Detoxification of Pesticides and Hazardous Wastes by the Microwave

5 Detoxification of Pesticides and Hazardous Wastes by the Microwave Plasma Process LIONEL J. BAILIN and BARRY L. HERTZLER Department of Chemistry, Lockheed Palo Alto Research Laboratory, 3251 Hanover Street, Palo Alto, CA 94304

Downloaded by UNIV OF MICHIGAN ANN ARBOR on May 23, 2016 | http://pubs.acs.org Publication Date: June 30, 1978 | doi: 10.1021/bk-1978-0073.ch005

DONALD A. OBERACKER Solid and Hazardous Waste Research Division, Municipal Environmental Research Laboratory, U.S. Environmental Protection Agency, Cincinnati, OH 45268

Of the approximately 10 million tons of toxic and hazardous wastes which are generated yearly in the United States, it has been estimated that 10 to 20% will need special methods for dis posal because of extreme difficulties in their treatment. These materials are made up in large part from pesticides which have been withdrawn from use, obsolete or below-specification toxic substances, industrial wastes from chemicals, explosives, etc., and biological residues, carcinogens, mutagens, and related mate rials (1). They exist in multiple ton quantities, as well as small centigram batches at a multitude of locations throughout the United States. They are, specifically, materials in search of a disposal method, and include the following exceedingly dangerous compounds and mixtures: ο Cancer-causing nitrosamines, vinyl and vinylidene chlorides, dioxin-containing organohalogens, and aromatic amine com pounds which heretofore have been considered only as oddities, or as being present only in small quantities ο Acute-toxicity organometallic compounds and heavy metal com plexes, such as mercury, arsenic, cadmium, and lead compounds, derived from industrial processes and pesticides ο Nerve-poisons from military sources, which include organophosphorus chemicals stockpiled above ground, and from pesti cide wastes which are only slightly less hazardous All of these are problem materials which give great concern to those who are responsible for their safe disposal. Their identi fication and sources (2) are abstracted in Table I. Current Disposal Techniques for Highly Toxic Materials For compounds of nominal toxicity, such as diluted DDT or other pesticides mixed with solvent or municipal sludges, on the order of LD50* of 500 or higher, notable achievements have been accomplished in thermal destruction, chemical and biological de toxification, and special landfill methods. However, with the ex ception of incinerator processing, relatively l i t t l e new technol*0ral lethal dose for 50% of test animals in mg/kg of body weight. 0-8412-0433-0/78/47-073-049$06.00/0 This chapter not subject to U.S. copyright. Published 1978 American C h e m i c a l Society

Kennedy; Disposal and Decontamination of Pesticides ACS Symposium Series; American Chemical Society: Washington, DC, 1978.


Nerve gases or G-agents

Pesticides (phosphonates, tMophosphonates)

Mercurials pestlcidee

Lead (tetraethyl lead)

Metal cyanides

Nickel carbonyl, Zn, Cd, Mn, Se, V,

•

•

•

•

Aromatic amines (e.g., benzidines)

Potyaromatlc hydrocarbons, PAH (dyes.

•

•

Carcinogens, teratogens, mutagens

Carcinogens

Male sterility In humane

Carcinogen*

Primary organ toxlna

Primary organ toxins In humane

Lipoid toxin

Anticholinesterase

Carcinogen

Anticholinesterase nerve toxin

(a) LDgo < 100 (oral lethal dose 80% test animals, < 100 mg/1 kg body weight). (b) Temporary method: Materials nave not been rendered chemically or btologlcaUy safe.

Nttrosemlnea (e.g., dimethyl nJtrosamlne)

•

Or*anonitro*en Compounds:

Vinyl and vlnylldene chlorides

e

PC Be, Kepooe, Mlrex, etc.

H exachlo robenzene (containing dioxin)

DBCP (dlbromocUoropropane)

•

•

Halofjenated Compounds-

Misc. Heavy metal compounds

Arsenical pesticides

•

OmnometaUlc Compounda:

FlaxiM retardent («.g., T r U " )

•

(phoaphooflfluoridate a)

•

•

Orgmnct^spoorus Compound.:

Classification

U.S. Navy smokes, flares, etc.

Centers.

Industrial, Hospitals, Universities, Cancer

Industrial waste streams and process bottoms

Fumleant/agricultural chemicals

Commercial, Agricultural

experimental complexes

Petroleum catalysts, pestlcidee,

Plating wastes, solids

Process wastes

Solids, solutions

100's of lb

100's of lb

l to 10 lb (throughout U.S.)

