Biochemical Engineering

The present study deals with the biohydrogen production from starch-containing wastewater collected from the textile industry in Taiwan. The effects of inoculums collected from different sources (sewage sludge, soil and cow dung), substrate concentrations (5–25 g COD/L) and pH (4.0–8.0) on hydrogen production from wastewater were investigated.The cow dung seed had the highest hydrogen production of 101 mL with hydrogen content in biogas of 32.2%. It corresponds to a hydrogen yield (HY) of 1.56 mol H2/mol hexose and hydrogen production rate (HPR) of 0.93 L/L/d. Response surface methodology was used to evaluate the effects of initial cultivation pH (4.0–8.0) and substrate concentration (5–25 g COD/L) on the hydrogen production at 35 °C. At pH 7.0 with a wastewater concentration of 20 g COD/L, a maximum hydrogen production of 66 mL with 31.9% H2 and corresponding to an HY of 0.97 mol H2/mol hexose and an HPR of 1.14 L/L/d were obtained. According to the response surface analysis, the optimal conditions for high HPR were a wastewater concentration of 13 g COD/L at an initial cultivation pH of 7.0. The main soluble metabolic products were acetate and butyrate for hydrogen fermentation from textile wastewater.► The textile wastewater containing starch is a potential energy resource for anaerobic hydrogen fermentation. ► The optimum initial cultivation pH for H2production was 7.0. ► The optimum wastewater concentration for H2 production was 13 g COD/L. ► The main soluble metabolic products were acetate and butyrate.

Ideal bacterial support medium for fixed film denitrification processes/bioreactors must be inexpensive, durable and possess large surface area with sufficient porosity. The present study has been focussed on removing nitrate nitrogen at two different nitrate nitrogen loading rates (60 (NLR I) and 120 (NLR II) mg l-1) from simulated aquaculture wastewater. Coconut coir fibre and a commercially available synthetic reticulated plastic media (Fujino Spirals) were used as packing medium in two independent upflow anaerobic packed bed column reactors. Removal of nitrate nitrogen was studied in correlation with other nutrients (COD, TKN, dissolved orthophosphate). Maximum removal of 97% at NLR-I and 99% at NLR – II of nitrate nitrogen was observed in with either media. Greater consistency in the case of COD removal of upto 81% was observed at NLR II where coconut coir was used as support medium compared to 72% COD removal by Fujino Spirals. The results observed indicate that the organic support medium is just as efficient in nitrate nitrogen removal as conventionally used synthetic support medium. The study is important as it specifically focuses on denitrification of aquaculture wastewater using cheaper organic support medium in anoxic bioreactors for the removal of nitrate nitrogen; which is seldom addressed as a significant problem.

Chemical process industries around the world are
desperately seeking for sustainable technology in the backdrop of
ever-increasing world population, demand for more employment,
industrialization and concern for environment. Process intensification
is one such way towards sustainability. The paper focuses on
development of a membrane-integrated production system for
monomer grade lactic acid with the advantages like, involvement of
less processing steps, less energy consumption and less chemical
requirement that make the system simple, flexible, compact and
environmentally benign. The particular modular design offers great
flexibility in operation of the system which the modern
manufacturing sector is demanding in this era of emaciated profit
margin. The continuous production system offered a reasonably high
flux of 76-77 L/ m-2 h-1 of greater than 95% pure L (+) lactic acid.

Background: Xylanases are important members of the hemicellulolytic enzyme system. Xylanase plays a vital role in the hydrolysis of major hemicellulosic component xylan and converts it into xylooligosaccharides and ultimately yields xylose. Cellulase-lacking or cellulase-poor xylanase with high temperature and pH stability has gained special attention, especially in paper and pulp industries. Most of the available literature highlighted the fungal xylanase production by optimizing environmental and cultural parameters. However, the importance of enzyme recovery from fermented biomass still needs attention. In this study, upstream and downstream process parameters were studied for enhancing xylanase production and extraction by a newly isolated Aspergillus tubingensis FDHN1 under solid-state fermentation using low-cost agro-residues. Results: In the present study, A. tubingensis FDHN1 was used for the xylanase, with very low level of cellulase, production under solid-state fermentation (SSF). Among various agro-residues, sorghum straw enhanced the xylanase production. Under optimized upstream conditions, the highest xylanase production 2,449 ± 23 U/g was observed. Upon characterization, crude xylanase showed stability over a broad range of pH 3.0 to 8.0 up to 24 h. The temperature stability revealed the nature of the xylanase to be thermostable. Native polyacrylamide gel electrophoresis (native PAGE) and zymogram analysis revealed the multiple forms of the xylanase. Due to the many industrially important characteristics of the xylanases, the study was elaborated for optimizing the downstream process parameters such as volume of extractant, extraction time, temperature and agitation speed to recover maximum xylanase from fermented sorghum straw. The highest amount of xylanase (4,105 ± 22 U/g) was recovered using 0.05 M sodium citrate buffer (pH 6.5) at 12:1 (v/w) extractant/solid ratio, 90-min extraction time, 150-rpm agitation speed and 40°C. Finally, detailed bioprocess optimization shows an overall 6.66-fold enhancement in the xylanase yield. Conclusions: The present study consolidates the importance of upstream and downstream process optimization for the overall enhancement in the xylanase production. The xylanase from A. tubingensis FDHN1 shows the stability at different pH and temperature, and it was also active in the presence of organic solvents. These properties of xylanase are very much important from an industrial application point of view.

