1Sewers are designed to have self-cleansing velocity to:APrevent deposition of solidsBIncrease pressureCReduce slopeDSave pipesView AnswerDiscussWorkspaceReportSaveEasy
2The activated sludge process is a:APhysical screeningBDisinfectionCBiological (secondary) treatmentDPrimary treatmentView AnswerDiscussWorkspaceReportSaveEasy
3COD measures:AOxygen needed to chemically oxidise organic matterBTurbidityCBiological oxygen use onlyDHardnessView AnswerDiscussWorkspaceReportSaveEasy
4BOD measures:AColourBpHCTotal solidsDOxygen needed by microorganisms to decompose organic matterView AnswerDiscussWorkspaceReportSaveEasy
5An oxidation pond treats sewage using:AFiltersBChemicals onlyCBacteria and algae in a symbiotic relationshipDUltraviolet lampsView AnswerDiscussWorkspaceReportSaveEasy