Synergistic combinations containing organo-bromine compounds and their use in the control of aerobacter aerogenes
United States Patent 1 91 .Shema et al.  
 [451 Apr. 22, 1975 1 SYNERGISTIC COMBINATIONS CONTAINING ORGANO-BROMINE COMPOUNDS AND THEIR USE IN THE CONTROL OF AEROBACTER AEROGENES [75] Inventors: Bernard F. Shema, Glenside; Robert H. Brink, Jr., Doylestown; Paul Swered, Philadelphia, all of Pa.  
 [73] Assignee&#39;: Betz Laboratories, Inc.. Trevose, Pa.  
 [22] Filed: Apr. 11, I974 [21] Appl. No.: 461,187  
  Related US. Application Data [62] Division of Scr. No. 161,961, July 12. 1971. Pat. No.  
 UNITED STATES PATENTS 7/1974 Shema ct al.  
 Bink, Jr. et a1. 71/67 Primary E.\&#39;aminer-.lames 0. Thomas, Jr. Attorney, Agent, or Firm--A1exander D. Ricci [57] ABSTRACT The present invention relates to certain processes and compositions useful for inhibiting and/or controlling the growth of slime in water and, in particular, water employed for industrial purposes. Water employed in the manufacture of pulp paper and water employed in cooling water systems, as well as other industrial waters, provide environments which are conducive to slime formation. The novel compositions of the present invention are mixtures which show unexpected synergistic activity against microorganisms, including bacteria, fungi and algae, which produce slime in aqueous systems. The slime, of course, is objectionable from an operational and/or aesthetic point of view. Specifically, the invention is directed to and the use of compositions comprising a combination of 5-ch1oro-4-phenyl-l, 2-dithiole-3-one and organobromine compounds (or mixtures thereof). The inventive compositions inhibit the growth of slime in water, or more specifically, possess biocidal activity against bacteria, fungi and/or algae. The organobromine compounds contemplated for use in accordance with the present invention may be exemplified by; bis-1, 4- bromoacetoxy-Z-butyne; bis-1, 4-bromoacetoxy-2- butene; alpha-bromo-p-methylacetophenone and beta-bromo-betanitrostyrene.  
 5 Claims, N0 Drawings SYNERGISTIC COMBINATIONS CONTAINING ()RGANO-BROMINE COMPOUNDS AND THEIR USE IN THE CONTROL OF AEROBACTER AEROGENES This is a division of application Ser. No. l(wl.9bl. filed July 12. l97l. now U.S. Pat. No. 3.839.008.  
 BACKGROUND OF THE INVENTION The formation of slime by microorganisms is a prob lem which attends many systems. For example. lagoons. lakes. ponds. pools and such systems as cooling water systems and pulp and paper mill systems all possess conditions which are conducive to the growth and reproduction of slime-forming microorganisms. In both oncethrough and recirculating cooling systems. for example. which employ large quantities of water as a cooling medium. the formation ofslime by microorganisms is an extensive and constant problem.  
  Airborne organisms are readily entrained in the water from cooling towers and find this warm medium an ideal environment for growth and multiplication. Aerobic and heliotropic organisms flourish on the tower proper while other organisms colonize and grow in such areas as the tower sump and the piping and passages ofthe cooling system. Such slime serves to deteriorate the tower structure in the ease ofwooden towers. In addition. the deposition of slime on metal surfaces promotes corrosion. Furthermore, slime carried through the cooling system plugs and fouls lines. valves. strainers. etc. and deposits on heat exchange surfaces. In the latter case. the impedance of heat transfer can greatly reduce the efficiency of the cooling system.  
