PERFORMANCE EVALUATION OF A DEVELOPED PADDLE AERATOR ON CATFISH EFFLUENTS IN LAGOS STATE, NIGERIA

Catfish production is one of the largest segments of fish culture in Lagos State, Nigeria. However, catfish effluents, which usually deteriorate the environment, need to be controlled. The effect of paddle-wheel aerator in catfish effluent was evaluated. The volume of catfish effluent was collected into two basins and diluted at given ratios. The paddle-wheel aerator was installed in one basin, while another basin served as control in determining the impact of paddle wheel aerator on catfish effluents. Water qualities such as Total Suspended Solids (TSS), Total Nitrogen (TN), Total Phosphorus (TP), Total Ammonia (TNH3) and Nitrite (NO2-N) and Biochemical oxygen demand (BOD5) examined and ana-lysed. Results indicated that paddle-wheel aerator reduced TSS (24.4±1.5 %), TN2-N (53.3±1.2 %) , TNH3-N (65.2±1.2 %) , NO2-N (97.1±1.1 %) , TP (61.8±1.1 %) and BOD5 (54 ±1.5 %). com-pared with natural purification 33.9±1.6 % of TSS, 22.7±1.4 % of TN2-N, 29.3±1.6 % of TNH3-N, 53.9±1.2 % of NO2-N, 21.6±1.5 % of TP and 15.4±1.6 % of BOD5 at the same dilution ratio There were significant different (P ≤0.05) between paddle wheel aerator and natural purification in concen-trations reduction. The paddle wheel aerator was found to be relevant in the water quality improve-ment and thus recommend for small and medium scale fish farmers in controlling effluents

Perkembangan Desain dan Kinerja Aerator Tipe Kincir

Paddle wheel aerator widely used in aquaculture because it has the function of aeration and circulation as well as their construction is simple. However, its efficiency is not maximized so it is still expensive inoperation because of the large power consumption. Aerator performance is an important factor in the selection and use of the aerator as it relates to investment and operating cost, so the paddle wheel aeratordesign development and improvement of the performance of the operation is still possible to do. Developing of three-dimensional blade with the optimum geomerty and blade development that can move is a solution that can be done. The study aims to review the principle of aeration, performance test, evaluation criteria, and performance comparison aerator design development that have been made so as to provide an alternative to the developing of performance improvement paddle wheel aerator. This article is a summary of the ''state of the art'' design and performance of a paddle wheel aerator development

Optical paddle-wheel

As an optically trapped micro-object spins in a fluid, there is a consequent flow in the fluid.. Since a free-floating optically-driven microrotor can be moved to a desired position, it can allow the controlled application of a directed flow in a particular location. Here we demonstrate the control and rotation of such a device, an optical paddle-wheel, using a multiple-beam trap. In contrast to the usual situation where rotation is around the beam axis, here we demonstrate rotation normal to this axis

Electronic paddle-wheels in a solid-state electrolyte

Solid-state superionic conductors (SSICs) are promising alternatives to liquid electrolytes in batteries and other energy storage technologies. The rational design of SSICs and ultimately their deployment in battery technologies is hindered by the lack of a thorough understanding of their ion conduction mechanisms. In SSICs containing molecular ions, rotational dynamics couple to translational diffusion to create a 'paddle-wheel' effect that facilitates conduction. The paddle-wheel mechanism explains many important features of molecular SSICs, but an explanation for ion conduction and anharmonic lattice dynamics in SSICs composed of monatomic ions is still needed. We predict that ion conduction in the classic SSIC AgI involves 'electronic paddle-wheels,' rotational motion of lone pairs that couple to and facilitate ion diffusion. The electronic paddle-wheel mechanism creates a universal perspective for understanding ion conductivity in both monatomic and molecular SSICs that will create design principles for engineering solid-state electrolytes from the electronic level up to the macroscale.Comment: 6 pages, 3 figure

Synthesis and characterization of three new Cu(II) paddle-wheel compounds with 1,3-benzodioxole-5-carboxylic acid

Three different paddle wheel compounds have been synthesized, each one via a different synthetic pathway. The first method is the reaction of Cu(MeCO2)2 H2O with 1,3-benzodioxole-5-carboxylic acid (Piperonylic acid, HPip) in a MeOH solution, yielding [Cu(m-Pip)2(MeOH)]2 (1). The second method is the transformation of the heteroleptic core paddle-wheel compound [Cu(m-MeCO2)(m-Pip)(MeOH)]2 into the homoleptic core paddle-wheel [Cu(m-Pip)2(DMSO)]2 2DMSO (2). Lastly, the third method is the substitution of the solvent molecule (DMF) present in the molecular array [Cu(m-Pip)2(DMF)]2 by 2-benzylpyridine (2-Bzpy) ligand, resulting in [Cu(m-Pip)2(2-Bzpy)]2 2.5MeOH H2O (3a). All compounds are characterized via EA, PXRD, ATR-FTIR, Far-IR and UV-Vis spectroscopy. For all three compounds, the X-ray crystal structure has been determined and their extended structures are discussed. Finally, TG/DTA measurements have been recorded