Estimated 1000's of lb

Estimated 1000's of l> (California)

1000's of lb

(Texas, California, New Jersey)

I to 100 lb, a few 1000'e of lb

ΙΟΟΟ'β of lb (East and West Coast)

100's of lb, gallons

100 to 1000 gallons

New Mexico)

100's of lb

SoUds

1 to 10,000 lb in various locations

Probable 1000·β of lb (California)

(Colorado, Utah, Maryland)

Several thousand lb

Thousands of gallons

Quantities and Location, Where Known

Holding ponds (Alexandria, Va. area)

Commercial, Industrial, Agricultural:

Unlabeled, unknown supplies

Outdated supplies

Pesticide manufacturing wastes

Commercial, Industrial, Agricultural:

Manufacturer

streams. Stored neutralization products

Military: Stored pure agents. Stored «mate

Source of Material

Unknown

Storage above and below ground

Storage and Incineration

Unknown

Storage above sad underground. Incineration

Storage above and underground

Wet oxidation, UV, oxonolyels

Storage above and underground

Storage above grote%d

Storage underground

Storage above ground

Incineration

Chemical disposal sites.

Storage^ above ground

Disposal Method

Identities and Known Sources of Highly Toxic and Hazardous Substances within Continental U.S.

Toxic Material

Table I.


8


5.

BAILIN ET

AL.

Detoxification of Pesticides and Wastes

51

ogy has been developed w i t h i n the l a s t 10 years f o r the d i s p o s a l of h i g h l y t o x i c , r e f r a c t o r y , and extremely p e r s i s t e n t wastes i n the form of concentrates, pure chemicals, o r n o n d i l u t e d process wastes. Current methods have been almost e x c l u s i v e l y underground l a n d f i l l , or aboveground warehouse or exposed-drum storage. This i s not a true d i s p o s a l , but a " h i d i n g " a c t i o n , i n that the mater i a l s are s t i l l t h e r e , i n p l a c e , w a i t i n g f o r a method which w i l l c a r r y out the d e t o x i f i c a t i o n e v e n t u a l l y . The substances w i l l a c t u a l l y remain f o r f u t u r e generations to be t r o u b l e d w i t h . P r e l i m i n a r y Microwave Plasma D e t o x i f i c a t i o n Studies Research on the decomposition of organic compounds by passage through a microwave discharge began at the Lockheed Palo A l t o Research Laboratory (LPARL) i n 1967. Since i t was w e l l known that microwave discharges could be used to promote a v a r i e t y of chemic a l r e a c t i o n s (3), i t was considered reasonable t h a t t h i s approach could be a p p l i e d t o the s c i s s i o n or d e s t r u c t i o n of bonds i n compounds which, f o r v a r i o u s reasons, were considered o b j e c t i o n a b l e . In a U. S. Army-supported program conducted during 1970-1972, the decomposition of t o x i c gas simulants was c a r r i e d out i n discharges c o n t a i n i n g h e l i u m and a i r i n which n e a r l y 100% decomposition of s e l e c t e d organophosphonate m a t e r i a l s was e f f e c t e d (4)· The mater i a l s were passed through a s m a l l 1-5 g/hr c a p a c i t y l a b o r a t o r y s i z e r e a c t o r , having a plasma volume of about 10 cm^. For commerc i a l o r p l a n t - s c a l e development of the process, i t was obvious that l a r g e - c a p a c i t y r e a c t o r s would be r e q u i r e d . When i t was d e t e r mined that l a r g e r s i z e microwave power a p p l i c a t o r s could be obt a i n e d on a custom b a s i s from microwave hardware s u p p l i e r s , the U. S. EPA, S o l i d and Hazardous Waste Research D i v i s i o n , M u n i c i p a l E n v i ronment a l Research Laboratory, C i n c i n n a t i , Ohio, supported the f o l l o w i n g study t o t e s t the process on s e v e r a l t o x i c p e s t i c i d e s and wastes. Program O b j e c t i v e s The primary o b j e c t i v e o f the program was e v a l u a t i o n of the e f f e c t i v e n e s s of an expanded s c a l e microwave plasma system f o r processing hazardous organic compounds, wastes, and p e s t i c i d e s of current i n t e r e s t . The r e a c t i o n products would a l s o be i d e n t i f i e d to v e r i f y that the products were innocuous, and to assess the p o s s i b i l i t y f o r recovery o f u s e f u l m a t e r i a l s as by-products. The data presented below describes the chemistry of the r e a c t i o n s , the i n i t i a l scale-up of microwave hardware, and an e v a l u a t i o n of the process i n which 450 to 3200 grams (1 t o 7 l b ) per h r were decomposed to harmless or r e a d i l y disposable e f f l u e n t s . Microwave Plasma C h a r a c t e r i s t i c s A plasma or discharge i s a p a r t i a l l y i o n i z e d gaseous mixture c o n s i s t i n g o f f r e e e l e c t r o n s , i o n s , and v a r i o u s n e u t r a l s p e c i e s . The f r e e e l e c t r o n s are the p r i n c i p a l i n i t i a t o r s of the plasma



