Membrane Anaerobic System (MAS) for Palm Oil Mill Effluent (POME) Treatment

The direct discharge of palm oil mill effluent (POME) wastewater causes serious environmental pollution due to its high chemical oxygen demand (COD) and biochemical oxygen demand (BOD). Traditional ways for POME treatment have both economic and environmental disadvantages. In this study, membrane anaerobic system (MAS) was used as an alternative, cost effective method for treating POME. Six steady states were attained as a part of a kinetic study that considered concentration ranges of 8,220 to 15,400 mg/l for mixed liquor suspended solids (MLSS) and 6, 329 to 13,244 mg/l for mixed liquor volatile suspended solids (MLVSS). Kinetic equations from Monod, Contois and Chen & Hashimoto were employed to describe the kinetics of POME treatment at organic loading rates ranging from 2 to 13 kg COD/m3/d. throughout the experiment, the removal efficiency of COD was from 94.8 to 96.5% with hydraulic retention time, HRT from 400.6 to 5.7 days. The growth yield coefficient, Y was found to be 0.62gVSS/g COD the specific microorganism decay rate was 0.21 d-1 and the methane gas yield production rate was between 0.25 l/g COD/d and 0.58 l/g COD/d. Steady state influent COD concentrations increased from 18,302 mg/l in the first steady state to 43,500 mg/l in the sixth steady state. The minimum solids retention time, which was obtained from the three kinetic models ranged from 5 to 12.3 days. The k values were in the range of and values were between 0.26 and 0.379 d-1. The solids retention time (SRT) decreased from 800 days to 11.6 days. The complete treatment reduced the COD content to 2279 mg/l equivalent to a reduction of 94.8% reduction from the original

Comparison of Essential Oil of Lemongrass (Cymbopogon Citratus) Extracted with Microwave-Assisted Hydrodistillation (MAHD) and Conventional Hydrodistillation (HD) Method

The increasing demand of essential oil has opened up wide opportunities for global marketing which leads to the requirement of its competitive product in market that comes with all the advantages in term of cost, quality and its production time. Microwave-assisted hydrodistillation (MAHD) method is an advance extraction technique that takes advantage of microwave heating with the conventional hydrodistillation (HD). This research was carried out to study the effect of different MAHD parameters which were water to plant material ratio (6:1, 8:1,10:1), microwave power (200 W,250W) and extraction time (30min,60min, 90min,120min) in extraction of essential oil from Lemongrass (Cymbopogon Citratus). Its extraction yield and major constituents were analyzed and the results were compared with those of conventional HD. The optimum parameters were found at water to plant material ratio of 8:1, microwave power of 250W and 90 minutes of extraction and the yield obtained under this condition was 1.46%. The gas chromatography/mass spectrometric (GC-MS) analysis showed that the content of main constituents which were neral, geranial and myrcene were almost similar in the essential oil extracted using MAHD and conventional HD. This has proved that the use of microwave irradiation did not adversely influence the composition of essential oils. Overall, the results obtained indicate that MAHD method provided a good alternative for the extraction of essential oil from Lemongrass (Cymbopogon Citratus)

Demulsification of petroleum emulsions using microwave separation method

The formation of emulsions during oil production and processing is a costly problem, both in terms of chemicals used and production losses. For economic and operational reasons, it is necessary to separate the water completely from crude oils before transporting or refining them. Experimental data are presented to show the influences of Triton X-100, low-sulfur wax residue (LSWR), sorbitan monooleate (Span 83) and sodium dodecyl sulfate (SDS) on the stability and microwave demulsification of petroleum emulsions. It was found that emulsion stability was related to several parameters including the surfactant concentration, water-to-oil phase ratio (10 to 90%), temperature and agitation speed. Based on this study, a possible emulsion-minimization approach utilizing microwave irradiation is suggested, which could be implemented in refineries. Compared with conventional heating, the use of microwave heating can significantly enhance the demulsification rate, reaching over 90 v/v% for the emulsions studied in this work

IN VITRO ANTI-ACETYL CHOLINESTERASE AND ANTIOXIDANT ACTIVITY OF SELECTED MALAYSIAN PLANTS

Objective: The aim of this study is to discover and identify the potential plant extracts that could be vital against Alzheimer's disease (AD). It is a neurodegenerative disease affecting the brain. The most promising target for the symptomatic treatment and slowing of AD progression is cholinesterase inhibitors from plants. Methods: To evaluate the antioxidant and anti-acetylcholinesterase (AChEI) activities leaves and roots were macerated and refluxed with ethanol extracts, from four medicinal plants, namely; C.asiatica, M.pudica, C.pumila, and L.camara. DPPH and β-carotene assays were used to determine antioxidant activity; whereas Ellman's colorimetric method was adopted to quantify AChEI activity. Results: The refluxed ethanol extract of M.pudica leaves exhibited the highest AChEI activity (IC50 = 0.047 mg/ml) and high antioxidant activity (β-carotene; IC50 = 0.14 mg/ml and DPPH; IC50 = 0.012 mg/ml). Conclusion: Results reveal that all plant extracts studied possess anti-oxidant properties. Most potent extracts could be a lead to novel antioxidants and acetyl cholinesterase inhibitors, for the treatment of AD. Keywords; Alzheimer's disease (AD); Acetylcholinesterase activity; Antioxidant activity; β-carotene; DPPH; Medicinal plants

