Phillips, Joseph M.

English

University of Central Florida (UCF): STARS (Showcase of Text, Archives, Research & Scholarship)

University of Central Florida STARS Retrospective Theses and Dissertations Spring 1972 A Proposed Approach to Protect Wastewater Biological Treatment Plants Against Toxic Contaminants Joseph M. Phillips University of Central Florida  Part of the Engineering Commons, and the Environmental Sciences Commons Find similar works at: https://stars.library.ucf.edu/rtd University of Central Florida Libraries http://library.ucf.edu This Masters Thesis (Open Access) is brought to you for free and open access by STARS. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of STARS. For more information, please contact STARS@ucf.edu. STARS Citation Phillips, Joseph M., "A Proposed Approach to Protect Wastewater Biological Treatment Plants Against Toxic Contaminants" (1972). Retrospective Theses and Dissertations. 29. https://stars.library.ucf.edu/rtd/29 A PROPOSED APPROACH TO PROTECT WASTEWATER BIOLOGICAL TREATMENT PLANTS AGAINST TOXIC CONTAMINANTS ~··· ... ; . ) BY JOSEPH M. PHILLIPS, JR. ·. A Research Report Presented in Partial Fulfillment of the Requirements for the Degree Master of Science in Environmental Systems Management FLORIDA .TECHNOLOGICAL UNIVERSITY June 1972 I. II. III. IV. v. VI. TABLE OF CONTENTS THE PROBLEM TOXIC LEVELS APPROACH TO SOLUTION RECOMMENDATIONS • • • • • • • 4t • • 0 • Determine Toxicity Levels for Particular Bacteria Obtain Instrumentation to .Monitor and Detect Toxic Haterials Install Holding Tanks or .Ponds Modify Plant for Alternate .Methods of Treatment Contract for Disposal of Untreated Wastes Installation Schedule Haintenance and Toxicity Level Redetermination Review Instrumentation Market Periodically CONCLUSIONS • • REFERENCES . . . . . . . . · iii 1 3 5 7 12 1838 1 I. THE PROBLEM Today the majority of municipal secondary wastewater trea tment plants in the United States utilize s ome form of biological t reatment, the two most common forms being trickl i ng filter s and activated sludge systems. But the bacterial action is subject to a reduction or even cessation due to the presence of toxic substances in the wast ewater. As. W. Wesley Eckenfelder, Jr. said,. "Since a one-shot dose of certain toxic . materials can completely upset a biological trec:.tment process, . " (1), it 'tvould be desirable for operators of such sys -terns to be able to safeguard their systems against being subj ec t ed to such conditions. However, in most texts on wastewater treatment, sewage systems, etc., the only mention of the subject is normally a statement to the effect that toxic materials should not be allowed to enter the waste-water collection system! This certainly is an ideal solution but is not always achievabl nor is an acceptable answer to an operator with tox ic substances already affecting his biological treatment faciliti es .. On the other hand, some texts .i gnore the pr oblem t o the extent that the words tox icity or t oxic materials do not ev en appear in the . index or table of contents (2). The situation v7as perhaps beBt summarized by an observation . in the Water Pollution Control Federation Journal (3) as follo'tvs : 2 Information Gap On Toxic Metals Noted. A recent University of North Carolina Workshop on the presence and effects of toxic metals in water underscored the need for more information on this subject. The conference, which was sponsored by the Water Resources Research Institute and included industrial, public, and academic representatives, -was concerned primarily with the status of knowledge relating to North Carolina waters. But the conclusions were basic enough to have broad implications: present monitoring programs are unsatisfactory; sufficient information on toxic metal use is unavailable; there is no coordination point for information; and maximum safe limits for drinking water are unknown. Although agreeing that the .subject of toxic materials in wastewater has been neglected; . ignored ·, or just "swept under the carpet," a search of the literature has been conducted in an attempt to gain some insight into the problem· and hopefully to suggest some steps that might lead to a solution to the problem . • :'>' ...... . "" .. ~, .. I ~ ~-~· ~~.·: 0 .