Epilepsy is a typical incessant neurological issue. Epilepsy seizures are the consequence of the transient and surprising electrical aggravation of the cerebrum. Around 50 million individuals worldwide have epilepsy, and about two out of each three new cases are found in creating nations. Epilepsy will probably happen in youthful youngsters or individuals beyond 65 years old years; nonetheless, it can happen at any age. The identification of epilepsy is conceivable by investigating EEG signals. In this paper we are using a technique to classify normal & epileptic EEG signal using k-means clustering algorithm in MATLAB. Further the SVM & Discriminant classifier in MATLAB Machine learning toolbox is used to classify the epileptic and normal EEG signal & wavelet transform is used to process the EEG signal. After the implementation of the signals there is ~70% accuracy with SVM classifier and ~93% accuracy with discriminant classifier.

Rice husk lean-combustion in a bubbling and atmospheric fluidized bed reactor (FBR) of 0.3 m diameter with expansion to 0.4 m in the freeboard zone and 3 m height was investigated. Experiment design – response surface methodology (RSM) – is used to evaluate both excess air and normal fluidizing velocity influence (independent and controllable variables), in the combustion efficiency (carbon transformation), bed and freeboard temperature and silica content in the ashes. Hot gases emissions (CO2, CO and NOx), crystallographic structure and morphology of the ash are also shown. A cold fluidization study is also presented. The values implemented in the equipment operation, excess air in the range of 40–125% and normal fluidization velocities (0.13–0.15 Nm/s) show that the values near the lower limit, encourage bed temperatures around 750 °C with higher carbon transformation efficiencies around 98%. However, this condition deteriorated the amorphous potential of silica present in the ash...

Progress on plasmid-based (pDNA) vaccines requires simpler and efficient cultivation techniques for their production. A prevalent problem in the cultivation of Escherichia coli (the main host for pDNA vaccines production) is the aerobic production of acetate. In this work, a metabolically engineered Escherichia coli strain with strongly reduced acetate formation was tested for the production of a plasmid vaccine at

Two bed media were tested (gravel and Filtralite) in shallow horizontal subsurface flow (HSSF) constructed wetlands in order to evaluate the removal of ammonia and nitrate for different types of wastewater (acetate-based and domestic wastewater) and different COD/N ratios. The use of Filtralite allowed both higher mass removal rates (1.1 g NH4–N m2 d1 and 3 g NO3–N m2 d1) and removal efficiencies (>62% for ammonia, 90–100% for nitrate), in less than 2 weeks, when compared to the ones observed with gravel. The COD/N ratio seems to have no significant influence on nitrate removal and the removal of both ammonia and nitrate seems to have involved not only the conventional pathways of nitrification–denitrification. The nitrogen loading rate of both ammonia (0.8–2.4 g NH4–N m2 d1) and nitrate (0.6–3.2 g NO3–N m2 d1) seem to have influenced the respective removal rates.

This research work evaluates the impact of stormwater infiltration on the removal of organics, solids, nitrogen and phosphorus in a LECA-based horizontal subsurface flow constructed wetland. Stormwater runoff for the period between January 2008 and June 2010 (30 months) was estimated for the drainage basin of the Vila Fernando wastewater treatment plant (constructed wetland system) and it was observed proportionality between the increase in surface runoff and the infiltration flow rate that reached the plant. The average stormwater infiltration rate that reached the plant was 67.4 m(3) d(-1) (77% of the influent flow rate into the plant). The 30 month monitoring campaign set up at one of the reed beds showed that stormwater infiltration led to a high variation of the hydraulic loading rate (HLR) throughout the bed, which affected its performance in the removal of organic matter, suspended solids and nitrogen. For a HLR below 20 cm d-1 the removal efficiencies for BOD5, COD and TSS doubled. The removal of nitrogen was too low and was associated with the weak development of nitrifying biofilm and the poor growth of reeds. However, it was observed a good relationship between the applied and removed loads for most of the parameters, which seems to indicate that the organic, solid, nitrogen and phosphorus loading rates influenced the respective removal rates. The use of a bed material with high specific surface area, such as LECA, can only improve the treatment capacity of horizontal subsurface flow systems if the organic and solid loading rates, as well as the HLR, can be effectively controlled.

Reclaimed water from small wastewater treatment facilities in the rural areas of the Beira Interior region (Portugal) may constitute an alternative water source for aquifer recharge. A 21-month monitoring period in a constructed wetland treatment system has shown that 21,500 m3 year−1 of treated wastewater
(reclaimed water) could be used for aquifer recharge. A GIS-based multi-criteria analysis was performed, combining ten thematic maps and economic, environmental and technical criteria, in order to produce a suitability map for the location of sites for reclaimed water infiltration. The areas chosen for aquifer
recharge with infiltration basins are mainly composed of anthrosol with more than 1 m deep and fine sand texture, which allows an average infiltration velocity of up to 1 m d−1. These characteristics will provide a final polishing treatment of the reclaimed water after infiltration (soil aquifer treatment (SAT)),
suitable for the removal of the residual load (trace organics, nutrients, heavy metals and pathogens).
The risk of groundwater contamination is low since the water table in the anthrosol areas ranges from 10 m to 50 m. On the other hand, these depths allow a guaranteed unsaturated area suitable for SAT. An area of 13,944 ha was selected for study, but only 1607 ha are suitable for reclaimed water infiltration.
Approximately 1280 m2 were considered enough to set up 4 infiltration basins to work in flooding and
drying cycles.