Packaged Foods & Produce
Wastewater generated from food production and agricultural activities often is a major source of pollutants in the environmental. It is also among the most difficult and costly waste to manage because food processing wastewater can contain large quantities of nutrients, organic carbon, nitrogenous organics, inorganics, suspended and dissolved solids, and it has high biochemical and chemical oxygen demands.
The types of treatment technologies used for food processing wastewater are not unusual among wastewater treatment options and include the typical array of biological and physical chemical treatments. In addition, many wastes or treated residues are acceptable for land application as beneficial soil fertilizers, which can mitigate much of the wastewater discharge concerns and costs. However, even those approaches can be problematic if excessive nutrient runoff occurs, particularly in cold weather.
In-plant recycling can be an attractive option for cleaning equipment, facilities and floors. Detergents or other additives may be employed for those nonfood contact applications, which may improve or complicate (emulsify) the subsequent treatment processes. The safety of the food product is paramount, and recycling within a process step can be allowed by law for certain food processes, such as chiller water and sanitizing water.
HydroFloTech has designed a fully modular and mobile (contained based) system for the Packaged Food and produce handling companies
Pre-Treatment Module: This module removes large solids and equalizes the water prior to any further treatment. The goal of this module to get the water provide the downstream treatment equipment with an equalized stream of water which if free from large solids.
Side Hill Screen / Grit Removal System: “Side hill” or “Grit Removal Systems” are used for the removal of large insoluble material from wastewater flows. These screens or systems are used on process and wastewater streams for particles that need to be removed to protect downstream systems. These screens can also be used for product recovery; large solids separation and mixed settleable solids for both municipal and industrial applications.
The HydroFloTech Side Hill Screen or Grit Removal System maximize solids removal in an easy to maintain unit. The screen is a barrier by which material larger than the gap or slot size may not pass, allowing the water to continue through.
Equalization Tank: HydroFloTech can work with an existing equalization “EQ” tank or provide one. Materials of construction can includes: Fiberglass (FRP), HDPE, steel (carbon steel or stainless steel), concrete, or even in-ground storage pits / ponds. The purpose of the equalization tank is to “equalize” and narrow any variances in water characteristics. The EQ tank also acts as a great buffer for two main purposes: First the EQ tank provides a buffer storage capacity in situations when there is a temporary surge in flowrate. This allows the system to be smaller than the peak surge flowrate. Secondly, the EQ tank also provides the ability to “narrow” any spikes in any contaminants.
Chemical Pre-Treatment and Solids / Fats & Oils Removal: This module chemically treats the water with pH adjustment (as necessary), coagulant and polymers to enhance the ability of HydroFloTech inclined plate clarifiers or dissolved air floatation systems (DAF) to effectively remove any Total Suspended Solids (TSS) or Fats, Oils and Grease (FOG).
ChemiSep Chemical Pre-Treatment System: The efficacy of any wastewater is as good as the pre-treatment of the wastewater prior to removal of any impurities. The HydroFloTech ChemiSep Pre-Treatment System provides great flexibility in treating various wastewater profiles:
- Stage 1 – pH Adjustment / Precipitation & Coagulation: pH is raised (or lowered) with the pH controller using caustic (or acid). A coagulant is added to cause precipitation of the solids. A “pin floc” is developed indicating that the suspended solids are precipitated.x
- Stage 2 – Flash Mix: The wastewater with it’s precipitated pin floc is introduced to the flash mix zone where a polymer flocculent is added. This stage maximizes flocculent dispersion throughout the coagulated wastewater.
- Stage 3 – Flocculation: The wastewater is now introduced to the slow mix zone to agglomerate the floc into larger particles suitable to be enmeshed with the air bubbles.
HydroFloat Dissolved Air Flotation (DAF) System:
The flocculated wastewater is introduced into the HydroFloat DAF inlet where the floc particles are comingled with a pressurized dissolved fine bubble recycle stream. The floc particles attach to the bubbles and float to the surface where they are mechanically skimmed into the float scum sludge chamber. The treated water then exits the end of the DAF and flows downstream to sewer or further treatment if necessary. The DAF system bubbles come from a Recycle Air Dissolving system that takes a portion of treated effluent, pressurizes it and introduces air to be dissolved. The dissolved air comes out of solution and forms a fine bubble stream when the pressure is released at the DAF entrance in the presence of floc wastewater.
BioSep MBBR System (BOD / COD Removal): This module removes Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) from the wastewater primarily through the BioSep MBBR system comes in handy if the water has high levels of BOD / COD (upwards of 500+ mg / l).
Basin: The MBBR process takes place in a basin/tank, also known as a bio-reactor or as an aeration tank. The size of this bio-reactor depends on the filtration needs of a particular plant. Influent enters this bio-reactor for treatment. MBBR aeration tanks are open at the top or vented adequately, exposing the water to the open air, which makes this an aerobic process of filtration.
Media: The basin is full of thousands of small plastic chips, called media or carriers. These media may occupy as much as 40 to 65% of the tank. Their design maximizes the surface area they provide for biofilm to grow on them. Many carriers resemble wheel-shaped, pucks They mirror the density of water, allowing them to mix throughout the fluid, rather than floating or sinking.
Aeration grid: Another thing that helps the media move effectively throughout the tank is an aeration grid. This device is essentially like a fan located at the bottom of the reactor tank. The aeration grid helps keep carriers in motion so they can come into contact with all the waste present and efficiently decompose it, and introduces more oxygen into the tank.
Sieve: The mesh material allows water to pass through, but keeps the plastic carriers inside the bio-reactor.
Clarifier: The bio-sludge generated through the BioSep MBBR System is removed by using a clarification system.
ChemiSep Pre-Treatment System: Water is run through two individual stages of tanks for separating the bio-sludge from the water.
Clarifier: The flocculated wastewater is introduced into the clarifier where the settling particles accumulate in the sludge chamber. The clarified water then exits the clarifier and flows downstream to sewer or further treatment if necessary.
Sludge Management Module: This module removes the precipitated solids from the water and converts those solids into dewatered “sludge” which may be eligible for re-use or landfill disposal.
Sludge Tank with Sludge Transfer Pump: The accumulated sludge is periodically removed from the clarifier and sent to a sludge holding tank where it further thickens for disposal or dewatering.
Sludge Dewatering: Sludge dewatering is typically handled by a HydroPress Filter Press or Screw Press. After processing a batch of “sludge” the filter press or screw press is emptied of “chrome cake” which is a semi solid of approximately 20-35 % solids. Chrome cake is high in chrome and sulfite and should be disposed of according to environmental regulations.
Re-Use Module: This module further reduces any remaining solids and biological / bacterial growth in the water to make it suitable for re-cycling or re-use.
RO System: The RO System removed any remaining dissolved solid (TDS) in the wastewater. The effluent coming out of the RO System is suitable for re-cycling / re-use.
UV Filter System: The UV Filter System finishing a final sanitizing of the water. The UV Filter System allows for the treated water to be used for most re-use / recycling purposes.