Biological wastewater treatment plants are a mini-ecosystem with multiple interactions between billions of bacteria, protozoa, metazoa and potentially other microbial forms. At any time, the populations shift and adjust to new influents, temperatures, pH, oxygen availability, macronutrients, sunlight and really anything that enters or influences the biomass. Instead of just calling it - the bugs as if it were one single item, consider the ecological chaos of a natural environment. We just have to control the environment to get the treatment results we need. Here are some basic considerations when evaluating a biomass:
While my above list is short, it makes for a very complex puzzle when you consider how each organisms responds to the above inputs.
With our new "additive" you will never have to remove solids from a waste treatment system - a myth that never ends
Another blog topic selected from online discussion groups. This one concerns miracle products that digest sludge to a point where wasting or dredging is not necessary.
While systems vary in waste solids makeup and improved solids digestion is possible if there is a limiting factor such as:
Sludge can be subdivided into categories based on time for degradation. Each system's sludge will be slightly different based on influent makeup and local conditions, but the general categories still hold.
Usually we can only improve degradation rates of Readily Digested and Slowly Digested fractions. With more complex treatment (getting everything correct), it is possible to remove recalcitrant organics but this takes time and effort. And, the inorganic/insoluble fraction must be removed as it will only accumulate in the system.
So, no matter what you do - wasting or removing solids is necessary. You can only enhance digestion rates and the impact of enhancements depends upon sludge makeup.
Recent internet discussions on palm oil mill effluent (POME) wastewater have focused on pressuring mill owners to install the latest in anaerobic digesters and other advanced wastewater systems. While these systems are very effective at treating the water, they are all very capital intesive or more simply, expensive. So what type of treatment system should a palm oil processing facility or pulp/paper mill in a remote area install?
I am going to buck the trend and recommend a lagoon system for POME wastewater. This recommendation is based on the following assumptions:
Experienced operators see gray/black water with high H2S odors, they confidently say the water is "septic". But what is "septic" water and what upstream biochemical conditions form the odorous, high oxygen demand water.
First septic water usually gets its dark gray color from reduced sulfides (S=) binding with iron to form iron sulfide. The binding into iron sulfide is a good thing and is often used to control H2S gas in collection systems. For quick reading, I'll give the characteristics of "septic water":
Septic Water Characteristics
Biochemistry of Septicity
How to Control Septicity in Collection Systems
Erik Rumbaugh has been involved in biological waste treatment for over 20 years. He has worked with industrial and municipal wastewater facilities to ensure optimal performance of their treatment systems. He is a founder of Aster Bio (www.asterbio.com) specializing in biological waste treatment.
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