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Methods for removing pollutants include membrane isolation, ion exchange, precipitation, transformation, and biosorption. Adsorption is a cost-effective method of treating industrial wastewater and a common commercial method for concentrating valuable molecules or eliminating contaminants. Banana peel is one of the largest underutilized agricultural wastes in Malaysia. A novel method of using a low-cost biosorbent made from banana peel and Evans blue (EB) dye as a target is the target of this study. The optimal conditions for EB dye adsorption occurred at a dye concentration of 200 mg/L, adsorbent dosages between 10 and 20 g/L, temperature of 25 °C, incubation time of 180 min, and agitation speeds of 100 rpm. Statistical discriminatory analysis showed that the pseudo-second-order kinetic model and the Redlich–Petersen isotherm model were the best models. The maximum adsorption capacity based on Langmuir's isotherm prediction was 58.51 mg g−1. A non–linear regression of the thermodynamic van't Hoff plot based on a dimensionless equilibrium constant resulted in negative values for Gibb's free energy and enthalpy, indicating that the adsorption process is spontaneous and exothermic. [ABSTRACT FROM AUTHOR]

Higher education students are frequently required to assess lecturers with a convenient, fast, and anonymous learning management system. Following the coronavirus disease 2019 (COVID-19) pandemic outbreak, Universiti Teknologi MARA Malaysia (UiTM) adopted a remote teaching and learning approach. This study examined how lecturers' professionalism, course impression, and facilitating conditions at UiTM affected undergraduate and graduate students' remote learning pre- and mid-pandemic. The higher prediction accuracy of the model demonstrated that students' remote learning activities were highly related to lecturers' professionalism, course impression, and facilitating conditions. The structural model demonstrated that the t-statistics of all measurement variables were significant at 1%. The strongest predictor of students' enjoyment of remote learning pre- and mid-pandemic was lecturers' professionalism. In the importance-performance matrix, lecturers' professionalism was in the quadrant for 'keep up the good work'. Facilitating conditions and course impression did not require further improvement even during the pandemic. The influence of remote learning was demonstrated in the students' graduation rates and grades. The results also presented theoretical and practical implications for the UiTM hybrid learning plan post-pandemic. [ABSTRACT FROM AUTHOR]

Juru River is one of the most polluted rivers in Malaysia. A dye-degrading bacterial consortium has been isolated from the river's sediment. This consortium JR3 consists of Pseudomonas aeruginosa MM01, Enterobacter sp. MM05 and Serratia marcescens MM06, which were able to decolorize up to 700 ppm of the Reactive Red 120 (RR120) dye under optimal conditions with limited substrate available. Substrate inhibition kinetics were investigated, and, based on the best model, Aiba, the maximum growth rate was 0.795 h-1, while the saturation constant and inhibitory constant were 0.185% and 0.14%, respectively. In addition, the influence of various metal ions on the growth and decolorization rate of this bacterial consortium on RR120 was investigated. Chromium showed the weakest effect on the decolorization of 200 ppm RR120, with 73.5% removal and bacterial growth of 11.461 log CFU mL-1. Zinc yielded the second weakest effect, followed by silver and lead, with percentages of RR120 decolorization of 63.8%, 54.6% and 50.5%, respectively. Meanwhile, cadmium, arsenic and copper reduced the decolorization of RR120 in consortium JR3 by half. Mercury strongly inhibited decolorization by 32.5%. Based on the least inhibited heavy metal in RR120 decolorization activity of consortium JR3, the best inhibitory kinetic model was Levenspiel, with a maximum growth rate of 0.632 h-1, while the saturation constant and inhibitory constants were 15.08% and 0.5783%, respectively. The metal-tolerant azo dye-degrading bacterial consortium will be very useful in dye remediation in metal-laden polluted environments. [ABSTRACT FROM AUTHOR]

