[ABSTRACT] Community CompostToilet and Urine Diversion System Using IAPMO WE...Kimberly L. King
Safely reducing the volume of municipal sewage sludge typically sent for processing by sewer avoidance via separation at the source/on-site remediation of humanure using compost toilets with urine diversion AKA humus (top soil factories). This sanitary compost schema uses the 2018 IAPMO WE-Stand Guidance rubric. Ultimately, a rich resource is generated that can be used as a soil amendment to grow food by tiny house stewards managing hyper-intense farming on tax-defaulted, urban lots.
Conducted over four years, performance of a humanure batch compost processor, clearly demonstrates that high temperatures were reliably achieved with subsequent pathogen elimination to acceptable levels prior to distribution of high quality humus to the local garden environment. Additionally, urine diversion has also allowed the community to reclaim nitrogen and other nutrients otherwise lost in conventional sewage systems. The system has resulted in large savings of potable water, and significant carbon sequestration.
[ABSTRACT] Community CompostToilet and Urine Diversion System Using IAPMO WE...Kimberly L. King
Safely reducing the volume of municipal sewage sludge typically sent for processing by sewer avoidance via separation at the source/on-site remediation of humanure using compost toilets with urine diversion AKA humus (top soil factories). This sanitary compost schema uses the 2018 IAPMO WE-Stand Guidance rubric. Ultimately, a rich resource is generated that can be used as a soil amendment to grow food by tiny house stewards managing hyper-intense farming on tax-defaulted, urban lots.
Conducted over four years, performance of a humanure batch compost processor, clearly demonstrates that high temperatures were reliably achieved with subsequent pathogen elimination to acceptable levels prior to distribution of high quality humus to the local garden environment. Additionally, urine diversion has also allowed the community to reclaim nitrogen and other nutrients otherwise lost in conventional sewage systems. The system has resulted in large savings of potable water, and significant carbon sequestration.
Characterization of organic compounds from biosolids of Buenos Aires City, Silvana Torri
Como citar este trabajo
Torri S.I., C. Alberti. 2012. Characterization of organic compounds from biosolids of Buenos Aires City, Journal of Soil Science and Plant Nutrition, 12 (1), 143-152
Pollotion is a risk that has, unfortunately, become an issue in most parts of the world; especially the developing world. The slides presented here are the summary of a study carried out to determine the effect of the use of Water hyacinth as Alternative and cheap treatment option for domestic sewage.
The American Reusable Textile Association shares how the textile service industry can further green its operations and promote the environmental benefits of its service and products — providing reusable textiles to the heatlhcare, hospitality and manufacturing industries.
Composition and Toxicity of Biogas Produced from DifferentFe.docxmccormicknadine86
Composition and Toxicity of Biogas Produced from Different
Feedstocks in California
Yin Li,† Christopher P. Alaimo,† Minji Kim,† Norman Y. Kado,§ Joshua Peppers,‡ Jian Xue,†
Chao Wan,† Peter G. Green,† Ruihong Zhang,‡ Bryan M. Jenkins,‡ Christoph F. A. Vogel,§
Stefan Wuertz,∥ Thomas M. Young,† and Michael J. Kleeman*,†
†Department of Civil and Environmental Engineering, ‡Department of Biological and Agricultural Engineering, and §Department of
Environmental Toxicology and Center for Health and the Environment, University of California − Davis, Davis, California 95616,
United States
∥Singapore Center for Environmental Life Sciences Engineering, Nanyang Technical University, Singapore 637551
*S Supporting Information
ABSTRACT: Biogas is a renewable energy source composed
of methane, carbon dioxide, and other trace compounds
produced from anaerobic digestion of organic matter. A
variety of feedstocks can be combined with different digestion
techniques that each yields biogas with different trace
compositions. California is expanding biogas production
systems to help meet greenhouse gas reduction goals. Here,
we report the composition of six California biogas streams
from three different feedstocks (dairy manure, food waste, and
municipal solid waste). The chemical and biological
composition of raw biogas is reported, and the toxicity of
combusted biogas is tested under fresh and photochemically
aged conditions. Results show that municipal waste biogas
contained elevated levels of chemicals associated with volatile chemical products such as aromatic hydrocarbons, siloxanes, and
certain halogenated hydrocarbons. Food waste biogas contained elevated levels of sulfur-containing compounds including
hydrogen sulfide, mercaptans, and sulfur dioxide. Biogas produced from dairy manure generally had lower concentrations of
trace chemicals, but the combustion products had slightly higher toxicity response compared to the other feedstocks.
