Chemical Industry
The chemical industry is a major user of water and generator of wastewater. Water is used throughout the supply chain from large integrated petrochemical facilities to smaller contract formulation and packaging facilities. Depending on the facility design and chemicals produced certain process technologies and treatment strategies will be more successful than others. Salt Creek Technologies can help you find the best strategy technically and economically for your company or client.
When evaluating existing or potential water and wastewater treatment systems for chemical plants it is important to first understand it's size and production objectives. In general facilities fall into two categories: large chemical production sites and smaller packaging, formulation and handling facilities.
Large Chemical Production Facilities
Large chemical production facilities produce commodity and specialty chemicals in large quantities that are typically intermediate products or sold in bulk quantities to major consumers (ie PTA, LDPE, HDPE, Pesticides, etc). Inside these facilities reactors, distillation columns, furnaces, absorbers, scrubbers, and boilers are used to produce and purify the products and they utilize water and produce wastewater in many ways, here are some that are most common:
Water Uses
Wastewater Sources
Typically large chemical facilities will have their own NPDES discharge permits with wastewater treatment plants consisting of primary treatment (FOG/TSS), secondary biological treatment (BOD/COD) and sometimes tertiary polishing (and/or reuse systems) to achieve stringent effluent requirements into local bodies of water. These large chemical plants will have fairly consistent and predictable wastewater streams so designs are tailored to the specific pollutants that are generated inside the plant and designed to run almost continuously.
Smaller Packaging, Formulation and Handling Facilities
At smaller chemical facilities bulk chemicals are brought in, processed and packaged into finished product. Typically these plants are more focused on blending, drying, and packaging operations although some reaction and separation processes may be employed. They are also batch operations rather than continuous producing a varying slate of products and formulations. Water uses and wastewater sources are the follwoing:
Water Uses
Wastewater Sources:
Smaller chemical facilities are usually reliant on discharge to the local POTWs, so there is a higher focus on meeting local requirements to ensure effective processing down stream at the municipal treatment plant and minimizing surcharges. The majority of the difficult to treat chemical wastes are segregated from the wastewater system and hauled off as special waste because the POTW is not set up to handle large quantities of these unique chemicals.
The wastewater generated at these facilities is usually much more variable due to the changing production runs and periodic cleaning procedures so having a flexible and robust system is typically a priority. Achieving consistent performance is typically a major pain point driving the need for automation, large EQ tanks and operator attention. POTW requirements typically have maximum limits on FOG and metal concentrations and begin surcharging chemical facilities if TSS and BOD/COD are above a certain level. In many cases the surcharges do not justify the cost of a secondary treatment facility but that is highly dependent on the individual POTW and geographical location.
When evaluating existing or potential water and wastewater treatment systems for chemical plants it is important to first understand it's size and production objectives. In general facilities fall into two categories: large chemical production sites and smaller packaging, formulation and handling facilities.
Large Chemical Production Facilities
Large chemical production facilities produce commodity and specialty chemicals in large quantities that are typically intermediate products or sold in bulk quantities to major consumers (ie PTA, LDPE, HDPE, Pesticides, etc). Inside these facilities reactors, distillation columns, furnaces, absorbers, scrubbers, and boilers are used to produce and purify the products and they utilize water and produce wastewater in many ways, here are some that are most common:
Water Uses
- Boiler Feed Water
- Cooling Water
- Process Water
Wastewater Sources
- Cooling tower blowdown
- Boiler blowdown
- Product Dryers
- Process contact water
- Site storm water
Typically large chemical facilities will have their own NPDES discharge permits with wastewater treatment plants consisting of primary treatment (FOG/TSS), secondary biological treatment (BOD/COD) and sometimes tertiary polishing (and/or reuse systems) to achieve stringent effluent requirements into local bodies of water. These large chemical plants will have fairly consistent and predictable wastewater streams so designs are tailored to the specific pollutants that are generated inside the plant and designed to run almost continuously.
Smaller Packaging, Formulation and Handling Facilities
At smaller chemical facilities bulk chemicals are brought in, processed and packaged into finished product. Typically these plants are more focused on blending, drying, and packaging operations although some reaction and separation processes may be employed. They are also batch operations rather than continuous producing a varying slate of products and formulations. Water uses and wastewater sources are the follwoing:
Water Uses
- Boiler Feed Water and Cooling Water - Required on a much smaller scale
- Product Water
- Cleaning and CIP
Wastewater Sources:
- Equipment Cleaning
- Product Dryers
- Emissions control devices
- General Facility Cleaning
- Boiler and Cooling Water Blowdown
Smaller chemical facilities are usually reliant on discharge to the local POTWs, so there is a higher focus on meeting local requirements to ensure effective processing down stream at the municipal treatment plant and minimizing surcharges. The majority of the difficult to treat chemical wastes are segregated from the wastewater system and hauled off as special waste because the POTW is not set up to handle large quantities of these unique chemicals.
The wastewater generated at these facilities is usually much more variable due to the changing production runs and periodic cleaning procedures so having a flexible and robust system is typically a priority. Achieving consistent performance is typically a major pain point driving the need for automation, large EQ tanks and operator attention. POTW requirements typically have maximum limits on FOG and metal concentrations and begin surcharging chemical facilities if TSS and BOD/COD are above a certain level. In many cases the surcharges do not justify the cost of a secondary treatment facility but that is highly dependent on the individual POTW and geographical location.
