model has been developed using three levels Box-Benkhen experimental design (BBD) technique to study the influence of several metal-assisted chemical etching (MACE) process variables on the properties of nanostructured silicon (Si) wafer. Five process variables are examined i.e. concentrations of silver (Ag), hydrofluoric acid (HF), deposition time, H2O2 concentration and etching time as a function of etching rate. Design-Expert® software (version 7.1) is used in formulating the RSM model of five factors with 46 experiments. A regression quadratic model is developed to correlate the process variables where the most significant factors are identified and validated using analysis of variance (ANOVA). The model for etching rate is found to be significant with R2 of 0.8, where both Ag concentrations and etching time are the major influence.

Developing an effective interface interaction between photoanode and electrolyte is crucial for achieving superior photocatalytic fuel cell (PFC) performance. In this aspect, the contribution of the medium or electrolyte properties in the PFC system such as dye concentration, ionic nature and active radicals play a decisive role. Herein, we constructed a PFC with ZnO loaded nickel foam (ZnO/Ni) photoanode to study the influence of initial dye concentration, pH and supporting electrolytes of different polyatomic anions on the PFC performance. The optimum initial dye concentration and pH for the PFC with reactive red 120 as organic pollutants were found to be 30 mg L−1 and 7.5, respectively. The PFC performance can be synergistically enhanced by the addition of three types of polyatomic anions (Na3PO4, Na2SO4 and NaNO3) as supporting electrolytes. In turn, PO43- had the greatest influence on the reduction of internal resistance (highest short circuit current, Jsc) which corresponded to the conductivity of dye solution. Eventually, the higher charge of polyatomic ions could contribute to higher energy conversion efficiency in PFC. Nonetheless, SO42- anions favoured the cleavage of aromatic compounds by the advantage of recycling between SO42- and SO4 - through hole scavenging activity. Comprehensively, our findings provided new insight into the selection of supporting electrolyte as well as the proposed mechanism of active radicals involved in PFC. Additionally, the ZnO/Ni photoanode demonstrated its excellent recyclability as it retained high PFC performance after five consecutive runs.

The production of palm oil, though, results in the generation of huge quantities of polluted wastewater normally referred as palm oil mill effluent (POME). It gives adverse impacts to the environment, particularly if it is not properly treated. POME are known to have various types of liquids, residual oil and suspended solid as it has very high strength waste in its untreated form. Although conventional biological processes are normally efficient for the degradation of pollutants occurring in wastewater, most of these compounds are not effectively removed. As a result, further treatment is needed to meet more stringent discharge standards of Department of Environment (DOE), Malaysia. This research focused on treatment of POME by using electro-oxidation process (EO). It was done to identify the performance of EO process for colour, chemical oxygen demand (COD), suspended solids (SS), and Ammoniacal-nitrogen NH3-N) removal as well as the relative effects of different operational parameters such as pH, type of electrodes and contact time. The pH was varied between 3 and 11, using Ferum (Fe) and Aluminium (Al) electrode, and contact time from 0 to 120 min. The most suitable pH, contact time and type of electrode were pH 3, 120 min and Aluminium electrode, respectively. Therefore, EO process at specified level can be used as an efficient and effective post-treatment technology to meet the standard regulatory requirements.

Dyes often being use in many manufacturing processes. Hence, the wastewater resulted from the manufacturing process contain colour which need to be removed before being emitted into any water bodies. Photocatalysis is a method which effectively treating wastewater using photocatalyst. ZnO is an example of semiconductor material which is use as a photocatalyst in the treatment method. Doping with transition metals can improve its properties to maximize its photocatalytic efficiency. In this study, the effect of zinc oxide (ZnO) and zinc oxide doped Fe (ZnO/Fe) photocatalyst for dye removal efficiency were investigated. The photocatalysts were successfully synthesized through sol-gel method and characterized by SEM, FTIR and EDX. The photocatalytic efficiency of ZnO and ZnO/Fe was studied by degrading methylene blue (MB) under the exposure of 3 hours of sunlight with varies operational condition. Optimal photocatalytic efficiency operating parameters were performed by Design Expert 10 using the Response Surface Method (RSM). ZnO appeared as regular shape compared to ZnO/Fe which most of the particles had clumped together. The removal efficiency of MB was increase when the dosage of catalyst increased. However, once the optimum dosage of catalyst exceeded, the removal efficiency of MB reduced. During the experiment, 30 mg of ZnO was capable to remove 90% of MB from the solution. When while, ZnO/Fe exhibited better result as it could remove up to 95% of MB using only 10 mg of ZnO/Fe during the treatment. It can be concluded that doping the ZnO with Fe could improve the catalytic ability of ZnO to degrade MB in wastewater.