52

DISPOSAL AND DECONTAMINATION OF PESTICIDES

r e a c t i o n s . When the e l e c t r o n s undergo i n e l a s t i c c o l l i s i o n s w i t h the r e a c t a n t s , they cause e i t h e r i o n i z a t i o n , which produces more e l e c t r o n s and i o n s , o r d i s s o c i a t i o n o f the reactants i n t o f r e e r a d i c a l s . These fragments, w i t h t h e i r unpaired e l e c t r o n s , can then undergo a s e r i e s o f r a p i d r e a c t i o n s t o the f i n a l products. The f r e e e l e c t r o n s are energized by t h e o s c i l l a t i n g e l e c t r i c f i e l d produced by the microwave energy (2450 MHz) a p p l i e d to the gas. I n t h i s way, the e l e c t r o n s couple the e l e c t r i c a l energy w i t h t h e reactants and f o r c e them to undergo the d e s i r e d r e a c t i o n s . The o s c i l l a t i n g e l e c t r i c f i e l d produced by the microwaves changes p o l a r i t y so r a p i d l y that the charged species i n t h e plasma reverse t h e i r d i r e c t i o n o f a c c e l e r a t i o n before they are swept to the w a l l s where they are l i k e l y t o be destroyed. Therefore, the plasma can be maintained without the use o f i n t e r n a l e l e c t r o d e s which a r e u s u a l l y r e q u i r e d f o r plasmas o p e r a t i n g a t lower frequencies. Consequently, there i s no problem w i t h i n t e r n a l e l e c t r o d e decomposit i o n from c o r r o s i v e species i n the plasma. The plasma used i n these i n v e s t i g a t i o n s i s operated a t r e duced pressures up t o a few hundred t o r r . This permits the f r e e e l e c t r o n s t o be energized to temperatures much higher than that o f the n e u t r a l gases, s i n c e a t these lower pressures there are many l e s s i n e l a s t i c c o l l i s i o n s o c c u r r i n g which would c o o l down the r e a c t i v e e l e c t r o n s . The e l e c t r o n "temperatures" a r e w e l l over 10,000°K (_3) , w h i l e the temperature o f the n e u t r a l gas i s l e s s than 1,000°K. By o p e r a t i n g under these n o n e q u i l i b r i u m c o n d i t i o n s , i t i s p o s s i b l e t o maintain t h e f r e e e l e c t r o n s a t h i g h temperatures without h e a t i n g the bulk n e u t r a l gas, thereby conserving e l e c t r i c a l energy. Since the plasma decomposition mechanism i s p r i n c i p a l l y e l e c t r o n i c , r a t h e r than thermal, the microwave a p p l i c a t o r power c o u p l i n g equipment can be maintained a t r e l a t i v e l y low temperatures . Thus, t h e m a t e r i a l s o f c o n s t r u c t i o n a s s o c i a t e d w i t h furnaces o r i n c i n e r a t o r equipment are g e n e r a l l y unnecessary, and maintenance expenses w i l l be low. I n a d d i t i o n , the systems are leak t i g h t , which i s a r e s u l t o f the requirement f o r working a t reduced pressures, thereby c o n t r i b u t i n g to a h i g h l e v e l o f s a f e t y i n o p e r a t i o n . Reference Ji may be consulted f o r a d d i t i o n a l i n f o r mation on these c h a r a c t e r i s t i c s . EQUIPMENT AND MATERIALS Microwave Plasma Systems Microwave plasmas were produced i n a l a b o r a t o r y - s i z e resonant c a v i t y , and by three dual-trough waveguide a p p l i c a t o r s . A block diagram o f the plasma system i s shown i n Figure 1, and app l i e s t o a l l systerns i r r e s p e c t i v e o f a p p l i c a t o r type o r power source. The l a b o r a t o r y s c a l e plasma was used during the i n i t i a l stages o f the study to determine product i d e n t i t i e s and convers i o n e f f i c i e n c i e s . The l a b o r a t o r y apparatus was e s s e n t i a l l y the same as t h a t u t i l i z e d p r e v i o u s l y f o r the decomposition o f organo-



BAJON ET AL.

Detoxification

of Pesticides

and Wastes

MATERIAL TO BE DETOXIFIED AND REACTANT GAS (OXYGEN)

MICROWAVE PLASMA REACTOR

TUNING CIRCUITRY

MICROWAVE POWER SOURCE

2450 MHz

GASES

PRODUCT RECEPTOR TRAPS

LIQUIDS, SOLIDS

ANALYTICAL INSTRUMENTATION FOR CHEMICAL ANALYSIS

VACUUM PUMP

Figure

I. Block diagram of microwave related components

plasma system and


54

DISPOSAL AND

DECONTAMINATION OF PESTICIDES

phosphonate compounds, but r e q u i r e d a m o d i f i c a t i o n i n technique f o r the dropwise i n t r o d u c t i o n of l i q u i d s . A g r a v i t y - f e e d pressuree q u a l i z e d dropping funnel o f approximately 100 cm c a p a c i t y was i n s t a l l e d at the input t o the plasma r e a c t o r f o r t h i s purpose. A method was a l s o r e q u i r e d to increase the time f o r passage o f the drops through the discharge. This was n e c e s s i t a t e d s i n c e the time of f a l l under vacuum through the plasma was too s h o r t , as evidenced by drops e x i t i n g the r e a c t o r without having reacted comp l e t e l y . A s o l u t i o n to the problem was obtained by u t i l i z i n g a hollow quartz mesh "basket" p o s i t i o n e d at the center of the plasma zone. Quartz mesh f i b e r s were loaded i n t o the basket to serve as a contact area f o r the drops. The basket contained a number of holes to a l l o w passage of the e f f l u e n t products. The residence time of the drops w i t h i n the basket were estimated to be 1/2 t o 1 sec, the time f o r r e a c t i o n f l a s h e s t o be completed i n the plasma zone. A schematic of the expanded s c a l e plasma system i s shown i n Figure 2. The microwave power a p p l i c a t o r and power supply hardware were s u p p l i e d by G e r l i n g Moore, Inc., Palo A l t o , CA. The p r i n c i p a l d i f f e r e n c e between the l a t t e r system and the l a b o r a t o r y model i n v o l v e s the method o f a p p l i c a t i o n of power to the r e a c t o r . In the l a b o r a t o r y u n i t , the a p p l i c a t o r was a resonant c a v i t y , V a r i a n A s s o c i a t e s , Model EC2DRS2, which was fed by a s i n g l e 2.5kW 2450-MHz power supply. I n the expanded s c a l e u n i t , a d u a l trough waveguide a p p l i c a t o r was used i n which each trough was fed by a 2.5-kW 2450-MHz power source. For a d d i t i o n a l i n f o r m a t i o n on the a p p l i c a t o r s , Reference j5 may be c o n s u l t e d . In the expanded s c a l e systems, the r e a c t o r tubes were f a b r i cated from transparent quartz of about 50 mm o.d., and 1.5-2.0 mm w a l l t h i c k n e s s . Quartz Raschig r i n g s and, i n some i n s t a n c e s , quartz wool plugs were used to f i l l s e c t i o n s of the r e a c t o r to increase the residence time w i t h i n the plasma zone. The l i q u i d feed system was based on a 1 - l i t e r p r e s s u r e - e q u a l i z e d v e r s i o n of the u n i t used f o r the l a b o r a t o r y s c a l e plasma t e s t s . For r e l a t i v e l y v o l a t i l e s o l u t i o n s , however, atmospheric pressure was maint a i n e d above the s o l u t i o n t o avoid vacuum pumping the s o l v e n t from the s o l u t i o n . In t h i s i n s t a n c e , a 250 cm v o l u m e t r i c dropping buret was used f o r feeding d i r e c t l y i n t o the r e a c t o r . Reduced pressures were obtained u s i n g a Welch DuoSeal Model 1397 o i l - s e a l e d 2-stage mechanical pump w i t h a f r e e a i r d i s p l a c e ment of 425 l i t e r s per min. Various c o l d t r a p c o n f i g u r a t i o n s were i n s t a l l e d between the r e a c t o r output and the pump f o r product c o l l e c t i o n , and to maintain c l e a n l i n e s s of the pump o i l . A photograph of t y p i c a l system components i s shown i n Figure 3. During the o p e r a t i o n of the microwave u n i t s , a Holaday Model HI 1500-3 microwave r a d i a t i o n monitor (Holaday I n d u s t r i e s , Inc., Edina, Minnesota), and a Narda Model B86B3 r a d i a t i o n monitor (Narda Microwave Corp., P l a i n v i e w , N.Y.) were used to monitor power leakage. Levels were l e s s than 1 mW/cm i n the immediate v i c i n i t y of the discharge tube.


3

3

2



5.

Detoxification

BAILIN ET AL.

of Pesticides

55

and Wastes

DROP-FEED BURET

QH MICROWAVE POWER SOURCE * s

MICROWAVE / APPLICATOR —

Ch MICROWAVE \ POWER SOURCE ^

RECEIVER Figure 2.

PLASMA REACTORI ION [TUBE -y PUMP /

/

FLOWMETER

[]

/

GAS SUPPLY

MASS SPECTROMETER •

3-WAY STOPCOCK

^-VARIABLE-LEAK I VALVE

'THROTTLE VALVE

MANOMETER SMALL VACUUM PUMP COLD TRAP

iff

THROTTLE VALVE

COLD TRAP

Schematic of expanded-scale microwave plasma system


MAIN VACUUM PUMP

56



Figure 3.

Microwave plasma detoxification system



5.

BAILIN ET AL.


