Industrial waste water generated in industrial establishments because of processes, activities or services are characterized by high concentrations of contaminants, such as organic contamination BOD and COD, suspended solids, oil, grease, hydrocarbons and metals among many others.
The biological treatment of wastewater is carried out through certain treatment processes which use microorganisms to eliminate contaminants, mostly organic, in the water. These processes take advantage of the microorganisms’ ability to assimilate organic matter and nutrients dissolved in wastewater (including nitrogen and phosphorus) for their own growth. When reproducing, they form macroscopic flocs with sufficient critical mass to remain suspended or adhered to a place, and subsequently they are separated by flotation, settling, filtration or other processes.
The mechanism of aerobic biological oxidation consists of the assimilation of biologically degradable organic matter by heterotrophic microorganisms in the presence of oxygen and nutrients.
Among the aerobic biological treatment systems are:
This treatment consists of developing a bacterial culture from the water to be purified (substrate) in a mixed and aerated tank (aeration tank). Under appropriate conditions, dispersed microorganisms will form flocs mixed liquor suspended solids [MLSS] which later will be separated by a solid-liquid separation process (sedimentation or membranes).
MBR (Membrane Bioreactor)
MBR systems can ensure discharges with minimal solid concentrations and very low agglomeration of BOD (biological oxygen demand). In most cases, these systems allow reuse of water in different processes or ensure compliance with regulatory requirements for the concentration of TSS (total suspended solids) and organic loading.
The MBR system should be understood as the combination of an activated sludge biological system and a membrane system that retains the biomass in the reactor and obtains a low solids effluent.
MBBR (Moving Bed Biofilm Reactor)
The biological treatment system with MBBR technology is a process that includes carrier elements that are freely suspended in the aerobic bioreactor (mobile bed) specially designed for the formation of biofilm. Bacteria grows and develops on the surface of the carriers.
Anaerobic digestion is one of the mechanisms most frequently used by nature to degrade organic substances. In fact, this conversion occurs in various environments, whether natural or in controlled systems such as digesters or anaerobic fermenters. This biological process is based on the transformation, through biochemical reactions, of contaminants in gas (biogas) whose main components are methane (CH4) and carbon dioxide (CO2).
Technologies for water treatment have been developed based on hermetic reactors. In these reactors, different types of microorganisms may be involved, but they are mainly drive by bacteria.
The two most commonly used digesters are:
The presence of metals in water, such as copper, mercury, chromium, nickel, zinc, lead and cadmium, is a significant environmental problem due to their high toxicity. To obtain a low metal concentrations in effluent, different methods and technologies can be used according to the particular removal features. Additionally, the metal which is recovered can be used as a byproduct in other processes.
The UNIPURE® process technology uses a unique mechanism for removing heavy metals. Coprecipitation on an iron matrix improves the efficiency of heavy metals removal, obtaining a simultaneous reduction of solids.
Heavy metals are captured in an insoluble iron matrix. This capture occurs because heavy metals are coprecipitated at the same time as iron, which is rapidly removed from the solution. In this process, the effectiveness of classical coprecipitation is optimized by prior association of heavy metals with the iron molecule. Heavy metals are related to iron in the solution by a mechanism of occlusion and adsorption, which creates an entropic effect or concentration that substantially increases metals removal, and it decreases iron requirements at the same time.
Ecopreneur is the exclusive representative of this technology to Chile, Peru and Colombia.
Metals which are soluble in water can be precipitated by the formation of metal hydroxide, reaching the pH range of lowest solubility of that hydroxide. This is widely used to separate metals from aqueous solutions, especially to remove metals as sole contaminants in the water. The presence of several different metals may require a serial process, working at the lowest solubility pH of each hydroxide formed.
The precipitated solids are coagulated, flocculated and separated in a settler, where Lamella® plate clarifiers are generally used.
In the absence of air wastewater treatment processes, and others involving degradation, transformation or accumulation of wastewater or organic matter, can generate odorous gases composed mainly of volatile organic compounds (VOC), hydrogen sulfide and ammonia.
Odor treatment designs are based on 3 stages:
1) Confinement of odors generation spaces (encapsulation).
2) Conduction of air to the treatment system
3) Odor treatment to remove the mentioned odoriferous compounds.
The treatment usually takes place in a biofilter, which consists of an organic or inorganic filter bed to support microorganisms that will remove the polluting gaseous compounds. The gas to be treated flows through the filter bed, then the compounds are transported from gas to a liquid phase, where they are degraded by the active biomass which adheres to the organic support surface.
Conditions which must be monitored in the system include pH, water content, nutrient concentration and the gas-liquid phase contact surface area. When these conditions are maintained and balanced, the system will work correctly and effectively remove the contaminating gases.
The main applications of odor treatment are:
• Collectors and lifting plants for sewage and wastewater in general
• Accumulation tanks (equalizers, sludge tanks)
• Head works and dewatering rooms
• Facilities where solid and liquid wastes of organic origin are handled (food processing plants and agricultural products in general)
Natural gas produced by anaerobic reactors for waste treatment, as well as gas generated in sanitary landfills, is a mixture rich in methane that must be treated to purify the gas and maximize its use and efficiency.
The main compound that is included with methane in this natural gas mixture is hydrogen sulfide (H2S). This compound can be separated with high efficiency as in the case of THIOPAQ® technology.
The main goal of this stage is to separate the solids that have not been considered to degrade in the upcoming biological processes.
Fine and Thick Solid Separation
In general terms, wastewater treatment systems start with the separation of coarse and fine solids through static, rotating or channel screens, among others, mostly self-cleaning. These solids separation systems are complemented by screws and conveyors, dewaters and compactors.
Coarse / Fine / Pre-treatment Equipment
Dissolved Air Flotation Systems (DAF)
The aeration system is the main part of an aerated biological treatment system, such as activated sludge, MBR, MBBR or others. The energy consumption of these systems comprises one of the main operational costs in this kind of plant. Thus, aeration systems have been developed to ensure the highest efficiency in order to achieve the lowest possible electric consumption. Ecopreneur counts on over 21 years of experience in selecting the best and most efficient aeration equipment for each particular plant.
• Aeration Panel
• Diffuse Aeration
One of the important variables to consider is the elimination of fecal coliforms to a level below 1,000 MPN/100ml. In a secondary treatment process, the coliform amount is significantly reduced, but this is not always enough to comply with the regulatory requirements, in which case requires the incorporation of a disinfection stage.
Ecopreneur disinfection treatments systems are:
• UV Radiation
Dissolved Air Flotation (DAF) systems are considered highly efficient equipment for the separation of suspended solids, oils, fats and hydrocarbons, as well as other contaminants in water treatment. They are especially used for solids removal at the primary stage of Industrial water treatment plants.
Ecopreneur has installed numerous DAF units for various industrial applications such as food, beverages, pig slurry, salmon farming, oil separation and more.
Zero Liquid Discharge (ZLD) treatments are advanced processes that allow our customers to meet the highest environmental standards.
They make viable those processes that generate effluents with higher salt contents, such as brines from membrane treatment, blowdown of cooling systems with high concentration cycles, chemical and mineral processing industries, leaching treatments, and more.
Ecopreneur has developed strategic alliances with leading worldwide companies with proven experience in this kind of treatment.
The process to be used is determined on a case-by-case basis and may incorporate advanced membranes, thermal and other processes.
Wastewater treatment processes whether physic-chemical and/or biological, involve the production of sludge (solid), which, to be used and/or disposed of, must follow a specific treatment to mitigate the environmental impact and comply with current regulations. Alternatively, the sludge may be used to generate electric or thermal energy.