Quality appraisal of effluent from Unayzah City wastewater treatment plant for irrigation reuse

الملخص EN

The suitability of the sewage effluent from Unayzah City (Central Region of Saudi Arabia) wastewater treatment plant for irrigation reuse was assessed during four consecutive years by considering some of its physico- chemical and microbiological characteristics.

Processing of the available data and thereafter comparing them with the locally and internationally acceptable quality standards for unrestricted and restricted irrigation reuse revealed that 1) (he expected yearly average volume of treated wastewater varies from 26.4 x 10s to 36x I05 in\ 2) the effluent under study is marginal with respect to its mean BOD level range (range: 14.3-17.8 mg/L) and mean total suspend- ed solids contents (range: 23.3-25.3 mg/L).

3) electric conductivity (EC) mmhos/cm and pH-value of effluent are within the acceptable quality limits and are not expected to cause severe problems, 4) high total coliform count (48.2 x I02- 137.9 x 102 MPN/100 ml) was evident inspite of achieving between 99,92-99.96% mean removal efficiency which renders the effluent unacceptable for unrestricted irrigation reuse bccause of public health hazards aspects.