  ln pulp and paper mill systems. slime formed by microorganisms is also frequently and. in fact. commonly encountered. Fouling or plugging by slime also occurs in the case of pulp and paper mill systems. Of greater significance, the slime becomes entrained in the paper produced to cause breakouts on the paper machines with consequent work stoppages and the loss of production time or unsightly blemishes in the final product&#39;. this. of course. results in rejects and wasted output. The previously discussed problems have resulted in the extensive utilization of biocides in cooling water and pulp and paper mill systems. Materials which have enjoyed widespread use in such applications include chlorine. organomercurials. chlorinated phenols. organobromides. and various organo-sulfur compounds. All of these compounds are generally useful or this purpose but each is attended by a variety of impediments. For example. chlorination is limited both by its specific toxicity for slimeforming organisms at economic levels and by the ability of chlorine to react which results in the expenditure of the chlorine before its full biocidal function may be achieved. Other biocides are attended by high costs. odor problems and hazards in respect to storage. use or handling which limit their utility. To date. no one compound or type of compound has achieved a clearly established predominance in respect to the applications discussed. Likewise. lagoons. ponds. lakes and even pools. either used for pleasure purposes or useful for industrial purposes for the disposal and storage of industrial wastes. become. during the warm weather. besieged by slime due to microorganism growth and reproduction. in the case of the recreational areas. the problem of infection. odor. etc.. is obvious. In the case of industrial storage or disposal of industrial materials. the microorganisms cause additional problems which must be eliminated prior to the materials use or the waste is treated for disposal.  
  lt is an object of the present invention to provide compositions for controlling slimc-forming microorganisms in aqueous systems. such as cooling water systems and pulp and paper mill systems. and for controlling slime formation or microorganism populations in aqueous bodies in general. Moreover. another object of the invention is the provision of methods for preserving materials and for controlling slime-forming microorganisms in any aqueous system which is conducive to the growth and reproduction of microorganisms. and. in particular. cooling water and paper and pulp mill systems. These methods employ a combination of 5- chloro-4-phenyl-l.2-dithiole-3-one and an organobromine compound (or mixtures thereof). The organobromine compound to be effective must possess the property of being biocidally active against bacteria. fungi and/or algae.  
  In the practice of the invention. the combination is added to the particular material to be preserved or to the system being treated. for example. cooling water systems. paper and pulp mill systems. pools. ponds. lagoons. lakes. etc.. in a quantity adequate to control the slime-forming microorganisms which are contained by. or which may become entrained in. the system which is treated. It has been found that such compositions and methods control the growth and occurrence ofsuch mi croorganisms as may populate these particular systems.  
 GENERAL DESCRlPTlON OF THE lNVENTlON As earlier stated. the inventive compositions comprise a combination of 5-chloro-4-phenyl-l .Z-dithiole- 3-one and a particular organo-bromine compound (or mixtures thereof) with either compound being present in such a quantity as to impart a synergistic behavior for the purpose to the composition as a whole. Preferably. the compositions contain a percentage by weight ranging from about 5 to of the dithiole-3-one compound and from about 5 to about 9571 of the organobromine compound. When these two ingredients are mixed either beforehand or by addition to the aqueous system individually. the resulting mixtures possess a high degree of slimicidal activity which could not have been predictedbeforehand from the known activity of the individual ingredients comprising the mixture. Accordingly. it is therefore possible to produce a more effective slime-control agent than has previously been available. Because of the enhanced activity of the mixture. the total quantity of biocide required for an effective treatment may be reduced. In addition. the high degree of biocidal effectiveness which is provided by each of the ingredients may be exploited without use of the higher concentrations of each. This feature is not only important and advantageous from an economical point of view. but also most desirable from the pollution or ecological standpoints. Specifically. in this regard. it may be pointed out that the smaller the amount of a chemical that is required for effective treatment. the smaller the problem in treating the wastes from these systems. ln both cooling water systems and in paper and pulp mill systems. certain discharge of waste water. e.g.. blowdown in cooling water systems. is a necessity. However. because of the current concern and legislation regarding the discharge of wastes. the effluent waste water must be treated to reduce and. hopefully. to eliminate any undesirable constituents. This treatment. of course. is time consuming and costly. Accordingly, a reduction in additive usage will result in a corresponding reduction in costs for the treatment of wastes containing these additives.  
