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This paper utilizes a statistical approach, the Taguchi optimization methodology (L16 orthogonal array), to determine the optimum conditions for the orange-G (OG) dye removal from aqueous solution by electrocoagulation (EC) using iron plate electrodes. The experimental parameters investigated were initial dye concentration (C0): 50-200 mg/l; initial pH (pH0): 2-8; supporting electrolyte (NaCl) concentration (m): 0-1.5 g/l; electrode gap (g):1-2.5 cm; and applied voltage (Vap): 6-24 V. These parameters were varied at four levels to see their effects on the removal efficiency (RE). Vap was found to be the most significant factor with a 24.6 percent contribution, followed by parameter C0 with 20.2 percent contribution to the RE. The predicted optimum value of RE for C0 = 200 mg/l was found to be 84.9 percent. Confirmation experiments have been performed to prove the effectiveness of the Taguchi technique after the optimum levels of process parameters are determined.

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Falling film towers are popular in process industries due to moderate air side pressure drop, less energy ingesting liquid distribution and easy cleanup features. Two major limitations of falling film towers are the uneven distribution of liquid across solid surfaces (maldistribution) and contraction of falling liquid film on the solid surface (poor wetting). Maldistribution of liquid is primarily dependent on the type of liquid distributor and scope of liquid flow (slit opening) across solid surfaces. In the current communication; the influence of liquid distributor on maldistribution problem of vertical plate falling film tower has been experimentally investigated. Four types of liquid distributors: plain tube, spray nozzle, perforated plate, and branch tube distributor have been tested. Effect of parameters: slit opening, liquid flow rate and the number of plates on maldistribution are also explored. It is found that branch tube distributor is best suited for vertical plate falling film tower application.

Plastics as air-liquid desiccant contacting surfaces are being explored as a promising alternative to metallic surfaces in falling film towers. Nevertheless, poor wetness of plastic has severely restricted its extensive practical applicability. In the current experimental study, surface modification technique is employed to enhance the dehumidification performance of single polypropylene plastic plate surface. Dehumidification ability of three kind of plastic plate surface: Plain PP plate, Modified PP plate A and Modified PP plate B were investigated and compared in an adiabatic vertical falling film tower. It was found that the best Modified PP plate offered 48.1 - 127.0% improvement in dehumidification effectiveness as compared to the Plain PP plate with an average improvement of 83.3%. Furthermore, a new correlation is developed to predict the dehumidification effectiveness of plastic and metallic surfaces of adiabatic/non-adiabatic falling film tower by incorporating the wetting factor and sensible cooling information in the correlation equation. The new approach takes into the account the sensible cooling (non-adiabatic absorber) of the desiccant solution in the upper half of the absorption column. The proposed correlation demonstrates excellent accord with eleven experimental datasets, with an average error of 12.7%.