Electrochemical degradation of textile dyeing industry effluent in batch and flow reactor systems

Electrochemical oxidation of organic pollutants present in the dye-bath and wash water effluents from the textile industry was carried out in batch, batch recirculation and recycle reactor configurations under different conditions of current density, treatment duration, effluent flow rate and electrode specific surface. COD reduction of 52.63% to 82.61% could be obtained when the Procion blue dye-bath effluent was treated in the batch reactor for 8 h. In batch recirculation reactor, the reduction was 94.3% for dye-bath effluent and 91.4 for wash water effluent after 6 h of operation at a current density of 5.0 A dm^?2 and flow rate of 100 L h^?1. The specific energy consumption was found to be 4.32 kWh (kg COD)^?1 for dye-bath effluent and 83.8 kWh (kg COD)^?1 for wash water effluent. The results for wash water effluent under continuous operation of recycle reactor conditions showed 52.86% of COD removal at recycle flow rate of 100 L h^?1 with discharge flow rate of 3 L h^?1. The specific energy consumption was found to be 11.9 kWh (kg COD)^?1.     

Feasibility of mild hard turning of stainless steel using coated carbide tool

Hard turning has been explored as an alternative to the traditional processing technique used to manufacture parts made of hardened steels. However, advanced cutting tool materials for hard turning applications are relatively expensive. The continuous developments in carbide tool material and its coating technology have offered inexpensive cutting tool alternatives for a mild range of hard turning operations. Commercially available TiAlN-coated carbide tool is utilized in this study to perform hard turning of stainless steel within the mild range (47–48 HRC) at various cutting parameters, i.e., cutting speed and feed. Empirical models to measure its performance by quantifying the effect of the cutting parameters to the tool’s service lifetime and the machined workpiece’s surface roughness are developed. The coated carbide tool performed hard turning with fair tool life and fine surface finish, especially at low cutting parameters as shown by the models’ solutions for the optimized input selection.     

Production of cellulases from coconut coir pith in solid state fermentation

Coconut coir pith, available in abundance especially in tropical countries, was studied as a substrate for the production of cellulase[1,4(1,3;1,4)-β-D -glucan 4-glucanohydrolase, EC 3.2.1.4] and β-D -glucosidase(β-D -glucoside glucohydrolase, EC 3.2.1.21) in solid state fermentation. The effects of fermentation time, nutrient level, substrate particle size and inoculum size have been examined for optimal production of these enzymes by the fungal strain Aspergillus niger NCIM 1005. The highest filter paper activity (FPA) of 4.11 IU g^?1, carboxyl methyl cellulose (CMCase) activity of 15·55 IU g^?1 and cellobiase activity of 9·31 IU g^?1 were obtained after 7 to 8 days of fermentation. Reese and Mandel's mineral solution in the substrate to mineral solution ratio of 1:10 (w/v) supported high cellulase and cellobiase activities. An inoculum size of 20–50% (v/v) based on the volume of mineral medium and substrate average particle size of 375 μm were optimum for enzyme production.     

Dispersion and Mass Transfer Effects on the Performance of an Immobilized Lipase Packed Bed Reactor During the Hydrolysis of Rice Bran Oil

The performance of an immobilized packed bed reactor for the hydrolysis of rice bran oil has been investigated and can be well described by a dispersion model with an average standard deviation of 0.0388. Global mass transfer coefficients estimated using the model and experimental data ranged from 0.095‐0.482 min^?1, depending on substrate flow rates. A dimensionless mass transfer correlation between the Sherwood number and the Reynolds number was obtained as NSh = 3.96 ×NRe^2.07.