57

A n a l y t i c a l Systems Mass s p e c t r o m e t r i c (MS) a n a l y s i s of the gases l e a v i n g the r e a c t o r was performed on a V a r i a n A s s o c i a t e s Model 974-0002 r e s i d u a l gas a n a l y z e r (quadrupole mass spectrometer) w i t h a range of 250 atomic mass u n i t s . A s m a l l q u a n t i t y of the gas was c o n t i n uously pumped past a v a r i a b l e - l e a k sampling v a l v e . The gases b l e d i n t o the mass spectrometer by the sampling v a l v e were pumped from the system by an i o n pump. The sampling system i s i n c l u d e d i n Figure 3. I n f r a r e d s p e c t r a of s o l i d and l i q u i d e f f l u e n t s c o l l e c t e d from the product r e c e i v e r and traps were obtained on a P e r k i n Elmer 621 i n f r a r e d spectrophotometer w i t h a range o f 4000 to 400 cm"" (2.5 to 25 microns). M a t e r i a l s to be analyzed were ground w i t h KBr and compressed i n t o p e l l e t s f o r scanning over the p r e s c r i b e d spectrum. V i s i b l e and u l t r a v i o l e t s p e c t r a from 200 to 700 nm on s o l i d and l i q u i d e f f l u e n t s were obtained on a Cary Model 14 Recording Spectrophotometer u s i n g c o n v e n t i o n a l procedures. A Finnegan Model 4021 GC/MS Data System was used toward comp l e t i o n o f the study f o r polyaromatic hydrocarbons. 1

P e s t i c i d e s , Hazardous Wastes » and Gases The m a t e r i a l s which were d e t o x i f i e d or decomposed are l i s t e d i n Table I I . S e l e c t i o n s were made on the b a s i s of the extent of the environmental problems which were a s s o c i a t e d w i t h these mater i a l s , EPA s i n t e r e s t , and the r e f r a c t o r y c h a r a c t e r i s t i c s of the m a t e r i a l s . The r e a c t a n t / c a r r i e r gases were the f o l l o w i n g : oxygen, 99.5% min. p u r i t y , Fed. Spec. BB-0-925(a), Type I ; argon, 99.995% min. p u r i t y , Mil-A-18455B. The oxygen contained 0.5% maximum i m p u r i t i e s , i n which approximately 0.05% was n i t r o g e n , the remainder being argon and other gases i n t r a c e amounts. 1

EXPERIMENTAL PROCEDURE In g e n e r a l , the procedure f o r o p e r a t i o n of both l a b o r a t o r y and expanded s c a l e u n i t s was the same as that d e s c r i b e d i n Reference C e r t a i n m o d i f i c a t i o n s were r e q u i r e d as the r e s u l t of d i f ferences i n feed technique, however. For example, when a vacuum dropping funnel was used f o r i n t r o d u c t i o n of a low v o l a t i l i t y f l u i d , the e n t i r e system, i n c l u d i n g the s e c t i o n above the l i q u i d , was evacuated to 1 t o r r . The pressure was then adjusted to about 10 t o r r by the a d d i t i o n o f oxygen o r argon. The microwave power was then turned on to s t a r t the plasma. A d d i t i o n a l gas was i n t r o duced to o b t a i n the d e s i r e d pressure and f l o w r a t e i n combination w i t h r e g u l a t i o n by the main t h r o t t l e v a l v e . The microwave power was set to the d e s i r e d l e v e l w i t h the t u n i n g c o n t r o l s adjusted to give minimum r e f l e c t e d power. A f t e r o b t a i n i n g a background MS scan (reactant gas f l o w i n g minus m a t e r i a l to be d e t o x i f i e d ) , a needle v a l v e at the bottom of the dropping funnel was opened to y i e l d the d e s i r e d feed r a t e . The gaseous e f f l u e n t from the plasma was then sampled and analyzed by MS. For methyl bromide gas, the


Kennedy; Disposal and Decontamination of Pesticides ACS Symposium Series; American Chemical Society: Washington, DC, 1978. ULV Aroclor 1242 Aroclor 1254

Troysan PMA-30

80% Powder Concentrate, Technical Grade, Code 9406 U.S. Navy MK 13 Mod Ο Marine Smoke and Illumination Signal

Monsanto

Matheson Gas

Troy Chemical Allied Chemical

Naval Weapons Support Center Crane, Indiana

Liquid Mixture

Commercial Gas

Commercial Aqueous Methanol Solution 1. Commercial Powder 2. Laboratory Aqueous Dispersion 3. Laboratory Methanol Solution 1. Laboratory Aqueous Dispersion 2. Laboratory Methyl Ethyl Ketone Solution

PCB's (Polychlorinated Biphenyls)

Methyl Bromide (99.5% min. purity)

Phenylmercuric Acetate (30% PMA solids)

Kepone (80% Active Ingredient, 20% Clay)

55.4% Xylene azo-/3~naphthol 18.9% l-Methylaminanthraquinone 18.0% Sucrose 1.8% Graphite 5.9% Silica Binder (KClOg oxidant excluded)

Chlorinated Hydrocarbon Waste

Brominated Hydrocarbon Rodenticide

Heavy Metal Fungicide

Chlorinated Hydrocarbon Pesticide

Polyaromatic Red Dye Mixture

Grade or Type

American Cyanamid

Manufacturer or Source

Pure Liquid

Form Tested

Malathion (95% min. purity)

Material

Pesticides and Hazardous Wastes for Detoxification Tests

Organophosphorous Pesticide

Classification

Table II.


5.

59


BAILIN ET AL.

p e s t i c i d e was f e d d i r e c t l y , bypassing the f u n n e l . Product t r a p s were an i c e water cooled r e c e i v e r , f o l l o w e d by one o r more l i q u i d n i t r o g e n (LN) o r d r y - i c e acetone t r a p s .


RESULTS Laboratory Scale Plasma Reactor Reactions i n the l a b o r a t o r y system were c a r r i e d out w i t h the t o x i c substances mixed w i t h oxygen o r argon. Although i t was w e l l known t h a t s i m p l e r o r g a n i c compounds exposed t o i n e r t gas plasmas would r e a c t t o form a v a r i e t y o f compounds, i n c l u d i n g p o l y mers ( 6 ) , n e v e r t h e l e s s , argon, i n a d d i t i o n t o oxygen, was evaluated f o r comparison w i t h the h e l i u m and a i r decomposition r e a c t i o n s p r e v i o u s l y r e p o r t e d . However, a f t e r o b s e r v i n g , f o r example, the o f f e n s i v e mercaptan/sulfide compounds which r e s u l t e d from the malathion-argon plasma r e a c t i o n s , the formation o f c a r bonaceous f l a k e depositee from methyl bromide-argon, plus a s s e s s i n g the p r o b a b i l i t y f o r the formation o f extremely t o x i c methyl mercury compounds from PMA and other organomercurials i n argon (or other i n e r t gases),emphasis was d i r e c t e d toward u t i l i z a t i o n of oxygen as t h e s o l e r e a c t a n t gas f o r use i n the expanded s c a l e system. D e t a i l s o f the l a b o r a t o r y r e a c t i o n s which l e d t o these conclusions are l i s t e d below. Melathion-oxygen. Cythion ULV grade malathion was passed through a 200 t o 250-W plasma at 100 t o 120 t o r r u s i n g the quartz basket technique. The r e a c t i o n s appeared t o occur spontaneously as the drops contacted the quartz f i b e r s . With the e x c e p t i o n o f a white e t c h zone and a h i g h v i s c o s i t y water-white l i q u i d t h a t formed below the plasma zone, a l l the products were gases. Mass spectrometry i n d i c a t e d CO 2* CO, S 0 , and H 0 as e f f l u e n t gases. I n f r a r e d spectroscopy showed t h e l i q u i d product t o be phosphoric a c i d . M a t e r i a l balances i n d i c a t e d t h a t metaphosphoric a c i d was the probable m a t e r i a l from which conversion t o orthophosphoric a c i d i n moist a i r occurred i n 1 to 2 days. A n a l y s i s f o r malathion i n the l i q u i d r e a c t i o n product was c a r r i e d out s p e c t r o p h o t o m e t r i e s l y i n the v i s i b l e r e g i o n ( 7 ) . Percent conversion was 99.98 + percent based on 0.016 percent malathion determined. P o l y c h l o r i n a t e d b i p h e n y l (PCB) - oxygen. Monsanto A r o c l o r 1242 l i q u i d was passed through a 250-W plasma at 100 t o r r . Mass balance showed no l i q u i d s a t t r i b u t a b l e to the s t a r t i n g m a t e r i a l . A l l the products o f decomposition were gases. On the b a s i s o f c o n t r o l runs i n the absence o f the plasma r e a c t i o n , percent conv e r s i o n was c a l c u l a t e d a t g r e a t e r than 99.9 percent. Gas products were i d e n t i f i e d as C 0 , CO, H 0 , H C l , C l , w i t h minor amounts of C1 0 and C0C1 . The l a t t e r gases, c h l o r i n e oxide and phosgene, were not observed i n the expanded s c a l e plasma r e a c t i o n s ; i n s t e a d , hydrogen c h l o r i d e was the p r i n c i p a l C l - c o n t a i n i n g product. Methyl bromide - oxygen. Gaseous methyl bromide was passed through a 300 t o 400-W 5 0 - t o r r oxygen plasma a t 2 t o 3 g/hr. The products o f r e a c t i o n were C 0 , CO, H 0, HBr, and B r . Oxides o f 2

