This is the first research update of 2019, and for those of us on the East Coast we have bid good riddance to 2018 and its incessant rainfall. Yet we read of extremes in other parts of the world, such as Australia and even part of our own Southwest U.S. where heat and drought have combined to stress soil. We are suffering from soil saturation, but elsewhere it is soil drought. Dr. Brown is drawn to the issue of soil erosion as one of the outcomes of drought and heat, as the stress results in increased soli surface erodibility. Dr. Brown's piece this month looks at the science that substantiates our industry's claim to the soil health attributes of biosolids, one of which is expressed in reduced erodibility. Faced with such drought stress, the farmer needs to draw upon every tool available to fight loss of soil.
To view the article abstracts from this months research update follow this link: NOVEMBER 2018 RESEARCH UPDATE
Lists? Checking it Twice!
Holidays are a time of making lists. I have many lists: my holiday cards lists, menu lists, gift lists and so on and so forth. Some believe that Santa makes a list of whose naughty and nice.
EPA has apparently tried to get into the spirit of lists his year too. They just released a list of 352 pollutants identified in biosolids. They tried to ape Santa with the naughty or nice designation but concluded that a lack of data or risk assessment tools precluded them from assigning these pollutants to their appropriate categories. Thanks a lot EPA. For me, that puts you in the Scrooge category. This month’s library, the last library of 2018, takes a quick look at that EPA list.
The first item in the library is the actual EPA document. As the document correctly points out, the 503 risk assessment process was science based. It also stressed the need to reevaluate the regulation periodically based on new information. EPA does not have the staff to do this in a very thorough fashion, and multiple decades of land application with no appreciable hazard and a lack of public outcry had placed this on the back burner. This report was actually written by the Office of the Inspector General (OIG) of the EPA and provided to the EPA Office of Water.
For this library I have cherry picked some of the contaminants discussed in the OIG report. While the summary calls out pharmaceuticals, steroids and flame retardants, those have been dealt with in depth in previous libraries. Of the 352 pollutants, the report calls out 61 that are not only not contained in shampoo, but are “acutely hazardous, hazardous or priority pollutants in other programs.” Here it appears that the consultants who wrote the report culled pollutants from other people’s lists. This included RCRA, the Priority pollutant list and the NIOSH hazardous drugs list (Table C1). In the RCRA list, compounds are either labeled with a ‘U’ or a ‘P’. U stands for toxic and P stands for acutely hazardous. The ‘P’ compounds are the focus of the next 4 articles in the library.
First it is important to note that these lists are typically made outside of a realistic context. The 503s considered concentrations in biosolids, pathways of exposure, and potential for risk based on actual use of biosolids in a real world context. The lists used by OIG have been generated without a consideration of use of biosolids and potential for exposure. If a compound has been detected in biosolids and has appeared on one of these lists, in the view of the OIG authors that is sufficient reason for it to rate inclusion. That may suggest it is worth looking into in greater detail, but it in no way means that its presence in biosolids puts biosolids use in the naughty category.
The first compound is dimethoate. Wikipedia is a great way to find out what dimethoate actually is. It is an organophosphate insecticide that was developed in the 1950s. In other words, it has been in use for decades. Wikipedia says that it is readily taken up by plants and distributed throughout plant tissues. The first article in the library was one of the only ones that I could find on this insecticide and biosolids (I even searched for dimethoate and sewage sludge). The authors sprayed the compound at 0.47 L acre-1 on broccoli and tested soils and runoff and infiltration water for traces of the compound. They tested this with soil amended with biosolids, yard waste compost and bare soil. The half-life of the insecticide was less than 14 days on the broccoli and ranged from 31 ng g on the biosolids to 135 ng g on the bare soil. It fell below detection on the soil amended with compost or biosolids within 5 days after spraying and within 8 days on the control. Biosolids also reduced runoff potential of the compound with no differences seen in water that had infiltrated into the soil. In other words, the takeaway for EPA OIG could be to ban it on the broccoli.
