Evaluation of solar powered water pumping system: the case study of three selected Abattoirs in Ibadan,Nigeria

In this paper, detailed and comprehensive analysis of the technical, environmental and economic benefits of providing adequate water supply using solar PV system for three selected abattoirs (Bodija, Akinyele and Iyana church abattoirs) in Ibadan are presented. First, an estimate of average daily water requirement for slaughtering and cleaning cattle is obtained for each of the abattoir. This was achieved through oral interviews conducted at the different abattoirs to arrive at a reliable estimate. Thereafter, the total water requirement, the water storage capacity and the electrical load requirement necessary for the sizing of solar PV system that will enhance the smooth operation of the abattoir are determined. Some of the key results revealed that the water requirements of the abattoirs are 208,780, 91,632 and 78,590 l/week, respectively. The most suitable submersible pump for the three abattoirs is 60GS50 (5hp, 60gallon/min Goulds series). The cost of pumping water and providing lighting for smooth operation of the abattoirs are $0.23, $0.21 and $0.19, respectively. The results also show that 16,300, 15,200 and 14,600 kg/yr of carbon dioxide as well as 46.37, 43.36 and 41.45 kg/yr of carbon monoxide could be avoided, respectively with the implementation of the project.     

Periodic characterization of alkyl-naphthalenes in stack gas and ambient air around a medical waste incinerator

Environmental Science and Pollution Research - Due to the subtle occurrence of environmental polycyclic aromatic hydrocarbon (PAHs) pollution from incinerators, it is seldom considered a...     

A mobile monitoring system to understand the processes controlling episodic events in Corpus Christi Bay

Corpus Christi Bay (TX, USA) is a shallow wind-driven bay and thereby, can be characterized as a highly pulsed system. It cycles through various episodic events such as hypoxia, water column stratification, sediment resuspension, flooding, etc. Understanding of the processes that control these events requires an efficient observation system that can measure various hydrodynamic and water quality parameters at the multitude of spatial and temporal scales of interest. As part of our effort to implement an efficient observation system for Corpus Christi Bay, a mobile monitoring system was developed that can acquire and visualize data measured by various submersible sensors on an undulating tow-body deployed behind a research vessel. Along with this system, we have installed a downward-looking Acoustic Doppler Current Profiler to measure the vertical profile of water currents. Real-time display of each measured parameter intensity (measured value relative to a pre-set peak value) guides in selecting the transect route to capture the event of interest. In addition, large synchronized datasets measured by this system provide an opportunity to understand the processes that control various episodic events in the bay. To illustrate the capability of this system, datasets from two research cruises are presented in this paper that help to clarify processes inducing an inverse estuary condition at the mouth of the ship channel and hypoxia at the bottom of the bay. These measured datasets can also be used to drive numerical models to understand various environmental phenomena that control the water quality of the bay.     

Estimation of “environmentally sensitive” dispersal ratios for chemical dispersants used in crude oil spill control

The toxicities of two dispersants (Biosolve and OSD 9460), Forcados light crude oil and their mixtures based on ratios 6:1, 9:1, and 12:1 (v/v) were evaluated against the juvenile stage of African catfish, Clarias gariepinus, in laboratory bioassays. On the basis of the derived toxicity indices, Biosolve (96-h LC₅₀ = 0.211 μl/l) was found to be about 27,284 times more toxic than crude oil (96-h LC₅₀ = 5.757 ml/l) and 6,450 times more toxic than OSD 9460 (96-h LC₅₀ = 1.361 ml/l). OSD 9460 was also found to be four times more toxic than crude oil when acting alone against C. gariepinus. Toxicity evaluations of the mixtures of crude oil/dispersants mixtures varied, depending largely upon the proportion of addition of the mixture components. The interactions between mixture of crude oil and Biosolve at the test ratios of 6:1, 9:1, and 12:1 were found to conform with the model of synergism (SR = 7,655, 14,876, and 8,792, respectively), and the mixtures were therefore more toxic than the crude oil acting singly. Similarly, the interactions between mixture of crude oil and OSD 9460 at the test ratios of 6:1 and 9:1 also conformed to the model of synergism (SR = 2.2 and 1.84, respectively). Interactions between the dispersant OSD 9460 and the crude oil at test ratio 12:1, however, conformed to the model of antagonism (SR = 0.84), indicating that the mixture was less toxic than crude oil acting alone. The results of the emulsification potential of OSD 9460 and Biosolve [measured in terms of optical transmittance (%)] prepared at the dispersal ratios 6:1, 9:1, and 12:1 revealed that the dispersal ratio of 6:1 achieved the highest emulsification of the crude oil with optical transmittance value of 4% and 6%, respectively. Estimation of an “environmentally sensitive” dispersal ratio for OSD 9460 and Biosolve revealed the optimum dispersal ratio for OSD 9460 range between ratios 7.5:1 and 9:1, while for Biosolve such an optimum dispersal ratio was indeterminate within the range of test dispersal ratios. The implications of these results in setting manufacturer’s and regulatory dispersal ratios for chemical dispersants used for oil spill control were discussed.