The Potential of Ultrasonic Membrane Anaerobic Systems in Treating Slaughterhouse Wastewater

Direct discharge of slaughterhouse wastewater causes serious environmental pollution due to its high chemical oxygen demand (COD), total suspended solids and biochemical oxygen demand. In this study, an ultrasonic-assisted membrane anaerobic system was used as a novel method for treating slaughterhouse wastewater. Six steady states were achieved, using concentrations of 7,800–13,620 mg/l for mixed liquor suspended solids and 5,359–11,424 mg/l for mixed liquor volatile suspended solids. Kinetic equations were used to describe the kinetics of treatment at organic loading rates of 3–11 kg COD/m3/d. The removal efficiency of COD was 94.8–96.5% with hydraulic retention times of 308.6–8.7 days. The growth yield coefficient was found to be 0.52 g VSS/g. COD was 0.21 d−1 and methane gas production rate was 0.24–0.56 l/g COD/d. Steady-state influent COD concentrations increased from 8,000 mg/l in the first steady state to 25,400 mg/l in the sixth steady state. The minimum solids retention time, θcmin obtained from the three kinetic models was 6–14.4 days. The k values were 0.35–0.519 g COD/g VSS.d and μmax values were between 0.26 and 0.379 d−1. The solids retention time decreased from 600 to 14.3 days. The complete treatment reduced the COD content and its removal efficiency reached to 94.8%

A hybrid ultrasonic membrane anaerobic system (UMAS) development for palm oil mill effluent (POME) treatment

The high chemical oxygen demand (COD) and biochemical oxygen demand (BOD) levels in palm oil mill effluent (POME) wastewater make it an environmental contaminant. Moreover, conventional POME wastewater treatment approaches pose economic and environmental risks. The present study employed an ultrasonic membrane anaerobic system (UMAS) to treat POME. Resultantly, six steady states were procured when a kinetic assessment involving 11,800–21,700 mg·L−1 of mixed liquor suspended solids (MLSS) and 9800–16,800 mg·L−1 of mixed liquor volatile suspended solids (MLVSS) was conducted. The POME treatment kinetics were explained with kinetic equations derived by Monod, Contois and Chen and Hashimoto for organic at loading rates within the 1–11 kg·COD·m−3·d−1 range. The UMAS proposed successfully removed 96.6–98.4% COD with a 7.5 day hydraulic retention time. The Y value was 0.67 g·VSS/g·COD, while the specific micro-organism decay rate, b was 0.24 day−1. Methane (CH4) gas production ranged from 0.24 to 0.59 litres per gram of COD daily. Once the initial steady state was achieved, the incoming COD concentrations increased to 88,100 mg·L−1. The three kinetic models recorded a minimum calculated solids retention time of 12.1 days with maximum substrate utilization rate, K values ranging from 0.340 to 0.527 COD·g−1·VSS·d−1 and maximum specific growth rate, µmax from 0.248 to 0.474 d−1. Furthermore, the solids retention time (SRT) was reduced from 500 to 12.1 days, resulting in a 98.4% COD level reduction to 1400 mg·L−1

Chemical composition and antimicrobial activity of Mint (Mentha) essential oil

Natural products of plant origin, such as essential oils have great benefit for human life. The objective of this study was to determine the chemical composition and antimicrobial activity of mint (mentha) essential oil (EO). The EO obtained by steam distillation and their constituents were determined by gas chromatography-mass spectrometry (GC-MS). The disc diffusion method was used for the determination of the antimicrobial activity. In the antimicrobial activity, the concentrations of 3.75, 7.5, 15, 30, 60μg/mL of mint essential oil were prepared and tested against four microbes; one Gram-positive: Staphylococcus aureus; two Gram-negative: Escherichia coli, Klebsiella pneumonia; and one fungal strain, Candida albicans. The oil content was 0.05% (v/w) and the GC-MS analysis led to the identification 42 components, the major components were found to be, Carvone (53.06%), D-limonene (25.65%), and Eucalyptol (2.56%). The inhibition zones of the oil were compared with standard ciprofloxacin. The results showed that the remarkable inhibition of the bacterial growth against the tested organisms. The microbial activity of mint essential oil was due to the presence of various secondary metabolites. Therefore, may warrant further research to determine the bioactive compound(s)