Abstract: The sweet whey resulting from cheese production is the most
polluting among all types of dairy waste waters given that it contains a huge
quantity of organic biodegradable matters. In this study, we realize a
physicochemical treatment of sweet whey, by coagulation-flocculation using
aluminum sulphate as a coagulant and sodium alginate as flocculent and a
biological treatment in suspension, using Pseudomonas fluorescens and Bacillus spp. The physicochemical treatment by coagulation-flocculation has reduced 33%
of the chemical oxygen demand, 45% of the turbidity, 72% of suspended matter
and 20% of total phosphorus. The biological treatment has reduced considerably
all the studied parameters; the organic charge determined by the chemical
oxygen demand (COD) has received a very significant reduction upto 90% using
Pseudomonas fluorescens during 20 days. On the other side, the biological
treatment realized with Bacillus spp. was less effective, reduced the COD with
54% under the same conditions of the treatment by Pseudomonas fluorescens and
for the same period. But these two bacteria are equally effective in reducing
the total nitrogen TN (92% reduction/20 days). This work presents a biotechnology for the treatment of sweet whey. It's an economic
method, simple and environment friendly.
