PERSNICKETY® BRAND 713 BIOLOGICAL INOCULANT
For Control of Hydrogen Sulfide In Open Tanks, Ponds and Lagoons

THE PROBLEM
Hydrogen sulfide (H₂S) has been the source of countless odor complaints directed to those responsible for operating municipal and industrial wastewater facilities -- probably the source for more complaints than any other malodorous compound. In addition to the rotten egg odor, H₂S poses serious corrosion problems costing many millions of dollars each year, serious health and safety concerns, and can diminish the effectiveness of any wastewater facility.

THE CAUSE
The biological transformations involved in the sulfur cycle are tremendously complex, but it is generally accurate to say that sulfate-reducing bacteria are the principal causal agents -- reducing sulfate to sulfide. The biological production of H₂S requires anaerobic conditions (conditions deficient in dissolved oxygen [DO]), but the problem often occurs where design intends largely aerobic conditions. For example, sludge blankets in clarifiers are frequent culprits; stabilization ponds often stratify with heavy loadings, creating anaerobic, facultative and aerobic layers. (See Figure 1.)

PERSNICKETY® 713 - A PROVEN AND HIGHLY EFFECTIVE BIOLOGICAL SOLUTION
There is no magic involved with the biological creation of H₂S. Neither is there any magic involved with its biological removal. PERSNICKETY® 713 is a carefully developed, precisely balanced blend of proprietary, naturally occurring, strict and facultative anaerobic bacteria in a liquid medium. They are selected and cultured for their ability to reduce H₂S to elemental sulfur, which is stored intercellularly. The function is as follows:

H₂S + PERSNICKETY® 713 ---> S + new PERSNICKETY® bacteria.

All members are non-toxic, non-pathogenic, harmless to aquatic life and compatible with other desirable bacteria found in wastewater. They become a synergistic part of the biomass, and simply do what nature intended them to do.

BENEFITS OF PERSNICKETY® 713
Primary - Complaints due to H₂S odors cease or are greatly diminished. As importantly, corrosion damage and the health and safety dangers posed by H₂S are correspondingly reduced. Cost of treatment is very competitive.

Secondary - Even low levels of highly toxic H₂S can adversely affect the health of a biomass, greatly reducing its activity and efficiency. The impact of H₂S varies in specific effect from location to location, but a detoxified, rejuvenated biomass will perform more efficiently. Thus, potential exists for improving biochemical oxygen demand (BOD) and solids removals and for decreasing accumulations of organic solids.

PERSNICKETY® 713 will also help to control animal and vegetable fats, oils and greases (FOG). These compounds are exceptionally stable and require extended time for breakdown. Certain members of 713 speed the process, creating intermediates (proteins, fatty acids, glycerols). These simpler compounds are converted far more readily by normally present bacteria. This benefit will usually be seen in domestic plants with normal domestic FOG loadings.

LIMITATIONS
PERSNICKETY® 713 is not appropriate in all circumstances. It is formulated to function in open tanks, ponds, lagoons, ditches and the like, where anaerobic conditions allow sulfate reducing bacteria to flourish and produce H₂S. It is not normally recommended for severely anaerobic conditions such as those found in anaerobic digesters and highly septic collection lines. Here are a few simple checks to determine appropriateness:

A biological process takes time. 713 populations must build to equal the problem. PERSNICKETY® 713 is not an instant answer, but once established (approximately 10 days), it serves remarkably well.

INOCULATION TECHNIQUES AND RATES
The application of PERSNICKETY® 713 is straightforward -- batch dose 2 times per day, either manually or by metered pump, at a point which provides maximum dispersion. All members of 713 will metabolize and reproduce. However, it is important to recognize that the normally present bacteria have an ecological advantage over those introduced. PERSNICKETY® 713 can never dominate a system. Without repeated inoculations, the 713 populations will be overwhelmed and will eventually disappear.

Table 1 details required rates of inoculation. The task is to build and maintain populations of PERSNICKETY® 713 in sufficient numbers to keep up with the amount of H₂S produced. Potential for H₂S production is governed by favorable conditions for its production and the amount of food available for conversion. The figures on the next page are good starting guidelines. Once H₂S is firmly controlled, it may be possible to reduce inoculation levels slowly and incrementally to determine minimum amounts.

IMPORTANT:

MEASURING RESULTS
Your nose will tell you of your success, but it will not quantify reductions in H₂S. Quantification can be accomplished using Standard Methods testing. Both the iodometric and methylene blue methods can suffer from interfering substances. It is vital to pretreat samples (Standard Methods 427 B. "Sample Pretreatment to Remove Interfering Substances or to Concentrate the Sulfide") for accurate results. Another, and very simple way to measure dissolved sulfide is to use sulfide ion analyzer tubes. They will provide a reading in less than two minutes, and are very useful field tools. They will not provide the precise accuracy of Standard Methods testing.

The importance of measuring reductions is two-fold. Firstly, reductions can be demonstrated to those concerned. As importantly, the measurements will allow you to optimize inoculation rates - i.e. if readings begin to creep up, increase; if control is steady and firm a decrease may be possible.

(Bench Testing - It is very difficult, if not impossible, to obtain results in laboratory studies which can be projected to a full-scale, dynamic system. In a small, confined culture, minute shifts in conditions can rapidly occur, affecting the entire colony, greatly favoring one species and skewing results. Conditions such as oxygen levels, anaerobiosis, carbon dioxide, pH, vitamins, amino acids, iron-chelating compounds, unsaturated fatty acids, nucleic acid bases, inorganic ions, trace elements, temperature, exoenzymes and many more are tremendously influential. Truly, with such complexities present, the only process known for determining the efficacy of a biological product is a full-scale field application.)

Limited Warranty:
Our only obligation shall be to replace or pay for any material proved defective.  Beyond the purchase price of materials supplied by us, we assume no liability for damages of any kind and the user accepts the product "as is" and without warranties, expressed or implied.  The suitability of the product for an intended use shall be solely up to the user.

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