Jar testing is a method for determining the treatment method that will be used when treating wastewater. Specifically, it helps to determine which chemicals will be needed and the proper dose rates for those chemicals. Jar testing is essentially a miniature batch treatment tank with all the variables under control of the operator. It usually consists of a "jar" or beaker of a known volume and a variable speed mixer.
The mixer can be as simple as a glass rod stirred by hand, a laboratory stir plate with a magnetic stir bar, or a motor driven metal impeller (similar to the mixers found in many wastewater treatment reaction tanks). It is also a good idea to have a pH meter for jar tests, as many of the reactions that occur during treatment require specific pH ranges.
As with any experimentation, it is good practice to take notes, keeping track of the additions and observations you make during the testing. A water sample should be taken from the equalization tank (a holdingtank where all wastewaters are intermingled before being pumped to the wastewater treatment system). You should sample a specific volume, usually a liter. Next, agitate the water in the jar, and measure the pH. In waters that may contain cleaner as well as dissolved metals, it is common to lower the pH to 2.5 - 3.0 with dilute sulfuric acid if it isn't already at the required pH.
Once the pH is lowered, you should being adding chemicals. Most often, coagulant is added at this stage. Coagulant is measured in parts per million (ppm), which is one milligram of something in one liter of water. In this case, one ppm is a one hundredth of a milliliter in one liter of water, with 1 milliliter in 1 liter of water equaling one thousand ppm. Coagulant addition may range from 1 to several thousand ppm depending on what is being treated. Allow the coagulant to mix in the water.
Next, the pH should be raised using dilute sodium hydroxide, usually to a range of 9.0 - 10.0. If required, because of complexors that might be present in the water tying up the metals, a metal precipitant can be added at a dose of 50 - 200 ppm. When metal precipitant is mixed well, the polymer should be added. In water being treated for metals, an anionic polymer is commonly used. Polymer addition should be made with good mixing to evenly distribute the polymer throughout the water. Mix for 30 to 60 seconds, then turn off the mixer. A heavy precipitate or floc should form and begin to settle to the bottom of the jar.
At this point, the jar test is complete, and a sample should be filtered and then taken to a treatability laboratory for analysis.
ProChem strives to help their customers establish the highest level of credibility and a positive reputation within the regulatory community. Their goal is to significantly reduce the amount of fresh water that manufacturers require by providing sustainable solutions that will also benefit the customer’s bottom line.
High Pressure Reverse Osmosis (I-PRO) - ProChem Reverse osmosis equipment has been used for many years to purify drinking water. It is used all over the world to desalinate seawater and bring fresh water to those with limited or no access to it. There are even household versions of reverse osmosis equipment to purify well water before it's fed into the ice maker, for example, More recently, this technology is being used in industrial facilities to recycle the wastewater from manufacturing processes.
Reverse osmosis equipment facilitates the natural osmosis process in reverse. Osmosis occurs when a less concentrated saline solution is drawn to the higher concentrated saline solution. For example, a flower's roots absorb water from the ground through osmosis. In reverse osmosis equipment, a semi-permeable membrane separates the higher concentrated water from the lower concentrated water. A little pressure is applied to the higher concentrated water, forcing it to flow through the membrane, where the salts and other particles become trapped. The result on the other side of the membrane is desalinated and filtered water.
The same reverse osmosis equipment has been scaled down for us in industrial facilities. Industrial reverse osmosis equipment uses a much higher pressure than desalination equipment, operating at 800 to 1,200 psi. Desalination equipment operates between 200 and 400 psi. Because of the higher pressure, the industrial reverse osmosis equipment can treat water with up to 35,000 ppm of total dissolved solids (TDS) while the desalination equipment treats water with TDS up to 1,500 ppm. This allows the industrial equipment to remove most any dissolved solid found in wastewater, such as heavy metals.
The effluent quality exceeds discharge permit limits and is ideal for reuse applications. It is being used to recycle industrial wastewater at a rate of 75% to 95%, instead of treating and discharging. The purify of the effluent can even be adjusted, depending upon what the manufacturing process requires. For example, electronics manufacturers require high purity water.
The disadvantage of industrial RO equipment is the rate at which membranes can become fouled. Replacing fouled membranes is expensive and requires the unit to be shut down. That's where preatreatment comes into play. With the right physical/chemical pretreatment process upstream, the life of the membranes inside the unit will be extended greatly. Cleaning membranes regularly can also extend their life.
Reverse osmosis is no longer just a treatment for drinking water. It enables manufacturers to conserve water in innovative ways by recycling their wastewater. For example, a manufacturer in Texas is using industrial reverse osmosis equipment to recycle both their industrial wastewater and the facility's sanitary water for reuse back into their manufacturing process.
There are hundreds of water treatment companies for manufacturers to choose from for their industrial water treatment needs. These companies advertise online, exhibit at trade shows, and send brochures to you. The first thing for you to understand is that not all of these companies are the same. They don't provide the same services and technologies, and they don't have the same philosophies. So, how do you determine which company is best for your facility's unique needs?
