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

CHAPTER FOUR 4.0 EQUIPMENT AND METHOD

4.1 EFFLUENT SAMPLE COLLECTION

4.1.1 BREWERY EFFLUENT COLLECTION Brewery effluent sample was collected from Nigeria Brewery in Enugu using a 25 liters Jerrican in July, 2009. The jerrican was filled to the brim with the brewery effluent in order to expel entrapped air within the jerrican. It was then corked and was left sealed until the commencement of the analysis (wright et al,1993). Preservatives were added before corking as required by the test method (APHA and AWWA, 1985) in order to avoid microbial action leading to chemical changes in the sample for the characterization.

4.1.2 COAL EFFLUENT COLLECTION Coal effluent sample was collected from Akwuke coal mine, Enugu, using a 25 liters jerrican in July, 2009. The jerrican was filled to the brim with the coal effluent in order to expel entrapped air, was corked and remained sealed until the commencement of the analysis (Wright et al, 1993). lxxv Preservatives were added before corking as required by the test method (APHA and AWWA, 1985) in order to avoid microbial action, leading to chemical changes in the sample for the characterization.

4.2 JAR TEST PROCEDURES

4.2.1 EQUIPMENT The equipment used in the coagulation flocculation study were:
a)Turbidometer
b)pH meter
c)Six- 1 litre beaker
d)Laboratory stirrer
e)Alkalinity measurement kit
f)Alum
g)Caustic acid
h)Sulphuric acid
i). mucuna pruriens

4.2.2 COAGULATION-FLOCCULATION EXPERIMENTAL PROCEDURES (JAR TEST) FOR DOSAGES AND PH VARIATIONS FOR BREWERY EFFLUENT.

This experiment contained a coagulation reaction of a control coagulant,. Alum and mucuna pruriens coagulant . Coagulation and flocculation of brewery effluent was performed using bench scale jar test. Suspensions were mixed using a stirrer. 2 minutes of rapid mixing, 15minutes of slow mixing and 30 minutes of settling followed. Coagulants (Alum and mucuna pruriens) were added at the beginning of the rapid mixing. During settling, the sample was withdrawn using pipette from 2cm depth to analyze their concentration. Coagulation pH was not adjusted during the jar test. Two types of measurements were performed. The first type was to determine the effects of coagulant dosage and coagulant mix during the coagulation and flocculation of the brewery effluent. The second was to determine the effect of variation with time during the coagulation process. The brewery effluent sample was immediately turned into calibrated beakers where they settled and readings of different concentrations were taken at different time intervals of 3,5,10,20,25 and 30 minutes. The same experiment was repeated 5 times with increasing dosages of Alum /MUC ratio (e.g 100 MUC/1000 Alum = 0.1) at different pH of 2,4,6 8 and 10 to know the effects of varying dosages and pH at the different time intervals. All the jar tests done were performed at the temperature of 28 + 20c using 200ml of brewery and coal effluents.

4.2.3 TURBIDITY MEASUREMENT Turbidity is a cloudy appearance of water caused by small particle suspended in it. Its analysis was conducted using a turbidity measuring instruments (a turbidometer) using the nephelometric standard method. The turbidity of the samples were measured using the insetting samples contained in a tube.

4.3.4 DETERMINATION OF THE pH VALUE

The different pH level of the different effluent was measured using a Delta 320 pH meter. The instrument was first calibrated with solutions of known pH. Two point calibration method was adopted in which two buffers of pH 4.01 at 25-30oc and 7.0 at 25-30oc were selected for calibration. After calibration, the pH of the sample (brewery effluent) was measured by dipping the probe containing the effluent sample at different time intervals (2,4,6,8,10 minutes).

4.2.5 DETERMINATION OF THE CONCENTRATION OF THE EFFLUENTS FOR COAGULATION PROCESSES. The concentration of the different effluent was measured by multiplying the turbidity got in NTU by 2.35 (Metcalf at al,2009).The concentration unit was converted to mg/l.

4.3 ADSORPTION EXPERIMENT

4.3.1PUMPKIN SEED ADSORBENT COLLECTION Pumpkin seeds were collected from Eke-Awka market, Awka. Anambra state. The seed were sun-dried for days, opened and the chaff of the inner seed removed. The seed shell of the pumpkin seeds were grinded with a manual grinding machine into granulated forms ready to be activated. The weight was taken and recorded.

4.3.2 PREPARATION OF PUMPKIN SEED
1). The pumpkin seed shells collected were grinded into smaller sizes to pass through a 3mm sieve and retain in a 1.5m sieve.
2). The raw material sample was weighed to be 608.70g .
3) 302g of pumpkin seed shell sample was weighed out and impregrated with equal amount of prepared acid solution i.e. 60% phosphoric acid. The mixture was turned with a glass rod to mix well and left for 24 hours for proper impregnation.
4). Likewise, 302g of the remaining pumpkin seed shell sample was impregnated in another prepared base solution (60% NH4Cl) and stirred also using a glass rod. It was left for 24hours.
5). At the end of the 24 hours, the mixtures were drained and dried separately in an oven operating between 60c-80oc for about 4 hours. lxxix 6). The seed shells were carbonized using a muffle furnace and burnt at 500oc for 2 hours (holding time). The furnance - make was KGYV BUDAPEST (KOHASZATI GYAREPITO VALLALAT BUDAPEST). The carbonization was done at SEDI, Scientific Equipment Development Institute, Enugu. Carbonization caused the samples to be porous and these pores helped adsorption to be achievable.
7). The carbonized samples were allowed to cool and then washed with distilled water until the tested pH of the water washed out became neutral or nearly neutral.
8). The samples were dried at 105oc for 4 hours and stored in air tight containers separately.
9). The samples were weighed again separately. 152g of activated acid pumpkin seed shells and 167g of activated base pumpkin seed shells were obtained.

4.3.3 PROCEDURE FOR PREPARATION OF 60% ACID (N3PO4) AND 60% BASE (NH4Cl) USED FOR IMPREGNATION.

A). Preparation of phosphoric acid:
1). 1.7g of H3PO4 was prepared per mole of the acid.
2). 57.64ml of H3PO4 was dissolved in 1000cm3 (1litre) of distilled water.
3). 400cm3 of the dissolved H3P04 was removed from (2)above and the remaining 600cm3 of the dissolved H3P04 was diluted using 1000cm3 of distilled water to get the required 60% solution of H3P04. 4). Grounded pumpkin seeds was then impregnated with the 60% of diluted H3PO4 .

B). Preparation of Ammonium chloride (NH4Cl)
1). 53.49g of NH4Cl was measured out.
2). It was dissolved in 1000ml of distilled water using a measuring cylinder.
3). 400ml of the dissolved NH3Cl was removed and stored in an air tight container.
4). The remaining 600ml was diluted up to 1000ml of NH4Cl solution distilled water. This gave a 60% diluted solution of NH4Cl.
5). The 60% diluted solution of NH4Cl was used to impregnate the grounded pumpkin seed shells.