  To demonstrate the synergism which is obtainable from the combination of the organo-bromine compounds with the 5-chloro4-phenyl-l.2-dithiole-3-one (supplied by Hercules Corporation under designation S-l612), various exemplary organo-bromine compounds were chosen. As earlier indicated. synergistic activity can be obtained by combining the dithiole- 3-one compound with any organo-bromine compound which exhibits growth inhibitory or biocidal activity with respect to bacteria. fungi and/or algae. The organo-bromine compounds which were chosen as representative are as follows: bis-l.4-bromoacetoxy-Z-butyne (Stauffer Chemical Co.: R-l7343); bis-1.4-bromoacetoxy-2-butene (Vineland Chemical Co.: V-IO); alpha-bromo-p methylacetophenone (Stauffer Chemical Co. N-3869) and beta-bromo-betanitrostyrene (Givaudan Corp.).  
  In order to illustrate the synergistic activity, the efficacy and the comparative effectiveness of the inventive compositions. various tests were utilized and will be described following.  
 SPECIFIC EMBODIMENTS EXAMPLE 1 SYNERGlSTlC COMBINATION:  
 Compound A: 5-chloro-4-phenyl-l,2-dithiole-3-one Compound B: bis-l.4-bromoacetoxy-Z-butyne The compositions of this Example contained 5-chloro-4-phenyl-l .2 dithiole-3-one (referred to as Compound A in the Test Equations and in Tables I through IC) and bis-1,4-bromoacetoxy-2-butyne (referred to as Compound B in The Test Equations and in Tables I through IC) in the weight ratios expressed in the Tables which follow. The compositions were tested for synergistic activity in accordance with the method described. The synergism test was utilized to evaluate each of the combinations of this Example and the following Examples. Synergistic lndex Test Synergistic activity was demonstrated by adding Compound A and Compound B in varying ratios and over a range of concentrations to liquid nutrient medium which was subsequently inoculated with a standard volume of suspension of the bacterium Acrobat-1e;- aerogenes. Following two days incubation, the lowest concentration of each ratio which prevented growth of the bacteria was taken as the end point. Growth or nogrowth was determined by turbidity or clarity. respectively. in the medium. End points for the various mixtures were then compared with end points for the pure active ingredients working alone in concomitantly prepared culture bottles. Synergism was determined by the method described by Kull et al. [F. C. Kull. P. C. Eisman. H. D. Sylwestrowicz and R. L. Mayer, Applied Microbiology. 9. 538-41. (1961)] and the relationships.  
  cn IC and, OIC/TIC 1.0 synergism TABLE I Weight Ratio End Point Data of A to B ppm ppm B OIC TIC OlC/TIC l00/0 8.0 8.0 /5 5.7 0.3 6.0 8.38 0.7! 50/50 5 0 5.0 I0.0 14.68 0.68 5/95 2 25 42.75 45.0 59.6 0.75 0/ I 00 9.0 9.0  
  It is evident from the data recorded in Table l that compositions of the present invention function to control slime growth due to microorganisms not only at equal portions of the respective ingredients, but also where just minor amounts of one or the other are present. This discovery of synergism at the lower levels is extremely valuable since it illustrates conclusively that the ingredients are compatible over the wide percentage by weight range.  
 BACTERICIDAL EFFECTIVENESS The bactericidal effectiveness of the mixture of Compound A and Compound B of this Example is demonstrated by the following Table in which the inhibiting power of a 50/50 by weight mixture of A and B is shown. Aerobacter aerogenes was employed as the test organism and a substrate technique was utilized. Specifically. the biocidal mixture was added in gradually increasing quantities to nutrient agar media which was then inoculated with A. aerogenes. The preparation was then incubated for 48 hours. The values set forth in the Table indicate the quantity of biocide required, in parts by weight for each one million parts by weight of the medium, in order to achieve completeinhibition of the growth of the test organism.  