The objectives of this study were to evaluate the effect of ozonation on the solubility and biodegradability of wastewater from poultry processing industry. In addition, the wastewater also characterized based on the COD fractionation. The wastewater sample used was collected from Advance Chicken Processing (M) Sdn. Bhd., Perlis, Malaysia. Ozonation process was carried out in a semi–batch glass reactor which has a 2 L volume. The COD fractionation of poultry wastewater indicated that non-biodegradable COD is predominant compare to other fractions. However, the wastewater is containing higher percentage biodegradable COD comprehensively. It is expected that ozonation treatment would transform both particulate and soluble non-biodegradable COD towards biodegradable constituent that easily remove by biodegradation. The removal of COD was significant at ozonation duration up to 5 min. However, COD removal efficiency was only increased slightly with the increased of the ozonation duration after 5 min. This may be due to the fact that ozonation for long time would possibly producing constituent that inhibit ozone dissociation.

Lignin is the main polymers in woody biomass aside cellulose and hemicelluloses Recently, nano-lignin is gaining importance due to the increasing demand for bio-based and bio-active nanomaterial fillers for many applications such as in composite and textile industries. Palm oil mill effluent (POME) is the main wastewater produce by palm oil mills. Anaerobically treated (AT-POME) contains high soluble lignin due to the anaerobic digestion of cellulosic material in POME. Nano-lignin was precipitated by adjusting the initial pH of AT-POME during the sonication process. Sulfuric acid (H2SO4), nitric acid (HNO3), hydrochloric acid (HCl) and phosphoric acid (H3PO4) were used to adjust the initial pH of AT-POME. Result shows that sulfuric acid was the most suitable acid to be used as it could recovered 96% of the soluble lignin in AT-POME. The presence of ultrasonic during the precipitation process had reduced the size to 383.4 nm. The optimum operating parameter for lignin recovery is at pH 4 using sulfuric acid and sonicated at 80 watts for 15 minutes. This study shows that sonication could reduce the size of precipitated lignin from AT-POME. In addition, removal of lignin from AT-POME also reduced the COD content of AT-POME.

Wastewater includes the Palm Oil Mill Effluent (POME) that gives adverse impacts to the environment especially for water pollution when it is not treated properly. POME are known to have various types of liquids, residual oil and suspended solid as it has very high strength waste in its untreated form. Although conventional biological processes are normally efficient for the degradation of pollutants occurring in wastewater, most of these compounds are not effectively removed. As a result, further treatment is needed to meet more stringent discharge standards of Department of Environment (DOE). This research focused on treatment of POME by using electro-oxidation process (EO). It was done to identify the performance of EO process for colour, chemical oxygen demand (COD), suspended solids (SS), ammoniacal-nitrogen (NH3-N), and turbidity removal as well as the relative effects of different operational parameters such as pH, type of electrodes and contact time. The pH was varied from 3 to 11, the electrodes were aluminium and iron and the contact time was from 0 to 120 min. The most suitable pH, contact time and type of electrode were pH 3, 120 min and Al electrode.

Photocatalytic fuel cell (PFC) is considered as a sustainable green technology which could degrade organic pollutant and generate electricity simultaneously. A synergistic double-sided ZnO/BaTiO

Aluminum and aluminum based material are significant industrial materials synthesis because of their abandonment, low weight and high-quality corrosion resistance. The most advances in aluminum processing are the ability to synthesize it’s under suitable chemical composition and conditions, a porous structure can be formed on the surface. Activated alumina particles (AAP) synthesized by the electrochemically process from aluminum have gained serious attention, inexpensive material that can be employed for water filtration due to its active surface. Thus, the paper present a review study based on recent progress and advances in synthesizing activated alumina, various techniques currently being used in preparing activated alumina and its characteristics are studied and summarized

Due to the extremely high content of organic pollutants, palm oil mill effluent (POME) requires multiple stages of treatment. At the primary stage, because of the high loading of organics, anaerobic treatment method was found to be the best practice nowadays. However, at the later stages, the treatment methods vary. As an option to available secondary and tertiary treatment method, we used an aerated heterogeneous Fenton process to remove chemical oxygen demand (COD) from anaerobically treated palm oil mill effluent (AT-POME). The Box–Behnken design (BBD) and response surface method (RSM) were used to design and optimize the performance of the process. Furthermore, the regression quadratic model representing the COD removal efficiency of aerated heterogeneous Fenton was developed and validated by the analysis of variances (ANOVA). The optimum parameters were determined as 3.91 g/l of nZVI dosage, 1.84 g/l of H 2 O 2 dosage, and 23.84 l/h of aeration and 240 min of reaction time. As 75% of COD was predicted to be removed at the optimum condition, the aerated heterogeneous Fenton process is a promising treatment method for AT-POME.