The second compound with a ‘P’ is N- nitrosodimethylamine (NDMA). Again, we turn to Wikipedia (may want to think about adding Wikipedia to your donation list this year). NDMA is a waste product of multiple processes and can be found in trace concentrations in certain foodstuffs (bacon and smoked meats). It is likely carcinogenic and is used to make rats get cancer for research. It can be generated during wastewater treatment when chlorine is added to effluent prior to release. It falls under the broad category of nitrosamines. The third article in the library used archived biosolids from a prior sewage sludge survey and tested them for the presence of these compounds. The study tested biosolids from a total of 74 treatment plants. NDMA was detected in 3% of the samples tested at a mean concentration of 504 ± 417 ng/g (ppb). That translates into it was likely found in one sample at a high level and above detection in two others, not found in the 71 other samples tested. Perhaps this high level could be attributed to an industrial source. It is also not clear that there would be a potential for the presence of this compound in 3% of the tested biosolids to result in any risk based on likely end uses of biosolids. Reported uses of this compound suggest that its presence in drinking water is likely a much more significant concern than concentrations in biosolids. In other words, cross this guy off the list too.
From here we go to beryllium (Be), an alkali earth metal, the same column on the periodic table as calcium and magnesium. Wikipedia says that Be is a rare element that is a component of traditional Christmas gifts such as emeralds and aquamarine. It can be added to metals such as aluminum and copper to improve their physical properties. It is used for aerospace applications as well as for x-ray equipment. The 4th article in the library is from Sweden. It reports testing results for a range of elements (including Be) in biosolids, animal manures and fertilizers. The report starts with a statement about how strict environmental policies are in Sweden and how tough their limits are. For the biosolids sampled, Be was below detection for just about all of them (46 out of 48) with a reported value of < 0.6 mg kg. In contrast it measured 5 mg kg in manures (n=12) and 0.2-2.3 mg kg in fertilizers (n=4). I don’t think that I need to add anything more on that one.
Finally, we go to chloroaniline 4 (4 -CA) and article #5. This compound is used for production of pesticides and drugs. It is a precursor of the antimicrobial compound chlorhexidine. The article that I found here focuses on the fate of two antimicrobial compounds, triclosan (TCS) and triclocarban (TCC) in soil columns +/- biosolids applied on the surface. In addition to looking at parent compounds, the authors also looked for degradation products of both compounds. They detected chloroaniline and suggest that it was formed from the hydrolysis of TCC. They also noted that it leached through the soil column. It was detected in the leachate as a minor metabolite of the compound itself and only in low concentrations for a fraction of the periods sampled. Metabolites and breakdown products of compounds can be more toxic than the parent compound. DDE, a by- product of DDT mineralization, is a classic example of this. While 4-CA was detected here, it was detected only fleetingly and it does not seem to be a major by -product of TCC decomposition. It’s ability to move through soil to groundwater is a concern and this may merit additional study. Here I would point out that the thorough risk assessment done on both TCS and TCC by George O’Connor at the University of Florida would likely have noted toxicities associated with the use of the parent compounds.
When you make your holiday lists- I would disregard this one from EPA. Happy New Year and see you in February.
Sally Brown, University of Washington
To view the article abstracts from this months research update follow this link: NOVEMBER 2018 RESEARCH UPDATE
Love for Cipro
I love Cipro. It is my antibiotic of choice when on the road to exotic destinations, where potable water only comes in bottles and where you have to check the seal on those to be sure.
I am not the only one who loves this drug. Ciprofloxacin falls into the broader class of antibiotics referred to as second generation quinolones. In 2010 (Wikipedia here), over 20 million prescriptions were written for Cipro, making it the 5th most common antibacterial in the US. People have appreciated Cipro since it was first introduced in 1987. A single dose of Cipro for an adult is 250 mg. A typical biosolids concentration is about 3 mg kg-1. If you have concerns about pharmaceuticals in biosolids and antibiotic resistance, Cipro is a good place to start. As cold and flu season is upon us, and as there are a new series of publications out on Cipro in biosolids from a very reliable source, that is what the November library is going to focus on.
We start with a paper by Caitlin Youngquist, a former local who had the privilege of working some with Craig and Andy at WSU for her MS. This paper is with other cooperators and describes the fate of Cipro in the La Connor, WA, biosolids composting facility. Concentrations of Cipro were tested, along with a range of other antibiotics, in the compost pile, prior to and post composting. Concentrations of all measured compounds were lower in the final product than in the initial pile. The authors also spiked some feedstock and put it back in the pile in small bags that could be retrieved. They periodically took samples from the bags and shook them up with water and then tested the water for microbial toxicity. A huge concern about antibiotics in soils is that they will harm the microbial community in soils. Short answer: they didn’t. So, Cipro and the other stuff tested goes away with composting, and microbes in the soil don’t flee the neighborhood when they hear that a ppb of Cipro has come to town.