2

2

2

2

2

2

2

2

2


DISPOSAL AND

60

DECONTAMINATION OF PESTICIDES

bromine were found i n the l i q u i d n i t r o g e n t r a p s , but were not otherwise observed at ambient temperatures. The extent o f the r e a c t i o n was determined by mass spectrometer, i n which the r a t i o s o f the CH Br i o n s i g n a l i n t e n s i t i e s before and d u r i n g the plasma r e a c t i o n s were compared. Decomposition was g r e a t e r than 99 p e r c e n t , which was the l i m i t of p r e c i s i o n of the mass spectrometer f o r t h i s chemical system. Phenylmercuric a c e t a t e - oxygen. Commercial Troysan PMA-30 s o l u t i o n was passed through 225 to 280-W plasmas at 120 t o r r . Mer cury metal was observed as a m e t a l l i c m i r r o r on the g l a s s t u b i n g downstream from the discharge zone. M a t e r i a l balance i n d i c a t e d >99.9% decomposition to the metal. Mass spectrometry showed the products formed i n a d d i t i o n t o Hg were H2O, CO2, and CO. There was no evidence of dimethyl mercury or other v o l a t i l e organomercurials. M a l a t h i o n - argon. Decomposition r e a c t i o n s were c a r r i e d out at 200-250 W, 100 t o r r , i n pure argon. The r e s u l t a n t y e l l o w brown products were extremely o f f e n s i v e and malodorous, s i m i l a r to mercaptan and d i s u l f i d e compounds. Because o f t h e i r p o t e n t i a l f o r very h i g h t o x i c i t y , f u r t h e r a n a l y s i s was not undertaken. Methyl bromide - argon. Methyl bromide was mixed w i t h argon and passed through 300 to 400-W plasmas at 50 t o r r . The products of r e a c t i o n estimated by mass spectrometer were B r , HBr, methane, e t h y l e n e , and a c e t y l e n e . Carbonaceous f l a k e d e p o s i t s were formed i n the r e a c t o r tube. Q u a n t i t a t i v e a n a l y s i s by MS showed t h a t not l e s s than 99 percent conversion had occurred.


3

2

Expanded Scale Plasma Reactor The approach taken i n the study was to o b t a i n maximum throughput, w i t h the o b j e c t i v e of a c h i e v i n g low process c o s t s . G e n e r a l l y , the t o t a l microwave power a v a i l a b l e , 4.2 to 4.7 kW, was a p p l i e d to the discharge. This allowed the plasma t o operate at h i g h e r p r e s s u r e s , thereby p e r m i t t i n g a maximum amount of oxygen to be used as the plasma gas f o r r e a c t i o n w i t h the p e s t i c i d e s and wastes. During the i n i t i a l r u n s , the S e r i e s A microwave power a p p l i c a t o r w i t h a 2.7 l i t e r r e a c t o r v o l . was used f o r plasma decomposi t i o n s o f A r o c l o r No. 1242 PCB. I t was determined that the l i q u i d had been decomposed and t h a t one of the r e a c t i o n products — a b l a c k s o o t - l i k e deposit which coated the product r e c e i v e r — con t a i n e d l i t t l e or no PCB, as determined by i n f r a r e d spectroscopy. A f t e r a d d i t i o n a l runs were c a r r i e d out i n which feed, p r e s s u r e , and absorbed power were v a r i e d , i t became apparent t h a t the r e a c t o r was too l a r g e i n volume f o r the power a v a i l a b l e . S e r i e s Β and C a p p l i c a t o r s , having r e a c t o r volumes 1.5 and 0.6 l i t e r s , respec t i v e l y , were e v a l u a t e d i n t u r n . The r e s u l t s are d e t a i l e d i n Table I I I and are d e s c r i b e d i n the f o l l o w i n g s e c t i o n s . M a l a t h i o n l i q u i d was drop-fed onto a porous, quartz wool bundle p o s i t i o n e d at the top power input to the plasma zone. By t h i s means, i n a mechanism s i m i l a r to that which was used i n the


Kennedy; Disposal and Decontamination of Pesticides ACS Symposium Series; American Chemical Society: Washington, DC, 1978. 360

13-25

206(0.4) 1020(2.25) 120-140

4.5 4.6

Β

C

31-62

31-88

> (b) Raschig Rings

720

45-60

>99.9999

Raschig Rings 300 35 - 6 0

4.6

C

68-58

Red Dye Mixture 15.5% Solids Aqueous Slurry

(a) Quartz (b) See text.

>99 Raschig Rings 810

30 - 70

4.6

C

38-38

Kepone 80/20 2- to 3-g Solid Discs (b)

>99 Raschig Rings None

35-50

4.2

C

99

Complete, estim. 99.99

100-120

Raschig Rings

Raschig Rings

792

792

38-36

(b)

2950(6.3)

2380(5.25) 100-120

Kepone 80/20 10?c Solids, Aqueous Slurry

4.3

4.0

Complete, estim. 99.99^ Complete, estim. 99.99

4.6

C

C

Raschig Rings

C

31-110

31-108

960

>99

Wool Plug

395

19-36

492(1.1)

4.2

Β

31-10

38-30

PMA Troysan PMA-30 Kepone 80/20 20% Methanol Solution

Troysan PMA-30

PMA

Troysan PMA-30

PCB Aroclor 1242 PCB Aroclor 1254 PMA >99

>99

Wool Plug

323

17-35

270(0.6)

4.6

Β

31-8

PCB Aroclor 1242 Solid Rings

99.9999

Wool Plug

480

28-30

480(1.1)

4.7

Β

31-46

Malathion "Cythion" ULV

.

