Studies On The Treatment Of Coal And Brewery Wastewater Using Adsorption And Coagulation– Flocculation Techniques

4.3.4 ABSORBANCE MEASUREMENT USING SPECTROPHOTOMETER

1. The spectrophotometer was set at 570 (wave length) which corresponded to the colour of the original solution of the effluent.

2. The curvette was filled to the level that the spectrophotometer could measure.

3. The measurement/reading shown by the spectrophotometer at different time intervals were taken as the absorbance (A) at the chosen time intervals.

4.3.5 BATCH ADSORPTION EXPERIMENT MEASUREMENTS

Five samples of activated acid pumpkin seed shells were measured out into five separate 200ml beakers in different quantities (o.2g, 0.4g, 0.6g, 0.8g, 1.0g). The particle sizes of the adsorbent ranged from 0.6mm- 1.0mm.Quantities of the brewery effluent were poured into the five beakers and the different quantities of the acid activated carbon were poured into the effluent-containing beakers. The five beakers were labeled A (0.2g), B(0.4g), C (0.6g), D (0.8g) E (1.0g). Also five magnetic stirrer tubes were labeled after the beakers and the effluent in each beaker containing different measurements of activated carbon were poured into the corresponding tubes.

The tubes were placed inside the spaces (holes) made out for them in the magnetic stirrer which was later covered and turned on. The mixtures were mechanically shaken at room temperature in the magnetic stirrer for a given time interval (5,10,15,20 - - -,60 min) after which it was stopped. The five different solutions were poured back into their corresponding named ,cleaned beakers which now contained a folded lxxxii filter paper (Whatman filter paper,cat no 1001 110,110mm) to filter out the adsorbent. The resulting effluent was poured into the curvette of the spectrophotometer and the rate of absorbance measured at room temperature. The various pH was taken at room temperature before and after the batch adsorption to ascertain the pH change. This experiment was repeated for base impregnated activated carbon with coal effluent.

4.3.6 THERMODYNAMIC STUDY

In the thermodynamic study, 1g of the adsorbent was prepared in 3 different beakers. A known volume of effluent water was collected and its initial concentration taken using the spectrophotometer. These beakers were shaken for a contact time of range between 5-60minutes at 100 rev/min, using a magnetic stirrer. The third beaker was used to test the concentration of the effluent at the different temperatures of 30oc, 35oc and 40oc. After each experiment, at the chosen temperature and time, the solute (adsorbent) was filtered using a filter paper and the final concentration of the effluent was taken. This was done using the acid and base adsorbents and the two different effluents.