Biodegradation of green he4b: co-substrate effect, biotransformation enzymes and metabolite toxicity analysis

A high exhaust reactive dye, Green HE4B (GHE4B) was 98% degraded in nutrient medium by Pseudomonas desmolyticum NCIM 2112 (pd2112) within 72 h at static condition. Decolorization time in synthetic 10 g/l molasses. Addition of 5 g/l peptone to NaCl medium had reduced decolorization time from 108 to 72 h. Beef extract do not contribute more to the inducing effect of peptone, however it is a good co-substrate in sucrose or urea containing NaCl medium. Intracellular lignin peroxidase (Lip), laccase and tyrosinase activities were induced by 150, 355 and 212%, respectively till maximum dye removal took place. Aminopyrine N-demethylase (AND) and dichlorophenol indophenol reductase (DCIP-reductase) activities in pd2112 were induced by 130 and 20%, respectively at 72 h of incubation during GHE4B decolorization. By high performance liquid chromatography (HPLC) analysis, 4-hydroxybenzene sulfonic acid and 4-amino, 6-hydroxynaphthalene 2-sulfonic acids were identified as metabolites formed during 24-72 h incubation. Fourier transform infrared spectroscopy (FTIR) analysis supports the formation of these aromatic amines. pd2112, aerobically degraded GHE4B metabolites (formed at static condition) showing stationary phase of 6 days. There was no germination inhibition of Sorghum bicolor and Triticum aestivum by GHE4B metabolites at 3,000 ppm concentration however untreated dye showed germination inhibition at the same concentration. GHE4B metabolites did not show any microbial toxicity at 10,000 ppm concentration

Hydrothermal carbonization of oil palm shell

Palm shell is one of the most plentiful wastes of the palm oil mill industry. This study identifies the capability of hydrothermal carbonization process (HTC) to convert palm shell into high energy hydrochar. The influence of reaction time and reaction temperature of the HTC process was investigated. The process parameters selected were temperature 200 °C to 240 °C, time 10 to 60min, and water to biomass ratio was fixed at 10 : 1 by weight %. Fourier transform infrared (FTIR), elemental, proximate, Burner Emmett and Teller (BET), thermo-gravime tric (TGA) analyses were performed to characterize the product and the feed. The heating value (HHV) was increased from 12.24 MJ/ kg (raw palm shell) to 22.11 MJ/kg (hydrochar produced at 240 °C and 60 min). The hydrochar yield exhibited a higher degree inverse proportionality with temperature and reaction time. Elemental analysis revealed an increase in carbon percentage and a proportional decrease in hydrogen and oxygen contents which caused higher value of HHV. The dehydration and decarboxylation reactions take place at higher temperatures during HTC resulting in the increase of carbon and decrease in oxygen values of hydrochar. The FESEM results reveal that the structure of raw palm shell was decomposed by HTC process. The pores on the surface of hydrochar increased as compared to the raw palm shell