 TABLE 1 Quantity (ppm) required for inhibition Biocidal Material of A. aerugem&#39;x Compound A (57:). Compound B (5% Inert (9071) FUNGICIDAL EFFECTIVENESS described procedure generally entails incorporating the biocide under test in a nutrient substrate such as agar. malt, etc. and pouring the resulting medium into a Petri dish and allowing the medium to solidify. A button of fungus inoculum is placed on the surface of the solidified medium and the medium is incubated for a period of 14 days. After the period. the diameter of the colony is measured and compared with the diameter of the centage kill (based on the initial count) may be calculated. In this evaluation the water sample was taken from a paper machine Saveall unit in the northeastern United States.  
  For the purposes of comparison, the mixture of A and B was evaluated together with two recognized commercial biocides, Pentachlorophenol and the Commercial Product described in Table 1.  
 TABLE 18 Quantity (ppm) for inhibition Biocidal Material I. ar muxmn .4. Minor Compound A (5% Compound B (S /r I00 I00 Inert (9071 l SLIME CONTROL EFFECTIVENESS The inventive methods and compositions were also tested with respect to their performance in the control of slime formation in industrial systems. In this test an industrial recirculating water was obtained from a system which was currently experiencing problems in respect to the formation of slime by microorganisms. Such tests do not demonstrate the efficiency of the biocide employed with respect to specific species of microorganisms but instead supply a practical demonstra tion of the efficacy of the biocide tested in relation to those communities of microorganisms which have evidenced their ability to form slime in actual industrial systems.  
  In the testing of recirculating water samples. a substrate evaluation was employed. In such testing identical portions of water samples are treated with varying concentrations of biocide and two portions are left untreated to serve as controls. The control portions are plated for total count at the beginning of biocide treatment and all portions are plated for total count at some suitable time period(s) after beginning biocide treatment. Using the counts obtained from plating. the per- In the foregoing type evaluation, a percentage kill of approximately percent is considered to be most acceptable for industrial purposes. A perusal of the recorded percentages clearly establishes that the composition of the present invention. although less concentrated with respect to active ingredients as compared to the two commercial products. gave excellent rates of kill even at low treatment levels. As earlier expressed. excellent performance of a biocidal composition at low treatment levels not only provides a most desirable cost performance index, but also provides most desirable advantages from the aspects of pollution abatement. waste treatment costs and the preservation of the ecological strain.  
 EXAMPLE 2 SYNERGISTIC COMBINATION:  
  Compound A: 5-chloro-4-phenyl-l,2-dithiole-3-one Compound B: Alpha-bromo-pmethylacetophenone The compositions of this Example contained 5- chloro-4-phenyl-l.2-dithiole-3-one (referred to as Compound A in the Test Equations and in Tables 2 through 2C )1 and alpha-bromo-p-methylacetophenone (referred to as Compound B in the Test Equations and in Tables 2 through 2C). The compositions of this Example were tested in accordance with the test procedures outlined in Example I. The data ascertained for the respective tests are recorded below under the commensurate Table. Synergistic Index Test For mixtures of Compounds A and B, and for Compound A and Compound B acting alone, the following results were observed:  
 TABLE 2 TABLE 28 Weight Ratio End Point Data Quantity (ppm) for inhibition of A to B ppm A ppm B OIC Tl OlC/TIC Biocidal Material I. (X/NHLYHIH A. nigvr lnitial Evalution Compound A (57,  
 1 /0 1 Compound B (5&#39;71). [00 100 95/5 x55 0.45 9.0 0.33 mm (9W) 50/50 (1.0 6.0 ill) l-LZQ 0 84 Secondary Emuaflun It) The composition was quite effective in controlling mm 14 fungus growth when it is considered that it contained /75 0.8 1&amp;2 l(1.0 20.83 0.77 I F &#39;1 10/90 2.2 19.x 22.0 23.15 0.95 only c 5/95 5 5 16.5 22.0 24.04 0.72 0/100 ZHl 25.0  
 SLlME CONTROL EFFECTIVENESS The above evaluations. initial and secondary.&#34; established that the compositions in the weight ratios evaluated all exhibited synergistic activity. As set forth The test procedure used was that explained in Example I. For comparative purposes. two commercial products were tested together with the composition of this Example. The results were:  
 in the explanation of the test earlier in this text. when OlC/TlC is less than l. then the two individual components are acting in a synergistic manner.  