Nano zero-valent iron (nZVI) has received great attention for its capability to treat wastewater. One of its applications is in an advanced oxidation process (AOP) called the sono-Fenton process. This study presents the characterization of the nZVI particle by its particle size, scanning electron microscope (SEM) images, transmission electron microscope (TEM) images, X-ray diffraction (XRD), energy dispersive X-ray (EDX) and X-ray photoelectron spectroscopy (XPS) analysis. Results show that the average size of nZVI is 49 nm and it has two layers. The outer layer (shell) is comprised of iron oxides (i.e. FeO) while the core is elemental iron (Fe). At pH 2, nZVI was found to be a good replacement for iron sulfate (FeSO4) as a ferrous iron (Fe2+) source in the sono-Fenton process. In addition, the removal process of organic pollutants from diluted palm oil mill effluent (POME) was also accelerated by ultrasound, particularly at higher intensity and longer sonication time. Eighty percent (80%) of the chemical oxygen demand (COD) was removed in 2 h instead of 24 h by silent degradation.

The present study focusing on the performances of advanced oxidation process by using ozonation method towards Methyl Orange based on the efficiency of colour removal and Chemical Oxygen Demand (COD) removal. Factorial design with response surface methodology (RSM) was used to evaluate the interaction between operational conditions, such as pH, initial concentration, contact time and persulfate dosage to obtain the optimum range conditions using a semi-batch reactor. The range of independent variables investigated were pH (3-11), initial concentration (100-500mg/L), contact time (10-50min) and persulfate dosage (20-100mM) while the response variables were colour removal and COD removal of Methyl Orange. The experimental results and statistical analysis showed all the parameters were significant. Thus, from this findings, optimization of operational conditions that had been suggested from the ozone/persulfate RSM analysis were (pH 3, 100 mg/L, 50min, 60mM) that would be produced 99% Colour Removal and 80% COD Removal and help in promoting an efficient ozonation process. The effect list data that showed the most contributed effects to increase the percentages of colour removal were pH and persulfate dosage whereas the contact time and initial concentration had the highest positive effects on the COD removal. Other than that, the interaction between pH, contact time and persulfate dosage were found to be the most influencing interaction. Therefore the least influencing interaction was interaction between persulfate dosage and pH. In this study, the correlation coefficient value R2 for colour removal and COD removal of Methyl Orange were R2= 0.9976 and R2= 0.9924 which suggested a good fit of the first-order regression model with the experimental data.

Lignin is one of the main structural polymers present in plant tissue. It can also be found as an isolated product of the pulp and paper industry. Palm oil mill effluent (POME) has been known as high strength industrial wastewater that is difficult to treat due to its large variety of inorganic and organic contents. The main purpose of this study is to recover soluble lignin from anaerobically treated palm oil mill effluent (AT-POME) and indirectly improves the quality of AT-POME. AT-POME was adjusted to different pH using different type of acids. Response Surface Methodology (RSM) was utilized to obtain the optimum operating parameters as well as to analyse the interaction between them. Model shows that 74.67 % of lignin can be recovered from AT-POME after 5 minutes reaction time using sulfuric acid (H2S04) at pH 5. Hence from the experiment, it was proved that simple pH adjustment could precipitate the soluble lignin from AT-POME.

Activated alumina is a high surface area and highly porous form of aluminum oxide that can be employed for contaminant species adsorb from ether gases or liquids without changing its form. The research in getting this material has generated huge interested. Thus, this paper presented preparation of activated alumina from chemical process. Pure aluminum (99.9% pure) reacted at room temperature with an aqueous NaOH in a reactor to produce a solution of sodium aluminate (NaAlO2). This solution was passed through filter paper and the clear filtrate was neutralized with H2SO4, to pH 6, 7 or 8, resulting in the precipitation of a white gel, Al(OH)3·XH2O. The washed gel for sulfate ions were dried at 80 °C for 6 h, a 60 mesh sieve was to separate and sort them into different sizes. The samples were then calcined (burn) for 3h in a muffle furnace, in air, at a heating rate of 2 °C min–1. The prepared activated alumina was further characterized for better understanding of its physical properties in order to predict its chemical mechanism.

Fenton process is one of the advanced oxidation processes (AOPs) used to remove complex organic pollutants in wastewater. In this study, instead of iron sulfate (FeSO4), nano zero valent iron (nZVI) was used as a major source of ferrous iron (Fe 2+ ). In order to enhance the process, ultrasound was utilized in this study. Results show that, with the aid of ultrasound, nZVI produced more Fe 2+ compared to FeSO4 at pH 2. Furthermore, combination of higher intensity and longer sonication time in Fenton process acceleratde the chemical oxygen demand (COD) removal from palm oil mill effluent (POME). Through the process, 80% of COD content was removed within 2 hours instead of 24 hours of silent degradation.