Rasyidah Alrozi

An overview of municipal solid waste management and landfill leachate treatment: Malaysia and Asian perspectives

Currently, generation of solid waste per capita in Malaysia is about 1.1xa0kg/day. Over 26,500xa0t of solid waste is disposed almost solely through 166 operating landfills in the country every day. Despite the availability of other disposal methods, landfill is the most widely accepted and prevalent method for municipal solid waste (MSW) disposal in developing countries, including Malaysia. This is mainly ascribed to its inherent forte in terms cost saving and simpler operational mechanism. However, there is a downside. Environmental pollution caused by the landfill leachate has been one of the typical dilemmas of landfilling method. Leachate is the liquid produced when water percolates through solid waste and contains dissolved or suspended materials from various disposed materials and biodecomposition processes. It is often a high-strength wastewater with extreme pH, chemical oxygen demand (COD), biochemical oxygen demand (BOD), inorganic salts and toxicity. Its composition differs over the time and space within a particular landfill, influenced by a broad spectrum of factors, namely waste composition, landfilling practice (solid waste contouring and compacting), local climatic conditions, landfill’s physico-chemical conditions, biogeochemistry and landfill age. This paper summarises an overview of landfill operation and leachate treatment availability reported in literature: a broad spectrum of landfill management opportunity, leachate parameter discussions and the way forward of landfill leachate treatment applicability.

Removal of direct blue 71 from aqueous solution by adsorption on rice husk carbon-clinoptilolite composite adsorbent

The adsorption performance of rice husk carbon-clinoptilolite (RHC-clinop) for the removal of Direct Blue 71 (DB71) in batch mode was investigated. The RHC-clinop was prepared by pre-determined mixes of clinoptilolite (clinop), rice husk carbon (RHC), and ordinary Portland cement (OPC). The OPC was used as binding agent. The adsorption experiments were conducted at different conditions of adsorbent dosage (0.21.2g), solution pH (2-12) and initial concentration (25-400 mg/L). DB71 adsorption uptake was found to increase with increase in initial concentration and contact time. The optimum adsorption of DB71 was favorable at pH 10 with adsorbent dosage of 1.0g. The experimental data was fitted well with Freundlich isotherm. Adsorption kinetic was found to follow the pseudo-second-order kinetic model with good correlation. The result indicates that the RHC-clinop is suitable for the removal of azo dye by adsorption process.

Removal of methylene blue dye from aqueous solution using pink guava (Psidium Guajava) waste-based activated carbon

The feasibility of using guava waste activated carbon (GWAC) for the methylene blue (MB) adsorption has been investigated. The GWAC was prepared using simple thermochemical activation method. The comparison on adsorption performance between GWAC and commercial activated carbon (CAC) were conducted using the batch adsorption study to determine the adsorption capacity for both adsorbents. The adsorption study was carried out at different initial concentrations of MB (50-500 mg/L) at temperature of 30 °C for 5 hours. The equilibrium data were analyzed using Langmuir and Freundlich isotherm models followed by kinetics study. The experimental data for both adsorbents were fitted well with Langmuir isotherm with a maximum monolayer adsorption capacity of 250.00 mg/g and 333.33 mg/g for GWAC and CAC, respectively. The peudo-second order kinetics was the best for the adsorption of MB by GWAC and CAC with good correlation. The results demonstrated that GWAC is an effective adsorbent for removal of MB and have potential to replace the commercial activated carbon for removal of dyes from wastewater.

Removal of methylene blue from aqueous solution by adsorption onto NaOH-treated rambutan peel

Adsorption of methylene blue (MB) by NaOH-treated rambutan peel (N-RP) was examined. The adsorption experiments were carried out under different conditions of initial concentration (25-500 mg/L), solution pH 2-12 and N-RP dose (0.05-1.0 g). The influence of these parameters on the adsorption capacity was studied using the batch process. MB adsorption uptake was found to increase with increase in initial concentration and contact time. The MB adsorption was unfavourable at pH<;4. Langmuir, Freundlich and Temkin isotherm models were used to illustrate the experimental isotherms and isotherms constant. The equilibrium data were best represented by Langmuir isothem model, showing maximum monolayer adsorption capacity of 231.34 mg/g. The rates of adsorption were found to obey the rules of pseudo-second order model with good correlation. The result suggested that the N-RP would be an excellent alternative for the removal of MB by adsorption process.

Preparation of rice husk carbon-clinoptilolite composite adsorbent for color removal from real textile wastewater: Effects of operating conditions

This study investigates the optimal operating conditions for preparation of rice husk carbon-clinoptilolite (RHC-clinop) composite adsorbent for color removal from dye house facility. Central composite design (CCD) was used to determine the effects of the four preparation variables; clinoptilolite (clinop), rice husk carbon (RHC), ordinary Portland cement (OPC) and water binder ratio (W/B) on percentage color removal and attrition. The significant factors on each experimental design response were identified from the analysis of variance (ANOVA). The optimum operating conditions for RHCclinop preparation were obtained by using clinop, RHC, OPC and W/B of 16g, 9g, 38g and 15mL, respectively, which resulted in 92% of color removal and 17% of attrition. FTIR analysis showed the chemical changes on the surface of the RHC-clinop prepared before and after batching tests. The RHC-clinop prepared in this study could be a promising composite adsorbent for dye waste water treatment due to high efficiency of color removal and least attrition.

Adsorption of reactive dye Remazol Brilliant Blue R from aqueous solutions by rambutan peel

Adsorption of Remazol Brilliant Blue R (RBBR) by rambutan peel (RP) was examined. The adsorption experiments were carried out under different conditions of initial concentration (25-500 mg/L), solution pH 2-12 and RP dose (0.05-1.2 g). The influence of these parameters on the adsorption capacity was studied using the batch process. RBBR adsorption uptake was found to increase with increase in initial concentration and contact time. The RBBR adsorption was favourable at pH<;4. Langmuir, Freundlich and Temkin isotherm models were used to illustrate the experimental isotherms and isotherms constant. The equilibrium data were best represented by Langmuir isotherm model, showing maximum monolayer adsorption capacity of 112.69 mg/g. The rates of adsorption were found to obey the rules of pseudo-second order model with good correlation. The results suggested that RP has high potential to be used as effective adsorbent for RBBR removal.

Removal of phenol from synthetic wastewater using carbon-mineral composite: Batch mechanisms and composition study

This study investigates the treatability of composite adsorbent made from waste materials and minerals which is widely available in Malaysia. The composite adsorbent was prepared based on wet attrition method which focuses on the determination of optimum dosage of each of raw materials amount by conventional design of experiment work. Zeolite, activated carbon, rice husk and limestone were ground to obtained particle size of 150u2005µm. 45.94% zeolite, 15.31% limestone, 4.38% activated carbon, 4.38% rice husk carbon and 30% of ordinary Portland cement (OPC). The mixture was mixed together under pre-determined mixing time. About 60% (by weight) of water was added and the mixture paste was allowed to harden for 24 hours and then submersed in water for three days for curing. Batch experimental study was performed on synthetic dissolving a known amount of solid crystal phenol with distilled water into the volumetric flasks. From the batch experimental study, it was revealed that the optimum shaking speed for remo...

Treatability of drinking water parameters from Kerian River by using carbon-mineral composite: Batch mechanisms and characterization study

There are many treatment processes over the world on river water. However, the simple and low cost technologies are quite limited. Therefore, the purpose of this study is to examine the turbidity, colour, pH, Total Dissolved Solid (TSS), Iron and Manganese from selected river water by a combination of activated carbon, limestone and polyvinyl alcohol which produces a composite media. The analyses for the parameters removal efficiency are conducted by using statistical analysis two ways Analysis of Variance (ANOVA). In batch study, the removal efficiency of all the mixture of composite media indicated the composite adsorbent could remove more than 50% of raw water contaminants which complies to National Drinking Water Quality Standard, 2000. The optimum mixing ratio of hydrophobic: hydrophilic is 1:7 and 1:2 which is 875.0g and 667.0g limestone, 125.0u2005g and 333.0u2005g activated carbon (AC) and water 375u2005ml with highest removal percentage for turbidity (91.86%), colour (93.44%), TSS (91.27%), iron (98.49%) and manganese (98.18%). The study indicated that the composite material has a good potential for further research and future application.There are many treatment processes over the world on river water. However, the simple and low cost technologies are quite limited. Therefore, the purpose of this study is to examine the turbidity, colour, pH, Total Dissolved Solid (TSS), Iron and Manganese from selected river water by a combination of activated carbon, limestone and polyvinyl alcohol which produces a composite media. The analyses for the parameters removal efficiency are conducted by using statistical analysis two ways Analysis of Variance (ANOVA). In batch study, the removal efficiency of all the mixture of composite media indicated the composite adsorbent could remove more than 50% of raw water contaminants which complies to National Drinking Water Quality Standard, 2000. The optimum mixing ratio of hydrophobic: hydrophilic is 1:7 and 1:2 which is 875.0g and 667.0g limestone, 125.0u2005g and 333.0u2005g activated carbon (AC) and water 375u2005ml with highest removal percentage for turbidity (91.86%), colour (93.44%), TSS (91.27%), iron (98.49%) and...

Removal of organic fractions from landfill leachate by casuarina equisetifolia activated carbon: Characteristics and adsorption mechanisms

In this research, the activated carbon prepared from tropical plant waste based Casuarinas Equisetifolia plant was activated through chemical activation by using potassium hydroxide (KOH) as the activating agent. The raw sample was carbonized following conventional heating via electric furnace at 600˚C with the increasing temperature 30˚C/minutes in one hour which was selected as the optimum condition. The prepared activated carbons exhibit mesoporous with the pore diameter within 0.2u2005µm to 20u2005µm. From the Scanning Electron Microscopy (SEM) micrographs, the morphology of the activated carbon indicated that they demonstrated high pore development on it surfaces. The effects of initial pH, contact time and adsorbent dosage onto the adsorption performances were evaluated through batch adsorption study. The COD removal increased when the adsorbent dosage was increased. The adsorption of COD and colour were best fitted by the Freundlich isotherm model compared to ammonia, which the correlation regressions, R2 ...

Current status of Pulau Burung Sanitary Landfill leachate treatment, Penang Malaysia

Leachate generation from landfill is known as the main pollution source associated with municipal solid waste (MSW). This is because landfill leachate is a complex liquid which contains numerous biodegradable and non-biodegradable pollutants such as organic matter, phenols, ammonia nitrogen, phosphate, heavy metals, and sulfide. If not properly treated and safely managed, landfill leachate may create environment hazard to surface and ground water as it can percolate throughout soils and subsoils, causing adverse impacts to receiving waters. Pulau Burung Sanitary Landfill (PBSL) which is the only sanitary landfill in Penang Malaysia has been in operation since 1991. Until now, PBSL receives over 1800 tonnes of MSW and industrial wastes from island and mainland of Penang daily. This paper evaluates current status of landfill leachate treatment research activities at PBSL. At this point, various types of treatment methods have been proposed to alleviate the risks of untreated leachate. However, some of the a...