Recycled Filter Carbon

Residential water filters and reverse osmosis units normally use filter carbon in some form, and the carbon used in residential units is normally new carbon. There is no program that we know of that recycles filter carbon from small household filter cartridges for reuse as filter carbon. Over the years some vendors have advertised recycling of spent filter cartridges, but these programs were, in our view,  more about marketing than recycling, designed to appeal to environmentally conscious customers and to promote cartridge replacement sales. Recycling of small cartridge carbon is simply not economically feasible.

However, carbon recycling does happen, and in a big way, with large industrial and municipal filter applications.

Here’s an interesting account of how carbon recycling works, from the Calgon Corporation, a major provider of filter carbon.

What should treatment operators know about the differences between virgin and reactivated GAC when evaluating options for PFC removal?

Although virgin and reactivated GAC may be of the same starting material and same activity level, they are two distinct products. Virgin GAC is an activated carbon product that has not been used in a previous application, so its quality and performance are consistent. Reactivated GAC is a product whose capacity was exhausted (spent) in a previous application and has undergone a high-temperature thermal process to destroy adsorbed material (remove contaminants) and restore a majority of the adsorptive capacity that allows the product to be reused in appropriate applications. The reactivation process alters the pore structure and can impact performance/quality, but can still provide a cost-effective treatment solution.

Within the term “reactivated GAC” it is also important to distinguish between a custom-reactivated GAC and a pool reactivated GAC. A custom-reactivated GAC is a product that has been previously used and spent in a specific customer’s application, removed from service, segregated from other spent GAC, reactivated, and returned to the same customer for reuse. In a pool reactivated product, spent carbons from a variety of customers’ applications are co-mingled, reactivated, and used for a variety of non-potable applications. The quality of a custom-reactivated product is generally higher than the quality of a pool-reactivated product, but is highly dependent on the application in which it was used, the reactivation conditions, and the initial carbon product. Custom reactivation is most economical for quantities above 20,000 pounds. It is vital to select a virgin material that can withstand multiple cycles of treatment and reactivation. A reagglomerated, bituminous, coal-based product has been shown to be a superior base product for reactivated GAC. 

Garfield Phone Ocean Pollution Case Solved

Since the 1980s pieces and parts of a bright orange novelty telephone depicting the cartoon cat Garfield have been appearing on beaches in Brittany in France. Not just an occasional phone.  A lot of them.

Until early 2019 the origin of these phones was a mystery. According to the BBC, the mystery was finally solved when a lost shipping container filled with Garfield phones “in a more complete condition than any found before them,” was discovered in a secluded sea cave accessible only during low tide. Unfortunately, the location of the lost shipping container makes recovery virtually impossible, so the Garfield phones are expected to continue to land on Brittany’s shores for years to come. Locals apparently are sick of picking them up. The seemingly endless supply illustrates how many small objects can be crammed into a single cargo container.

Incidents like the Garfield phone event have contributed to the belief that lost shipping containers are a major cause of ocean pollution.

Are wayward containers polluting global waterways at alarming rates?

Most of the time there are about 6,000 container ships active on the world’s seas and waterways to facilitate global trade. Lost containers represent only about one thousandth of 1 percent of the roughly 130 million container loads shipped each year, according to the World Shipping Council (WSC), which publishes results of a member survey every three years. According to the WSC:

For its 2017 report, the latest available, WSC gathered data for 2014-2016. The average annual number of containers lost at sea, excluding catastrophic events, was 612 during the period. That number is down about 16 percent compared to the average of 733 units lost each year for the previous three-year period. When catastrophic losses are included, defined as 50 or more containers in a single incident, the total number of containers lost at sea averaged 1,390 annually for the most recent period. That’s still a 48 percent reduction from the average annual losses of 2,683 estimated during the previous three-year period.

By comparison, an estimated 8 million metric tons of plastic pollution — a substantial amount from single-use plastic bottles and grocery sacks — finds its way into the oceans each year.

Clearly, though a thousand plus gigantic shipping containers lost at sea annually can spew out a lot of weird telephones and other assorted debris, the amount of  garbage they dump into the seas seems small when compared with the ongoing rivers of plastic put forth daily by everyday human activities.

This plastic is not from a lost ship container but from humans going about their daily business.

Are Nitrates Taken in Through the Skin?

