water and wastewater treatment

When you flush the toilet do you ever think, “Man, all this good stuff is just going to waste?” Ok, probably not. But in the future your home or office may be partially heated by that human waste, thanks to geothermal sewage. What exactly is geothermal sewage, you cringe? It’s the process by which the heat from a wastewater line is repurposed to heat a nearby facility such as a hotel or apartment building. The heat transfer is accomplished by filtering solids from the wastewater and passes through a heat pump before reaching the building.

In China geothermal sewage has already been installed in a few buildings, including the Beijing Train Station. Now a wastewater treatment facility in Philadelphia is beginning the first US trial with this technology. It is a company in Philadelphia, NovaThermal Energy, that is making geothermal sewage possible by developing a proprietary filter material that can efficiently remove waste without requiring pretreatment.

Currently the technology requires that a target building be adjacent to large sewer mains, but if this pilot project is successful it could change our attitudes about sewage (and poop). David Henderson of XPV Capital in Toronto may have said it best: “Wastewater is a terrible name for wastewater. There are incredibly valuable resources in a wastewater flow: energy, nutrients, other materials, water itself.” It’s just a matter of separating the good from the bad.

Read this Forbes piece for more information

An especially pungent use for glass fiber filters is described in the latest issue of the Soil Science Society of America Journal. In the paper, “Influence of Dissolved Carbon and Nitrogen on Mineralization of Dilute Liquid Dairy Manure” two scientists from the University of California examined the wastewater used to flush dairy cow waste for the presence of these elements.

On dairy farms in which the milk cows are confined, water is used to flush away the manure and is then stored in lagoons to be treated for coarse solids before being re-applied to crop fields through irrigation. Refuse reuse if you will. One problem with this procedure is that if there is too much dissolved Carbon or Nitrogen in the wastewater it can create groundwater contamination.

For this study, the researchers collected wastewater samples from seven lagoons and analyzed them in order to investigate the relationship between the starting levels of Nitrogen and Carbon and the wastewater’s mineralization behavior. Their methodology included determinations of Totals Solids (TS) and Total Suspended Solids (TSS) by filtering the manure through a series of glass fiber filters, including the Advantec GF75 (0.3 micron) at several points. The GF75 was also used to filter wastewater samples prior to gravimetric analysis.

In this case, the authors found that the amount of Nitrogen that will be mineralized for crop consumption is very likely due to how much dissolved Carbon and Nitrogen is present on denitrification. Further investigation will be needed before scientists can accurately predict how much Nitrogen the crops treated with this water are actually exposed to.

The full paper is available here for American Society of Agronomy subscribers.

A recently completed test in Poland found that enhancing ultrafiltration (UF) flat sheet membranes with an anionic polymer increased the membrane’s ability to purify samples of galvanized wastewater. For this experiment, the researchers tested multiple concentrations of wastewater infused with zinc, nickel, and copper ions against EW and MW designation flat sheet membranes that were infused with a polyelectrolyte, in this case polysodium 4-styrenesulfonate (PSSS) with cation-exchange properties. The result was a more-efficient metal binding agent, enabling 97-99% retention of the target metals.

The EW membrane is made with Polysulfone while the MW is a modified Polyacrylonitrile known as Ultrafilic. Both designations ably treated the galvanized wastewater, but the MW membrane did have 2-3 times higher permeate flux values due to the membrane’s higher permeability.

In addition to membrane separation, common treatment options for galvanized wastewater include chemical processing and the ion exchange method. Unlike these other methods however, an effective membrane separation methodology has the potential to remove higher concentrations of effluent in a continuous process so these findings could impact how galvanic wastewater is processed in the future.

You can read the published paper here.

The Environmental Protection Agency announced last week that they are planning to develop standards for wastewater discharges produced by natural gas extraction from underground coalbed and shale formations (a process commonly referred to as “Fracking”). This method of extraction involves fracturing rock formations by injecting them with a pressurized fluid consisting mostly of water, a little bit of sand, and some chemical additives as well. The debate over the possible environmental consequences of fracking is a hot button issue right now, and since its popularity has grown to the point where it now accounts for about 15% of all natural gas production in the US, it is understandable that the EPA wants to look into setting some uniform regulations.

Any potential EPA standards in this area can be broken down into two areas: shale gas standards and coalbed methane standards. In shale gas extraction, wastewater is prohibited from being discharged into waterways. Instead, it is either recycled back into use or sent to a treatment plant. Unfortunately, many of these treatment plants are not properly equipped to handle shale gas wastewater so the EPA will look into standards that could be implemented on wastewater before it reaches the treatment plant.

Creating a coalbed methane standard for wastewater treatment is a little bit trickier, since there aren’t any national standards for it yet. Currently it is up to individual states to regulate where the wastewater is discharged and what pre-treatment standards to follow. The EPA is hoping to address the matter by creating a uniform standard for the whole nation.

Based on the current EPA schedule, a proposed rule should come in 2013 for coalbed methane and 2014 for shale gas. This is to allow the EPA time to consult with stakeholders and allow for public comment.

You can read the full announcement from the EPA here.

The simple act of machine washing our clothes may be causing serious environmental damage, according to a new study from University College Dublin. A research team led by Dr. Mark Browne has traced a path from washing machine wastewater to abnormally high concentrations of microplastic debris found all over the world. The problem arises because the synthetic fibers that many of today’s clothes are made of, polyester and acrylic, get rinsed by the machine. While we may not notice it, one cycle can strip as much 1,900 fibers off each piece of synthetic clothing! These dangerous fibers eventually make their way to the ocean and wash up on our beaches. Research also shows that the pollutants are eaten by mussels and locusts, which can then work their way up the food chain to humans.