Airborne microbes might pose an environmental hazard when present in high concentration in indoor environments, resulting in potential health problems. In Malaysia, there is only limited information currently available on individual exposure to bioaerosols. The aim of this study was to assess the level of bacterial and fungal contaminations in two air-conditioned laboratories in STRIDE's Main Complex, Kajang, Selangor. The study was conducted in three sampling locations (two laboratories and one outdoor). Each measurement was conducted in three time intervals (morning, noon and evening). Each air sample was collected for 2 min at sampling flow rate of 28.3 L/min. The samples were assessed in the laboratory for enumeration of viable bacteria and fungi. Agar plates for bacteria were incubated at 35oC for 24-48 h. The outdoor environment showed bacteria count of 120 CFU/m3, which is still acceptable based on the limit set by the World Health Organization (WHO) (500 CFU/m3). However, it showed very high fungal count of 2,537 CFU/m3, which exceeded the limit set by the American Conference of Governmental Industrial Hygienists (ACGIH) (1,000 CFU/m3). The average concentration of the bacterial and fungal aerosols on the two studied laboratories did not exceed the limits. The analysis of microbial contamination showed that the concentration of bacterial and fungal aerosols were higher outdoors than indoors. The results obtained in this study indicated that the two laboratories' exposure to airborne bacteria and fungi is generally low and safe for laboratory workers. [ABSTRACT FROM AUTHOR]

Airborne microbes might pose an environmental hazard when present in high concentration in indoor environments, resulting in potential health problems. In Malaysia, there is only limited information currently available on individual exposure to bioaerosols. The aim of this study was to assess the level of bacterial and fungal contaminations in two air-conditioned laboratories in STRIDE's Main Complex, Kajang, Selangor. The study was conducted in three sampling locations (two laboratories and one outdoor). Each measurement was conducted in three time intervals (morning, noon and evening). Each air sample was collected for 2 min at sampling flow rate of 28.3 L/min. The samples were assessed in the laboratory for enumeration of viable bacteria and fungi. Agar plates for bacteria were incubated at 35oC for 24-48 h. The outdoor environment showed bacteria count of 120 CFU/m3, which is still acceptable based on the limit set by the World Health Organization (WHO) (500 CFU/m3). However, it showed very high fungal count of 2,537 CFU/m3, which exceeded the limit set by the American Conference of Governmental Industrial Hygienists (ACGIH) (1,000 CFU/m3). The average concentration of the bacterial and fungal aerosols on the two studied laboratories did not exceed the limits. The analysis of microbial contamination showed that the concentration of bacterial and fungal aerosols were higher outdoors than indoors. The results obtained in this study indicated that the two laboratories' exposure to airborne bacteria and fungi is generally low and safe for laboratory workers. [ABSTRACT FROM AUTHOR]

Various microorganisms, including bacteria, fungi and protozoans, have been shown to colonise and replicate in dental unit water lines (DUWLs), resulting in the formation of biofilms. The quality of dental unit water is of considerable importance since patients and dental staffs are regularly exposed to water and aerosols generated from DUWLs. A total of 95 dental unit water samples from 11 Malaysian Armed Forces (MAF) Dental Centres were collected in the period of 7 months, from August 2008 to February 2009. The results obtained from this study indicate that 9.47 % of the samples were contaminated with Pseudomonas aeruginosa. The presence of Pseudomonas aeruginosa was confirmed using the polymerase chain reaction (PCR) technique. DNA sequencing determined that they were closely related to Pseudomonas aeruginosa strain R285, while a few were related to Pseudomonas aeruginosa PA7. [ABSTRACT FROM AUTHOR]

New and renewable fuels are the major alternative to conventional fossil fuels. Biomass is a form of agricultural residues and is becoming popular among new renewable energy sources especially in an agricultural country such as Malaysia. Among the biomass, rice husk represents one of the highest agricultural wastes in Malaysia. Pyrolysis of biomass is one of the most important thermal conversion processes to produce bio-oil. The aim of the present study is to determine the characteristics and thermal degradation behavior of rice husk via thermal gravimeiric analysis (TGA). Chemical analyses show that rice husk contains a high amount of organic constituents of hemi-cellulose (24%), cellulose (29%), and lignin (12.2%). Furthermore, the TG results show that the lignin is relatively more thermally stable than hemi-cellulose and cellulose. Evaluation of biomass resources as potential feedstock for conversion to bio-fuel generally requires information about proximate analysis, ultimate analysis, organic component analysis (hemi-cellulose, cellulose and lignin contents), and calorific value determination. [ABSTRACT FROM AUTHOR]