 BACTERlClDAL EFFECTlVENESS The bactericidal effectiveness of the combination of this Example was tested in accordance with the procedure outlined in Example I. The values obtained are recorded in Table 2A which follows:  
 TABLE 2A Quantity (ppm) required for inhibition Bioeidal Material of A &#39;uvrngmn-x Compound A (57: l. Compound B (571 Inert (9071 The above data established that the combination effectively inhibited the growth ofthc particular bacterial strain.  
 FUNGlClDAL EFFECTIVENESS The effectiveness of the composition of Example 2 was tested in accordance with the procedures set forth in Example I. The results were:  
  The results obtained with the lower percentage active compositions of the present invention were quite obviously impressive. The results were vastly superior to the Commercial Product which has found widespread acceptance and use. Moreover, the high activity of the low treatment level is extremely attractive from an economic viewpoint aswell as from the aspect of the treatment of wastes containing the biocidal composition.  
 EXAMPLE 3 SYNERGlSTlC COMBINATION:  
 Compound A: 5-chloro-4-phenyl-l.2-dithiole-3-one Compound B: bis-l,4-bromoacetoxy-2-butene The combinations of this Example contained 5- chloro-4-phenyll .2-dithiole-3-one (hereafter referred to as Compound A); and bis-1,4-bromoacetoxy-2- butene (referred to in this Example as Compound B).  
 As with the previous Examples, combinations of these ingredients were tested in accordance with the various test procedures outlined in Example 1. The data obtained isrecorded in the following Tables 3 through 3C. 7 Synergistic lndex Test For mixtures of Compounds A and B, and for Compound A and Compound B acting alone, the following results were observed:  
 TABLE 3 Again, the slime control effectiveness of the instant composition was much superior to the commercial products at low treatment ranges and was significantly Weight Ratio End Point Data ofA to 8 ppm A ppm B 01C TIC OlC/TlC better overall as compared to the 22% active Commer- 5 (52% gs cial Product.  
  4. 0.25 5.0 10.34 0.48 50/50 5.0 5.0 10.0 15.00 0.07 EXAMPLE 4 5 95 0.625 11.875 2.5 2 .27 046 1, l SYNERGISTIC COMBINATION:  
  Compound A: -chloro-4-phenyl-1.2-dithiole-3-one Compound B: Beta-bromo-beta-nitrostyrene The results obtained for this particular combination Synergistic lndex Test established unequivocally that the two ingredients be- The synergistic activity of the combinations of 5- have synergistically together. chloro-4-phenyl-1.2-dithiole-3-one (referred to as Compound A) and beta-bromo-beta-nitrostyrene (re- BACTERICIDAL EFFECTIVENESS ferred to in this Example as Compound B) was evalu- This test procedure as described in Example 1 was ated in accordance with the test described. The results utilized. The results established that the composition were as follows: was effective in controlling this strain of bacteria. For mixtures of Compounds A and B, and for Com- TABLE 3A m pound A and Compound B acting alone. the following results were observed:  
  Quantity (ppm) TABLE 4 required for inhibition Biocidal Material of .4. uurugem-s Weight Ratio End Point Data Compound A (5% of A to B ppm A ppm B OlC TIC OlC/TlC Compound B (571). 200  
 lnert (90%) 100/0 5.0 5.0  
  95/5 4.75 0.25 5.0 .07 0.99 50/50 2.0 2.0 4.0 5.83 0.69 5/95 0.25 4.75 5.0 6.86 0.73 FUNGICIDAL EFFECTIVENESS The fungicidal activity of the composition of this Example was tested in accordance with the procedure All of the combinations tested exhibited an OlC/TIC previously described. The results were: of less than 1 which, of course, established that the in TABLE 33 dividual ngredients operated in concert to produce a 35 synergistic result.  
  Quunlil; 032&#39;&#34; for inhibifio&#34; BACTERICIDAL EFFECTlVENESS Biocidal Material P. m xmxum .4. nigt&#39;r The efficacy of the compositions of this Example was g g g 00 00 tested in accordance with the procedure outlined ear- &#34;ififim fg 40 lier. The results of the test clearly established that the combination of the instant invention is effective even at low percentages of active ingredients.  
