Biological Wastewater Treatment

Our wastewater treatment technologies are straight out of Nature’s Laboratory and are a proven alternative for the effective sewage treatment and industrial wastewater treatment . Our bio enzymes for wastewater treatment target a wide range of industries and municipal bodies and are custom designed to effectively and substantially degrade organic waste. With Organica and a little help from nature, you can reduce sludge volume, operational costs, curb foul odour and significantly lower COD and BOD levels in the water. Organica is well known for its wide range for nature friendly products which include Cleanmaxx®. This bio enzyme is an effective biological wastewater treatment solution for sewage and industrial wastewater treatment.  

Wastewater treatment

Wastewater- Definition The process of removing contaminants from the sewage or industrial wastewater and improving physico-chemical and biological characteristics of water using various physical, chemical and biological processes that allows safe discharge of used water into the environment or reuse of water for domestic or industrial purpose is known as waste water treatment. Waste water treatment is usually performed in a sewage treatment plant for sewage water and effluent treatment plant for industrial wastewater. Types of wastewater Depending on the source of origin, waste water can be classified as domestic waste water also known as sewage water and industrial waste water also known as effluent. The sewage water usually consists of liquid discharge from sanitary facility, cooking bathing, laundry and other domestic use coming from residential, commercial or institutional source. The water discharge originating from wide variety of manufacturing processes from commercial and industrial sector is known as industrial waste water or effluent. Wastewater treatment The process of removing contaminants from the sewage or industrial waste water and improving physico-chemical and biological characteristics of water using various physical, chemical and biological processes that allows safe discharge of used water into the environment or reuse of water for domestic or industrial purpose is known as waste water treatment. Waste water treatment is usually performed in a sewage treatment plant for sewage water and effluent treatment plant for industrial wastewater. Stages of wastewater treatment The wastewater treatment consists of 3 stages. Primary stage consists of various techniques for removal of large solid material from the incoming water. Bar screening filters out any large solid material like wood, plastic, rags etc. Primary clarifier allows settling of solids via gravity, sometimes coagulants and flocculants are used to precipitate and settle the dissolved solids. Secondary treatment of wastewater (or it is commonly known as biological wastewater treatment) is the microbe mediated wastewater treatment coming from primary clarifier. It involves aerobic , anaerobic treatment or combination of both processes to treat the organic material in the waste water by reducing COD, nitrogen, phosphorus etc. The tertiary stage is the final stage of waste water treatment to improve the water quality to a level that allows the discharge of water into the environment or reuse of treated water. It involves processes like disinfection, membrane filtration, carbon filtration etc.   Types of wastewater treatment plants The most common types of waste water treatment plant are effluent treatment plant (ETP), sewage treatment plant (STP) and common and combined effluent treatment plant (CETP). Effluent treatment plants (ETP) are usually used by industries with high manufacturing capacities such as textile, pharmaceutical, chemical industries etc. containing organic or inorganic wastewater or combination of both with high COD, TDS, extreme pH making the wastewater highly toxic. Effluent treatment plants are selected and designed according to the type and volume of industrial effluent that is incurrent. Sewage treatment plants remove contaminants from domestic waste water like residential colonies, institutions, hospitality industries etc. STPs contain waste water with a high amount of organic material that can be treated without much difficulty. Common effluent treatment plant (CETPs) are designed to treat wastewater from various small scale industries that are not able to treat effluents on site at a common effluent treatment plant. CETPs are usually constructed in industrial estates or industrial development corporations (IDC).  

What Are the Role of microbes

Role of microbes in wastewater treatment Microorganisms are intrinsic to the secondary treatment of wastewater. This is because they are mediators in the degradation of organic material present in the wastewater. In biological wastewater treatment, microbes consume the organic material present in wastewater as a source of food containing carbon, nitrogen, phosphorus and other essential nutrients to grow. In return, they convert the high molecular toxic contaminants into smaller non-toxic material that can be discharged safely into the environment. Choosing microbes as candidates for wastewater treatment Secondary treatment of wastewater requires a combination of different microorganisms. Most common bacteria or waste water treatment are Bacillus and Pseudomonas species. There is variety of Bacillus species like B. licheniformis, B. subtilis, B. megaterium, B. pumilus, B. coagulans etc.while in Pseudomans P. aeruginosa, P. putida, P. fluorescens etc. potential strains of these bacteria are most commonly used to treat pollutants present in waste water treatment system. The basis of microbes being chosen for treating wastewater, solely depends upon their genetic and enzymatic machinery that make them capable of degrading substrates found in certain types of wastewater. Apart from this there are higher life forms such as free swimming ciliates, stalked ciliates, rotifers, tardigrades that help in creating bio ezymes for wastewater treatment by feeding of free bacterial cells and help in maintaining good flocculation in wastewater treatment system. Critical parameters for optimal microbial growth in secondary treatment of wastewater Optimal growth of microorganisms in a wastewater treatment system requires a balanced functioning of various parameters.