-t ~==~F===============================================~-=======~== 3 II. TOXIC LEVELS Almost all references to toxicity levels in the literatur e are concerned with survival of small fish in flowing streams. However a few levels of toxicity for bacteria found in trickling filters and activated sludge systems were found and can give an indication of the toxic level for a particular combination ·of bacteria at one point in time for that observed system. Material Cyanide Mercury Mercury . Copper Copper Chromium Chromium Chromium Phenols Toxic Level 0.5 mg/1 0.1 mg/1 >0.2 mg/1 5 mg/1 10 mg/1 0.5 mg/1 ~.0 mg/1 <50 mg/1 high concen-tration TABLE .. l Remarks Severe inhibition (4) Some biological inhibition (5) Essentially no oxygen uptake (5) Slight inhibition (5) Complete retardation (5) Somewha·t inhibitory (5) Very toxic (5) No significant reduction in eff i ~iency , in pilot scale activated sludge plant (6) Completely knock out bacteria (7) Also, some general sta t ement s on toxicity were fo und , such as : ''Copper-bearing wastes are biologically toxic, precluding biological methods of trea t ment in t he. handling of these wastes" (8); "roxie com-pounds and metals may be present in sewage, especially industrial 4 waste. These include phenols and aldehydes as well as hexavalent chromium, copper, cadmium, tin and nickel. Above certain thresholds, they are toxic to bacteria .•. " (9); "Due to the large number of .. -variables encountered in such tests, no limits for precision and accuracy are given." (10); "Specially adapt~d bacteria can metabolize the phenols, but it is best to avoid use of phenols." (11); and "Heavy metals exhibit a toxicity in ow concentrations to biological sludges." (12); "Among the toxic organic compounds are the pes ticides used to kill insects, rodents and weeds." (13). ·. . I ... ,·· ·.· ,I "'====#===========================- =====tF=== 5 III. APPROACH TO SOLUTION The levels of toxicity certainly point out that the standard solution to this problem, i.e. don't let it get into the collection system!! would be nice but we have acknowledged the possibility of the occurrence of toxic materials in the wastewater. But ,.,hat about the approach of not letting the liquid waste containing the lethal (to bacteria) concentration of toxic material enter the treatment plant except under programmed conditions? · . If the presence of greater than desired levels of toxic materi~ can be detected at a point sufficiently far enough upstream from the treatment plant, the influent to the plant could be diverted to a hold-ing tank or pond. The diversion would continue until the concentration of toxic material was below the minimum desired level. It is a recognized fact that the most desirable method of oper-ating a waste treatment plant is at a constant flow, (14) and this diversion of flo'v for some period of time violates that concep t. How-ever, after flow was resumed, the bacteria 'would still be ali...-e and able to resume their work rather than being dead as a result of the continuous flow carrying the toxic substances to them. After diversion to the holding tank or pond, tests vmuld be made to determine the specific toxic material and its concentration. When this determination is completed, there are three courses of action which might be followed . 6 The simplest is to mix the toxic waste with the normal waste water influent to the treatment plant at a rate which dilutes it to a level at which the bacteria can assimilate it during the regular method of treatment. The second course of action which might be followed in the case of a toxic substance which is not amenable to the treatment method normally employed, is that the course of treatment might be modified to one more suited to treatment of that particular toxic substance. An example of this would be for cyanide containing wastes which ~annot be treated in sludge tanks since the organisms involved cannot exist in the relatively violent conditions in the tank. However, these wastes can be treated in a slow rate filtration process (15) . . The third possible course of action would be· resorted to if the toxic waste is determined to be one which it is not desirable to sub-ject the plant to at any level. In this case, the waste could be dis-posed of by hiring a firm which specializes in picking up and treating toxic materials in a specialized plant (Example: Hyon Waste Management Services, Inc.). Each of these three approaches requires more eff ort, time and money than just sitting back and letting the toxic wast e enter t he treatment plant. But the important thing is that the bacter i a ar e now still alive and the plant will not be out of operation f or sever a l days or weeks while the daily quota of untreated sewage and wastewater con-tinues to arrive at the pla~~ for trea t ment. -.... 44.: .. "'' -.. . . . 7 . ··-- . .. - .. ... . . .. IV. RECOMMENDATIONS . ... , . ·. Determine Toxicity Levels for Partfcular Bacteria The bacteria in the biological treatment facilities of each plant are a unique mixture existing only at that plant. The particular combination is determined primarily by the composition of the waste-water influent to the plant. Therefore, each plant must determine the toxicity levels of its bacteria to each toxic material. Diff erent treatment plants will have different toxicity levels. For example, notice the different levels of toxicity reported for chromium in Table 1. The levels should be re-determined periodically in order to stay abreast of any change in the influent wastewater." .