Rather than calling every water treatment company you find online to ask for a quote or a sales pitch, I recommend that you make a list of what it is you want from a company. I'm not talking about products, like deciding you want polymer or ion-exchange columns. That is only part of the list. Rather, you should decide as a package what attributes, qualifications, and peripheral services you want the water treatment company to offer.
Create your wish list, and don't limit yourself. It is possible to find one company who provides all the services you need. For example, do you need them to install the equipment? Do you already have a filter cloth supplier? Do you need consultation and engineering too? Many companies offer more than just equipment or chemicals. Some companies provide engineering services and will custom tailor solutions to each application. Some provide outsourcing services and operate your systems on a daily basis.
Location is something to consider: Many manufacturers maintain a successful relationship with their water treatment company from states away. Don't limit yourself by looking only locally.
Online research is a great tool for finding out who a company really is and what they really offer. Now that you know what you are looking for, you can narrow down your call list to companies who offer at least most of what's on your wish list. Don't just look at their products listed in bold text, read their case studies, look at their networks on social media. This will help you understand the company's philosophy, credentials, and the type of people you will be interacting with.
Monitoring capabilities are something to consider: Gathering and reporting data performance data for wastewater treatment is becoming a key part of facility management for manufacturers. Some use that data to identify product defects earlier and prevent further production loss.
Contact only the companies that meet all or most of your wish list requirements. Be ready to discuss the scope of your needs and answer questions about your goals, permits, and current treatment process.
Water analysis is something to consider: If the company you contact does not mention wanting to test your water, consider lowering that company on your list and looking elsewhere. Analyzing the water that needs to be treated is the only way for a water treatment company to offer any real solutions, quotations, or guidance to you.
Finding the right company now could mean that you are not searching for a new one later. Decide what your need for your facility, and then find out which water treatment company best meets your needs.
Manufacturing facilities in the U.S. consume high volumes of water in order to manufacture goods for the public. That water is regulated by federal and local government when it is fed into the facility and when it is discharged from the facility (as wastewater). Recycling this wastewater can eliminate the need to discharge water altogether, reducing the amount of water a facility consumes significantly. Reducing water consumption saves the manufacturer money and reduces their impact on the environment. Here are the top 3 reasons why manufacturers recycle and reuse their process water.
Manufacturers are using their existing brand power to lead by example and support water conservation efforts. Mandates from corporate headquarters are passed to their U.S. manufacturing facilities to recycle water, reduce water consumption, and demonstrate environmental stewardship overall. These companies recognize those efforts as a social responsibility, understanding also that consumers favor companies who are taking action to improve the impact they have on their community and the environment.
Manufacturers within states that experience drought (short term or long term) are impacted by water price increases and state-wide conservation mandates. These impacts can turn into production losses and even downtime, if the facility does not have access to the water volume they need to keep up with regular production. An industrial wastewater recycling system (a closed loop process) ensures that the facility has the volume of water they need for production, even during a drought. Manufacturers who use water recycling systems report reuse rates varying between 80% and 95%. The reuse rate is dependent upon the facilities wastewater quality and the technology used in the recycling system. At any rate, this is a viable long-term solution for facilities in drought-prone regions.
Manufacturers are routinely trying to cut back expenses. Often they look to cut operation costs, which include expenses associated with water. Facilities incur several ongoing water-related costs. They purchase water form the city, purchase and maintain wastewater treatment equipment, employ personnel to operate the treatment equipment, and pay fees associated with discharge permits. Additionally, if a manufacturer is out of compliance with their discharge permit, they can also incur penalty fees and even face legal action. While the cost per gallon of water varies, more manufacturers are finding they can save money by recycling what they already use. Water recycling practices can also provide added benefits such as extending the life of process and treatment equipment (due to the high quality of the recycled water).
Recycling industrial wastewater allows manufacturers to reuse the water they have already purchased, which saves the money, mitigates impacts from drought conditions, and promotes the company as environmental stewards. There are many big name companies who recycle their wastewater, and they usually promote these activities online and in annual reports that are also available to the public. With just a little research, you can learn about the environmental initiatives of your favorite brands.
In the face of impending changes to the power industry's ELG limitations from the EPA, facilities are looking for a cost-effective solution for meeting stricter limits now and in the future.
This table outlines the proposed limits on the most heavily restricted contaminants and their concentrations found in FGD waste streams (that were used to test I-PRO technology).
Traditional treatment methods utilize physical/chemical treatment and biological treatment, and then discharge the water. Doing so, however, still leaves room for permit violations. Traditional systems are also very large in size and are capital expensive.
Zero-liquid discharge is the best option for power generation facilities to meet these low ELG limits, as it the only method that will ensure 100% compliance now and in the future. ProChem's I-PRO technology in conjunction with solidification or evaporation can provide power generation facility's with an economical solution for meeting currently proposed regulations and future regulations.
The following data is based upon a total daily flow of 100,000 gallons (average).