S.K. Kamarudin

Isotherm equilibria of Mn2+ biosorption in drinking water treatment by locally isolated Bacillus species and sewage activated sludge

Manganese (Mn(2+)) is one of the inorganic contaminant that causes problem to water treatment and water distribution due to the accumulation on water piping systems. In this study, Bacillus sp. and sewage activated sludge (SAS) were investigated as biosorbents in laboratory-scale experiments. The study showed that Bacillus sp. was a more effective biosorbent than SAS. The experimental data were fitted to the Langmuir (Langmuir-1 & Langmuir-2), Freundlich, Temkin, Dubinin-Radushkevich (D-R) and Redlich-Peterson (R-P) isotherms to obtain the characteristic parameters of each model. Mn(2+) biosorption by Bacillus sp. was found to be significantly better fitted to the Langmuir-1 isotherm than the other isotherms, while the D-R isotherm was the best fit for SAS; i.e., the χ(2) value was smaller than that for the Freundlich, Temkin, and R-P isotherms. According to the evaluation using the Langmuir-1 isotherm, the maximum biosorption capacities of Mn(2+) onto Bacillus sp. and SAS were 43.5 mg Mn(2+)/g biomass and 12.7 mg Mn(2+)/g biomass, respectively. The data fitted using the D-R isotherm showed that the Mn(2+) biosorption processes by both Bacillus sp. and SAS occurred via the chemical ion-exchange mechanism between the functional groups and Mn(2+) ion.

Effective microbes for simultaneous bio-oxidation of ammonia and manganese in biological aerated filter system

This study determined the most effective microbes acting as ammonia-oxidising (AOB) and manganese-oxidising bacteria (MnOB) for the simultaneous removal of ammonia (NH(4)(+)-N) and manganese (Mn(2+)) from water. Two conditions of mixed culture of bacteria: an acclimatised mixed culture (mixed culture: MC) in a 5-L bioreactor and biofilm attached on a plastic medium (stages of mixed culture: SMC) in a biological aerated filter were isolated and identified using Biolog MicroSystem and 16S rRNA sequencing. A screening test for determining the most effective microbe in the removal of NH(4)(+)-N and Mn(2+) was initially performed using SMC and MC, respectively, and found that Bacillus cereus was the most effective microbe for the removal of NH(4)(+)-N and Mn(2+). Moreover, the simultaneous NH(4)(+)-N and Mn(2+) removal (above 95% removal for both NH(4)(+)-N and Mn(2+)) was achieved using a biological aerated filter under various operating conditions. Thus, the strain could act as an effective microbe of AOB and a MnOB for the simultaneous removal of NH(4)(+)-N and Mn(2+).

Microwave-assisted transesterification of jatropha and waste frying palm oil

The utilisation of non-edible oil as a biodiesel feedstock is expected to minimise the utilisation of food-grade oil for industrial applications. The microwave-assisted transesterification process was adopted to obtain the biodiesel from jatropha oil and waste frying palm oil (WFPO). The transesterification process was carried out in the presence of methanol with a methanol to oil ratio of 12:1 and a catalyst (sodium hydroxide). The effect of transesterification reaction parameters such as quantity of the catalyst, reaction temperature and time on the biodiesel yield and purity has been investigated. The optimised reaction temperature, time and catalyst concentration was 65 °C, 7 min and 1% by weight, respectively. The highest percentage yield (89.7 for jatropha and 88.63 for WFPO) and purity (99.65 for jatropha and 99.45 for WFPO) of biodiesel was observed with the optimised process parameters. The fuel properties of the obtained biodiesel were tested according to European Union draft standards. The obtained results suggested that microwave radiation may be employed in the transesterifcation process to reduce the reaction time and temperature.

Production of methanol from biomass waste via pyrolysis

The production of methanol from agricultural, forestry, livestock, poultry, and fishery waste via pyrolysis was investigated. Pyrolysis was conducted in a tube furnace at 450-500 °C. Sugarcane bagasse showed the methanol production (5.93 wt.%), followed by roots and sawdust with 4.36 and 4.22 wt.%, respectively. Animal waste offered the lowest content of methanol, as only 0.46, 0.80, and 0.61 wt.% were obtained from fishery, goat, and cow waste, respectively. It was also observed that the percentage of methanol increased with an increase in volatile compounds while the percentage of ethanol increased with the percentage of ash and fix carbon. The data indicate that, pyrolysis is a means for production of methanol and ethanol after further optimization of the process and sample treatment.

Recognition of Relevant ORP, pH, and DO Bending Points in Ammonia Removal from Drinking Water through Online BAF System

This study was undertaken to identify the relevant bending points in ORP, pH, and DO profiles in ammonia removal through online monitoring. A novelty BAF system as newl application for drinking water treatment that equipped with ORP, pH, DO and sensors was used. Two types of polluted drinking water strength (low and high strength) with various concentrations and aeration flow were treated at a fixed-time reaction of 24 h. Experiments were conducted at four track studies (TS) of TS1 ( 50 mg/L, aeration 0.3 L/min), TS2 ( = 100 mg/L, aeration 2.0 L/min), TS3 ( 100 mg/L, no aeration) and TS4 ( 10 mg/L, aeration 0.1 L/min). The results showed that the removal of was more than 95% for TS1, TS2, and TS4. From the online monitoring performances, DO elbow and ammonia valley appeared in ORP and pH profiles, respectively. Similarly, new positive plateaus were observed in DO, indicating that the nitrifiers stopped to consume the DO after was completely removed. Hence, based on the bending points, the aeration system is possible to be automatically stopped just after DO elbow and ammonia valley appears in order to save the energy consumption and to shorten the time demands for the drinking water treatment process.