Atmospheric aging performed in a photochemical smog chamber did not strongly change the toxicity (oxidative capacity or
mutagenicity) of biogas combustion exhaust.
1. INTRODUCTION
Biogas is a renewable fuel produced from the anaerobic
digestion of organic feedstocks including municipal waste, farm
waste, food waste, and energy crops. Raw biogas typically
consists of methane (50−75%), carbon dioxide (25−50%),
and smaller amounts of nitrogen (2−8%). Trace levels of
hydrogen sulfide, ammonia, hydrogen, and various volatile
organic compounds are also present in biogas depending on
the feedstock.1 Life cycle assessment studies have shown that
deploying biogas technologies can effectively reduce green-
house gas (GHG) emissions and, therefore, reduce the climate
impact of energy consumption.2−4 Biogas production and
utilization practices also help diversify energy systems while
simultaneously promoting sustainable waste management
practices.1,5 California is promoting biogas utilization by
mandating the low carbon fuels, ...
PowerPoint Presentation for Microalgae Undergraduate Research Project at UPRA...Joseph Barnes
This is the PowerPoint presentation I prepared for my research project which is attempting to enhance the growth of microalgae for purposes of generated biofuel. This presentation covers my undergraduate research project at the UPRA during the fall semester of 2014 under the department of physics and chemistry. The phase in the research covered by this presentation involves attempting to grow C. vulgaris, a green microalgae, to the density of 1 gram per liter or more by supplementing the growth media with carbon dioxide gas. Unfortunately, although we failed to reach our mark of 1 g/L, we did learn how mixing carbon dioxide gas with aeration is better than directly injecting the gas into the growth media. Also, we were able to improve the biomass density compared to our earlier attempts.
Characterization of organic compounds from biosolids of Buenos Aires City, Silvana Torri
Como citar este trabajo
Torri S.I., C. Alberti. 2012. Characterization of organic compounds from biosolids of Buenos Aires City, Journal of Soil Science and Plant Nutrition, 12 (1), 143-152
Pollotion is a risk that has, unfortunately, become an issue in most parts of the world; especially the developing world. The slides presented here are the summary of a study carried out to determine the effect of the use of Water hyacinth as Alternative and cheap treatment option for domestic sewage.
The American Reusable Textile Association shares how the textile service industry can further green its operations and promote the environmental benefits of its service and products — providing reusable textiles to the heatlhcare, hospitality and manufacturing industries.
Composition and Toxicity of Biogas Produced from DifferentFe.docxmccormicknadine86
Composition and Toxicity of Biogas Produced from Different
Feedstocks in California
Yin Li,† Christopher P. Alaimo,† Minji Kim,† Norman Y. Kado,§ Joshua Peppers,‡ Jian Xue,†
Chao Wan,† Peter G. Green,† Ruihong Zhang,‡ Bryan M. Jenkins,‡ Christoph F. A. Vogel,§
Stefan Wuertz,∥ Thomas M. Young,† and Michael J. Kleeman*,†
†Department of Civil and Environmental Engineering, ‡Department of Biological and Agricultural Engineering, and §Department of
Environmental Toxicology and Center for Health and the Environment, University of California − Davis, Davis, California 95616,
United States
∥Singapore Center for Environmental Life Sciences Engineering, Nanyang Technical University, Singapore 637551
*S Supporting Information
ABSTRACT: Biogas is a renewable energy source composed
of methane, carbon dioxide, and other trace compounds
produced from anaerobic digestion of organic matter. A
variety of feedstocks can be combined with different digestion
techniques that each yields biogas with different trace
compositions. California is expanding biogas production
systems to help meet greenhouse gas reduction goals. Here,
we report the composition of six California biogas streams
from three different feedstocks (dairy manure, food waste, and
municipal solid waste). The chemical and biological
composition of raw biogas is reported, and the toxicity of
combusted biogas is tested under fresh and photochemically
aged conditions. Results show that municipal waste biogas
contained elevated levels of chemicals associated with volatile chemical products such as aromatic hydrocarbons, siloxanes, and
certain halogenated hydrocarbons. Food waste biogas contained elevated levels of sulfur-containing compounds including
hydrogen sulfide, mercaptans, and sulfur dioxide. Biogas produced from dairy manure generally had lower concentrations of
trace chemicals, but the combustion products had slightly higher toxicity response compared to the other feedstocks.
