No abstract

Adsorption of a basic dye, safranin, from aqueous solutions onto activated carbon prepared from corncobs (ACCC) has been investigated. Various experiments have been carried out using batch adsorption technique to study the effects of the process variables, which include initial pH, adsorbent dosage, initial dye concentration, particle size, temperature, and agitation speed, on the adsorption process. The adsorption of safranin onto the adsorbent was found to improve with the increase in adsorbent dosage and finer mesh size. Maximum adsorption was observed at pH > pHzpc in the pH values ranging from 5 to 9. It was observed that the rate of adsorption improves with increasing temperature and the process is endothermic with an ΔH value of 35.698 kJ/mol. The kinetics followed is first order in nature. The results showed that both Langmuir and Freundlich isotherms fit the equilibrium data. Also, the results revealed that activated carbon from corncob, an agricultural waste biomass, proved to be an excellent low-cost sorbent.

Biocatalysis based effluent treatment has outclassed the presently favored physico-chemical treatments due to nil sludge production and monetary savings. Azo dyes are commonly employed in the leather industry and pose a great threat to the environment. Here, we show the degradation of C. I. Acid blue 113 using horseradish peroxidase (HRP) assisted with H2O2 as a co-substrate. It was observed that 0.08 U HRP can degrade 3 mL of 30 mg/L dye up to 80% within 45 min with the assistance of 14 μL of H2O2 at pH 6.6 and 30°C. The feasibility of using the immobilized HRP for dye degradation was also examined and the results show up to 76% dye degradation under similar conditions to that of free HRP with the exception of longer contact time of 240 min. Recycling studies reveal that the immobilized HRP can be recycled up to 3 times for dye degradation. Kinetics drawn for the free HRP catalyzed reaction marked a lower Km and higher Vmax values, which denotes a proper and faster affinity of the enzyme towards the dye, when compared to the immobilized HRP. The applicability of HRP for treating the actual tannery dye-house wastewater was also demonstrated.Electronic supplementary materialThe online version of this article (doi:10.1186/2193-1801-2-341) contains supplementary material, which is available to authorized users.

In today's modern world, families face a great challenge to take care of their ailing grandparents. Providing the right medicines at the right time to the elders is quite impossible due to their busy schedule. To overcome this situation, proposing household "AUTONOMOUS CONCIERGE ROBOT" which can take care of sick & old people. Since it is autonomous robot, it needs to navigate the house to reach the patient position from its position; also it needs to avoid the obstacle while moving. Major task of Concierge Robot is to nurses the patient with the medicines at the right moment, intimates the same to the family member and it also remind if there is any shortage of medicine. Suppose if the patient does not respond or in absence of patient it will remind to the family members. The patient medication details can be reviewed by family member when it required.