1.Removal of COD, BOD and nutrients in swine manure wastewater using freshwater green microalgae
Kah Aik TAN ; Norhashimah MORAD ; Ahmad HARLINA ; Siew Lu ONG
Malaysian Journal of Microbiology 2018;14(2):187-194
Aims:The aim of this study was to investigate the effectiveness of freshwater green microalgae in remediating swine manure wastewater. Two different species of freshwater green microalgae (Scenedesmus quadricaudaand Stigeocloniumsp.) were used in this study.Methodology and results:Laboratory experiments were performed to compare the growth rate and nutrients (total phosphorus, ammonia nitrogen, nitrate nitrogen and nitrite nitrogen) uptake by these two species of microalgae in swine manure wastewater. Experimental work was carried out for 14 days at room temperature of 30±1 °C with about 1520 Lux of light intensity. The results showed that both microalgae grew well in swine manure wastewater. S.quadricaudaperformed better in remediating swine manure wastewater, by reducing 83.99% of COD, 80.39% of BOD5, 84.78% of total phosphorus (TP), 91.79% of ammonia nitrogen (NH3-N), 89.79% of nitrate nitrogen (NO3-N) and 87.14% of nitrite nitrogen (NO2-N) compared to Stigeocloniumsp. which was only able to remove 79.26% of COD, 76.27% of BOD5,75.17% of TP, 86.42% of NH3-N, 84.38% of NO3-N and 82.38 NO2-N.Conclusion, significance and impact of study:The results of this study indicate that these two species of microalgae have potential to be used in the remediation of swine manure wastewate
2.Risk Factors and Prediction Models for Retinopathy of Prematurity
Mallika Premsenthil ; Mohamad Aziz Salowi ; Mohamad Adam Bujang ; Adeline Kueh ; Chong Min Siew ; Kala Sumugam ; Chan Lee Gaik ; Tan Aik Kah
Malaysian Journal of Medical Sciences 2015;22(5):57-63
Objectives: To develop a simple prediction model for the pre-screening of Retinopathy of
Prematurity (ROP) among preterm babies.
Methods: This was a prospective study. The test dataset (January 2007 until December 2010)
was used to construct risk prediction models, and the validation dataset (January 2011 until March
2012) was used to validate the models developed from the test dataset. Two prediction models were
produced using the test dataset based on logistic regression equations in which the development of
ROP was used as the outcome.
Results: The sensitivity and specificity for model 1 [gestational age (GA), birth weight (BW),
intraventricular haemorrhage (IVH) and respiratory distress syndrome (RDS)] was 82 % and
81.7%, respectively; for model 2, (GA and BW) the sensitivity and specificity were 80.5% and 80.3%,
respectively.
Conclusion: Model 2 was preferable, as it only required two predictors (GA and BW). Our
models can be used for the early prevention of ROP to avoid poor outcomes.
3.Post-treatment of palm oil mill effluent (POME) using freshwater green microalgae145-
Kah Aik TAN ; Norhashimah MORAD ; Ismail NORLI ; Japareng LALUNG ; Wan Maznah Wan Omar
Malaysian Journal of Microbiology 2018;14(2):145-151
Aims:The effectiveness of microalgae in the post-treatment of palm oil mill effluent (POME) was being investigated for colourremoval and COD reduction. Methodology and results:Raw POME, obtained from a local palm oil mill and treated with anaerobic and aerobic processes for 50 days and 16 days of hydraulic retention time (HRT) respectively, was then used in the phycoremediation study. Three different species of microalgae (Ankistrodesmus falcatus, Scenedesmus sp. and Chlorellasp.) were inoculated in a culture media which contained 20%, 40% and 60% dilution of POME. The pH of thetreated POME sample was not adjusted and fixed at the original pH of about pH 8-9. The growth of the microalgae was determined every 2 days based on their chlorophyll concentration. Chlorellasp. showed the best adaptation and grew well in all dilutions of the treated POME sample and subsequently chosen for remediation of the POME sample without any dilution.Conclusion, significance and impact of study:Chemical oxygen demand (COD) and colour removal of POME were determined every 2 days. Chlorellasp. performed well with COD reduction and colour removal of 67.87% and 53.26%, respectively.