Atmospheric aging performed in a photochemical smog chamber did not strongly change the toxicity (oxidative capacity or
mutagenicity) of biogas combustion exhaust.
1. INTRODUCTION
Biogas is a renewable fuel produced from the anaerobic
digestion of organic feedstocks including municipal waste, farm
waste, food waste, and energy crops. Raw biogas typically
consists of methane (50−75%), carbon dioxide (25−50%),
and smaller amounts of nitrogen (2−8%). Trace levels of
hydrogen sulfide, ammonia, hydrogen, and various volatile
organic compounds are also present in biogas depending on
the feedstock.1 Life cycle assessment studies have shown that
deploying biogas technologies can effectively reduce green-
house gas (GHG) emissions and, therefore, reduce the climate
impact of energy consumption.2−4 Biogas production and
utilization practices also help diversify energy systems while
simultaneously promoting sustainable waste management
practices.1,5 California is promoting biogas utilization by
mandating the low carbon fuels, ...
PowerPoint Presentation for Microalgae Undergraduate Research Project at UPRA...Joseph Barnes
This is the PowerPoint presentation I prepared for my research project which is attempting to enhance the growth of microalgae for purposes of generated biofuel. This presentation covers my undergraduate research project at the UPRA during the fall semester of 2014 under the department of physics and chemistry. The phase in the research covered by this presentation involves attempting to grow C. vulgaris, a green microalgae, to the density of 1 gram per liter or more by supplementing the growth media with carbon dioxide gas. Unfortunately, although we failed to reach our mark of 1 g/L, we did learn how mixing carbon dioxide gas with aeration is better than directly injecting the gas into the growth media. Also, we were able to improve the biomass density compared to our earlier attempts.
International waste management strategiesAhmed Ali
The waste hierarchy refers to the "3 Rs" reduce, reuse and recycle, which classify waste management strategies according to their desirability in terms of waste minimisation. The waste hierarchy remains the cornerstone of most waste minimisation strategies.
http://socceronlinetv.com/aff-suzuki-cup-2016-final-live/
http://socceronlinetv.com/aff-suzuki-cup-2016-final-live-streaming/
http://socceronlinetv.com/thailand-vs-indonesia-live-streaming/
https://www.linkedin.com/pulse/aff-suzuki-cup-2016-final-live-streaming-thailand-vs-indonesia-ali
https://twitter.com/i/moments/809777680317026304
International waste management strategiesAhmed Ali
The waste hierarchy refers to the "3 Rs" reduce, reuse and recycle, which classify waste management strategies according to their desirability in terms of waste minimisation. The waste hierarchy remains the cornerstone of most waste minimisation strategies.
http://socceronlinetv.com/thailand-vs-indonesia-live-streaming/
http://socceronlinetv.com/aff-suzuki-cup-2016-final-live-streaming/
http://socceronlinetv.com/aff-suzuki-cup-2016-final-live/
Dr. Gregory Thoma - Pork’s Carbon FootprintJohn Blue
Pork’s Carbon Footprint - Dr. Gregory Thoma, professor, agriculture chemical engineering, University of Arkansas, Fayetteville, from the Minnesota Pork Congress, January 20-21, 2010, Minneapolis, MN, USA.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
SAP Sapphire 2024 - ASUG301 building better apps with SAP Fiori.pdfPeter Spielvogel
Building better applications for business users with SAP Fiori.
• What is SAP Fiori and why it matters to you
• How a better user experience drives measurable business benefits
• How to get started with SAP Fiori today
• How SAP Fiori elements accelerates application development
• How SAP Build Code includes SAP Fiori tools and other generative artificial intelligence capabilities
• How SAP Fiori paves the way for using AI in SAP apps
Elevating Tactical DDD Patterns Through Object CalisthenicsDorra BARTAGUIZ
After immersing yourself in the blue book and its red counterpart, attending DDD-focused conferences, and applying tactical patterns, you're left with a crucial question: How do I ensure my design is effective? Tactical patterns within Domain-Driven Design (DDD) serve as guiding principles for creating clear and manageable domain models. However, achieving success with these patterns requires additional guidance. Interestingly, we've observed that a set of constraints initially designed for training purposes remarkably aligns with effective pattern implementation, offering a more ‘mechanical’ approach. Let's explore together how Object Calisthenics can elevate the design of your tactical DDD patterns, offering concrete help for those venturing into DDD for the first time!
