Biomedical subjects

Amarjeet Bassi

Publications and source records attributed to Amarjeet Bassi.

5 recordsLinked to original sources

PubMed2006

Hydrolytic pretreatment of oily wastewater by immobilized lipase.

The purpose of this study was to evaluate the hydrolysis of wastewater with high oil and grease (O&G) concentration from a pet food industry using immobilized lipase (IL) as a pretreatment step for anaerobic treatment through batch and continuous-flow experiments. The intrinsic Michaelis constant (K(m)) and maximum reaction rate (V(max)) were estimated experimentally and the K(m) value of IL (22.5g O&G/L) was six-folds higher than that of the free lipase (FL) (3.6gO&G/L), whereas V(max) of both FL (31.3mM/gmin) and IL (33.1mM/gmin) were similar. Preliminary batch anaerobic respirometric experiments showed that chemical oxygen demand (COD) and O&G reduction were 49 and 45% without pretreatment and 65 and 64% with IL pretreatment respectively, while the maximum growth rate (micromax) for pretreated wastewater (0.17d(-1)) was 3.4-folds higher than that of raw wastewater (0.05d(-1)) with similar Monod half-saturation constants (K(s) approximately 2.7gCOD/L). The continuous-flow experimental study showed the feasibility of employing the hybrid packed bed reactor (PBR)-upflow anaerobic sludge blanket (UASB) system for the treatment of high-strength oily wastewater, as reflected by its ability to operate at an oil loading rate (LR) of 4.9kgO&G/m(3)d (to the PBR) without any problems for a period of 100days. During pseudo-steady-state conditions, the hybrid UASB produced relatively higher biogas compared to the control UASB, The effluent COD and O&G concentrations of hybrid system were 100mg/L lower than that of the control UASB reactor and no foam production was observed in the hybrid UASB compared to the control UASB reactor.

Anaerobiosis↗

PubMed2006

Long-term performance of high-rate anaerobic reactors for the treatment of oily wastewater.

Complex oily wastewater from a food industry was treated in three different UASB reactors at different operating conditions. Although all three systems achieved fat, oil, and grease (FOG) and COD removal efficiencies above 80% at an organic loading of 3 kg COD/m3 x d, system performance deteriorated sharply at higher loading rates, and the presence of high FOG caused a severe sludge flotation resulting in failure. Initially, FOG accumulated onto the biomass which led to sludge flotation and washout of biomass. The loss of sludge in the bed increased the FOG loading to the biomass and failure ensued. Contrary to previous findings, accumulation of FOG rather than influent FOG concentrations or volumetric FOG loading rate was the most importantfactor governing the high-rate anaerobic reactor performance. The critical accumulated FOG loading was identified as 1.04 +/- 0.13 g FOG/g VSS for all three reactors. Furthermore, FOG accumulation onto the biomass was identified mainly as palmitic acid (>60%) whereas the feed LCFA contained only 30% of palmitic acid and 50% of oleic acid.

Anaerobiosis↗

PubMed2006

Pre-treatment of high oil and grease pet food industrial wastewaters using immobilized lipase hydrolyzation.

Wastewaters generating from pet food industries contain high concentration of oil and grease (O&G), which is difficult to treat through conventional biological treatment systems. In this study, the hydrolysis of O&G originating from pet food industrial wastewater was evaluated. Candida rugosa lipase was immobilized in calcium alginate beads and applied in the hydrolysis experiment. Results showed that approximately 50% of the O&G was hydrolyzed due to the enzyme activity. A significant increment in COD and VFA production was also observed. The immobilized lipase activity was confirmed with p-nitrophenyl palmitate (pNPP) before and after O&G hydrolysis. During the 3-day experiment, approximately 65% of the beads were recovered and after the hydrolysis, approximately 70% of the enzyme activity remained in the beads. This study shows the potential of immobilized lipase as a pre-treatment step in biological treatment of pet food manufacturing wastewater.

Animal Feed↗

PubMed2005

Electro-kinetic dewatering of oily sludges.

An oily sludge from a rendering facility was treated using electro-kinetic (EK) techniques employing two different experimental designs. The bench scale used vertical electrodes under different operational conditions, i.e. varied electrode spacing at 4, 6 and 8 cm with electric potential of 10, 20 and 30 V, respectively. The highest water removal efficiency (56.3%) at bench scale was achieved at a 4 cm spacing and 30 V. Comparison of the water removal efficiency (51.9%) achieved at the 20 V at 4 cm spacing showed that power consumption at 30 V was 1.5 times larger than that at 20 V, suggesting a further increase of electric potential is unnecessary. The solids content increased from an initial 5 to 11.5 and 14.1% for 20 and 30 V, respectively. The removal of oil and grease (O&G) was not significant at this experimental design. Another larger scale experiment using a pair of horizontal electrodes in a cylinder with 15 cm i.d. was conducted at 60 V at an initial spacing of 22 cm. More than 40.0% of water was removed and a very efficient oil separation from the sludge was achieved indicating the viability of electro-kinetic recovery of oil from industrial sludge.

Electrochemistry↗

PubMed2002

Continuous protein recovery from whey using liquid-solid circulating fluidized bed ion-exchange extraction.

A liquid-solid circulating fluidized bed (LSCFB) continuous ion-exchange extraction system has been investigated for total protein recovery from whey solutions under various operating conditions. The effectiveness of a dynamic seal was evaluated between the riser and the downcomer, and the best conditions for the establishment of this seal were established. Start-up studies indicated that the system is robust and stable. Under optimal conditions, a productivity of 8.2 g of total protein removed per hour per kilogram of resin was achieved with a protein removal efficiency of 78.4%. However, higher overall protein recovery of up to 90% was also achieved under other conditions, with lower protein concentration in the effluent and a lower overall productivity.

Bioreactors↗