 SLlME CONTROL EFFECTIVENESS TABLE 4A The slime control effectiveness of the present com- Quamm. (ppm) pos1t1on was evaluated using actual paper m ll water as required for inhibition explained under the procedure outlined in Example l. Bmc&#39;dal Maler&#39;al As with the previous Examples, the composition was compoundmsqr) compared with commercially available products using Compound B (5%). this test. 50 (907) TABLE 3C Quantity of Percent kill Biocldal Material biocide (ppm) after 6 hours Compound A (5%). Compound 8 (5%), lnert 5 67 10 85 25 98 50 93 I00 96 Pentachlorophenol (100%) 5 48 10 8| 25 100 50 100 I00 100 Commercial Product (22% active-See Table 1C) 5 34 10 52 25 76 50 70 100 86 FUNGlClDAL EFFECTIVENESS The fungicidal activity of the composition of this Example was tested in accordance with the procedure found that either aqueous or non-aqueous solvents are generally suitable in the preparation of compositions of the invention, e.g., methyl cellosolve, organic solvents such as the aliphatic and aromatic hydrocarbons, e.g.,  
 previously. described. The result of this evaluation was kerosene. Based p the synergism study as Outlined as follows.  
  above, it was ascertained that in the treatment of pa- TABLE 43 per-mill and cooling water, effective biocidal action is obtained when the concentration or treatment level of Qunntit) (pp for inhibition the combination or admixture of biocides is between Biocidal Material P. tar muslin: .4. nigvr 5 a -t r illi t 1 000 rt illi d Compound A (5%). preferably between 1 and 100 parts per million, based Compound B (57!). so 100 upon the total content of the aqueous system treated, (907) such as the total quantity of cooling water or paper mill 5 water. SLIME CONTROL EFFECTIVENESS The compositions may also be utilizedfor the preservation of slurries and emulsions containing carbohy- AS in the Previous Examples and in the manner Set drates, proteins, fats, oils, etc.; dosage levels for this forth in the previous Examples, the slime control effecpurpose range i h i i i f() 5 to 5% Th compotiveness of the composition of the Example was tested. iti f h invention hi h can b prepared b The outcome of this evaluation and the data derived merely bi i h respective i di d i using the Commercial Products are set forth in the foling th r ughly at standard conditions may be fed conlowing Table: tinuously to the treated system, e.g., by means of a me- TABLE 4C Quantity of Percent kill Biocidal Material biocide(ppm) after 6 hours Compound A (5%), Comppund B (5%), Inert (90%) 5 73 2 3? 50 97 100 98 Pentachlorophenol l007c) 5 48 l0 8] I00 50 I00 100 100 Commercial Product (22% active-See Table 1C) 5 34 u 7 $2 is 50 70 100 86 Thercomposition of this Example, as with the previ- &#39;tered pump, or may be fed periodically at predeterous Examples, exhibited overall desirable and attracmined intervals calculated to control the growth of tive slime control capacity. Of special interest is the slime-forming organisms in the system. Naturally, in fact that low treatment levels of the composition were the treatment of cooling water, the feeding of the incapable of controlling the slime-forming organisms. ventive compositions must be designed to compensate When the inventive compositions are employed in for blowdown in those systems which employ that expethe treatment of cooling or paper mill water, they are dient. preferably utilized in the form of relatively dilute solu- Although the foregoing has been specifically directed tions or dispersions. For example, a preferred solution to liquid formulations, the combinations of the invencomprises between 5 to 65% by weight of the synergistion may, of course, be formulated dry with well-known tic combination in admixture with various solvents and pelletizing agents, e.g., sodium chloride, talc, alumisolubilizing agents. An example of such a synergistic nate, etc. to produce solid pellets or briquettes which biocidal product comprises from about 5 to 10% by are added directly to the systems to be treated. The pelweight of the bromo-nitrostyrene, from about 5 to 10% lets or briquettes, of course, dissolve in accordance by weight of the 5-chloro-4-phenyl-l,2-dithiole-3-one with predetermined conditions or rates. and the remainder composed of such materials as sur- In describing the inventive subject matter, the exfactants, stabilizers, organic solvents, such as alkanols, pression composition&#34; has been utilized. However, it aromatic hydrocarbons, and/or water. is to be understood that physical compositions or com- Surfactants such as the alkylaryl polyether alcohols, binations are not the sole utility of the invention. If, for polyether alcohols, sulfonates and sulfates, and the example, the separate ingredients of the &#34;composition&#34; like, may be employed to enhance the dispersibility and are added independently to a particular system, it is instability of these dispersions. The foregoing solutions of the biocidal compositions are utilized in order to insure the rapid and uniform dispersibility of the biocides within the industrial water which is treated. It has been tended that this usage of the subject matter is within the scope of the invention and is to be construed within the broad interpretation of composition and/or combination.  
