Biological Wastewater Treatment
Most large-scale wastewater treatment with a large portion of organic pollutants are treated biologically. In many cases, natural occuring microbes can be cultivated and utilized within the system. However, achieving a stable and constant discharge parameter is never an easy task! An effective way of maintaining a stable output is by adding pollutant-specific microbial products regularly to keep the treatment system at a sound and healthy state. We have a wide range of pollutant-specific wastewater treatment products to cater to many different industrial wastewater treatment systems.
Biological Wastewater Treatment
The main problem with the effluent from dairies and meat processing plants is the large amounts of animal fats present. These create major problems by coating drains, pumps, pumping stations, inlet screens and primary clarifiers. In many activated sludge plants, excessive quantities of fat can give rise to Nocardia foaming which causes major operational problems. While the bulk of the fats/grease is removed in Dissolved Air Flotation (DAF) units or grease interceptors the remainder must be treated in the wastewater treatment system. Other components of the effluent such as proteins, blood and lactose contribute to an effluent with a high BOD.learn more
The effluent from the meat processing industry contains high levels of proteins in the form of blood and muscle. There are also considerable quantities of animal fats and in slaughtering facilities, of manure. Due to the nature of the industry, there are seasonal variations in the flow and organic loading based on the kill. Effluents containing blood are highly coloured and due to their very high organic strength, they can cause oxygen depletion in an activated sludge treatment plant. The degradation of proteins gives rise to the production of considerable quantities of ammonia. It is therefore important that the proteins are broken down efficiently so that nitrification can be established in the wastewater treatment plant.learn more
The effluent from plant processing industries contains large quantities of organic materials such as starch, cellulose, hemicellulose, sugars, protein, etc. In many instances, plant processing is operated on a seasonal basis depending on the harvesting of the crops. Industries which are associated with plant processing include: -
- Vegetable canning/freezing
- Fruit canning/juice extraction
- Wine production
- Sugar production
While the degradation of residual sugars and protein are relatively easy, the degradation of starches, cellulose and hemicellulose are more difficult. This can result in poor effluent quality.
The effluent from the pulp and paper industry contains large quantities of plant organic materials such as cellulose, hemicellulose, lignin, starch, etc. In addition, there are many organic chemicals arising from the papermaking process, particularly from bleaching and deinking. The pulp and paper industry is characterised by discharging very large volumes of warm water with variable organic strength and pH. This causes a number of problems with the treatment of such effluents. The variability in composition and the wide range of compounds in the effluent require biomass with a broad range of activities to effectively treat it. Due to the large volumes, it is necessary to have biomass with good settling characteristics so that a clarified final effluent can be produced.
While the degradation of starches is relatively easy, the degradation of cellulose, hemicellulose, lignin and organic chemicals are more difficult. This can result in poor effluent quality.learn more
The effluent arising from the production of organic chemicals can contain a very wide range of compounds. Due to the nature of the processes used in chemical synthesis, there can be major variations in the composition of the influent to the treatment plant. Some of the industries that produce a wide range of aliphatic and aromatic chemicals requiring treatment include:-
· Solvent production
· Printing Inks
Since there is such a wide diversity of industries and of compounds present in these wastewaters it is important to have a microbial product with a wide range of strains capable of dealing with the problem. Such a product is Biofixit 5400GC.learn more
Oil refineries and petrochemical production plants produce effluents that contain a complex mix of compounds. These compounds are derived from the crude oil that is the primary feedstock for these plants. Among the compounds found in these effluents are aliphatic, aromatic, polar and asphaltenes. The compounds can range from volatile aliphatics and aromatics to heavy tars and waxes. Since there is such a structurally complex range of hydrocarbons present it can be difficult to establish efficient biomass to treat it. It is therefore important to select a product with a broad range of strains and degradative abilities. The product of choice is Biofixit 5500HC.learn more
Surfactants in wastewater streams cause major problems when they enter treatment plants. Under the influence of aeration they produce massive amounts of foam which can be unsightly and causes problems with oxygen transfer. This has a detrimental effect on the performance of the treatment plant and can cause unsightly scum to carry across to secondary clarifiers and coat all surfaces. When surfactants enter watercourses such as streams or lakes they cause problems with oxygen transfer to aquatic life such as fish by coating their gills. This results in fish kills.
Surfactants consist of a wide range of different compounds with differing characteristics, including soaps, wetting agents, emulsifiers, detergents, etc. Since they are not part of the natural environment it is difficult for the bacteria in treatment systems to biodegrade them effectively.learn more
Sulphides develop in wastewaters from the anaerobic decomposition of organic matter containing sulphur or from the reduction of sulphites and sulphates. The most common sulphide encountered is hydrogen sulphide (H2S). This is a colourless, inflammable gas with the characteristic odour of rotten eggs - a foul smell.
Odour control is a major concern in the operation of many municipal and industrial wastewater treatment plants. Foul odours are a public nuisance and give rise to unfavourable publicity. Environmental legislation is becoming stricter all the time especially in relation to odours / air emissions released adjacent to sensitive areas such as housing, recreation parks, schools, etc.learn more
The biological degradation of the effluent from many industries and, indeed municipal effluent, gives rise to the production of ammonia (NH3) in addition to carbon dioxide (CO2) and water (H2O). Since ammonia is toxic to fish and other aquatic life at very low levels and can lead to eutrophication in receiving waters it is extremely important that it is removed before final discharge. This removal process is known as nitrification and involves the oxidation of ammonia. The process is carried out by specialised organisms called nitrifying bacteria. These organisms grow at a very slow rate compared to the other microbes in a wastewater treatment system and are very sensitive to chemicals and environmental conditions. It is therefore very easy for nitrification activity to be lost and it can be slow or difficult to restore. Under these circumstances the proactive approach is to add nitrifying cultures.learn more
A wide range of aromatic compounds is contained in the effluents from many chemical processes. Due to the nature of the processes used in chemical synthesis there can be major variations in the composition of the influent to the treatment plant. Some of the aromatic chemicals involved are phenols, benzene, toluene, ethyl benzene, xylene (BTEX), aniline, etc. Some of the industries which produce effluents containing these aromatics include:
- Solvent production
- Wood preservatives
Since there is such a wide diversity of industries and of aromatic compounds present in these effluents it is important to have a microbial product with a broad range of strains capable of dealing with the problem.