Encryption in Microsoft 365 - ExpertsLive Netherlands 2024Albert Hoitingh
In this session I delve into the encryption technology used in Microsoft 365 and Microsoft Purview. Including the concepts of Customer Key and Double Key Encryption.
Le nuove frontiere dell'AI nell'RPA con UiPath Autopilot™UiPathCommunity
In questo evento online gratuito, organizzato dalla Community Italiana di UiPath, potrai esplorare le nuove funzionalità di Autopilot, il tool che integra l'Intelligenza Artificiale nei processi di sviluppo e utilizzo delle Automazioni.
📕 Vedremo insieme alcuni esempi dell'utilizzo di Autopilot in diversi tool della Suite UiPath:
Autopilot per Studio Web
Autopilot per Studio
Autopilot per Apps
Clipboard AI
GenAI applicata alla Document Understanding
👨🏫👨💻 Speakers:
Stefano Negro, UiPath MVPx3, RPA Tech Lead @ BSP Consultant
Flavio Martinelli, UiPath MVP 2023, Technical Account Manager @UiPath
Andrei Tasca, RPA Solutions Team Lead @NTT Data
Epistemic Interaction - tuning interfaces to provide information for AI supportAlan Dix
Paper presented at SYNERGY workshop at AVI 2024, Genoa, Italy. 3rd June 2024
https://alandix.com/academic/papers/synergy2024-epistemic/
As machine learning integrates deeper into human-computer interactions, the concept of epistemic interaction emerges, aiming to refine these interactions to enhance system adaptability. This approach encourages minor, intentional adjustments in user behaviour to enrich the data available for system learning. This paper introduces epistemic interaction within the context of human-system communication, illustrating how deliberate interaction design can improve system understanding and adaptation. Through concrete examples, we demonstrate the potential of epistemic interaction to significantly advance human-computer interaction by leveraging intuitive human communication strategies to inform system design and functionality, offering a novel pathway for enriching user-system engagements.
State of ICS and IoT Cyber Threat Landscape Report 2024 previewPrayukth K V
The IoT and OT threat landscape report has been prepared by the Threat Research Team at Sectrio using data from Sectrio, cyber threat intelligence farming facilities spread across over 85 cities around the world. In addition, Sectrio also runs AI-based advanced threat and payload engagement facilities that serve as sinks to attract and engage sophisticated threat actors, and newer malware including new variants and latent threats that are at an earlier stage of development.
The latest edition of the OT/ICS and IoT security Threat Landscape Report 2024 also covers:
State of global ICS asset and network exposure
Sectoral targets and attacks as well as the cost of ransom
Global APT activity, AI usage, actor and tactic profiles, and implications
Rise in volumes of AI-powered cyberattacks
Major cyber events in 2024
Malware and malicious payload trends
Cyberattack types and targets
Vulnerability exploit attempts on CVEs
Attacks on counties – USA
Expansion of bot farms – how, where, and why
In-depth analysis of the cyber threat landscape across North America, South America, Europe, APAC, and the Middle East
Why are attacks on smart factories rising?
Cyber risk predictions
Axis of attacks – Europe
Systemic attacks in the Middle East
Download the full report from here:
https://sectrio.com/resources/ot-threat-landscape-reports/sectrio-releases-ot-ics-and-iot-security-threat-landscape-report-2024/
Accelerate your Kubernetes clusters with Varnish CachingThijs Feryn
A presentation about the usage and availability of Varnish on Kubernetes. This talk explores the capabilities of Varnish caching and shows how to use the Varnish Helm chart to deploy it to Kubernetes.
This presentation was delivered at K8SUG Singapore. See https://feryn.eu/presentations/accelerate-your-kubernetes-clusters-with-varnish-caching-k8sug-singapore-28-2024 for more details.
DevOps and Testing slides at DASA ConnectKari Kakkonen
My and Rik Marselis slides at 30.5.2024 DASA Connect conference. We discuss about what is testing, then what is agile testing and finally what is Testing in DevOps. Finally we had lovely workshop with the participants trying to find out different ways to think about quality and testing in different parts of the DevOps infinity loop.
GraphRAG is All You need? LLM & Knowledge GraphGuy Korland
Guy Korland, CEO and Co-founder of FalkorDB, will review two articles on the integration of language models with knowledge graphs.