There is growing evidence that nitrates in water are a serious threat to human health, that nitrate levels in water supplies, both public and private, are steadily increasing, and that the longstanding 10 part per million regulatory allowable is way too lenient.

The bright side of the nitrate issue, though, is that home treatment for nitrates is relatively easy and inexpensive. Like many other problem contaminants, lead, arsenic, and PFAS, for example, nitrates are almost entirely an ingestion issue.  Nitrates are dangerous when swallowed, but of no great concern for other household exposures like bathing, washing clothing, or cleaning.

Here’s what the World Health Organization says:

Similarly, the US Environmental Protection Agency says:

Nitrates in water used for showering or bathing is not a health concern. Nitrates in drinking water above the federal standard (10mg/L) can be very harmful if ingested, so a treatment device on taps that dispense water primarily for drinking or cooking is recommended.

The Oregon State Health Authority says that high nitrate water should not be used for drinking or preparing food, but that it is safe for gardening, washing dishes, cleaning, and laundry.  Bathing?  “Nitrate does not easily enter the body through the skin. Bathing, swimming and showering with water that has levels of nitrate over 10 mg/L is safe as long as you avoid swallowing the water. Supervise small children when they are bathing and brushing teeth to ensure they do not swallow the water.”

The practical lesson from this is that point of use treatment for nitrates is the easy solution  An undersink reverse osmosis unit or a small undersink filter with a nitrate cartridge can provide high quality drinking water. Nitrate removal for water for the rest of the home is not essential.

Millions of tons of nitrate from industrial farming find their way into America’s drinking water each year, causing thousands of cases of cancer and other health problems, an environmental advocacy group says.

In a new report, researchers from the Environmental Working Group (EWG) quantify the risk. They say nitrate is responsible for nearly 12,600 cases of cancer a year.

“Industrialized farming relies heavily on nitrate fertilizers that can run off into the water table used by drinking water utilities,” said Sydney Evans, a science analyst at EWG.

The risk varies from region to region, she said, noting that many small farming communities have the highest nitrate levels in their water — and the highest risk. Iowa and California, two heavily agricultural states, were found to have the most nitrate-related cancer cases.

A Yale University researcher who reviewed the report said the danger it highlights is clear and exists throughout the country.

“An immediate response is warranted, so that we are not poisoning our water to produce our food,” said Dr. David Katz, director of the Yale-Griffin Prevention Research Center in New Haven, Conn.

The report said 80% of the nitrate-related cancers were colorectal, with ovarian, thyroid, kidney and bladder cancer accounting for the rest. Treatment costs up to $1.5 billion a year, according to the report.

Nitrate in tap water also has been tied to serious health issues for infants, the researchers said. Among them: nearly 3,000 babies with very low birth weight; more than 1,700 preterm births; and 41 cases of neural tube defects each year in the United States.

Katz said that although the study has limitations, it makes a compelling case that nitrates from what he described as “agriculture as usual” in the United States are “imposing grave costs measured in both lives and dollars.”

Meanwhile, Evans called on the U.S. Environmental Protection Agency (EPA) to revisit its public health standards for drinking water. A main mission of her group is to prevent nitrate from fouling drinking water.

Since 1962, the federal standard for nitrate in drinking water has stood at 10 milligrams per liter. The report said problems have been found at one-tenth of that level.

The EPA was slated to re-evaluate its standards with an eye to reducing the permissible level in drinking water, but the Trump administration canceled those plans, Evans said.

For tap water to be safe, she said, nitrate levels would have to be 70 times lower than today.

Nitrate is hard and costly to filter out of water, Evans said. Some towns and cities, however, do remove it and pass along the cost to residents.

Private wells can also have high nitrate levels. People who rely on well water have to spend thousands of dollars to add reverse osmosis systems if they want to remove nitrate, Evans said.

SOURCE: Texas A&M ​University ​Health Science ​Center

WaterOnline.

As Water Scarcity Increases, Desalination Plants Are on the Rise

by Jim Robbins

Some 30 miles north of San Diego, along the Pacific Coast, sits the Claude “Bud” Lewis Carlsbad Desalination Plant, the largest effort to turn saltwater into freshwater in North America.