· Obtain Instrumentation to Monitor and Detect Toxic Materials •.' I The instrumentation is the key to the whole situation. It must be capable of operating unattended for long periods of time pro-tected against a variety of ambient field conditions. Hopefully it should be low cost, as simple as possible, rugged and maintenance free. Unfortunately, most of the instruments which are used to de-teet levels of toxicity are too complicated or too slow (up to seven days for some methods) to be used for this application. Hopefully, this may soon change. AU. S. Depar tment of the Interior report recently recommended that "studies be initiat ed to de-vise improved field detection . techniques with high detection sensitivi-ties for those substances v7hich cannot presently be detected a t ~==~~=======================================================~== 8 critical concentration levels 11 (16). Also, a recent magazine article reported on ratings of laboratory analytical methods for water pollution These ratings showed that automated methods for metals (atomic absorp-tion and emission spectroscopy), and ions (coloremetric and specific electrodes) and a partially automated method for pesticides (gas chromatography) are now available (17). Perhaps these will be further developed to the point that they can meet the requirements for monitor-ing detection devices. At the present time, Technicon . Industrial Systems of Tarrytown , New York markets an Autoanalyzer II .system which they report can be adapted for monitoring water pollution. Perhaps this system can be adapted to meet the requirements for a monitoring-detection device of toxic materials. Install Holding Tanks or Ponds After it has been determined that suitable instrumentation can be obtained, adequate holding capacity for the wastewater contaminated with toxic materials should be installed. One economical approach to this might be the use of a pit or a lagoon formed by an earthen dam, lined with a synthetic rubber. The Carlisle Tire and Rubber Division of the Carlisle Corporation advertises Sure-Seal Elastomeric Membranes and Sure-Seal Rubber Membrane for appli-cation of this type (18). Of course, for installations storiLg toxic materials, the lagoon, holding basin, etc . should be surrounded by a suitable fence. 9 Modify Plant for Alternate Methods of Trea tment When the plans have been completed for the holding tanks or ponds, the treatment plant itself should t hen b e modified to allow alternate methods of treatment. These might include a slow rate t rick-ling filter for use with cyanide waste in place of the activated s ludge stage. Or perhaps, the Bio-Carb process of Internationa l Hydronocs Corp. could be used in place of either the activated sludge or trickling filter stage. It is described as "particularly useful f or treo.ting constituents which are toxic to organix~s at moderate concentrctions bu t degradable at low concentrations'' (19). Figure 1 shows a plant with a l l three systems in parallel thus allow~ng any one of the three to be selected. Contract for Disposal of Untreated Wa stes After it has been determined what toxic wastes and at wha t con-centration can be treated by the wastewater ·treatment plant, pr ov i s ions should be made for treatment and disposal of those wa s tes which it is not desirable to subject the treatment plant to. One example of these would be cyanide wastes in event of a decision no t to provied .3.n alternative to the activated s ludge me t hod of biological treatment. One approach t o disposal of untreatable wastes would b e to contract for their r emoval and treatment by one of t he companies which specialize. i n this servic e (20). One side benefit of this approach might be that i n t he event of "iden t i fying the source of the toxic waste, a major portion of t he cos t of dealing \.vith it v70uld be on record and scarcely debatable. 10 ~ollection system 'li Reg~lator (Combined Se\ver) Plant Influent Gates '~ Mechanical Screens Grit Removal Raw Wastewater PIImnc:: ( '. overflow Bypass 1- Effluent Recirculation Trickling Filter I~ Secondary Clarifier Bio-Carb Activated _ ~ludge _ Aeration Tank l I I I I I Slurlge Disposal ~ I 1 Sludge Dewat ering t I I . ~ ~ A Anaerobic . ! 1 Digestion Retunl -~ 'f'. Sludge .. I ~ Waste I sludge 1 Bypass y , Primary Sludge ~----i""t"~--~., Sedimentation!- - - -;; ......1.