The next 4 papers are hot off the press (actually, to be published in 2019) and are from Harman Sidhu’s PhD thesis. Harman had the privilege of working with George O’Connor at the University of Florida as his main advisor. The work here on Cipro (and azithromycin) follows the same pattern as the work of two of George’s previous students, Liz Snyder and Manmeet Pannu (now with the WA DOE Biosolids program). Both of those students did enough testing on the behavior of antimicrobials (TCC and TCS) to conduct risk assessments. Both (except for one type of bird and TCC, if I remember correctly, posed negligible risks). That is the conclusion here as well (spoiler alert). But let’s walk through the papers to get there.
The first paper (2nd in the library) tests the impact of both antibiotics added in ‘environmentally relevant’ concentrations in biosolids to earthworms and soil microbes. That is a critical piece here -- the biosolids matrix can impact availability of these compounds and their behavior in soils. Using relevant concentrations here is also very important. Other studies have seen an impact when compounds are added to soil at unreasonable rates (rates not found in biosolids), and those results have been interpreted to have real world applications. Not the case with these studies. Here biosolids were from the Chicago program and had relatively low concentrations of both antibiotics (1 ppm for Cipro and 0.6 ppm for Azithromycin). Biosolids were added to soil at 20 Mg/ha, and in a second part of the study pure biosolids were spiked with the two compounds at low, medium and high concentrations. The high concentration here was the 95th percentile concentration as reported in the 2009 EPA survey. Harman tested earthworm survivability and accumulation for earthworms and nutrient cycling and respiration for microbes. They also measured extractability and total concentrations of both antibiotics over time. Again, apparently the antibiotics make good neighbors; they are quiet and spend most of their time at home. In the soils and biosolids tested, in the presence of both antibiotics, the earthworms went about their business and the microbes theirs with no impact. The earthworms did eat some of the antibiotics and had bioaccumulation factors greater than 1. That means that the concentration in the worms was higher than in the soil. This was the only concern of the work. Finally, both antibiotics did not degrade quickly but had very low availability. That low availability is likely at least partially responsible for the absence of harm in both studies so far.
The third paper in the library, and the 2nd from Harman, tested the potential for plant uptake and toxicity of the same two antibiotics. Radishes, lettuce (both typically high accumulating crops) and tall fescue were grown in biosolids-amended soils. Here they also included soils spiked with the antibiotics with no biosolids, admitting that they were just looking for trouble. They didn’t find any. Eat all of the lettuce and radishes you want- they may make you healthy, but they won’t expose you to antibiotics. Cows, too, can eat all the tall fescue they want without fear of exposure to antibiotics. Feedlots are where they have to worry about that.
The 4th paper is the risk assessment. In this paper, the researchers took all of the data that they had accumulated and used it to carry out a traditional risk assessment. Both EPA methodology and World Health Organization methodology were used. They considered potential impacts on people, soil microbes and predators. Predators here refers primarily to animals like birds that eat bugs from soil. Negligible risk was the conclusion. You would have to have concentrations of antibiotics higher than are found in biosolids to even start to worry.
This all leads to the fifth and final paper in the library. This could also have been the first paper in the library. Here Harman looks at what happens when you add biosolids to soils that contain these two antibiotics. They tested how strongly biosolids bind these two antibiotics as well as how strongly the antibiotics are bound in regular soils. A range of methods were used to try to pry the antibiotics off the soil and biosolids. It turns out that there was a great deal of hysteresis – meaning that sticking antibiotics onto biosolids was a whole lot easier than prying them off, with less than 3% of the total antibiotics coming off adsorption sites. The conclusion from all of this is that the biosolids bind the antibiotics so tightly that they are pretty much a non-issue in a soil environment.
Hard to ask for better results than this. Cipro is a great companion for travel and a great neighbor in a soil system. I still love Cipro.
Sally Brown provides an excellent overview of the research and its meaningfulness to our industry. Also, she calls out Ned Beecher at NEBRA for his excellent leadership in watching and responding to this issue from policy, practice and science viewpoints. For that, MABA will be joining many others in our industry in providing financial support for Ned's work.