Each day 100 million gallons of seawater are pushed through semi-permeable membranes to create 50 million gallons of water that is piped to municipal users. Carlsbad, which became fully operational in 2015, creates about 10 percent of the fresh water the 3.1 million people in the region use, at about twice the cost of the other main source of water.

Expensive, yes, but vital for the fact that it is local and reliable. “Drought is a recurring condition here in California,” said Jeremy Crutchfield, water resources manager at the San Diego County Water Authority. “We just came out of a five-year drought in 2017. The plant has reduced our reliance on imported supplies, which is challenging at times here in California. So it’s a component for reliability.”

A second plant, similar to Carlsbad, is being built in Huntington, California, with the same 50-million-gallon-a-day capability. Currently there are 11 desalination plants in California, and 10 more are proposed.

The cost of desalinated water has been coming down as the technology evolves and the cost of other sources increases.

It’s been a long time coming for desalination — de-sal for short. For decades, we have been told it would one day turn oceans of saltwater into fresh and quench the world’s thirst. But progress has been slow.

That is now changing, as desalination is coming into play in many places around the world. Several factors are converging to bring new plants on line. Population has boomed in many water-stressed places, including parts of China, India, South Africa, and the United States, especially in Arizona and California. In addition, drought — some of it driven by a changing climate — is occurring in many regions that not that long ago thought their supplies were ample.

San Diego is one of those places. With just 12 inches of rain a year in the Mediterranean climate of Southern California and no groundwater, the region gets half of its water from the distant Colorado River. The amount of snow that falls in the Rocky Mountains and keeps that mighty river flowing, however, has greatly diminished over the last two decades and according to some researchers may be part of a permanent aridification of the West. Climate change is a very real phenomenon for water managers throughout the Southwest and elsewhere.

Meanwhile, the cost of desalinated water has been coming down as the technology evolves and the cost of other sources increases. In the last three decades, the cost of desalination has dropped by more than half.

A boom in de-sal, though, doesn’t mean that everywhere with access to the sea has found a new source of freshwater. Circumstances play a large role. “As populations increase and existing surface water supplies are being tapped out or groundwater is depleted or polluted, then the problems are acute and there are choices to be made” about de-sal, said Michael Kiparsky of the Wheeler Water Institute at the UC Berkeley School of Law. “There are places around the world where de-sal makes economic sense, where there is high pressure on the water resources plus a lot of available energy resources,” such as the Middle East.

De-sal proponents acknowledge the industry must confront and solve some serious environmental issues if it is to continue to grow. Desalination requires vast amounts of energy, which in some places are currently provided by fossil fuels. Kiparsky warns of a feedback loop where more de-sal is needed as the planet warms, which leads to more greenhouse gas emissions. In addition, there are serious concerns about the damage to marine life from the plant’s intake systems and extra-salty wastewater.

The first large-scale de-sal plants were built in the 1960s, and there are now some 20,000 facilities globally that turn seawater into fresh. The kingdom of Saudi Arabia, with very little freshwater and cheap energy costs for the fossil fuels it uses in its de-sal plants, produces the most freshwater of any nation, a fifth of the world’s total.

Australia and Israel are also major players. When the Millennium Drought gripped southeastern Australia from the late 1990s until 2009, water systems in the region dropped to small fractions of their storage capacity. Facing a crisis, Perth, Melbourne, and other cities embarked on a large desalination plant spree. The plant in Melbourne, which provided its first water in 2017, cost $3.5 billion to build and provides a third of the city’s supply. It’s critical because the region has had below-average rainfall for 18 of the last 20 years.

Israel, too, is all-in on desalination. It has five large plants in operation, and plans for five more. Chronic water shortages there are now a thing of the past, as more than half of the country’s domestic needs are met with water from the Mediterranean.

Globally, more than 300 million people now get their water from de-salination plants, according to the International Desalination Association.

But despite the need, de-sal plants will not be built on every coastline. Foremost among the barriers is the cost of constructing a plant and the cost of processing the water. The San Diego County Water Authority pays about $1,200 for an acre-foot of water sourced from the Colorado River and the Sacramento San Joaquin River Delta and pumped hundreds of miles to Southern California. The same amount from the Carlsbad plant — enough to supply a family of five for a year — costs about $2,200. As Lake Mead — the reservoir of Colorado River water on the Nevada-Arizona border that supplies San Diego — drops precipitously, it may someday, perhaps in the next several years, no longer be able to supply San Diego. Certainty is paramount.

