Wastewater discharge contains a high level of contaminants that require sufficient
treatment for further reuse and legitimate applications. This study examined the effect of
seasonal variations on treatment performance, and data was generated at duration of one
year on a monthly basis. Generally, physicochemical and microbial parameters in the
wastewater retain better performance in spring and autumn than summer and winter. In this
work Pseudomonas putida was isolated, identified, examined for its role in biodegradation
of organic matter and wastewater treatment and the isolate showed potential to improve the
BOD, COD, TSS. The results indicated that the treatment of wastewater for effluent was at
acceptable level according to national regulations. The range of parameters of treated
effluent during Autumn and Spring is better than Summer and Winter. The highest BOD
after chemical treatment (DAF) was recorded during Spring which also gives the highest
ratio after Chemical treatment (DAF) and after biological treatment (Effluent). The highest
COD after Chemical treatment (DAF) was recorded during Spring which also gives the
highest ratio after Chemical treatment (DAF)/ after biological treatment (Effluent). COD
and BOD values were significantly different among Autumn, Spring and Winter as the P
value < 0.05. Total Suspended solids (TSS) results indicated that the Effluent highest values
were during Summer. While the Effluent lowest values of regional average were scored
during Spring. Volatile Suspended Solids (VSS) results indicated that the DAF highest
values were during Autumn. While the DAF lowest values were scored during Spring. The
Effluent lowest Total phosphorous value was during Autumn. The Effluent lowest Oil &
grease values were during Autumn. The Effluent lowest values of Settleable solids were
during Spring. The Highest log10 number of total bacterial count and bacterial count by
membrane filter methods were recorded in the sequencing batch reactor tank (SBR)
(Aeration tank) after chemical treatment and this stage is considered the reactions phase of
bacterial biological treatment.