Dr. Brown emphasizes that the real life risks of PFAS in biosolids is exceedingly small, and, due to reduced manufacturing, decreasingly small at that. She also reminds us that PFAS is a ubiquitous chemical, in consumer products, most notably food packaging, but that the greater environmental sources are from manufacturers, not consumer products. Biosolids is a conduit, not a source, of PFAS. Continue with the blurb below, and if you want a copy of this opinion-piece blurb and the journal articles Dr. Brown cites, go to our website, for which you will need to log-in. And, as always, if you care to receive the original articles, just send a note to firstname.lastname@example.org.Read More
Everybody knows 55 C x 5 x 3. A compost pile has to reach 55º for 5 turns with a total of 3 days at temperature between turns. Those are the requirements to reach pathogen kill to make sure that the compost is Class A and is safe for general use. In our world that is pretty much the ‘apple a day’ equivalent. Recently Tania Gheseger from Metro Vancouver asked me for papers that show that that same 55 x 5 x 3 kills weed seeds too. My first reaction was to tell her that ‘everybody knows that’, thinking that it was part of the general wisdom rather than a conclusion from peer reviewed studies.Read More
To view the article abstracts from this months research update follow this link: OCTOBER 2018 RESEARCH UPDATE
The Spin Cycle
I am getting old for sure, old enough that I am not getting upset about microplastics (MP) in biosolids and old enough to know that microplastics are nothing new. After all, polyester is a form of plastic. If you think that John Travolta’s white suit in Staying Alive was made from natural fibers, I have a bridge I’d like to sell you. This is not to say that I don’t think that plastic is a major environmental issue, it most certainly is. Large scale plastic contamination of aquatic systems is an even bigger problem than the great Pacific garbage patch (https://www.theoceancleanup.com/great-pacific-garbage-patch/).
Waste plastic on land is also a huge issue. The first article in the July 2017 library is proof of the scope of this issue. In that article, the authors argue that plastic is the signature contaminant of the Anthropocene. As of 2015, we have generated 5 billion tons of the stuff -- enough to wrap the planet in Saran. In other words, plastic pollution is an enormous problem. Microplastics are just very small pieces of plastic (< 5 mm). Some are visible to the naked eye and many are not. Basically, as long as plastic has been around, little pieces of plastic have also been around. Are microplastics in biosolids a real concern?
The first article says absolutely. It is a two pager from the front section of Environmental Science and Technology. This is a very well-respected journal that often breaks critical stories. It is also a journal that features articles that focus on the sky is falling approach to science. Their big article about zucchini plants on carbamazepine is just one example of this. In many cases, when a new contaminant is identified, scientist test the worst case, meaning high (unrealistic) concentrations of contaminant are tested, not in a matrix (added straight not with biosolids). While demonstrating that something is possible in theory, this approach very often has no bearing in real life. For example, in theory I could run a marathon in under 3 hours. In reality I was able to jog a significant portion of the Biofest 2-mile fun run with only periodic walk breaks.
In this piece, the authors argue that land application of biosolids is a major pathway for introduction of microplastics into the environment. Sources that are identified include small pieces from tires, household dust and water from washing machines, and erosion of paints. The authors seem to focus on combined sewer systems. The authors say that between 1270 and 2130 tons of micro plastics are generated by every million people annually. That comes to up to 8 mg of microplastics per hectare per year. They then extend this to an estimate of between 44 000 and 300 000 tons of microplastics applied to farmlands in North America each year through the land application of biosolids. Those numbers sound a bit fishy to me. So, let’s do a quick calculation. If you figure that half of the microplastics that are generated end up in the wastewater treatment system and 90% of those end up in the biosolids and each person makes about 30 kg of dry biosolids a year, that means that about 5% of the biosolids is made up of microplastics. Sounds off by an order of magnitude or three to me. Five percentage points is what you typically see in terms of nitrogen content, not the percentage of plastic content.
For those reading this who work with compost, the second article in the library suggests that you aren’t off the hook on this one. This article looked at digestates from 4 plants and two composts and found microplastics in all but the energy crop digester. Between 10 and 150 particles (between 1 and 5 mm) were found for each dry kg of material tested. Dry weights of the plastic particles were not given. In other words, anything that comes from people will contain plastic, including biosolids, digestates and composts. These were all screened materials. It is just that the particles are small enough to pass through screens.