Aquaculture sector plays important role for the economic development in Malaysia, but environmental concerns are arising due to the pollution caused by the discharge of untreated wastewater. Coagulation-flocculation-sedimentation is currently the best practice of aquaculture wastewater treatment. This research aims to compare the performance of chemical-based (alum) and bio-based (neem leaves) coagulants in treating aquaculture effluent while also studying the economic feasibility. Alum showed higher removal efficiencies of total suspended solid (99.7%), turbidity (98.8%), and color (97.3%), while neem coagulant showed a lower dosage needed to achieve the optimum performance. The total cost included capital and operational costs, while total benefit included the potential of water reuse and reclaimed valuable products from sludge. The net profit reveals negative values for both scenarios, while cost-benefit ratio showed 0 and 0.06 values for alum and neem coagulants, respectively. These values indicated that both scenarios are not feasible to gain economical profit, while the utilization of neem coagulant present benefit for water reuse and sludge utilization. A deeper analysis using Social Return on Investment (SROI) method is suggested to include the non-traditional calculation in cost-benefit analysis such as social and environmental values of the scenarios. [ABSTRACT FROM AUTHOR]

Biochar has the potential to increase crop yields on degraded, tropical soils. It can be readily produced in rural community settings using low-cost technology and is most economically feasible if produced from local biomass or waste residues. Biochar was produced from Leucaena biomass using low-cost pyrolysis and sequential pot experiments were then conducted in Malaysia on three degraded soils. We first evaluated the effect of Leucaena biochar on yields of Amaranthus , a leafy vegetable crop and measured changes to soil pH and nutrient availability over two growth cycles. We then tested whether any yield response to biochar was dependent upon the rate of biochar or fertilizer application. We found that biochar application at 30 t ha−1 with maximal fertilizer increased yields between 17 and 53% on very strongly acidic soil. Biochar added at 15 t ha−1 with maximal fertilizer increased yield by 54% on strongly acidic soil whilst there was no significant yield response on fertilized, slightly acidic soil. Unfertilized biochar treatments showed small yield responses across all soils over 2 growth cycles (9–11%), but yields were much lower than in fertilized treatments. Biochar also decreased short-term N availability when applied with fertilizers, which may improve nitrogen retention and substantially increased soil pH. This may reduce mobility of Fe, Mn and Al ions, which were negatively associated with yield. Our results suggest that Leucaena biochar can elicit a positive crop yield response but only when combined with fertilizer additions on very strongly to strongly acidic tropical soils. • Low cost Leucaena biochar improved crop yield only on very acidic tropical soils. • Biochar reduced short term soil N availability, potentially improving N retention. • Increased yield was associated with high soil Mg and low Fe, Mn and Al availability. [ABSTRACT FROM AUTHOR]

Bioelectrochemical sensors for environment monitoring have the potential to provide facility operators with real-time data, allowing for better and more timely decision-making regarding water and wastewater treatment. To assess the robustness and sensitivity of the Sentry™ biosensor in local conditions, it was tested in Malaysia using domestically available wastewater. The study objectives included (1) enrich the biosensor locally, (2) operate and test the biosensor with local domestic wastewater, and (3) determine the biosensor's responsiveness to model pollutants through pollutant spike and immersion test as well as response to absence of wastewater. Lab-scale operation shows the biosensor was successfully enriched with (1) local University Kebangsaan Malaysia's, microbial community strain collection and (2) local municipal wastewater microflora, operated for more than 50 days with a stable yet responsive carbon consumption rate (CCR) signal. Meanwhile, two independent biosensors were also enriched and operated in Indah Water Research Centre's crude sewage holding tank, showing a stable response to the wastewater. Next, a pilot scale setup was constructed to test the enriched biosensors for the spiked-pollutant test. The biosensors showed a proportional CCR response (pollutant presence detected) towards several organic compounds in the sewage, including ethanol, chicken blood, and dilution of tested sewage but less to curry powder, methanol, and isopropanol. Conversely, there was no significant response (pollutant presence not detected) towards hexane, Congo red, engine oil, and paint, which may be due to their non-biodegradability and/or insoluble nature. Additionally, the biosensors were exposed to air for 6 h to assess their robustness towards aerobic shock with a positive result. Overall, the study suggested that the biosensor could be a powerful monitoring tool, given its responsiveness towards organic compounds in sewage under normal conditions., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)