• • Aeration In case of an aerobic treatment system, a properly aerated system makes sure there is enough dissolved oxygen content for growth and multiplication of microbial population.
  • pH Neutral pH provides a favorable environment for optimum growth of microorganisms.
  • Loading rate A balanced organic loading rate makes sure that there is optimum supply of organic matter that allows floc formation in the system.

Defining the residence time of secondary wastewater treatment system Residence time in wastewater system can be described as the time duration for which solids like organic material or microorganisms are present in activated sludge system or the time available for interaction of microorganism and organic matter for its degradation also known as mean cell residence time(MCRT). The residence is dependent on the inflow and outflow of the effluent and is calculated by dividing volume of the secondary tank by the flow rate of the effluent. A well balanced residence time allows optimum degradation of pollutants in wastewater treatment system.   Why cowdung is not the best solution for wastewater treatment? Cowdung contains microorganisms that are found in gut of cattles, they are best suited to degrade the food consumed by cattles. If you consider the composition of an effluent, it varies depending on the industry type, products and by-products produced in manufacturing plant. It becomes difficult for microorganisms accustomed to one source of food to have a reliable impact when transferred to completely different and harsh environment. They cannot therefore treat the wastewater as efficiently. Cowdung is also a source of wide variety of pathogenic bacteria. An increased load of pathogenic bacteria in your waste water system can have negative impact for the secondary treatment process or when released into the environment. There is no substitute for a well researched product that is tailor made to suit the effluent and the process of treatment.   Ascertaining the biological health of wastewater system In a wastewater system, maintenance of desired microbial population is essential to optimise the efficacy of the secondary treatment of wastewater. The biological health of wastewater needs to be monitored at regular intervals to keep up to date the health of the system. Microscopic examinations allow you to understand the density of floc formation, free bacterial cells, presence and type of higher life forms present in system, density of filamentous bacteria. Similarly microbial count analysis can help in understanding the microbial count and microbial diversity per milliliter of effluent sample. Such analysis of effluent undergoing biological wastewater treatment at regular intervals can provide an inside view into the biological health of the wastewater system.   Higher life forms indicate wastewater system health Higher life forms include a wide variety of microscopic organisms like ciliates, flagellates, rotifers, tardigrades etc. and are indicative of the health of your wastewater treatment plant. Higher life forms are very sensitive to any kind of changes in a biological wastewater treatment system. The absence of higher life forms in the system indicate a high level of toxicity in the effluent that can be due to presence of toxic compounds, high COD, high TDS or extreme pH. Different types of higher life forms develop during different phases of sludge development in the secondary treatment of water, hence dominance of certain types of higher life form at a given time can help in understanding the stage and age of sludge development. Observation of artefacts of higher life forms can indicate some kind of shock load to the system such as oxygen depletion, pH fluctuation, entry of any toxic compound into the system that may have caused their sudden death. Hence, higher life forms are good indicators for the health of your effluent system.  

Biological processes

Difference between aerobic and anaerobic wastewater treatment An aerobic process involves a set of microorganisms that grow optimally in presence of oxygen. Anaerobic wastewater treatment involves microorganisms that grow in absence of oxygen. It is an energy-intensive process as it utilizes continuous electricity for aeration and monitoring of the aeration parameters. Because of accelerated microbial activity, the retention time for waste degradation is lesser than that required for anaerobic treatment. Selecting the process for biological wastewater treatment in an industry is based on various factors such as :

• Availability of land As the anaerobic process requires high retention time, the space required to maintain large volume of effluents for longer duration is more.
• Cost of Operations In terms of cost of operations, the maintenance of aerobic facility is increases OPEX costs as it requires continuous supply of oxygen, monitoring various parameters and maintenance of moving parts at regular interval. Anaerobic process is comparatively cost effective method for secondary treatment of water as no additional energy input is required.
• Effluent type and energy recovery When the effluent water contains high organic content, energy can be recovered from the waste water in the form of biogas via anaerobic treatment but the process requires high level of monitoring and maintenance. Energy recovery from aerobic treatment can be carried out from the organic sludge mixed with microbial biomass occasionally if the substrate is suitable.

Types of industries that require wastewater treatment Generally every type of manufacturing industry has a process that leads to the generation of wastewater. Any industry that oroduces wastewater containing organic loads, toxic compounds, high COD, nitrates, phosphates and TDS levels, that can be hazardous to aquatic and plant life when discharged into the environment without treatment requires treatment of its wastewater. Some of common industries include pharmaceutical, food processing, dairy processing, distillery, chemical, petrochemicals, paint, textile and dye industries.  

Maintaining treatment processes

Removal of pathogens in wastewater treatment Pathogens are microorganisms that can potentially be harmful to humans, animals or aquatic life on ingestion or exposure. Pathogens can be removed in a waste water treatment plant chemically, physically or biologically in the secondary and tertiary steps of treatment. Depending on the contamination levels that exist and environmental, health and safety levels that are expected, the type of pathogen removal process to be employed differs. Causes for breakdown of secondary treatment systems A smooth functioning of biological wastewater treatment systems is dependent on various parameters. Breakdown of secondary system is usually associated with reduced growth of desirable microorganisms or increased growth of undesirable microorganisms that can lead to lesser reduction of COD , nitrogen and excessive foaming. A choked or non-functional aerator system can lead to anoxic environment favoring the growth of undesirable microorganisms. pH fluctuations to the extreme can lead to an unfavorable environment for microbial growth. Irregular or disproportionate sludge wasting and sludge recirculation can lead to accumulation of sludge in the tank reducing the capacity for waste water treatment. Shock loads of any kind can also spur complete breakdown of the secondary treatment system. Preventing shock loads to secondary treatment system A change in any parameter of the effluent system that can disturb the ecosystem of secondary treatment can be considered as shock load. There are several factors that can lead to shock load and hence it is necessary monitor and maintain the characteristics of incoming effluent and waste water system for smooth functioning of treatment plant. Some of the factors that can lead to shock load are as follows:

• Aeration Reduction in dissolved oxygen content in the effluent system can create anoxic environment in the system promoting the growth of undesirable microflora in the system.
• Toxic compounds An entry of highly toxic compound into effluent stream can hamper the microbial growth reducing the MLSS in the secondary system.
• pH shift Sudden shift of pH to either acidic or alkaline side can affect the growth of microorganisms of the affecting the system.

  Organic loading rate- the rate of inflow and outflow of effluent should be maintained to achieve an optimum residence time. Large fluctuations in the flow can change the organic loading rate of the system. Uses of treated wastewater An effluent or sewage water cannot be used directly for any purpose but when this wastewater is properly treated and the characteristics of water is brought under environmental safety standards the water can be reused for variety of purposes like using water for cooling jackets in industries, gardening, irrigation of non food crops, flushing toilets, curing the construction sites etc., reducing the load on fresh water systems.  

FAQs

1. My aerobic wastewater system is not working efficiently, which microbial culture can help me out with these? And: First of all, we would like you to get in touch with one of our experts. Also why don’t you check Cleanmaxx® -Aerobic microbial culture. It is one of the most effective biological wastewater treatment enzyme for aerobic systems. This bio enzyme contains specialised heterogenous concentrated consortium of uniquely functional bacteria with a high proliferative capacity and tenacity that can withstand and treat any hostile effluent water. To know more about microbial culture for industrial wastewater treatment , Click here    2. How can I increase biogas production and treatment efficiency in my Anaerobic system? Ans: Anaerobic wastewater systems are tough to stabilize. They are very sensitive and require presence of diverse microbes to complete, Hydrolysis, Acidogenesis, Acetogenesis & Methanogenesis process. Cleanmaxx® ANB provides a highly diverse facultative anaerobes which strengthen and stabilize an anaerobic wastewater system. It maximizes reduction the COD – BOD parameters while simultaneously enhancing biogas production capacity & minimizing sludge volume.To know more about this, Click here 3. I require Nutrients for my biological system, how can Organica Biotech help me? And: In any Biological system it is important to maintain C:N:P ratio in order to reach good treatment efficiency. We would suggest you to go with MICROBSTER which is a bio enzyme for wastewater treatment. It is a 100% natural eco-friendly nutrient additive that is a blend of nitrogen, phosphorus, micronutrients as well as biostimulants that are crucial to biomass development for sewage and industrial wastewater treatment. Our experts at Organica will guide you throughout the dosing process. To know more about this, Click here 4. I have excessive build-up of fats, oils, and grease in oil and grease traps which results in the emission of foul odour, what should I do? Ans: We at Organica Biotech have specifically developed Cleanmaxx FOG for degrading excessive build-ups of Fats, Oil & Grease. Microbes present in Cleanmaxx® FOG are selectively cultivated and are highly target-specific. These microbes get activated when mixed in water. Upon activation they completely degrade organic waste during industrial wastewater treatment, ensuring that the emission of foul odour is curbed.  Click here for more details. 5. My STP cannot handle tough urban waters with high Organic load and diverse pollutants, how does Cleanmaxx STP helps in treating such water? Ans: Cleanmaxx® STP mode of action essentially comprises of two major steps. The initial step involves the breakdown of complex compounds into simple polymers. These polymers are further degraded to form carbon dioxide and water. A major portion of all man-made and natural contaminants present in municipal wastewater can be effectively degraded by Cleanmaxx® STP. It consists of specialized strains of bacteria that survive and perform under shock loads. Click here for more details. 6. I want to understand the current health of my Biological system, what should I do? Ans: Our Biocheck study helps in analysing the current health and status of the biological system at your sewage or industrial wastewater treatment plant. To know more about this Click here 7. Do all microbes perform in a biological wastewater treatment with equal efficiency? And: Microbes show greater biological diversity than any other life forms on the planet. Depending on the environment, food and genetics of the microbe, their capacity to degrade and treat different kinds of waste varies. In an industrial wastewater treatment plant, the greatest deciding factor for microbial treatment performance is the type of effluent as well as the type of treatment. Therefore, not all microbes can perform in a biological wastewater treatment with equal efficiency. With our repertoire of diverse products to suit every plant’s need, all you need to do is get in touch with our team to find the right product for your plant. Remember, the key to efficient sewage and industrial wastewater treatment in your plant lies in choosing the right microbial partner. 8. Which is the most efficient technology for secondary treatment of wastewater? And: Bio enzymes for wastewater treatment can be created using various established technologies like activated sludge system (ASP), Moving bed biofilm reactor (MBBR), Membrane bioreactor (MBR), Sequencing batch reactors (SBR), Rotating biological contactor (RBC), aerated lagoons, aerobic granular sludge technology, Upflow anaerobic sludge blanket (UASB), anaerobic lagoons, Anoxic reactor, anamox etc. But the selection for industrial wastewater treatment through biological treatment is based on the type of industrial effluent, parameters to be treated, space availability etc. Irrespective of the type of treatment process you choose, ultimately the efficiency of the industrial wastewater treatment depends on the efficiency of the microbes inhabiting the secondary wastewater treatment unit. 9. Can I reduce ammonia by secondary treatment of wastewater? And: Presence of ammonia in an industrial wastewater treatment plant can lead to toxicity. The concentration of ammonia can be reduced by secondary treatment of wastewater with microbial action where the ammonia is first oxidized to nitrites and nitrates, this process is known as nitrification. Further, nitrates are reduced to nitrogen gas which is released into the atmosphere, this process is known as denitrification. Denitrification is especially crucial since the release of nitrates into the environment can cause eutrophication or algal bloom. 10. How do I achieve efficient COD reduction when the effluent in my wastewater treatment plant contains high TDS (Total Dissolved Solids)? And: In general, high amounts of total dissolved solids, restrict the growth of microbes due to the osmotic stress TDS creates on the microbe. The microorganisms present in Cleanmaxx are specially selected for their ability to sustain high TDS effluents and still provide efficient COD reduction in an industrial wastewater treatment plant. 