1. Unifying Large Language Models and Knowledge Graphs: A Roadmap.
https://arxiv.org/abs/2306.08302
2. Microsoft Research's GraphRAG paper and a review paper on various uses of knowledge graphs:
https://www.microsoft.com/en-us/research/blog/graphrag-unlocking-llm-discovery-on-narrative-private-data/
Smart TV Buyer Insights Survey 2024 by 91mobiles.pdf91mobiles
91mobiles recently conducted a Smart TV Buyer Insights Survey in which we asked over 3,000 respondents about the TV they own, aspects they look at on a new TV, and their TV buying preferences.
Securing your Kubernetes cluster_ a step-by-step guide to success !KatiaHIMEUR1
Today, after several years of existence, an extremely active community and an ultra-dynamic ecosystem, Kubernetes has established itself as the de facto standard in container orchestration. Thanks to a wide range of managed services, it has never been so easy to set up a ready-to-use Kubernetes cluster.
However, this ease of use means that the subject of security in Kubernetes is often left for later, or even neglected. This exposes companies to significant risks.
In this talk, I'll show you step-by-step how to secure your Kubernetes cluster for greater peace of mind and reliability.
A tale of scale & speed: How the US Navy is enabling software delivery from l...sonjaschweigert1
Rapid and secure feature delivery is a goal across every application team and every branch of the DoD. The Navy’s DevSecOps platform, Party Barge, has achieved:
- Reduction in onboarding time from 5 weeks to 1 day
- Improved developer experience and productivity through actionable findings and reduction of false positives
- Maintenance of superior security standards and inherent policy enforcement with Authorization to Operate (ATO)
Development teams can ship efficiently and ensure applications are cyber ready for Navy Authorizing Officials (AOs). In this webinar, Sigma Defense and Anchore will give attendees a look behind the scenes and demo secure pipeline automation and security artifacts that speed up application ATO and time to production.
We will cover:
- How to remove silos in DevSecOps
- How to build efficient development pipeline roles and component templates
- How to deliver security artifacts that matter for ATO’s (SBOMs, vulnerability reports, and policy evidence)
- How to streamline operations with automated policy checks on container images
A tale of scale & speed: How the US Navy is enabling software delivery from l...
Horowitz shor tversion
1. VOC emissions from organics management: Measurement, speciation and mitigation Robert Horowitz California Dept. of Resources, Recycling & Recovery (CalRecycle) [email_address]
12. 2009 San Joaquin APCD study Study: Irrigation system used within 3 hours before turning redu c ed emissions by 24% over first 3 weeks New Rule 4566 : Facilities between 10,000-200,000 tons/year must achieve 24% reduction Study: Pseudo-biofilter compost cap reduced emissions by 53% over first three weeks. New Rule 4566 : Facilities over 200,000 tpy must achieve 53% emissions reduction
18. Too hot? DMDS : strong garlic odor Too much woody material (carbon)? Terpenes Too much grass or food (nitrogen)? Amines : smells fishy, putrid or dead Too dense? Mercaptans : smells like rotten cabbage Not enough oxygen? More odors of all kinds Lots of food? Volatile Fatty Acids : smells fecal, sweaty, vinegar
19.
20.
21.
22. Thank You Bob Horowitz (916) 341-6523 [email_address] http://www.calrecycle.ca.gov/Organics/Air/default.htm
Editor's Notes
This is the short version of my talk. I have a long version too. Even so, I probably have too many slides for the time allotted. So I will try to talk slow. Especially now that there are translaters. If I start talking too fast maybe someone can give me a sign (like Occupy Wall street)
One of the reasons California has the most developed composting sector in the US is a law passed in 1989. It said that every city and county had to recycle half their waste, and also that composting is recycling. In California it is mostly warm, plants grow profusely and in some places yards are big—especially compared to European city yards, so homes generate a lot of yard waste and local officials figured out pretty quick that recycling these types of organic wastes was a smart way to get to that 50% mandate . In 2011 , there were some amendments to the law. That included a GOAL of 75% statewide diversion by 2020 . CalRecycle, where I work, is tasked with achieving this goal. The new law said that businesses and apartments must also recycle. In many places in CA, businesses and apartment dwellers DO recycle, but not everywhere , so this law will ensure that the contributions of the commercial and multi-family sectors to the recycling rate will be going up.
