Complete Zero Discharge Waste Treatment System

Ask Met-Chem about a Zero Discharge System

Customer

Fortune 500 manufacturer of heavy equipment

Problem

The object of this project is to use wastewater treatment and water recycling technologies to achieve zero liquid discharge of wastewater from the surface finishing process. This was a brand new building, a new line, and a new wastewater treatment system.

Although the Waste Water Treatment System is not intended to discharge to a municipal sewer system, the system had to be designed to meet the federal pre-treatment standards for standard wastewater discharge for heavy metals, toxic organics, total suspended solids and a discharge pH between 6.0 and 9.0. It was also essential that the filter cake solids be between 20-50%.

Size requirements were that the entire system must be installed in area 120’ x 35’ building addition.

With this proposal, we needed to supply

Preventive maintenance schedule and training
Critical spare parts recommendations
Field testing, start-up, and installation
Equipment warranties
OSHA safety standards
Fresh RO System
Wastewater collection
Wastewater treatment equipment
Sludge precipitation and dewatering equipment
Water reuse
Process RO water supply
Engineering information

Process

We began with a general discussion of the system requirements and expectations including how automated the system needed to be. There were several proposals that were modified as discussions continued regarding the type of treatment that would be best for this brand new application. We sent our engineering staff and project manager to the facility in order to go through the project and site details that needed to be considered.

Prior to the installation of the system, Met-Chem submitted drawings to a certified engineer in order to have them sign off, indicating that the proposed system was in compliance with that state’s wastewater treatment and discharge requirements. Once the system was approved, we began manufacturing the equipment.
We were working with tight time constraints to get this system built, installed and running.

Solution

We started with the basic water treatment equipment which included wastewater collection, pH adjust, solids settling and dewatering. The key pieces of equipment installed included collection and treatment tanks, sludge thickening tank, clarifier, filter press water softeners, reverse osmosis system, cationic and anionic polymer feed, pumps, meters, level controls, and alarms.

After standard chemical precipitation, the clarifier water had to be cleaned up to be reused on the process line. Following the clarifier, the water went through sand filters, carbon filters, cartridge filters, bag filters and then through an ultrafiltration system and finally to a reverse osmosis system to provide clean water that could be used on the process line. The contaminants from the filters and the ultrafiltration and reverse osmosis went to a waste reverse osmosis system to squeeze out as much water out of the waste for reuse while the remaining wastewater was sent to holding tanks for haul off. The plan was to add evaporation equipment to these waste holding tanks to reduce this haul off water by 90% when the end user had more capital money available in the next budget year. This system allowed the customer to send no water to sewer, reuse 98% of the wastewater on the process line and only haul off 2% of their water as waste (which can be reduced to .2% if evaporation equipment was added on the waste haul off tanks.)

Met-Chem handled the entire project in-house from start to finish. We manufactured the equipment, installed the system, and personally handled the on-site troubleshooting and training of waste treatment personnel at the facility.

All requirements were met within the allotted timeframe, including installation and startup. The system continues to function as originally designed.