Is Municipal Sludge useful?

Once Municipal waste water is treated, the sludge, also known as BioSolids, are dried and applied to land as fertilizer. There is a lot of controversy over this use of sludge. Harmful effects and beneficial effects with data and testing on both sides are hotly debated. All this resulted in the EPA Part 503 rule dealing with the disposal of sludge on land.

One of the best accounts of the effects of the bugs/pollutants in the sludge after treatment, is in the book - The Big Necessity. A chapter called BioSolids explains the Citizens and the Municipality's point of view. a must read.

EPA rules referred to as the 503 rule, addresses the pathogens ( bugs) in the residual sludge ( Biosolids) . States need to adopt this or make there own rules up. These rules are very difficult to follow, police or implement. so there is uncertainty and confusion with each state having it's own set of codes and rules.

In a recent publication of the EPA, about 3300 water treatment plants were tested for residual pollutants ( these are plants treating > 1 Mil. gallons a day ). Trace elements of Pharmaceuticals were found in most of the effluent. Antibiotics and endocrine disruptors appear to be the problem pollutants that persist ( although in Trace amounts ) in the treated water.

Now the EPA will study the "fate an degradation rate" of these pollutants .. that is , how fast do these pollutants degrade to become harmless to humans, and what concentrations do they need to be in, to be harmful in the first place.

Countering the EPA's report is a report out today that shows estrogen in mineral water bottles, leaching out of plastic as XenoHormone ( compound that mimics a hormone)



... to be continued..

Manure: new source of renewable energy

In 2008, Dairy Manure from 3 stares contributes to half of 125 digesters installed in USA. PA, NY and WI are large Dairy states with the most installed anaerobic digesters.
In Europe, UK and Germany lead the installed base with > 70% energy generated by digesters. There are 1000s of Digesters in Europe and only 125 in USA. We have tapped less than 2 % of the energy potential from this renewable source: Manure.( 6500 farms are potential sites for digesters) Environmental Impact

Digester Gas, Methane (CH4) is 20x more harmful than CO2. Burning CH4 and converting it to energy, solves the GHG emissions problem and CO2 offsets (direct and indirect) can be encashed with the imminent cap-and-trade regs system.

Technology

One of the problems with the experience of farmers in USA is the bedding contamination in the digester. Most large farms (CAFOs) in USA have cows bedded on Sand. Cows on Sawdust or woodchips are prone to higher cull rates and poor milk quality. Cows on Sand, on the other hand, have longer life, live healthy and produce better and more milk.

But sand clogs the digester. There is need to eliminate the sand from the digester before it can get to the digesters. Over the last decade, 90 out of 100 digesters stopped working due to contamination, or lack of proper anaerobic process technology.

Nowadays, complete mix technology, a process started in Europe, is catching on.. The issue with sand is being addressed with a removal process installed in farms with about 95% to 99% removal of sand. The Parkson sand saver can be viewed on YouTube.

Energy and device efficiency: in a Cap-and-Trade system

When cap and trade comes into force, later this year, there is pressure to cut CO2 emissions from the burning of coal to make electricity, especially from coal burning plants. Natural gas, a cleaner fuel, is preferred to coal. Nat. Gas emits about 0.5kg CO2 per kWhr of electricity and coal burning power plants emit 0.8Kg to 1.2Kg depending on type of coal.

Natural Gas vs. Conventional Coal based power.

For A Conventional Plant, getting to the lower level of a natural gas plant amounts to a 50% reduction in emissions
Impact on electricity prices, increases cost by up to 50%...
If all these costs are passed on to consumers, and you pay 10 cents per kWhr your new bill is 15 cents.
Such higher prices begin to make Alternative sources of energy viable ... wind, solar, Biogas, etc (with Subsidies) start competing with conventional CO2 coal plants at these prices.


At these price rise, Energy Efficiency of power devices begins to get significant attention.

Example of Efficient devices: In a waste water treatment plant, the biggest energy bill is aeration, about 60% to 70% of the cost. For a bill of $100/- for the plant - $70 is the energy to aerate. Now the electricity price goes up 50%. And your bill is $150/- !!
Switching to efficient devices of Aeration like Parkson's HiOx fine bubble diffusers, is the easiest way to save money.

Energy not used = CO2 emissions not emitted = CO2 credits. These credits can be traded, once cap-and-trade is in place. Depending on which fuel is displaced, CO2 emitted is different. (Coal / Natural gas).

Water, Waste & Energy

Today is my first blog, I have been reading about energy efficiency at the oil endgame website . you can download a free summary.
http://www.oilendgame.com/pdfs/WtOEg_ExecSummary.pdf

It's an interesting hypothesis that improvements in energy efficiency can eliminate a good deal of waste and once it's adopted on a massive scale, will cause demand of oil to weaken and therefore price.

In the area of water and waste water, about 70% of the electricity in a waste water plant is consumed in the aeration of waste water. Oxygenated waste is broken down by bacteria to eliminate organic matter in the waste water. Therefore getting even a 10% efficiency in the performance of aeration will result in significant savings of energy.