Iranica Journal of Energy and Environment (IJEE)

6-10

Authors: A. K. Yadav

Day by day the energy consumption is very rapidly increasing. The world’s fossil fuel supply will be depleted in future. The rate of energy consumption is increasing the supply is depleted resulting in inflation and energy shortage. This is called the energy crisis. Alternate or renewable energy resources are very essential to develop for future energy requirement. Biodiesel is the best alternative to petrodiesel. The present research work deals with the production of biodiesel from Kusum oil. Kusum oil methyl ester (KOME) was produced using a two-stage esterification cum transesterification process on account of the high free fatty acid (FFA) contents of the oil. From the above study it may be concluded that Kusum oil is a promising feedstock for biodiesel production and may be the best alternative of petro-diesel The biodiesel property of Kusum oil methyl ester (KOME) has been characterized and it shows that KOME meets the properties of biodiesel as stated in ASTM/EN standards.

18-25

Authors: C. Kurinjimalar, G.Kavitha, S. S. Begum , G. Rajaram, S.Nagaraj, N. Senthilkumar and R. Rengasamy

Biofuel production by a sustainable method using microalgae is entirely dependent on biomass production. However, commercialization at large scale using microalgae is a major obstacle using analytical grade growth nutrients, due to their cost effectiveness. Hence, development of a cost effective method is essential to reduce the production cost. Therefore, the present study envisaged the effect of low-cost commercial fertilizers such as urea, sodium bicarbonate, magnesium sulfate, potash and di-ammonium phosphate as growth nutrients for the production of biomass and total lipid of Botryococcus braunii were made. The biomass and total lipid production were optimized using Response Surface Methodology by 2 5 Central Composite Design. The result showed 225 mg L -1 of urea, 650 mg L -1 of sodium bicarbonate, 225 mg L -1 of magnesium sulfate, 150 mg L -1 of potash and 15 mg L -1 of di-ammonium phosphate supported the algal growth with a maximum biomass and total lipid of 0.792 gL -1 dry wt.. and 260 mg L -1 dry wt.., respectively. The biomass productivity of alga B. brauniiat the above condition recorded as 0.04 gL -1 day -1 with a generation time of 1.90 days.

31-35

Authors: N. Azimi, G.D. Najafpour and M. Sadeghpoor

In this study the performance of integrated fixed film activated sludge system (IFAS) in Amol industrial wastewater treatment plant (Amol, Iran) in treatment of food industrial wastewater was investigated. In addition, kinetic coefficients were evaluated for the system. The capacity of this system was 1700 cubic meters per day; that includes different process comprising physical and biological treatment, disinfection, sludge thickening, digestion and dewatering. COD removal efficiency and kinetic coefficients including yield coefficient (Y), half saturation coefficient (Ks), maximum substrate utilization rate constant (k) and endogenous decay coefficient (kd) were evaluated. The obtained results demonstrated that except Ks other coefficient were in the normal range that was frequently reported for conventional activated sludge in the literature. The COD removal efficiency was about 98 to 99 percent. The results indicated that there is a direct relationship between the variation of kd and Ks with effluent substrate concentration; while, the relationship between rate constant (k) and effluent COD is reversed. Finally, the effect of increasing sludge retention time (SRT) on COD removal was also studied. It was concluded that COD removal increased with an increase active solid retention time to a certain point, behind that point there was no significant changes observed.

44-47

Authors: P. Hartwig

The energy demand of the wastewater treatment is contributing with a significant share to the running costs. Through optimization of the technology and the process control, the specific energy demand can be reduced to < 20 kWh/PE∙year. Only with the technology of anaerobic digestion of the sewage sludge and additional co-substrates a complete covering of the energy demand is possible. The treatment of the additional organic residues in the digester increases the specific gas production, contributes to a good economy of the wastewater treatment and solves at the same time an organic waste problem. As co-substrates a wide range of organic residues are available, like grease, residues from food production (slaughterhouse, fruit juice, diary etc.) and agricultural residues or products. Also the organic fraction of the solid waste is an effective co-substrate after a suitable pre-treatment. For application of this technology for smaller plants, a compact technology with an integrated digester has been developed (H-Batch system). Use of organic solid waste fraction as substrate (DUPLEX-technology) an energetic autarkic operation is possible for wastewater treatment plants larger than around 15,000 PE. This technology can especially been applied where the infrastructure for the waste water treatment and the solid waste treatment has to be developed at the same time.

56-60

Authors: M. A. I. Juel, S. A. Syed and T. K. Dey

Activated sludge process is feasible and extensively method used for biological treatment of sewage and industrial wastewaters. The system is usually designed based on the simplified hydraulic related parameters. But design of biological treatment system based on hydraulic considerations is not reasonable to ensure efficient treatment due to the extensive variation in the composition of wastewater and also for complex nature of biochemical reactions occurring in the treatment processes. Hence kinetic approach can be an option for appropriate design of biological treatment systems rather than hydraulic parameters considerations. The present study is aimed to develop kinetic coefficients for the treatment of chrome-tannery wastewater using activated sludge process. A laboratory-scale treatment unit subsuming an aeration tank and a clarifier were used for this system. The treatment unit was operated continuously for 80 days by varying the hydraulic retention time from 3 to 12 days. BOD for both influent and effluent as well as mixed liquor volatile suspended solid (MLVSS) of aeration tank were determined at different retention time to yield data for kinetic coefficients. The substrate utilization rate coefficient (k) was 0.624 day −1 while the half velocity constant (K S ) was 38.42 mg/L, yield coefficient (Y) was found to be 0.674 mgMLVSS/mgBOD and the endogenous decay coefficient (K d ) was found as 0.068 day -1 . These coefficients can be utilized for the rational design of activated sludge system for the treatment of chrome tannery wastewater.

67-70

Authors: Essien I. E. and Inyang, A.

The exposure level of gamma radiation and its consequent annual dose rate from the blocks faculty of sciences University of Uyo, Nigeria were investigated. An in -situ measurements of the exposure level were conducted using Radex radiation meter model RD 1212. The mean exposure measured for the different locations within the departments ranged between 0.096 ± 0.003 µSv/h µSv/h to 0.140± 0.007 µSv/h and the corresponding calculated annual dose rate (ADR ) ranged between 0.742 ± 0.021 mSv/y to 0.981± 0.049 mSv/y with department of chemistry contributing the highest value. Taking the football field as the reference site, the results show that the presence of chemicals have slightly increased the radiation level in the studied area; but not large enough for being concern as the annual dose rate is below the acceptable dose limit of 1mSv/y for the public and 20mSv/y occupational limit for personnel in the department. The area of study is new hence it is recommended that routine radiation level monitoring should be carried out for possible rise in the radiation level to be observed. For the safety, it is recommended for staff and students should spend less time indoors. The proper application of gamma rays are used for sterilization and cancer therapy.