Friday, June 30, 2006
Bioteq: The business of recycling mine wastewater by biological H2S gas
H2S is a critical problem in water and wastewater industry, it corrodes pipes (see the picture) and generates offensive rotten egg odor problems. Moreover, it is extremely toxic in very small concentrations in the air. Now a Canadian startup Bioteq Environmental is installing mine wastewater treatment plants based on a bioreactor that generates H2S gas to reduce the metal content of these residues. The plants must smell like hell and be extremely dangerous to the environment but they are sited on remote mining locations. This company, apparently, is a good investment opportunity.
I quote an analyst: "Bioteq Environmental is an undiscovered gem of a company that cleans the wastewater that comes off of a mine while simultaneously extracting the metals which are left in the water. Bioteq operates three plants and has three more under construction and four on tap. Bioteq is past the technology testing phase and about to enter a period of dramatic growth. With plants with life spans that last 40 to 50 years, and with minimal ongoing capital expenditures, Bioteq is about to become a cash cow. In four years, with 15 plants churning out on average $3-4 million in cash flow, Bioteq could climb close to $9 a share, or more than 400% higher than its current stock price. "
I have yet to form an opinion on that, but I am qualified to talk about the technological aspect. The idea is to have a biological reactor on site, where sulfur bacteria fed on sulphur rich substrate feedstuff liberate the H2S gas in abundance. This gas is bubbled through the mine wastewater and the H2S reduces the metals and precipitates them as copper, nickel, zinc, cobalt, etc. sulphates. They can extract copper for $0.60 a pound or nickel for $2.08 a pound.
The original idea of using sulphur reducing bacteria to remediate abandoned mines is being tried by the EPA noe for almost two decades. In the figure left above (EPA) they injected manure into an abandoned mine (Orphan Boy Mine) and let the H2S generated to precipitate the metal content of the water. In about ten years they succeeded in reducing metal content to reasonable levels. No recuperation of metals was intended. I have never heard of high concentration H2S gas except for separation of heavy water, which is an order of magnitude more complex than mining technology.
(1) The process of biological generation of H2S does not seem really patentable.
(2) The steady operation of a biological reactor in a remote site seems difficult.
(3) Biological reactors are sensible to temperature and local conditions.
(4) They are alternative ways of generating H2S, such as chemical reduction.
(5) H2S can be bought as liquid gas and transported to the site.
(6) The recuperation of the metal from the precipitate liberates sulphur - another problem.
(7) Alternative technologies: Reverse Osmosis. This technology is coming of age, membranes are cheaper and the technology is safe.
(8) H2S is extremely poisonous gas. It may not be a safe workable technology.
(9) H2S is corrosive and equipment maintenance will be a headache.
A wastewater engineer's problem is to reduce or eliminate the generation of H2S so I am unfamiliar with the opposite problem of generating it cheaply and abundantly. I use the Pomeroy formula based on effective BOD and temperature and reaction time. With BODeff = 1000 mg/lt and temperature of 32 Cent. and a reaction time of 5 or 6 hours, such as the conditions of the Rosh Ha Ayin - Biuv Dan WWTP (25 km) I get H2S in the range of a few hundred miligrams/cu m. Very smelly and corrosive, but enough to produce copper in kilogram scale?
Post Scriptum (July 1) : I just read about an explosive detecting handheld device purportodly working as a magnetic interpherometer activated by typical chemical bonds in explosives, but which is a fraud, but made 100 million dollars for its promoters. Could this be an ecologically attractive and basically feasible idea, whose main purpose is to sell stock? I dont know.