As a part of this study Dr. Browne’s team investigated 18 sites on six continents and through forensic analysis was able to match the proportions of polyester and acrylic fiber present in these sites with their proportions in clothing. They also found a correlation between sites with greater-than-average concentrations of microplastics and their exposure to washing machine wastewater.

Microplastic debris doesn’t get a lot of attention now in the environmental community, but as the human population grows and synthetic fibers become more commonplace, they have the potential to be a major concern in the future. Since it is likely that any solution to the problem will include standard or experimental methods of wastewater treatment, including filtration (see Flat Sheet Membranes), we’ll continue to look out for possible cures.

Read the full study from the ACS Journal of Environmental Science & Technology
Learn more about the work of Dr. Browne

On September 1st a new web portal created specifically for water and wastewater management will officially launch to fill the industry’s need for a comprehensive database on water infrastructure in the United States. Dubbed WATERiD, this project is funded by Virginia Tech and it is the brainchild of Sunil Sinha, a National Science Foundation Career Award recipient for his work in sustainable water infrastructure management systems.

One of the biggest problems in water utility management is figuring out when to replace pipelines and equipment, before things break and cause serious problems. It’s estimated that at least 2 million miles of the nation’s infrastructure is nearing the end of its useful life, and at present there is no singular resource for utilities to consult when making a decision on when to make replacements. This is the primary need WATERiD is looking to address. By collecting various technical papers, case studies, and research data this knowledge base can minimize the loss of institutional memory that occurs when a senior operator in a location leaves.

Over the past year Virginia Tech students and researchers have been busy visiting 87 different water and wastewater utilities around the country. So far they have compiled around 100 different case studies along with 300 technical descriptions and another 100 technology data sheets. All of this information will serve plant managers to make more informed decisions regarding their equipment and more efficiently manage their assets. Having a concentrated resource will especially benefit the smaller utilities that might otherwise be unable to gain such knowledge independently.

A key difference between WATERiD and other online databases is that the individual users will not have editing capabilities, a la Wikipedia. Instead, the information will be maintained by Virginia Tech’s Institute for Critical Technology and Applied Science’s Center of Excellence in Sustainable Water Infrastructure Management (VTICTASCESWIM???). Users are still highly encouraged to share their experiences, and WATERiD will be completely free to all users.

Read Virginia Tech's announcement
Visit the official WATERiD site

After our last post discussing how experiments with carbon nanotubes (CNT’s) might greatly improve the effectiveness of reverse osmosis desalination now comes a new report from the Institute of Physics that shows researchers are getting closer to making this a reality. Already over a billion people do not have regular access to clean water and the problem will likely get worse as the demand for drinkable water is expected to grow dramatically in the near future. With natural sources increasingly scarce, this urgent need means there is an intense global interest in any potentially viable forms of water purification.

Right now the main issues preventing RO desalination on a large-scale basis are that the membranes used to perform seawater to freshwater separation do not remove salt ions with enough efficiency and they also require great amounts of energy (and therefore expense) in order to purify the water. Jason Reese, a Professor of Thermodynamics and Fluid Mechanics at the University of Strathclyde and also the author of this report, states, “The holy grail of reverse-osmosis desalination is combining high water-transport rates with efficient salt-ion rejection.” Incredibly, these little carbon nanotubes may be able to satisfy both of these requirements for widespread adoption.

Early tests and simulations have shown that CNT membranes could have water permeability that is 20 times greater than today’s materials. Additionally, carbon nanotubes can be chemically tailored to better reject salt ions, thus improving upon the desalination process in multiple key areas.

While it is still early, these features are promising enough that scientists such as Professor Reese feel it is a very real possibility that this application of nanotechnology could be used to curtail our growing water demand.

Read more about this report here.

Here’s further evidence that monitoring your company's waste output is something you should probably keep an eye on…

Yesterday the former environmental, health & safety manager for AMCAN Beverages, Inc. (A subsidiary of Coca-Cola) pled guilty to falsifying reports about their plant's wastewater discharge. He now faces up to 3 years in prison and/or upwards of $250,000 in fines for directing employees to dilute wastewater samples before they were sent for off-site testing and then reporting on the tampered results.

The company was caught when the City of American Canyon’s own wastewater treatment plant staterd experiencing operational problems relating to Biological Oxygen Demand (BOD) and Total Suspended Solids (TSS) measurements and began a covert investigation into industrial discharges in the area, leading them to AMCAN.

If only Captain Planet was still around to call on, he'd take pollution down to zero...

Read more details on the case here.

And yes, we do offer plenty of different products for TSS measurements as well as bench scale systems for municipal/industrial waste and wastewater purification.

For the rest of the month we're offering 10% off filters for water analysis! Check out the Sterile MCE Membrane filter as well as the GA-55 and GC-50 Glass Fiber Filters for treating water and wastewater. It's a great opportunity to stock up on any variety of these frequently used models...

Starting this week you can power your process filtration units and membrane test cells with the full line of flat sheet membranes from TriSep Corporation! These membrane elements are designed to provide premium efficiency in water treatment applications.

What is especially great about this news is that now you can get these membranes in precut sizes to fit the CF042, Sepa CF, and HP4750 membrane test cell (individual sheets are available too)! Performing desalination and wastewater purification just got a lot easier…

See the full announcement here.