The third article takes a hard look at the premier pathway for microplastics from the home to the treatment plant: the washing machine. An estimated 1900 fibers are released per wash (from the 4th article). Did you ever think that you would be looking at the spin cycle for contaminants in biosolids? The authors looked at microplastic release from polyester textiles in a laboratory version of a washing machine. They considered different types of fabrics, and different detergents, temperatures, and lengths of cycle. Using detergent resulted in more microplastics release. Most of the fabric pieces released were between 100 and 800 mm long. You are welcome to read this article to get a detailed description of what types of fabrics shed the most fibers and factors in the textiles that result in loss of threads. The authors point out that installing a filter in the washer would miss most of the microplastics and suggest that the way to reduce loss is to better engineer fabrics. Forget flow diagrams, go to engineering school to design better polyester.
The particles leave the clothes in the washing machine and enter into the sewer system. The fourth article traces the fate of these particles during wastewater treatment. It turns out that different biosolids stabilization systems produce different amounts of microplastics. The systems that involve the harshest environments, lime stabilization and thermal drying, tend to produce the most microplastics (up to 13 675 per kg dry matter). In contrast, anaerobic digestion, a relatively gentle process, produces fewer microplastics (2000-4000 per kg dry matter). The article includes lots of pictures of different particles if you want to see the variety.
The final article looks at impact in a soil system. Again, this article is from Environmental Science and Technology, and, again, this article looks at scenarios that are completely removed from the real world. The authors added microplastics to a sandy loam soil at concentrations of up to 2%. With a typical soil bulk density, this concentration is the equivalent of 20 tons of microplastics per acre. They found that polyester increased soil water holding capacity and that polyester, polyacrylic and polyethylene all decreased bulk density. That makes sense. If you were to add plastic to soil at such high rates, the total weighs a whole lot less than soil minerals (a/k/a rocks). They also found that two of the three decreased microbial activity, although if you look at the data, that conclusion is not so clear. And, if you look at so many of the long- term studies of both compost and biosolids application to soils, you see benefits. More recent studies have confirmed health of the soil microbial community in long- term sites. It turns out that the organic matter and nutrients provided by the composts and biosolids do much more to help the soils in ‘Staying Alive’ than any white pant suit fibers do to harm them.
Sally Brown, University of Washington
In this month's Research Update, Dr. Brown looks at the consistent interest among scientists in mechanisms by which microbes adapt to challenge of antibiotics and how the microbes then pass these adaptations, via antibiotic resistant genes (ARGs), out into the world. This is an important issue for the big picture issue of the diminishing effectiveness of antibiotics in protecting from human diseases. A spotlight has been shone on wastewater treatment plants, concentrated animal feeding operations, and fish farms as principal environmental pathways for the spread of ARGs. Biosolids-borne ARGs are in the umbrella of this spotlight. Her bottom line, after a review of 5 journal articles is that ARGs in biosolids are not a major concern,Read More
Dear Biosolids Friends,
Dr. Brown takes us to the other side of the world, to the largest of the Polynesian islands, New Zealand. For all of the difference in the landscape, tree species, wastewater treatment processes, the benefits of biosolids for forest application are a mirror to the benefits we realize here in North America. We don't often get to visit in our biosolids careers so exotic a location, so Dr. Brown gives us a snap shot. Continue with the blurb below and, if you cwant a copy of this opinion-piece blurb and the articles Dr. Brown cites, go to our website, for which you will need to log-in. And, as always, if you care to receive the original articles, just send a note to email@example.com.
