LETTERS Mine waters Dear Sir: The formation of the International Mine Water Association (IMWA) has been established with the following main objectives: 1. to improve exploitation of mineral deposits consistent with the desirable standards of safety against water hazards 2. to increase protection of the environment against the impact of mine drainage and related activities 3. to improve the utilization of mine waters 4. to improve technology and economy of mine drainage control operations 5. to create a forum for international exchange of information concerning the latest developments in the field of mine water problems. The pressing needs of persons involved with mine water problems encouraged us to establish an international authoritative body, to provide individuals and institutions with a better opportunity to benefit from worldwide experiences in this field. Dr. Rafael Fernlndez-Rubio Professor of Hydrogeology and International Mine Water Association Secretary Department of Hydrogeology University of Granada Apdo. de Correos 556 Granada, Spain
~
P.O.Box 2980
College Station, Texas 77840 (713) 693-1711
CIRCLE 18 ON READER SERVICE CARD
608
Environmental Science & Technology
Activated carbon use Dear Sir: I have read the article on activated carbon adsorption (ES& T , May 1981, p. 502) and appreciate the opportunity to make the following observations. The need for “predictive generalizations” of the adsorption process may be needed to prove broad applicability in the legislative process, but this need is only superficial when applying adsorption to purification problems. Hundreds of adsorption facilities throughout the world have been installed as a result of rather simple technical evaluation techniques followed by a comparison of the results with real alternatives. Until the advent of RCRA, the alternative of disposal of toxic wastes by landfill has been lawful and relatively cheap compared to destruction techniques. Processes such as adsorption and oxidation, which provide ultimate destruction, therefore have been clar-
ified as costly and "in need of improvements." This change in regulatory posture will cause engineers to creatively solve such problems of toxic wastes by applying the teachings of Dr. Weber and other researchers who have studied these technologies and have provided us with a sound engineering base. Many of the adsorption failures "of the '70s" have been traced to rather simple water chemistry phenomena and are not adsorption system problems per se. The failure to recognize and control bacterial slimes, unstable water in regard to hardness, and suspended solids concentrations have caused many adsorption process breakdowns. Application of wafer treatment chemistry to wastewater adsorption treatment systems will avoid many of these bothersome problems. In summary, the use of adsorption will experience rapid growth with existing technology when environmentally unacceptable alternatives to disposal of toxic wastes have been eliminated. Furthermore, adsorption system failures will be greatly reduced by more careful study and control of the water chemistry surrounding the adsorption process.
" , , rre-Gleaned
RaaAv-Tn-l Icq
EPA* Water Sampling Vials
~~
Ready for immediate use, E-PAK 40 rnl vials eliminate the time and hassle involved
\
in detergent washing, rinsing, oven drying and fully assembling 40 ml vials, caps and Teflon@
liconedisctpriortotheir usk fordsaetewate impling. EPAKs meet all €PA requirements Id use the exact vials, caps and septa stated in $*bl4$,29 and Dec. 3,1979 Federal Registers. 3510 E-Pak Water Sampling Vials 40 ml. PreCleand, Pkg of 6 dz $122
Pierce Chemical Company. Box 117. Rakford. IL 61105 i875 968 (n47 Telex 910 631 3419
1
Donald G. Hager
President. Rubel and Haeer. Inc. Consulting Engineers Tucson, Ariz. 8571 1
.
Genetic Engineering of Symbiotic lYitrogsn phntion and Colwnmtlon of Fixed nitrogen
edited by J X 4 p M , R.C..-V and R.C. lhlbLu
NRC associateships Dear Sir: This letter is addressed to former National Research Council Research Associates and Visiting Scientists Research Associates. The National Research Council Research Associateship Programs (tenable in federal laboratories) have been in existence over 25 years and now have about 3500 alumni in the sciences and engineering. The council is interested in locating former NRC Research Associates in order to verify certain information and to assess the value of the programs in their career development. Would you help by sending us your correct mailing address, dates of tenure, and the name of the laboratory where you pursued the NRC Research Associateship? We are grateful for your assistance in this endeavor. Please contact: F. A. Crump Assistant to the Director of
Associateships National Research Council 2101 Constitution Ave. Washington, D.C. 20418
D A Pampn, D.W. R.hu.
Developa a basic undemanding of the genetics, physiolow. and biochemistry of synbiotic PI, W o n and the effect of denibification on this h e d nitrogen. Basic Life Sciences. Volume I 7. approx 875 pp.. illus.. 1981, $69.50
w...spect.rolUetIyof Prb* by M M S.
Pollut.nt.
staph^ IL I*b.lu,and Ily 1). Hlw m e n both the experienced mu spectroscopist and novice a convenient source of comprehensive information on 129 priority poUulanu. 320 pp., illus., 1981. $29.50
Skeletal Qrowtb of Aquatic 0rg.ni.llU Bblogkd k o d of~EnvLPnmanW C b e edited by DOMU C. Rhond8and Richard A. Ld. Re&& the exciting new advances in bivalved mollusc and coral skeletal research in recent years. Topics in Ceobiofcgu.Volume 1 . 764 pp.. illus., 1980, $47.50
Provides a focal point lor new developments in this area for scientists from a wide range of disciplines. Subscription: Volume I . 1981 (4 issues) $60.00
Send for p u r free axamhatbn c o d
[pkngm] 233 Spring Street,New York, N.Y.
10013
I CIRCLE 9 ON READER SERVICE CARD
Volume 15. Number 6, June 1981 609