OXYGEN INCREASE ON MODIFIED PADDLE WHEEL OF MARINE AND FISHERIES POLYTECHNIC OF SIDOARJO

One type of aeration device is a paddle wheel which is the most common aerator used for aquaculture ponds (Wyban et al. 1989; Moore & Whitis 1999; Laksitanonta et al., 2003). The aeration rate is influenced by the surface area of water and air contact, the difference of oxygen concentration, coating film coefficient and turbulence (Boyd 1998) The geometry, and speed of the spin mill affect aeration performance (Peterson & Walker 2002; Moulick et al., 2002). Aerator performance is an important factor in the selection and use of aerators as they relate to investment and operational costs, so that the development of aerator design and improved operating performance is still possible to do. The purpose of this research is to know the comparison of paddle wheel performance result of modified design versus paddle wheels manufacturer. The research was designed with 2 (two) different types of paddle wheel which is the treatment of 1 (one) paddle wheel from the modified of construction design with a power of 0.37 kwh-1 0.5 hp and the treatment of 2 (two) artificial paddle wheel from manufacturer with 0.78 kwh-1 1 hp. Statistical analysis use T-test. The results of research is modified Paddle wheel (Treatment 1) was increased of DO = 2.56 ppm; Coverage area = 418929,6 cm2; diameter bursts= 132.2 cm. Conventional paddle wheel performance (treatment 2) was increased of DO = 2.54 ppm; Coverage area = 41983,8 cm2; The diameter of the bursts is 130.2cm. The t test results (statistic) on all variables showed no significant different (p= 0.595). This means the performance of the modified paddle wheel with 0.37 KWh-1 0.5 hp one phase is the same as the conventional paddle wheel performance with 0.78KWh-1 1 hp two phase power but there are energy saving 0.41 KWh-1

Coordination chemistry of perhalogenated cyclopentadienes and alkynes. 8. Pentakis(dimethylsilyl)cymantrene

Starting from [q5-C5Br5]M n(CO),, the first r-complex of a cyclopentadienyl ligand with five silyl substituents, [q 5-C5(SiMe2H)5M] n(CO),, was prepared by a series of halogen-lithium exchange reactions, followed by silylation with SiMe2HCI. The crystal structure determination of this compound shows a highly symmetrical "paddle wheel" orientation of the five silyl groups around the cyclopentadienyl ring

Oxygen Transfer Rate Efficiency of Paddle Wheel Aerators in Intensive Shrimp Ponds

The purpose of this study was to determine the oxygen transfer rate efficiency of paddle wheel aerators in intensive shrimp farming. This study was conducted with the causal ex-pose facto concept by comparing the performance of paddle wheel aerator. The results showed that water quality in Pond 1 (1 HP) and Pond 2 (2 HP) only brightness which do not comply with water quality standards. The oxygen transfer rate paddle wheel aerator was 1 HP of 3.20 (2.82-3.65) mgO2/hours and for 2 HP of 2.12 (1.68-2.89) mgO2/hours. The dissolved oxygen in Pond 1 (1 HP) was 5.25 mg/L and Pond 2 (2 HP) was 5.63 mg/L. The shrimp growth rate in pond 1 is 1.95 (0.01-4.0 gr/day) and pond 2 is 1.25 (0.01-2.55 gr/day). Dissolved oxygen in pond 1 (1 HP) ranged from 4.15-7.26 mg/L and pond 2 (2 HP) ranged from 4.03-8.31 mg/L. Dynamic modeling results show a description the energy input to paddle wheel aerator will gradually decrease from 2 kW to 0.25 kW. The results of this study concluded that the use of a 1 HP paddle wheel aerator has a better oxygen transfer rate and shrimp pond performance than using a 2 HP paddle wheel aerator

Vorticity associated with multiple jets in a crossflow

Vortex patterns from multiple subsonic jets exiting perpendicularly through a flat plate into a subsonic crossflow were investigated. Tandem and transverse jet configurations were examined using a paddle wheel sensor to indicate the presence and relative magnitude of streamwise vorticity in the flow. Results are presented in the form of contour plots of rotational speed of the paddle wheel as measured in planes downstream from the jets and perpendicular to the crossflow. Well developed diffuse contrarotating vortices were observed for the configurations studied. The location and strength of these vortices depended on the multiple jet configuration and the distance downstream from the jets