Dear Biosolids Friends,
Dr. Brown swallows hard and takes on an overview of the environmental fingerprint of society's use of pharmaceutical and personal care products (PPCPs). She reminds us that, by the sheer numbers and spread of humanity and through our sophisticated instrumentation, when we look for traces of PPCPs in our water enviornment, we will find traces of PPCPs. The traces may be in the parts per trillion concentrations, but they are there, released from feedlots, septic tank and sewage treatment plants. What does this mean? The reports Dr. Brown reviews do not offer insight into that question, but she does try to point out that the land application of biosolids is not the meaningful source, nor are our WWRFs to blame. If you have people, you have PPCPs. Continue with the blurb below and, if you can, try to wrap your head around 7 billion people and a part per trillion, For a copy of this opinion-piece blurb and the articles Dr. Brown cites, go to our website, for which you will need to log-in. And, as always, if you care to receive the original articles, just send a note to firstname.lastname@example.org.Read More
Dr. Brown provides a useful recap of nitrogen availability in organic amendments. Her colleagues in the Pacific Northwest have for over a generation been leaders in research into soil nitrogen interactions, with a focus on the role of soil amendments in plant nutrition. Her review of several of the seminal papers, old and new, are a reminder that the term "compost" embraces so wide a variety of materials, that no single approach to using compost for providing nutrients will work. Bottom line is that biosolids compost, with a characteristically high percent nitrogen, may indeed be used both for soil building and for fertilization. Most commonly available composts may actually draw nitrogen from the soil in response to the carbon addition. Nevertheless,, Dr. Brown leaves us with the "2 Percent Rule" offered by Dr. Bary. So, continue with the blurb below and learn more. For a copy of this opinion-piece blurb and her abstracts of cited literature, go to our website, for which you will need to log-in. And, as always, if you care to receive the original articles, just send a note to email@example.com.
MARCH 2018 RESEARCH UPDATE
We have ahead for us a new year of research summaries from the University of Washington's Dr. Sally Brown. In this February Research Updates Dr .Brown looks at the strong case for biosolids recycling that stems from the looming global climate change challenge. Biosolids is not merely a source of macronutiients in place of chemical fertilizers. We learn that biosolids alters soil qualities in an array of positive ways that accomplish carbon sequestration and a rebirth of soil health. We learn that the carbon in biosolids stays with soil far longer than most carbon sources used as soil amendments, hence it is a superior source of carbon for sequestration. We also learn that the Sylvis, a service company in British Columbia, is preparing a model for calculating carbon credits from biosolids application. Don't miss out on this blurb and please visit the abstracts. For a copy of this opinion-piece blurb and her abstracts of cited literature, go to our website, for which you will need to log-in. And, as always, if you care to receive the original articles, just send a note to firstname.lastname@example.org.
FEBRUARY 2018 RESEARCH UPDATE
Welcome to December, the holiday season and a turn toward winter, frozen ground, snow and ice. But for Dr. Sally Brown, at work in the Northwest U.S., clouds and rain set the tone of the season. So her thoughts in the December Research Updates turn to the performance of "green infrastructure," those increasingly common bioswales and detention ponds amidst our parking lots, commercial developments and "complete streets." She is particularly interested in how these devices are deployed, not so much for moderating the hydrology of stormwater discharge to streams, but for their ability to alter the quality of water, especially reducing toxicity of stormwater to aquatic life. She faces an establishment that, at the starting gate, is biased against biosolids-based components of bioswale soil mixtures, because of presumptions that biosolids-borne metals and nutrients work at cross purposes to high water quality. That may not be so, particularly for those biosolids with iron and aluminum compounds that can adsorb and chelate contaminants. So, here is Dr. Brown's take on the new research into this area of specialty soil mixes for stormwater management. For a copy of this opinion-piece blurb and her abstracts of cited literature, go to our website, for which you will need to log-in. And, as always, if you care to receive the original articles, just send a note to email@example.com
DECEMBER 2017 RESEARCH UPDATE
Welcome to November, and very nearly the eve of Thanksgiving. I, for one, am thankful for the extraordinary talent and commitment of so many people in our field of environmental stewardship, and especially for the on-going work of Dr. Sally Brown. She brings us a review of THALLIUM this month. What? I don't remember the last time I have given a moment's thought to this element. But it is, after all, an element created at the last supernova in our part of the Universe, so it is present in biosolids, just as is every element, very nearly. As we learn fromSally, its presence in biosolids is a barometer of its occurrence in the geological basement on which our communities reside, and yes its environmental relevance is subject to evaluation, but not really concern. For a copy of this opinion piece blurb and her abstracts of here cited literature go to our website. for which you will need to log-in. And, as always, if you care to receive the original articles, just send a note to firstname.lastname@example.org
NOVEMBER 2017 RESEARCH UPDATE
Dear Biosolids Friends,
Welcome to October! Halloween is on its way, have you decided on your costume? But if you are prone to being scared by politics, economy, wildfires, hurricane, etc., one thing you don't need to be afraid of is biosolids. This fact Dr Brown makes crystal clear in her October blurb. For a copy of this opinion piece blurb and her abstracts of here cited literature go to our website., for which you will need to log-in. And, as always, if you care to receive the original articles, just send a note to email@example.com
OCTOBER 2017 RESEARCH UPDATE
Dr. Sally Brown drills down into the release of micro constituents from land application sites in her September 2017 science review, She is irked by the framing of research results in "sky is falling" ways, and shows, in her dive into the details of the protocols, just how minuscule are the loadings that occur from land application. She supports her critique of one Colorado study with results of others, particularly one with manure, in which the results are framed in objective terms. She circles around to the obvious starting point, namely the context of the human origin of these compounds to begin with and the other pathways of potential environmental exposure in addition to biosolids recycling.