This is a satellite view of a typical California compost facility. Most composting in CA is still relatively low-tech , in giant elongated piles, called windrows . This is a low cost and efficient way to do things, by simply amplifying the processes nature has been using for millenia. Each one of these are probably 2 meters tall, 3 or 4 meters wide, and maybe 50 meters long. Open windrow composting is the dominant type of facility in California . Land is still very cheap in the Western US . So is landfilling. In some places, you can landfill a ton of material for as little as 15 Euro . Also, there is no landfill directive like here in the EU. Organic wastes do NOT have be stabilized before landfilling . So composting facilities compete with landfills for feedstocks. If they raise their tipping fees too much they may lose their raw materials to somebody else who will accept them for less.
Most of the compost is purchased by agriculture. California produces 20 percent of the dairy products in the US (talk more about that later), and more than half of the country's fruits, nuts and vegetable s. California produces around 90% of the grapes in the US, and the wine industry was an early adaptor to compost production and use. So, composting is important to agriculture, but farmers don’t want to pay very much for compost, the average price for finished compost is probably around 10 euro per ton . Nitrogen fertilizer is still pretty cheap. So composting in the US it’s a high-volume business that depends on low-cost production . The problem is that air and water quality compliance is not low cost . Air and water It turns out that paving a 20-hectare pad to protect groundwater would be rather expensive, actually. It turns out that giant pipes full of pressurized air pumps and biofilters are expensive to build and operate. So our infrastructure will have to be modernized but the economics don’t support that . And now we are raising the bar in terms of our recycling goals, but it is becoming very challenging to open new organics facilities and we might even lose a few facilities before the next generation of facilities is ready to come on line..
There is a relatively new type of system that has a good combination of emissions control and costs . Already a few have been built in California, both for greenwaste/foodwaste and also for biosolids composting. There are several vendors of these systems, these photos are from some facilities designed and built by a company called Engineered Compost Systems, or ECS . One of the things ECS does that is a little different is that they have these inflatable sausages that that are inflated under the pile when it is formed. After the piles settles a bit, the sausages are deflated and removed, leaving an air channel which is used to aerate the pile. After a few weeks, the pile can be turned with an ordinary windrow turner , taking advantage of some of the existing machinery. These types of systems are a good bridge from open windrow composting to the modern systems that we need, and they have some water quality and water use advantages over open piles, as well.
Ozone high up in the stratosphere is good, it protects us from harmful radiation. But ozone at ground level is bad for humans, bad for plants, bad for crops. In the US where pollution exceeds national standards, the Clean Air Act requires local air quality management agencies to do everything possible to reduce ozone levels. That also means reduce ozone precursors like VOC s. This year , two California air quality districts enacted regulations to reduce emissions from open compost windrows. These are the first two such regulations in the US. Any new composting facilities in these areas will be built to much higher standards , and will cost a lot more to construct, more than the economics of composting can support in the US. The people who are already composting will be allowed to continue operating for now, but will have to change the way they manage their piles. USCC 2009 Houston Texas A Compost Air Emissions Primer Jan. 27, 2009
So here is the US. California is the third largest state, way out here on the Left coast. Point out SJV, airflow from Bay into SJV, 7 million people living in Bay Area, refineries, port, industry, long commutes. Sierra Nevada mountains, up to 4000 meters, and that this area has some of the highest ozone levels in the USA. SCAQMD, big mountains to its east, over 3000 meters, LA, Sacramento and SF.
The first people to test compost piles for emissions in CA was the air district in the Los Angeles area, known as the AQMD . They have traditionally had the worst air in America and have been leaders many air pollution control techniques. The air in Los Angeles now is much, much better than it was 20 or 40 years ago. These numbers are called emissions factors , and what this means is for every short ton of feedstock, the early studies said we could expect little less than 4 pounds of VOCs. I converted this to mg per kg.. CalRecycle and the AQMD did some testing at this time, trying to see if lasers and traditional measurement techniques using flux chambers, (point to it) this little device here which is barely a half meter across. There was not good correlation between these methods. We also did some work on process controls and found, that a windrow with a lot of woody material gave off less emissions than one with a lot of grassy material. We also found that a turned windrow gave off more emissions than a static pile, but that it also matured faster.