Biodiesel Progress in Malaysia

Abstract Considering the current rate of extraction, Malaysias crude oil reserves are expected to diminish after 20 years. The anticipated diminution of fossil fuel reserves are the main reason for the exploration of alternatives to petroleum diesel. Malaysia introduced its biofuel policy in the year 2005 with an objective to reduce the countrys fuel import bill, further promoting the demand for palm oil, which is expected to be the primary commodity for biofuel production in Malaysia as well as to shore up the price of palm oil. The present review article discussed the progress of biodiesel in Malaysia with a special emphasis on the development, benefits, and policies.

Removal of ion in drinking water treatment using locally isolated heterotrophic nitrifier

ABSTRACT Batch removal treatment of from drinking water was carried using locally isolated heterotrophic nitrifier of Bacillus cereus I6. This work investigates the effect of initial concentration (5–25 mg/L), initial pH (pH 3–10) and inoculum size (0.5–3.0% v/v) on the removal of . From the isolation, screening and identification, heterotrophic B. cereus I6 (98% similarity) was the most potential degrading strain in removal. The removal was high at initial concentration of 5 mg/L (62%), initial pH of 5 (69.5%) and inoculum size of 3.0% v/v (85%). The removal decreased from 62 to 24.8% when the initial concentration was increased, while it had increased from 29 to 85% when the inoculum size was being increased. The most suitable conditions for removal by heterotrophic of B. cereus I6 was observed at an initial pH of 5.

Study on the physical and chemical composition of agro wastes for the production of 5-hydroxymethylfurfural

Treated sludge, goat manure, sugarcane bagasse, empty fruit bunches of oil palm (EFBP) and dry leaves are agro wastes that have high potential for use as feedstocks for the production of 5-hydroxymethylfurfural (5-HMF). The focus of this study is to investigate the production of 5-HMF from agro wastes via co-hydrothermal (CHT) treatment and extraction. Present study include examine on agro wastes physical and chemical properties and also their thermal degradation behaviour. The analysis of the bio-oil products is conducted by FTIR and GC-MS. Co-hydrothermal experiments were conducted at a temperature of 300°C with an experimental time of 15min, followed by alcohol extraction. Highest carbon and hydrogen content are 45.94% and 6.49% (dry leaves) with maximum high heating value 18.39MJ/kg (dry leaves) and fix carbon value 6.60 (goat manure). Through CHT about 39% 5-HMF, 22.97% carboxylic acids, 0.97% of aromatic and 0.73% aldehyde obtained.

Review on utilization of the pervaporation membrane for passive vapor feed direct methanol fuel cell

The Direct Methanol Fuel Cell (DMFC) is a promising portable power source for mobile electronic devices because of its advantages including easy fuel storage, high energy density, low temperature operation and compact structure. In DMFC, methanol is used as a fuel source where it can be fed in liquid or vapor phase. However, the vapor feed DMFC has an advantage over the liquid feed system as it has the potential to have a higher operating temperature to increase the reaction rates and power outputs, to enhance the mass transfers, to reduce methanol crossover, reliable for high methanol concentration and it can increase the fuel cell performance. Methanol vapor can be delivered to the anode by using a pervaporation membrane, heating the liquid methanol or another method that compatible. Therefore, this paper is a review on vapor feed DMFC as a better energy source than liquid feed DMFC, the pervaporation membrane used to vaporize methanol feed from the reservoir and its applications in vapor feed DMFC.

Methyl Esters Selectivity of Transesterification Reaction with Homogenous Alkaline Catalyst to Produce Biodiesel in Batch, Plug Flow, and Continuous Stirred Tank Reactors

Selectivity concept is essential in establishing the best operating conditions for attaining maximum production of the desired product. For complex reaction such as biodiesel fuel synthesis, kinetic studies of transesterification reaction have revealed the mechanism of the reaction and rate constants. The objectives of this research are to develop the kinetic parameters for determination of methyl esters and glycerol selectivity, evaluate the significance of the reverse reaction in transesterification reaction, and examine the influence of reaction characteristics (reaction temperature, methanol to oil molar ratio, and the amount of catalyst) on selectivity. For this study, published reaction rate constants of transesterification reaction were used to develop mathematical expressions for selectivities. In order to examine the base case and reversible transesterification, two calculation schemes (Case  1 and Case  2) were established. An enhanced selectivity was found in the base case of transesterification reaction. The selectivity was greatly improved at optimum reaction temperature (60°C), molar ratio (9 : 1), catalyst concentration (1.5 wt.%), and low free fatty acid feedstock. Further research might explore the application of selectivity for specifying reactor configurations.