Finding of coefficients and oxidizable nitrogen from palm oil mill effluent (POME) for activated sludge models(ASMs)

Activated Sludge Models (ASMs) have been widely used as a basis for further model development in wastewater treatment processes. Values for parameters to be used are vital for the accuracy of the modeling approach. The objective of this study is to determine coefficients of the system, and oxidizable nitrogen of palm oil mill effluent (POME). A continuous stirred tank reactor (CSTR), with continuous flow for 20 hours, was used in this study. The DO profile for 11 days was monitored. The total, soluble, insoluble COD and soluble ammonia nitrogen were measured at the beginning and end of the experiment. Also, the coefficients and oxidizable nitrogen fractions are determined

The effect of mixed liquor suspended solids (MLSS) on biofouling in a hybrid membrane bioreactor for the treatment of high concentration organic wastewater

Biofouling is a crucial factor in membrane bioreactor (MBR) applications, particularly for high organic loading operations. This paper reports a study on biofouling in an MBR to establish a relationship between critical flux, J(c), mixed liquor suspended solids (MLSS) (ranging from 5 to 20 g L(-1)) and volumetric loading rate (6.3 kg COD m(-3) h(-1)) of palm oil mill effluent (POME). A lab-scale 100 L hybrid MBR consisting of anaerobic, anoxic, and aerobic reactors was used with flat sheet microfiltration (MF) submerged in the aerobic compartment. The food-to-microorganism (F/M) ratio was maintained at 0.18 kg COD kg(-1) MLSSd(-1). The biofouling tendency of the membrane was obtained based on the flux against the transmembrane pressure (TMP) behaviour. The critical flux is sensitive to the MLSS. At the MLSS 20 g L(-1) the critical flux is about four times lower than that for the MLSS concentration of 5 g L(-1). The results showed high removal efficiency of denitrification and nitrification up to 97% at the MLSS concentration 20 g L(-1.) The results show that the operation has to compromise between a high and a low MLSS concentration. The former will favour a higher removal rate, while the latter will favour a higher critical flux

A case study of green building in Malaysia: cost saving analysis

The building sector consumes about forty percent of world energy, making energy efficiency in existing buildings an important issue. This study has been undertaken to investigate energy consumption of a building that has been redesigned to incorporate energy efficient features. It was found that the introduction of energy efficient features has helped to achieve savings up to 46% of the total spent on energy particularly based on electricity bills

Respirometric analysis of activated sludge models from palm oil mill effluent

Activatedsludgemodels (ASMs) have been widely used as a basis for further model development in wastewater treatment processes. Values for parameters to be used are vital for the accuracy of the modeling approach. A continuous stirred tank reactor (CSTR), as open respirometer with continuous flow for 20 h is used in ASMs. The dissolved oxygen (DO) profile for 11 days was monitored. It was found the mass transfer coefficient KLa is 0.3 h-1 during lag and start feed phase and 0.01 h-1 during stop feed phase, while the heterotrophic yield coefficient YH is 0.44. Some of the chemical oxygen demand (COD) fractionations of palmoilmilleffluent (POME) using respirometric test in ASM models are Ss 50 mg/L, SI 16,600 mg/L, XS 25,550 mg/L, and XI 2,800 mg/L. The comparison of experimental and ASM1 from OUR concentration is found to fit well

Intracellular biopolymer productions using mixed microbial cultures from fermented POME

This study aimed to produce polyhydroxyalkanoates (PHAs) from organic wastes by mixed bacterial cultures using anaerobic-aerobic fermentation systems. Palm oil mill effluent (POME) was used as an organic source, which was cultivated in a two-step-process of acidogenesis and acid polymerization. POME was operated in a continuous flow anaerobic reactor to access volatile fatty acids (VFAs) for PHAs production. During fermentation, VFA concentration was produced in the range of 5 to 8 g/L and the COD concentration reduced up to 80% from 65 g/L. The VFA from anaerobic fermentation was then utilised for PHA production using a mixed culture in availability of aerobic bioreactor. Production of PHAs was recorded high when using a high volume of substrates because of the higher VFA concentration. Even though the maximum PHA content was observed at only 40% of the cell dried weight (CDW), their production and performance are significant in mixed microbial culture

Raw material resource for biodegradable plastic production from cafeteria wastes

This study presents treatment performance of cafeteria waste and polyhydroxyalkanoate (PHA) production in two stage process through an up-flow anaerobic sludge bed (UASB) and sequencing batch reactor (SBR). COD removal efficiency was found as follows: SBR, 93; and UASB - SBR, 95.4%. In addition, 30% ammoniacal nitrogen (AN) was noted at high aerobic condition and phosphate (PO4) removal efficiency increased at high anoxic conditions. Volatile fatty acid (VFA) intermediates such as acetic acid increased from 505 up to 4315 mg.l-1 in effluent of UASB reactor and successfully consumed in SBR for PHA production. Acetic acid concentration was reduced significantly in SBR from 4315 to 50 mg.l-1. During this period, PHA production was increased to 68% over cell dried weight, confirming effectiveness of sequential UASB-SBR system in producing bioplastic from cafeteria waste

Enhancing antimicrobial properties of poly(vinylidene fluoride)/hexafluoropropylene copolymer membrane by electron beam induced grafting of: N -vinyl-2-pyrrolidone and iodine immobilization

Highly efficient antimicrobial properties were imparted to a solution cast poly(vinylidene fluoride)-co-hexafluoropolypropylene (PVDF-co-HFP) NF membrane by modification with povidone-iodine (PVP-I2) complex using electron beam (EB) induced grafting of N-vinyl-2-pyrrolidone (NVP) and subsequent iodine immobilisation. The changes in the morphology of the PVDF-co-HFP membrane in correlation with preparation procedure (NVP grafting and I2 loading) were monitored by a field emission scanning electron microscope (FESEM) whereas, the variation in chemical composition was investigated with FTIR-ATR, UV-vis/NIR and energy dispersive X-ray (EDX). The free surface energy and hydrophilicity/hydrophobicity of the membranes were studied using contact angle measurements. The antimicrobial activity of I2 loaded membrane was evaluated against Gram negative Escherichia coli and Gram positive Staphylococcus aureus in comparison with pristine and PVP grafted membranes. The pure water permeation flux and bacterial suspension filtration through the membranes were also investigated. The use of radiation grafting with EB was found to be highly effective in modification of PVDF-co-HFP membrane by imparting PVP ligands capable of hosting I2 and conferring it very strong antimicrobial activity. Moreover, the obtained membrane is highly promising for water disinfection applications

A case study of green building in Malaysia: cost saving analysis

The building sector consumes about forty percent of world energy, making energy efficiency in existing buildings an important issue. This study has been undertaken to investigate energy consumption of a building that has been redesigned to incorporate energy efficient features. It was found that the introduction of energy efficient features has helped to achieve savings up to 46% of the total spent on energy particularly based on electricity bills