A wastewater treatment plant treats sewage or industrial wastewater before discharging it. Typically, the plant will remove solid materials in the primary treatment. The remaining liquids then are treated for dissolved and suspended organic material in secondary treatment, and finally, disinfection treatment kills disease-causing microorganisms.

Sewage sludge undergoes treatment as well and then is removed from the plant. The majority of wastewater treatment plant costs – around 70 percent – are related to solids removal from the plant, as most plants need to pay to have them trucked away. With this high cost, solids ratios must be known and effectively controlled.

Representative sampling, which is consistent, accurate and repeatable, means that characteristics of one sample are the same as that of the entire batch. Automatic sampling provides the most reliable composite of solids and liquids. 

How automatic sampling saves time, money

Why is this? When a treatment plant chooses to conduct its sampling manually, the sampling must be done round-the-clock, especially in large plants. In fact, each manual sample typically takes 10 minutes, including cleanup time, every couple of hours. Plus, the ideal sampling point often is not in an easily reachable location, and it is stinky and sloppy. The spigot is under intense pressure, leading to messes and compromised operator safety. Labor costs are high due to the many sampling points required and the time operators waste cleaning up messes. And for all that work, manual sampling is highly inaccurate, failing to provide representative samples.

Sentry® ISOLOK® automatic samplers are the samplers of choice to effectively sample sludge from a pressurized line, capturing fixed sample volume at fixed time intervals for uniformity and consistency. An isolation valve, ISOVALVE®, allows the samplers to be easily removed for inspection or servicing while process lines remain pressurized.

With no spillage of materials, customers have found the sampler to be safe, clean, reliable and simple to use. Because the sampler automatically captures fixed sample volume at fixed time intervals, human error is greatly reduced. This means samples are uniform and consistent for analysis and process control.

Best of all, Sentry ISOLOK automatic samplers help plants increase safety and efficiency and greatly decrease labor costs, as operators typically need to collect the sample containers just once per day.

One customer was spending nearly $12,000 in labor costs per site to manually sample, which took about 10 minutes every two hours around the clock. The customer saved more than $81,000 per year in labor costs after implementing the Sentry ISOLOK samplers in the blending and digestion system and initial sludge outflow monitoring from the primary clarifiers in all its sites. Now, an operator needs to visit the sampler only once a day.

“The samplers have worked so well for us,” the customer said. “Maintenance has been very easy, too. Occasionally we might replace a set of seals, which takes about 20 minutes… but that’s needed so seldom that we’ve never set up any schedule. We’ve found that these samplers generally run for years with no problems.”

Learn more about Sentry ISOLOK samplers for solids and wastewater here.

This article was originally published on our website.