Dairy manure pellets and palm oil mill effluent as alternative nutrient sources in cultivating Sporosarcina pasteurii for calcium carbonate bioprecipitation.

Microbially induced carbonate precipitation (MICP) is a process that hydrolysis urea by microbial urease to fill the pore spaces of soil with induced calcium carbonate (CaCO3 ) precipitates, which eventually results in improved or solidified soil. This research explored the possibility of using dairy manure pellets (DMP) and palm oil mill effluent (POME) as alternative nutrient sources for Sporosarcina pasteurii cultivation and CaCO3 bioprecipitation. Different concentrations (20-80 g l-1 ) of DMP and POME were used to propagate the cells of S. pasteurii under laboratory conditions. The measured CaCO3 contents for MICP soil specimens that were treated with bacterial cultures grown in DMP medium (60%, w/v) was 15·30 ± 0·04 g ml-1 and POME medium (40%, v/v) was 15·49 ± 0·05 g ml-1 after 21 days curing. The scanning electron microscopy showed that soil treated with DMP had rhombohedral structure-like crystals with smooth surfaces, whilst that of POME entailed ring-like cubical formation with rough surfaces Electron dispersive X-ray analysis was able to identify a high mass percentage of chemical element compositions (Ca, C and O), whilst spectrum from Fourier-transform infrared spectroscopy confirmed the vibration peak intensities for CaCO3 . Atomic force microscopy further showed clear topographical differences on the crystal surface structures that were formed around the MICP treated soil samples. These nutrient sources (DMP and POME) showed encouraging potential cultivation mediums to address high costs related to bacterial cultivation and biocementation treatment.

Characteristics of developed granules containing selected decolourising bacteria for the degradation of textile wastewater.

Textile wastewater, one of the most polluted industrial effluents, generally contains substantial amount of dyes and chemicals that will cause increase in the COD, colour and toxicity of receiving water bodies if not properly treated. Current treatment methods include chemical and biological processes; the efficiency of the biological treatment method however, remains uncertain since the discharged effluent is still highly coloured. In this study, granules consisting mixed culture of decolourising bacteria were developed and the physical and morphological characteristics were determined. After the sixth week of development, the granules were 3-10 mm in diameter, having good settling property with settling velocity of 70 m/h, sludge volume index (SVI) of 90 to 130 mL/g, integrity coefficient of 3.7, and density of 66 g/l. Their abilities to treat sterilised raw textile wastewater were evaluated based on the removal efficiencies of COD (initial ranging from 200 to 3,000 mg/L), colour (initial ranging from 450 to 2000 ADMI) of sterilised raw textile wastewater with pH from 6.8 to 9.4. Using a sequential anaerobic-aerobic treatment cycle with hydraulic retention time (HRT) of 24 h, maximum removal of colour and COD achieved was 90% and 80%, respectively.

Reduction and biofixation of carbon dioxide in palm oil mill effluent using developed microbial granules containing photosynthetic pigments.

The developed microbial granules containing photosynthetic pigments had successfully achieved approximately 18-21% of carbon dioxide (CO2) removal in POME for one complete SBR cycle. Also, the granules had reached CO2 removal at 15-29% within 24h and removal of 25% after 5 days. Both results were inconsistent possibly due to the slow mass transfer rate of CO2 from gas to liquid as well as the simultaneous effect of CO2 production and respiration among the microbes. Furthermore, results showed the removal of CO2 from air increases proportionally with the CO2 removed in liquid. The CO2 biofixation of granules attained was approximately 0.23g/L/day for a week. Using the regression model, the removal of CO2 between liquid and gas, CO2 biofixation rate were highly correlated with the treatment time. A statistically significant relationship was obtained between CO2 concentration in liquid, biomass productivity and treatment time for the CO2 biofixation rate of the granules.

Iodine content in urine samples among Malays and aborigines.

A study was conducted to compare the urinary iodine concentrations in populations from Pahang, Central Malaysia, with those in the capital city Kuala Lumpur, and to compare those of Malays from villages at Batu Talam, Batu Malim, FELDA Sungai Koyan and Hulu Sungai with neighboring aboriginal settlements at Lanai and Buntu. Two hundred and forty urine samples were collected randomly among the population (male 1 1 1 and female 129). The urinary iodine concentrations, measured by the ashing method, among Malays were as follows: Batu Talam 1.1-7.6 micrograms/dl, Batu Malim 1.4-6.6 micrograms/dl, FELDA Sungai Koyan 0.5-6.9 micrograms/dl and Hulu Sungai 0.6-9.9 micrograms/dl. Among aborigines, the urinary iodine levels were 0.1-2.9 micrograms/dl in Lanai and 1.7-6.5 micrograms/dl in Buntu. There was a significant difference in the levels of urinary iodine with regard to gender, but not regarding age. The aborigines had significantly lower iodine levels than Malays (P < 0.001). This difference was also significant with regard to location. The urinary iodine content in Kuala Lumpur was the highest and that in the aboriginal Lanai village was the lowest. Thus, the study showed that the levels of iodine in the urine were influenced by ethnicity and geographic location.