Effect of Calcium Hydroxide and Poly Aluminum Ferric Chloride Concentration on Water Quality Parameters of Meat Processing Plant Effluent
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Date
2013
Journal Title
Journal ISSN
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Publisher
Uva Wellassa University of Sri Lanka
Abstract
As long as the world population continues to grow and demand for food products increase, there
are number of environmental and health issues arising. Treatment of both solid wastes and
waste water from the meat processing industry has been one of the greatest concerns of the
worldwide agro industrial sector, mainly due to the restrictions that international trade
agreements have imposed regarding their use and their environmental issues. Many types of
substances, when discharged into a receiving body of water, degrade the water quality to such
an extent that beneficial uses of the stream are no longer attainable. Normally meat processing
plant discharges waste water with high biochemical oxygen demand (BOD), chemical oxygen
demand (COD), total suspended solids (TSS), total dissolved solids (TDS), fat and grease
content, turbidity and electrical conductivity (EC). Therefore, waste water should be properly
treated before discharging in to the natural water body. Sedimentation and flocculation is one of
the waste treatment methods which can be used to maintain water quality parameters within
acceptable limits. Poly Aluminum Ferric Chloride (PAFC) is an efficient and cheap flocculent
used to treat industrial effluents. However, the efficiency of PAFC is affected by the pH of
waste water. Calcium Hydroxide (Ca(OH)2) is one of the alkaline commonly used to maintain
pH of waste water (Hammer, 2009). Hence, this research was carried out to determine the
appropriate dose of Ca(OH)2 and PAFC for the effluent treatment plant of a meat processing
factory.
Methodology
The current study was carried out at the effluent treatment plant (ETP) of the Gills Food
Products Private Limited, Wattala. Laboratory analysis was completed at the chemistry
laboratory of Uva Wellassa University. First, ETP was studied well to decide the parameters
that need to be changed in order to meet water quality parameters of treated effluent with
Environmental Protection Agency (EPA) standards. Selected parameters (dose of Ca(OH) 2 and
PAFC) were changed in two separate stages of ETP. Amount of Ca(OH)2 (Ca = 54.092 %
(w/w)) was changed at first retention tank and amount of PAFC (Al2O3 = 29 % (w/w), Fe = 4.5
% (w/w)) was changed at the clarifier of the ETP. Laboratory scale preliminary trials were
conducted (jar test) to select the effective range of chemicals.
Laboratory scale preliminary trials were used for selecting effective weight ranges of two
chemicals. The amount of Ca(OH)2 were changed as; 5 kg and 7 kg. The selected amounts of
PAFC were 1 kg, 3 kg and 4 kg. Accordingly, there were six treatments as; 5 kg of Ca(OH) 2 and
1 kg of PAFC (T1), 5 kg of Ca(OH)2 and 3 kg of PAFC (T2), 5 kg of Ca(OH)2 and 4 kg of PAFC
(T3), 7 kg of Ca(OH)2 and 1 kg of PAFC (T4), 7 kg of Ca(OH)2 and 3 kg of PAFC (T5) and 7 kg
of Ca(OH)2 and 4 kg of PAFC (T6). Existing amounts of chemicals were used as the control (4
kg of Ca(OH)2 and 2 kg of PAFC). These combinations were changed once a week. Selected
weight of Ca(OH)2 and PAFC were measured using an analytical balance (IND 221, china) and
it was dissolved in 20 L of distilled water at ambient temperature. Ca(OH) 2 and PAFC solutions
day of the week. The rate
of adding chemicals was 150 mL per hour. Water samples were collected at 4 locations of the
ETP. Those are discharge point from the factory, first collection tank, clarifier and final
discharge point. Collected water samples were used to analyze COD, BOD, Dissolved Oxygen
(DO) level, TSS, TDS, Turbidity, EC, pH, temperature and color absorbance for determining
the effluent quality for each treatment. A Complete Randomized Design (CRD) was used for the
experiment. Analysis of variance was followed by a mean separation procedure using Duncan’s
Multiple Range test. Analyses were performed using SAS (SAS institute Inc., Cary, NC, USA).
The data obtained were analyzed at 0.05 level of significance.
Description
Keywords
Animal Sciences, Food Science, Food Technology, Meat, Meat Production, Waste Water Treatment