Visit MABA's upgraded website for a library of these research updates and to review the science abstracts referenced in them.. Also, you should now be able to contact me at firstname.lastname@example.org directly for any of the papers Dr. Brown cites in her "blurbs."Read More
Dr. Sally Brown digs into soil mixes in her August 2017 science review, Public agencies and service companies that prepare biosolids for "distribution and marketing," must meet, at a minimum, the Part 503 standards for safety that are termed Class A EQ. But Sally notes that the "value added" by biosolids is in attributes that goes beyond regulatory standards. The performance is in objective measurements of the quality of plant growth. Her review this month is on several studies that deploy testing parameters, some common to horticultural sciences, that compare soil mixes that deploy biosolids components with standard horticultural soil blends. Biosolids is a strong ingredient by almost any measure, except in some applications and climates where soluble salts are a challenge for horticultural crops. The final item she reviews is a bit different, in that it suggests that biosolids as a soil ingredient may improve the health-giving nutrient content of crops.Read More
Dr. Sally Brown reviews for July 2017 the topic of plastics, She reviews journal articles that cover the presence of plastics in wastewater and biosolids and their environmental fate, including soil The most salient point for me is that, despite their ubiquity in our world, the ultimate fate of plastic is poorly known to science. What we do know is that, over time, plastic fibers, fragments and beads continually reduce in size, making them ingestible to micro fauna, aquatic and terrestrial. The impact of plastics on the viability of these small animals, including worms, is not established. We should all be looking forward to advances in polymer chemistry that replace recalcitrant oil-based plastics with degradable plant based plastics. We as environmental stewards ought to advocate for this change.Read More
Dr. Sally Brown reviews biochar in her June 2017 Research Update. Co-incidentally my most recent Biosolids TOPICS "The op Ten" included bichar as a topic.Pyrolysis holds a special place in the hearts of anti-biosolids activists these days, as this technology is spoken reverentially for its ability to transform biosolids into fuel and biochar.
Aside from the great variety of pyrolysis approaches and feedstocks, Dr, Brown explains that, though biochar convincingly sequesters carbon in soil, biochar's effectiveness in soil has a wide huge variety of impacts, not all good. Clearly, predicting what biochar works and what doesn't work as a soil amendment to improve crop growth is nigh impossible, without specific field trials. Pyrolysis is not a foolproof solution for biosolids management, and neither is the biochar it yields a dependably great soil amendment.Read More
Dr. Sally Brown reviews in her May 2017 Research Update a question few of us have ever given thought. What happens to the polymer used in dewatering once the cake gets to land application? Are there any adverse effects of this chemical ingredient to soil microbes or plants?. When this question was posed to Dr. Brown she realized she had no good response. So she takes a look at that issue and reports to us. to this call was the same as mine -- let's take a look at the science.
MABA has just launched a new website, and we will find a new way to bring the details of Dr. Brown's review. Also, you should now be able to contact me at email@example.com directly for any of the papers by Dr. Brown.Read More
Dr. Brown is helping out here. While not a new topic for her, many of us had not been paying attention until NEBRA's Ned Beecher called the alarm for a regulatory threat arising in New Hampshire for the future of land application. That threat is tied to PFOAs (perfluorooctanoic acids), or more generally to the class called PFAS (perfluoroalkyl substances), "emerging" as a compound of human health concern. These compounds arrive in biosolids from consumer products and tapwater; they do not degrade; and when placed on the ground, some portion can migrate to groundwater. Not what we want to know. Many new science articles are appearing, and Dr. Brown gives us an overview.Read More