11. What is the difference between aerobic and anaerobic treatment of wastewater? Ans: The main difference between aerobic and anaerobic treatment of wastewater is that an aerobic wastewater treatment process utilizes microbes that require oxygen to respire and degrade organic matter present. In anaerobic wastewater treatment, the degradation of organic matter occurs in the absence of oxygen using anaerobic microbes. 12. For secondary treatment of wastewater, what mode is better suited, aerobic or anaerobic treatment of wastewater? Ans: The aerobic process is less energy efficient but provides effective secondary treatment of wastewater with lesser retention time and space requirement. While anaerobic treatment is energy efficient but treatment of wastewater requires high retention time with huge space requirement. Anaerobic treatment is usually chosen when the organic load is excessively high or the wastewater contains xenobiotic (tough to degrade biologically) compounds. Many industries deploy both, the aerobic and anaerobic treatment process. 13. Is the presence of filamentous bacteria in my biological wastewater treatment plant a cause of worry? Ans: In a biological wastewater treatment plant, filamentous bacteria form the backbone of floc formation that leads to a healthy sludge. So presence of filamentous bacteria in small amounts is desirable. But high density of filamentous bacteria could indicate that the food to microbe ratio, pH, dissolved oxygen may not be optimal in your wastewater treatment plant. Investigating the root cause is important as continued presence of high amount of filamentous bacteria causes heavy foaming and other issues which could badly affect your treatment efficiency. 14. How do I analyse the toxicity of the effluent in my wastewater treatment plant? Ans: The presence of higher life forms such as ciliates, flagellates, rotifers etc. in a biological wastewater treatment plant indicates that the effluent is non-toxic or has very low level of toxicity. The absence of higher life forms and microbes indicates that the effluent in your wastewater treatment plant is toxic and needs to undergo an additional treatment. 15. Can I reduce toxicity of my effluent using biological wastewater treatment? Ans: Yes, in a biological wastewater treatment plant, microbial action can break down high molecular weight toxic compounds into smaller molecules to use it as a food source, thereby reducing the toxicity of the effluent. But this must be tested at a pilot scale, while deploying bioremediation products of your choice. You can do this by using our BioSure  services. Get in touch with us to know more. 16. How do I decide the volume and rate of sludge wasting in my wastewater treatment plant? Ans: The sludge recirculation of a wastewater treatment plant is usually decided on the basis of MLSS & MLVSS present in your system and settling characteristics of your sludge. 17. How can I understand the efficiency of my biological wastewater treatment plant without the use of microscope? Ans: Studying various microbes and analyzing the total microbial count of a sample from your secondary wastewater treatment unit can give you an in-depth view to the health of your biological wastewater treatment plant. But in absence of a microscope or a testing facility, physical characteristics such as odour, colour, turbidity, foam etc of effluent can indicate health of wastewater treatment plant. Estimation of the sludge volume index is an important way to understand the condition of your wastewater treatment plant. Here, we understand the sludge development in an aeration tank and the settling ability of the sludge, both of which are positive indicators of the biological health of your effluent. 18. What is the ideal DO level for a wastewater treatment plant? Ans: In a wastewater treatment plant usually D.O level between 1 to 2 mg/L is maintained. Low DO levels can hamper microbial growth and thus reduce the treatment efficiency of your treatment plant. 19. What is the reason for rise in DO level during secondary treatment of wastewater? Ans: During the secondary treatment of wastewater the most common reasons for increase in D.O are reduction is MLSS, high organic loading rate or introduction of wastewater from a toxic stream. Drops in respiration rate due to lowered metabolic activity of microbes in the secondary wastewater treatment unit could result in sudden increase in dissolved oxygen. 20. How can I replicate the process of biological wastewater treatment at pilot scale? Ans: It is very difficult to replicate the actual biological process on a lab scale or a pilot scale, but with our specially designed  Biosure method, we can test the efficacy of our robust wastewater bioremediation products with effluent from your plant. This method will provide you a very realistic scenario and a solution. 21. Will the addition of microorganisms to primary tank increase the efficiency of secondary treatment of wastewater? Ans: In a primary treatment tank, the effluent is subjected to chemical treatment, where conditions may not be conducive for microbial growth like that of biological treatment plant. High amounts of alum, polyelectrolytes or other chemical settling agents are harmful to microbes along with fluctuating pH. So normally it is not advisable to add microorganisms in a primary tank. 22. Does the presence of heavy metals in effluent affect my secondary treatment of wastewater? Ans: Heavy metals have been known to be toxic for microorganisms and can hinder their growth. The microbes present in Cleanmaxx can sustain in presence of heavy metals. High concentration of heavy metals in wastewater treatment plant can inhibit the growth of microbes, in this case chemical scrubbing and other methods must be employed before the effluent undergoes biological treatment. 23. Can both organic and inorganic components of wastewater can be treated in a biological wastewater treatment plant? And: Technically only organic matter in a wastewater can be treated in a biological wastewater treatment system, as microorganisms can use only organic compound as their food source, but  some inorganic compounds can also be consumed by the microbes provided you have the right microbial strain in your biological units.