Chinese/Japanese Chemists study heavy metals from sewage sludge burning.

[NNadir]

A large amount of sewage sludge is produced in the world every year. In China, the total production of sewage sludge was up to 450 000 000 tons in 2003.1 The problem of how to deal
with the sludge is one of the most serious environmental issues...

...A technical guideline for the handling and disposal of urban waste released in 1992 in Germany3 requires that the organic content of any material deposited in landfill sites must be less than 5% from 2005, which obviously indicates that only incineration slag or ash is suitable for landfilling. Therefore, it is anticipated that incineration will be increasingly used...

However, incineration has obvious shortcomings, such as the emission of dioxins and heavy metals. In particular, the concentration of heavy metals in sewage sludge is critically high and the emission standards for toxic metals during sewage sludge incineration are now stricter than before. Thus, a study on how to control and reduce the emission of toxic metals during incineration is extremely urgent. Up to now, much research into the behavior and transformation of heavy metals during thermal processes has been conducted.3-11 However, this research only concentrated on how to stabilize or reduce the emission of heavy metals, primarily using sorbents.12-15 Few studies have considered the separation of heavy and alkali metals in the flue gas, especially the reuse and recycling of metals during waste thermal processes. As mentioned above, the concentrations of several heavy metals (Pb, Cu, and Zn) are very high in sewage sludge. Heavy metals can account for approximately 0.5-2.0% and in some cases even up to 4% of the total dry weight...16-19

In the ASAP section of Energy and Fuels. Abstract is here: http://pubs.acs.org/cgi-bin/abstract.cgi/enfuem/asap/abs/ef0501602.html

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I am surprised at the mass of sewage sludge in China.

The sludge is said to have a calorific value approximately equal to that of brown coal, which is about 20,000 GJ/ton. If true, the amount of sewage sludge in China represents about 9 exajoules of primary energy.

China currently consumes about 50 exajoules of energy, most of it from coal.

[phantom power]

1. Doesn't that imply certain things about the heavy metals...

present in the humans that emitted the sewage in the first place?

[jpak]

2. Heavy metals in sewage sludge are primarily from industrial sources

Separate the human waste stream from the industrial/storm water stream and the metals content of the sludge will be very low.

Anaerobic digestion of sewage would also significantly reduce sludge volume and produce biogas as well....

[NNadir]

3. Really?

Have you ever contemplated the chemistry of soder?

What elements constitute the waste pipes of most third and first world countries?

It happens that plumbers refer to "lead waste."

The subject is China, not Coral Springs, Florida, and the conditional verb is not applied here. To wit, it's not "would" but "is."

If China is to use sewage sludge to ameliorate coal use in the immediate global climate change crisis, they really don't have time to completely restructure their sewage infrastructure.

The world has two decades at most in the current crisis.

[jpak]

4. It's "solder" not "soder" and lead pipes and lead solder

are no longer used in potable water supplies...

...and China is a leader in biogas production...

http://english.people.com.cn/english/200010/26/eng20001026_53623.html

<snip>

China has placed importance on biogas technology development since the 1970s, and founded a nationwide network for the research and application of biogas, he added.

There are 7.6 million Chinese households with biogas digesters already, which can generate nearly 200 million cubic meters of biogas annually, and 748 large and medium-sized digesters treating 20-million-ton waste nationwide.

The country has also set up over 500,000 sewage treatment facilities, with an annual treating capacity of 200 million cubic meters.

China will expand its biogas application in more sectors, focusing on increasing the efficiency of biogas projects, said Wang Xiwu, president of the China Biogas Society.

<snip>

Horseshit and bullshit should be shoveled into digesters too....

:rofl:

[NNadir]

5. And the answer in exajoules is?

In fact, the article is written by Chinese and Japanese Chemists, not a bunch of googlers.

The article, in fact, is not a speculative editorial, but it is a research paper that includes scientific data.

China gets most of its energy from coal, although it is expected to become one of the world's great nuclear power powers in short order.

People who take global climate change seriously, recognize that China is and has a problem. People who don't know shit, don't.

However with 450,000,000 tons of sewage sludge, as reported in the paper, China would seem to have a significant potential for producing electricity from sewage sludge. This would seem to represent the reason that the chemists referenced herein are researching the behavior of the heavy metals known to be involved in sewage processing. They are engaged in a serious effort to understand potential problems and find strategies for addressing them. They certainly are not engaged in a feel good fantasy.

As I noted in my previous post, the absolute potential for this capacity, assuming that all of China's sewage sludge were recovered and recycled, would be about 9 exajoules, close to 20% of its current enery demand, ignoring process energy. It would be really exciting if a major nation existed that got 20% of its energy by renewable means - not counting hydroelectricity. If it is true that China produces processes 20 million tons of sewage already in biodigesters - and that the claim isn't more of the same overly optimistic inflated representations (aka shit) that we are used to hearing from renewable partisans - they only have another 95% of their sewage sludge to recover. One of the critical and short supplies in China is known to be water. The question of whether or not this is water to build enough digesters to get the other 430 million metric tons, is certainly an interesting question.

One hopes they can. Nine exajoules is nothing to shake a stick at. That is serious energy. China is certainly making the effort as this research paper indicates. I expect that the paper will stand up very well to peer scrutiny. It looks like good science to me. There's no handwaving in it, as best I can see.

Whether China is prepared to scale up this particular strategy by a factor of 20 is not for me to determine. I note that most claims of rapid and timely (in the sense that global climate change is a current disaster) of renewable energy are just balderdash. If they weren't balderdash, there would be no climate change crisis.