These are RESULTS from CalRecycle’s next study, the most ambitious attempt in the US to quantify the non-methane VOC emissions from open windrow composting, and to test some potential mitigation measures. More than 100 emissions samples were analyzed for this study, probably 5 times more than any of the studies before or since. We came up with a number for straight green waste of about 450 mg per kg, or about one pound of VOC emissions per ton of material. This is just for a windrow process and does not count grinding operations or piles of newly received materials just hanging around. Since this study has been done, there have been other studies done privately , at private facilities, that have found much higher rates of emissions, maybe 20 or 30 times higher. Private sector folks do not publish their data . So I think the truth is, emissions factors are highly variable. Where you set down the little flux chamber really matters, because it is small and the pile is big. Emissions vary hoiur by hour . Put down the flux chamber 5 feet away you could get a very different number . First mention of the pseudo-fiofilter compost cap.
The pseudo-biofilter compost cap is basically a layer of fully composted material on top of a row of freshly ground organic material. This management technique takes advantage of materials on site , such as finished product and oversized materials screened out of finished product, we call them “overs”. Large particles reduce the density of the compost mixture and allow airflow, so when you finally mix the cap into the pile you get a second benefit. You are going to hear about the cap three more times in this presentation. Basically, the microbes living in the finished compost eat up the VOCs migrating up from the actively composting materials; it’s their lunch . In the Modesto study, they ate about three quarters of the emissions over the first two weeks.
In 2009 the San Joaquin Valley Air Pollution Control District contracted for its own study of mitigation measures for open windrow composting. Several methods were tried, and two were deemed to be effective. The first was that irrigating piles within three hours before turning, so that the top of the pile is pretty wet, reduced emissions by 24%. Based on this study, the district created a regulation which requires composters to measure the moisture in the top of the compost pile before turning, and to add water if it is too dry. The irrigation system does not have to look like this, but this certainly is an inexpensive way to do it. The pseudo-biofilter compost cap was proven effective again. These caps were made of unscreened finished compost, they were re-applied every time the pile was turned for the first 3 weeks. So the APCD wrote a regulation that said really big compost facilities had to cover each new windrow with a compost cap, and keep it covered for 3 weeks. These numbers are in short tons, but even with that, 200,000 per year is a very big facility.
The studies that I did with my colleague, Dr. Peter Green at the University of California, Davis, are fundamentally different than all previous studies of composting process VOC emissions. In the past, everyone tried to answer the question, “How much VOCs ?” As I’ve said, it varies… a lot . Dr. Green and I wanted to answer a different question; what kind of VOCs, and even more importantly, do they make ozone ? Because the point of all these air quality regulations is not to protect us from VOCs, though some may be dangerous, but to reduce the build up of ground-level ozone in our cities and the places downwind from them. The assumption has been, if you have VOCs, you make ozone . That’s what Clean Air Act says . Unfortunately, it’s not really true. Not all VOCs are created equal. Some are highly reactive, others are not. A pound of isoprene makes 10 times more ozone than a pound of ethanol. A pound of acetaldehyde makes 10x more ozone than a pound of methanol. Where do compost emissions fit in?
This is the portable ozone formation chamber. It is just small enough to tow behind a pickup truck. Inside the chamber is a 1000-liter teflon bag and banks of lights that mimic the ultraviolet radiation of a typical California summer day. We use a photo-acoustic meter to make real-time ozone measurements in the bag. Later on, we compare these measurements to modeled estimates of ozone formation. The modeled emissions are based on gas samples captured in stainless steel canisters and in sorbent tubes. We take those samples back to a lab and run them through a chromatograph to find out what kinds of gases are in the mix, then that information goes into computer model which predicts how much ozone will be formed. When we compare the two results, they should be fairly close. If they are, then we know we have identified all of the important constituents in the emissions sample. You can see we use a wind tunnel here instead of a flux chamber . This helps reduce the moisture in the sample, which is important for the photo-acoustic measurement. One other thing is added to the 1000-liter teflon bag is a surrogate air that is formulated to match the atmosphere that is found in the San Joaquin Valley on a typical summer day. Because we are not adding composting emissions to a pristine environment, we don’t have one of those. We are adding these emissions to an atmosphere that already has a lot of different stuff in it, and we want to see if we are increasing the amount of ozone that would be formed under those conditions .
We had three rounds of studies , first to get a baseline of different aged piles of greenwaste, we included tipping piles and compost windrows up to 3 weeks old. In our second experiment we test overs , which are the oversized materials screened out of finished compost, not much ozone formation there. We also used overs as a pseudo-biofilter compost cap, and found it reduced observed ozone formation as well as ozone formation predicted by the model. Late last year, a group representing sewage treatment plant operators found out about our efforts, and commissioned our team to study ozone formation from bio-solids co-composting . With pretty much the same results. The bottom line, composting emissions did not form much ozone in the chamber, and the model did not predict that they would. I’m not saying they did not form ANY ozone, but the increase over the surrogate air which mimicked the San Joaquin Valley was very minimal . Compounds like ethanol do form ozone, but they are kind of like the nerdy kids at a school dance. (do they know what nerdy means?) In a diverse atmosphere, there are other compounds which are more attractive (reactive). Every once in a while they get lucky, but most of the time the NOx is going to dance with somebody else.
In California we have this thing called MIR , maximum incremental reactivity. Here in Europe, you have POCP, which stands for Photochemical Ozone Creation Potential . It is basically a measure of relative reactivity; how much more likely is one compound to form ozone versus another. In this slide, we look at how composting compares to other emissions sources , including baselines such as cars and pickup trucks, not heavy duty trucks. We also have the average urban VOC mix here, and two different isomers of pinene, which is a moderately reactive VOC, about 4.5 on a scale that can go up to about 15 . As you can see, the reactivity of composting emissions is quite low, and very close to cow manure . Compost and cow patties are about 1/3 as potent as the typical mix of VOCs found in urban areas . The one agricultural source which is actually fairly potent is silage , the fermented grain and vegetative matter fed to dairy cows. The team from UC Davis tested a lot of different agricultural sources in the San Joaquin Valley, and this was probably the most important revelation. The dairy farmers were not pleased to hear this, but the fact is that the emissions from dairy silage may contribute as much to air pollution in the San Joaquin Valley as automobiles , because there are something on the order of 3 million cows in the Valley, and last I heard, they like to eat every day. The good news is that this should be a win-win situation , because the same management practices which reduce emissions will preserve the value of the food .
The CCORP report grew out of an environment where composting facilities were increasingly being encroached by neighbors in fast-growing communities, and were having trouble with their new neighbors. It was an attempt to bring some science to the issue, and to find out which odor mitigation strategies might work. The best performing mitigation, again, was the pseudo-biofilter compost cap, which worked on the biggest vareity of compounds, whereas some of the commercial applications were only effective against some of the odor compounds. This report runs more than 100 pages and is available for free from the CalRecycle web site.
Based on the literature search performed for the CCORP study, these are some of the potential impacts of variations in the composting parameters and how they might impact emissions, but this is all situational. Some of it is intuitive ; too much nitrogen or not enough carbon in the feedstock and some of it goes up into the air as ammonia or amines. And what the report points out is you need to measure AVAILABLE carbon when calculating a C:N ratio. If you are only measuring total carbon you are overestimating the amount of carbon in your pile, which will likely result in too much nitrogen, and resulting in amine odors, which are not all that pleasant. Similarly, the relationship with temperature is not always straightforward . Certainly, high temperatures indicate healthy microbes and fast decomposition , which is good. Temperature increase up to a certain point does not correlate with more odors, because odorous intermediate products are being broken down. But at very high temperatures , say above 75 C, dimethyl disulfide or DMDS can form rapidly but cannot be degraded biologically. So, my advice if you have odor problems is to download this report for free from our website, and I will have the address in a few seconds.
One more study is underway and funded by CalRecycle . This is part of California’s efforts to assess its greenhouse gas balances as directed under a landmark climate change bill passed in 2006 . Early action measures called for collaborative research on nitrous oxide , which is around 300x more potent than CO2, and closely tied to intensively farmed lands . We are working with a team of researchers to determine what role composting might play in reducing N2O from farming. This is part of a larger effort to establish GHG baselines for a variety of agricultural production systems in California, a very big, multi-year project. Unfortunately, I don’t have any data from this study for you today, and it’s going to be a couple of years until I do, so you’ll have to invite me back in 2014 and I will be happy to report on that!
Every one of the CalRecycle studies I’ve mentioned today is available free on the internet. This is the true beauty of publicly-financed research. So please take advantage of that. The top page is my web page, where there are many links. Go down the line and recap study results.
So, here is the money slide, the summary. If you can remember these points then it was worth it to you, for me to travel across the world. Because it’s going to be worth it for me no matter what! Thank you so much for listening.
If you have any questions… take them now or stop me any time during the conference. Happy to talk to anybody about this subject.