Industrial facilities must meet EPA and local wastewater requirements for effluent, including those under the Clean Water Act. Failing to do so can result in severe fines that quickly escalate. Although the type of industry and specific operational practices determine the type of wastewater generated, most involve suspended solids, heavy metals, organic compounds or a mix of other pollutants. Under the Clean Water Act, for example, the Environmental Protection Agency has identified 65 materials and classes of materials as “toxic pollutants,” of which 126 specific substances have been designated as “priority” toxic pollutants.
For many industrial facilities, addressing these requirements means installing a wastewater treatment system that effectively separates the contaminants from the wastewater so it can be discharged legally into sewer systems or reused. Traditional industrial wastewater treatment systems can be complex, however. They often require multiple steps, several chemicals and a considerable amount of labor. Even when the process is nominally automated, technicians must still monitor the equipment in person. This usually requires oversight of mixing and separation, adding of chemicals and other tasks required to keep the process moving. Even then, the water produced can still fall below mandated requirements.
Although paying to have industrial wastewater hauled away is also an option, it is extraordinarily expensive. It is much more cost effective to treat industrial wastewater at its source. Doing so allows treated effluent to go into a sewer, and treated sludge that passes a toxicity characteristics leaching procedure (TCLP) test can be disposed of as nonhazardous waste in a local landfill.
Complying with EPA and local wastewater regulation has become much easier with more fully automated, wastewater treatment systems, fortunately. Such systems can help industrial facilities reliably meet regulatory wastewater requirements as well as reduce the costs of treatment, labor and disposal when the proper separating agents are used.
Teamed with effective separating agents, modern automated wastewater treatment systems can provide industrial manufacturers with a cost-effective system to remain compliant with local ordinances and EPA regulations.
Automated Wastewater Treatment
In contrast to labor-intensive multiple-step processes, automated wastewater treatment can help to streamline production — usually with a one-step process — while lowering costs at industrial facilities.
For instance, an automated wastewater treatment system can eliminate the need to monitor equipment in person while complying with EPA and locally mandated requirements. Such automated systems separate suspended solids, emulsified oil and heavy metals. They encapsulate the contaminants, producing an easily dewaterable sludge. The water typically is separated using a dewatering table or bag filters before it is discharged into sewer systems or further filtered for reuse as process water. Other options for dewatering include using a filter press or rotary drum vacuum. The resulting solids are non-leachable and are considered nonhazardous, so they will pass required testing.
Such systems are available as manual batch processors, semi-automatic and automatic. They can be designed as a closed-loop system for water reuse, or they can provide a legally dischargeable effluent suitable for the sewer system. A new, fully customized system is not always required. In many cases, an industrial facility’s current wastewater treatment system can simply be modified. Because every wastewater stream is unique to its industry and application, each wastewater treatment solution must be evaluated and tailored to the application.
The first step in evaluating the potential cost savings and effectiveness of a new system is to sample the wastewater to determine its chemical makeup. This is followed by a full review of local water authority requirements. The volume of wastewater that will be treated also is analyzed to determine if a batch unit or flow-through system is required. Other considerations include any size restrictions so the system fits within the facility’s available footprint.
An automated wastewater treatment system can eliminate the need to monitor equipment in person while complying with EPA and locally mandated requirements. Such automated systems separate suspended solids, emulsified oil and heavy metals, and they can encapsulate the contaminants, producing an easily de-waterable sludge.
Case In Point
One example of a successful automated wastewater treatment installation involves one of the largest independent corrugated manufacturers. The company processes more than 8 million ft2 of corrugated packaging and displays per day. The corrugated manufacturer sought out an automated water treatment solution because the company wanted to treat wastewater from the washdown of its flexographic printing presses more effectively. (Various inks are used in the flexographic manufacturing process.)
For this application, the corrugated manufacturer selected a fully automated wastewater system using a proprietary separating agent. The system included:
- A high volume, flow-through mix unit.
- A large-capacity feed hopper.
- A bag housing for solids removal.
- A self-indexing dewatering table.
- Final polishing vessels.
Sensors ensure proper material flow and operation, and onscreen audio-visual alerts indicate if anything requires attention.
The fully automated system means that instead of the typical labor-intensive, in-person equipment monitoring, the mix chambers’ motors are controlled electronically by human machine interface (HMI). They can be adjusted remotely, along with the mix motor speed and powder feed, by the water treatment system provider. The industrial wastewater equipment provider also can utilize the equipment’s integrated webcams as needed to view the mixing chambers for flocculants formation, floc structure, color and water clarity. Remote access also enables viewing alert conditions on the touchscreen and provides the ability to reset the machine if needed.
Despite all the advances in automating wastewater treatment equipment, any such system requires effective separating agents that agglomerate with the solids in the wastewater so that the solids can be safely and effectively separated out.
While equipment advances related to automating wastewater treatment equipment are important, any such system also requires effective separating agents. Such agents agglomerate the solids in the wastewater so that they can be safely and effectively separated out.
Among the materials used for agglomeration, one wastewater treatment equipment provider uses a special type of bentonite clay. These wastewater treatment chemicals are formulated to break oil and water emulsion, provide heavy-metals removal and promote flocculation, agglomeration and suspended-solids removal.
Bentonite has a large specific surface area with a net negative charge that makes it a particularly effective adsorbent and ion exchange for wastewater treatment. (It is suited for applications to remove heavy metals, organic pollutants, nutrients, etc.) As such, bentonite is essential to effectively encapsulate the materials. Usually, this can be achieved in a one-step treatment, which lowers process and disposal costs.
In contrast, polymer-based products do not encapsulate the toxins. Systems that use that type of separating agent may have waste products leach out over time or upon further agitation.
In conclusion, modern automated systems — along with effective separating agents — can provide manufacturers with a cost-effective means to remain compliant with local ordinances and EPA regulations. PC