De-sal, however, is plagued by some serious environmental problems. There are two types of desalination – thermal, which heats up water and then captures the condensation, and reverse osmosis, which forces seawater through the pores of a membrane that are many times smaller than the diameter of a human hair. This traps salt molecules, but allows the smaller water molecules to go through. Both require a great deal of energy, and greenhouse gas emissions created by the power needed — especially in the Middle East, where fossil fuels generate electricity — are a significant contributor to global warming.

There are ecological impacts as well. It takes two gallons of seawater to make a gallon of freshwater, which means the gallon left behind is briny. It is disposed of by returning it to the ocean and — if not done properly by diffusing it over large areas — can deplete the ocean of oxygen and have negative impacts on sea life.

A study by the U.N. Institute for Water, Environment and Health published earlier this year contends that the problem of brine waste has been underestimated by 50 percent and that, when mixed with the chemicals meant to keep systems from fouling, the brine is toxic and causes serious pollution.

Another problem comes from the sucking in of seawater for processing. When a fish or other large organism gets stuck on the intake screen, it dies or is injured; in addition, fish larvae, eggs, and plankton get sucked into the system and are killed.

“At our intake we [draw in] tiny little organisms, that amount to about a pound and a half of adult fish per day,” said Jessica Jones, a spokesperson for Poseidon Water, which owns the Carlsbad plant. “To mitigate that we are restoring 66 acres of wetlands in San Diego Bay. And we just got a new intake permitted which will lessen the impacts.”

According to Heather Cooley, research director at the Pacific Institute, “There are a lot of unknowns around the impact on sea life. There hasn’t been a lot of monitoring at the facilities.” A strategy increasingly being used to obviate, or reduce, that problem is to bury the seawater intakes beneath the seafloor and use the sandy ocean bottom as a natural filter.

In 2016, California passed the Desalination Amendment, which tightened regulations for intake and brine disposal. Proponents of desalination contend the changes have been onerous and are slowing the march toward a de-sal future.

Because of the cost of seawater processing and the impacts on the ocean, much of the recent desalination growth has involved the use of brackish water. The solids in brackish water are one-tenth the amount in ocean water, and that makes the process much cheaper.

Arizona, perpetually short on water and facing a Colorado River supply shortage, is looking at both a seawater de-sal plant in partnership with Mexico — which has the ocean access that the state lacks — and at plants that can treat the 600 million acre-feet of brackish water deposits the state estimates it has.

Texas, meanwhile, now has 49 municipal de-sal plants that process brackish water, both surface and subsurface. San Antonio currently is building what will be the largest brackish water de-sal plant in the country. In its first phase, it produces 12 million gallons a day, enough for 40,000 families, but by 2026, the plant — known as H2Oaks — will produce 30 million gallons a day. Brackish water de-sal costs $1,000 to $2,000 per acre-foot.

The Pacific Institute’s Cooley argues that before building de-sal plants, municipalities should fully implement conservation programs, promote potable re-use — the re-use of wastewater, also known as toilet-to-tap recycling — or treat storm water runoff. “It makes sense to do the cheaper options first and leave the more expensive options down the road to be developed when you need them,” she said.

Reprinted from Grist.   Published originally in YaleE360.

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Chemical Dosage Instructions for Pure Water Products’ Chemical Feed Systems

Spectraguard: Dosing to protect large RO units from hardness and iron damage. These are “round number” recommendations for dosing concentrated Spectraguard liquid for the Watts RO units that we supply. Settings are for the Stenner 0.2-3.0 gpd peristaltic pump.

Happy Garden Hose Day

The stately lawn of the Serpentine Sackler Gallery in London’s Kensington Gardens was for a year home to a unique sight–a sculptural fountain made of an unruly jumble of ordinary garden hoses. French artist Bertrand Lavier created the sculpture, entitled Fountain, for a yearlong installation that ended October 4, 2015. Lavier specializes in sculptures made of “found objects.”

Lavier’s piece reminds us of the grace, the versatility, and the beauty of the common garden hose as the nation celebrates National Garden Hose Day on June 18.

PFAS Producers Face Increasing Legal Onslaught

The Associated Press reports a landslide of litigation directed at companies responsible for the nation’s PFAS crisis: