ABC Wastewater Level 3 – Lab Questions and correct Answers

ABC Wastewater Level 3 – Lab Questions and correct Answers To have significant meaning for laboratory tests of the evaluation of a wastewater treatment plant's performance the best method of sampling is A. Grab sampling B. Hourly sampling C. Sampling during peak flow D. Proportional composite sampling E. Automatic sampling D. Proportional composite sampling BOD samples should be collected before chlorination because A. Chlorine reacts with the buffer solution B. Chlorine interferes with the activity of organisms C. Chlorine reacts with the calcium ions D. Chlorine affects the alkalinity B. Chlorine interferes with the activity of organisms A water sample is "fixed" in the field by A. Keeping the sample in a Cipolletti device B. Anchoring the container to the stream bed C. Adding chemicals to prevent the changing of water quality D. Maintaining a constant sample temperature of 95° F C. Adding chemicals to prevent the changing of water quality The best procedure for determining the SS of a plant effluent is to analyze A. A 24-hr composite sample of the effluent B. A grab sample of the effluent at high flow C. A grab sample of the effluent at low flow D. A series of grab samples taken at different times during the day A. A 24-hr composite sample of the effluent A sample obtained by taking portions of wastewater at a collection point in proportion to the flow is called A. A most probable number (MPN) B. A weighted composite C. A routine sample D. A bacterial-solids sample B. A weighted composite Settleable solids by volume are determined through the use of A. A Nessler tube B. A Kjeldahl flask C. A Gooch crucible D. An Imhoff cone D. An Imhoff cone The settleable solids test is primarily used to A. Measure the volume of solids that may be removed by settling tanks B. Determine the BOD required for treatment C. Measure the rate of decomposition of organic volatile solids D. Determine the amount of chlorine required A. Measure the volume of solids that may be removed by settling tanks The standard total SS test requires the Gooch crucible fiber glass mat and solids to be dried in the oven at A. 95° C B. 103° C C. 110° C D. 115.5° C B. 103° C The SS content of wastewater is most accurately measured by A. Filtering the sample through a specially prepared filter; drying the filter and material retained on it in an oven at 103° C; weighing the filter; and determining its added weight caused by the solids retained B. Evaporating the sample and weighing the residue C. Centrifuging the sample and measuring the volume of solids separated from the liquid D. Distilling the sample after acidification with sulfuric acid and titrating the distillate with N sodium hydroxide