~ Thi ckening Liquid Re t urns -- WastevTat er ---- Sludge Figure 1. --Common Processes i n Secondary Wastevmter Treatment -~====~~================================================================-===·======~===== 11 Installation Once the plant modifications and the construction of the holding tanks or ponds are completed, the r·,onitoring-detection instrumenta tion should be installed. When these installations are completed and checked out, there remains only two things to do. Schedule Maintenance and Toxicity Level Redetermination A preventive maintenance and .re-calibration schedules ould be established for the monitoring-detection instrumentation. Oth e.r portion of the system should be integrated .into the regular maintenance schedule of the treatment plant. Also a program should be initiated to periodically red etermine t the toxicity levels for each toxic contaminant which is being monitored. Any significant changes should be reflected in a new detection level for the instrumentation monitoring that contaminant. Review Instrumentation Market Periodically The final step is to periodically review the instrumentat i on market to determine if any device has been developed or modified to de-tect any toxic contaminant which is not being monitored by the· current system. Of course, any new devices which are available at an acceptabl e cost should be purchased and incorpora t ed into the system . 12 V. CONCLUSIONS -. -The adoption of the system descr ibed in this report will pro-teet the biological system of the treatment plant against the particular toxic contaminants for which it is possible to obtain monitoring detection instrumentation. - ' .. . . ~."' 13 VI. REFERENCES 1. W. Wesley Eckenfelder, Jr., Industrial Water Pollution Control, McGraw-Hill Book Co., New York, 1966. p . 13 . 2. W. W. Eckenfelder, Jr. and D. J. O'Connor, Biological Has te Treatment, Pergamon Press, New York. 1961 . 3. , Journal Water Pollution Control Federation , Vol. ~4 , No . 2, February 1972. p. 353. 4. E. A. Pearson, Kinetics of Biological ~reatment in Advances in Water Quality Improvements, Gloyne and Eckenf elder, eds . ~ustin, Texas. Uni versity of Texas Press, 1968. 5. Frank D. Schaumberg, A Ne\v Concept in Sample Preservation. Journal Waste Pollution Control Feder~tion, Vol. 43, No . 8, August 1971. pp. 1672-3. · 6. H. S,. Azad and G. K. Chen, Activated Sludge , Journal Wat er Pollution Control Federation, Vol. 43, No. 6~ June 1971 . p. 1114. 7. C. Fred Gurnham, Ed. ·Industrial Hastewater Control, Academic Press, New York. 1965. p. 457. 8. Harold E. Bassett, ·sewage and Sewag e Treatment, John Wil ey and Sons, Inc. New York, Sixth Edition . 1947. p. 561. 9. American Public Harks Association, Feasibility of Computer Control of Hastev7ater Treatment, U. S. Government Prin t ing Off i ce , Washington , D. C. December 1970. 17090 DOY 12/70 . p. 13. 10. , Test for Inhibitory Toxicity of Wastewater . Manualof Indus trial \.Jater and Indu s tria l Waste \.Jat er, Second Edition American Society for Testing and Mater ials . Philadelphia, Pa. 1966. p. 749 . · 11. C. Fred Gurnham, Ed . Industrial Wast e\vater Control , Academic Press, New Yo_rk. 1964. p. 460 . 12. w. W.esley Eckenf elder, Jr., Industr i al l.Jat er Pollution Control , l1cGrm.;r- Hill Book Co . Nevl York . 1966. p. 151. 14 13. Thomas R. Camp, Water and Its Impurities, Reinhold Book Corp. New York, 1963. p. 3. 14. American Public Works Assoc_i_a_!; ion, Feas ibility of Comput er Con-trol of Wastewater Treatment, U. S. Government Printing ·office , Washington , D. C. Dec . 1970. 17090 DOY 12/70. p. 54. 15. J. W. Abson and K. H. Todhunt er, Effluent Disposal in Biochemical and Biological Engineering Science, Ed. N. Blakebrough, Vol. 1, Academic Pr ess, New York 1967. p. 337. 16. G. W. Dawson, et al, Control of Spillage of Hazardous Pol luting Substances. FWQA, U. S. Dept. of the Interior 15090 FOZ 10/70 1970. p. 51. 17. Boris Ragant, "Spinoffs are not Enough" Astronautics and Aeronautics, Vol. 10, .. No . . 5, May 1972, p. 68. 18. , Carlisle Tire and Rubber . Division, Carlisle Corpor ation, Carlisle, Pa. Form No. SW8-50M-1070 and SSI-5M-771. 19. , Bio-Carb-Process Description, International Hydronocis Corporation, Box 910, R-4, Princeton, N.J. "1971. 20. , A New Service for Industry, Hyon Waste Management Services Inc. 11700 Stoney Island Ave., Chicago, Ill. 

A Proposed Approach to Protect Wastewater Biological Treatment Plants Against Toxic Contaminants

https://stars.library.ucf.edu/cgi/viewcontent.cgi?article=1028&amp;context=rtd

A Proposed Approach to Protect Wastewater Biological Treatment Plants Against Toxic Contaminants

Abstract

Similar works

Full text

Available Versions

University of Central Florida (UCF): STARS (Showcase of Text, Archives, Research & Scholarship)