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.
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.
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.