  As would be expected, the inventive composition may be added to the cooling water or paper and pulp mill systems at any convenient point. Naturally, in once-through or non-circulating systems. the composition must be added upstream from the point or points at which microorganism control is desired. in circulating systems or pulp and paper systems. the compositions must be added at any point provided that the time lapse and the conditions experienced between point of addition and the point at which the effect of the composition is to be experienced are not so drastic as to result in the neutralization of the effect of the composition.  
  Although the invention has been described specifically as being directed to specific compositions comprising -chloro4-phenyl-l.2-dithiole-3-one in combination with the butyne as described in Example I, the acetophenone of Example 2. the butene of Example 3 or the styrene of Example 4, it is obvious that homologues, analogues. etc. of the dithiole-3-one compound certainly are operable for the purpose. Likewise. the derivatives of the specially exemplified organobromine compounds also have utility in the present inventive concept. Moreover. as earlier described, mixtures of the various organo-bromine compounds would also serve the purpose. The provision, of course. is that the organo-bromine compound possesses biocidal or growth inhibitory capacity with respect to bacteria. fungi. and algae.  
  It should be noted that while the evidence has been derived from the treatment of samples taken from paper and pulp mill aqueous systems, the compositions and methods of the present invention are broadly applicable to the treatment of aesthetic waters as well as industrial waters such as cooling waters which are plagued by deposits formed by slime-forming organisms, or by the very presence of such organisms.  
 Having thus described the invention what is claimed 1. Method for controlling the growth of the microorganism Aerobacter Aerogenes in an aqueous system in which said microorganism is found which comprises addding to said system so as to contact said microorganism an effective amount of a combination comprising 5-chloro-4-phenyl-one.2-dithiole-3-l and bis] ,4- bromoacetoxy-Z-butyne. where the weight ratio of the dithiole to the butyne is from to 5% to 5 to 95%.  
  2. The method of claim 1 where said weight ratio is 50 to 50%.  
  3. The method of claim 1 where said combination is added to said system in an amount of from 0.5 to about 1.000 parts by weight of said combination per million parts by weight of said aqueous system.  
  4. A composition which is effective in controlling the growth of microorganism Aerobacter Aerogenes in aqueous systems where said microorganism is found which comprises 5-chloro-4-phenyl-one,2-dithiole-3-l and bis-l,4-bromoacetoxy-2-butyne, where the weight ratio of the dithiole to the butyne is from 95 to 5% to 5 to 95%.  
 S. The composition of claim 4 where said weight ratio is50to50%.  
 &#39; UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 79, D d April 22, 1975 l Bernard F. Shema et a1 It is certified that error appears in the above-identified patentand that said Letters Patent are hereby corrected as shown below:  
 In column 4, the last line of Table I, both occurrences of &#34;9. O should read 90. O  
 In column 7, the next to last line of Table 2,, 0. 72&#34; should read 0.92  
 Signed and Sealed this seventeenth D 3) of February 1 976 [SEAL] Arrest:  
 RUTH C. MASON 1 C. MARSHALL DANN Arresting Officer (ummissioner ufPatents and Trademarks