99.9988

Wool Plug

361

28-46

504(1.1)

3.7

Β

31-16

Malathion "Cythion" ULV

_

Conversion (%)

a

Reactor Packing( )

Microwave Feed Rate [g/hr Power (lb/hr)] (kW)

Run No.

Pesticide/Waste

Applicator Series

Oxygen Gas Flow (liters/hr)

Summary of Expanded-Scale Oxygen Plasma Reactions Pressure Range (torr)

Table III.



8x4

8X8

38-8

438-14

8x8

31-110

10 x 10

8x8

31-108

38-6

8x8

Ring Size o.d. x Length (mm)

31-88

Run No.

31

31

34

45

45

16

Bed Length (cm)

13.2 to 16.0

13.2 to 18.4

13.2

13.2

13.2

8 to 16

Oxygen Flow (Standard liter/min)

130

112

115

120

120

120

Top

75

60

42

60

64

90

Bottom

Pressure (torr)

4.7

4.6

4.3

4.3

4.0

4.6

Microwave Power (kW)

8.0

6.0

4.25

6.5

5.25

2.25

Throughput (lb/hr)

CH3OH component observed at 8 lb/hr

Smanest rings in series

Largest rings in series

Repeat of 31-108

Reactor completely filled with rings

Reactor filled approximately one-half with rings

Notes

Effect of Packed Bed on PMA-30 (Phenylmercuric Acetate) Conversion in Series C Plasma System

Packing of 4 5-mm i.d. Reactor

Table IV·


to

5.

BAUJN ET AL.

Detoxification

of Pesticides

and

l a b o r a t o r y - s c a l e system, l a r g e numbers o f s m a l l e r d r o p l e t s were produced w i t h i n the m a t r i x o f the wool, and p r o p e l l e d by the gas stream through the plasma. Products were S, S 0 , C 0 , CO, and H 0, p l u s a l i q u i d phosphoric a c i d . During the r e a c t i o n , d e p o s i t s o f a dark yellow-brown s u l f u r product mixed w i t h a c l e a r water-white h i g h v i s c o s i t y l i q u i d were formed which flowed s l o w l y down the s i d e s o f t h e r e a c t o r i n t o the r e c e i v e r . No carbonaceous o r o t h e r products resembling the s t a r t i n g m a t e r i a l were observed. Spectrophotometric a n a l y s i s o f the l i q u i d s from the two r e a c t i o n s gave residues of 12 ppm and 1 ppm malathion. P o l y c h l o r i n a t e d b i p h e n y l s (PCB s) y i e l d e d H C l , C 0 , CO, and H 0 as determined by MS. No C1 0 o r C0C1 was observed. There was formation o f some soot i n the product r e c e i v e r ; i n f r a r e d a n a l y s i s gave no i n d i c a t i o n of PCB r e s i d u e s . I t was determined, however, that at throughput l e v e l s o f about 1 kg (2 l b ) per h r i n the Β a p p l i c a t o r system, complete r e a c t i o n had not o c c u r r e d . T h i s was determined by i n f r a r e d a n a l y s i s o f the b l a c k t a r - l i k e l i q u i d products i n the r e c e i v e r t r a p which i n d i c a t e d the presence o f PCB s t a r t i n g m a t e r i a l . Consequently, the S e r i e s C a p p l i c a t o r was t e s t e d next to determine i t s usefulness f o r i n c r e a s i n g the l e v e l of throughput. Phenylmercuric a c e t a t e , Troysan PMA-30 s o l u t i o n , was passed through the S e r i e s C system i n s e v e r a l runs to determine the e f f e c t of the shortened l e n g t h o f the a p p l i c a t o r , as w e l l as t o de termine the e f f e c t o f quartz plugs and r i n g s i n the r e a c t o r tube. The r e a c t i o n was considered complete i f none of the methanol com ponent was found by mass spectrometry i n the e f f l u e n t gas. Mass spectrometer s e n s i t i v i t y was. 2 t o 3 p a r t s per thousand f o r methanol, based on c o n t r o l runs performed i n the absence o f the plasma. The MS a n a l y s i s showed t h a t a t a throughput o f 3600 g (8 l b ) per h r , s m a l l amounts of methanol were detected i n the e f f l u e n t . This i n d i c a t e d that maximum d e t o x i f i c a t i o n o r d e s t r u c t i o n o f PMA-30 would occur at about 7 l b s / h r . The p r i n c i p a l gases o f the r e a c t i o n were C 0 , CO, and H 0. V o l a t i l e organomercurials were not detec ted by MS. M e t a l l i c mercury was d e p o s i t e d i n the traps downstream from the plasma. Experiments were performed t o modify the residence time o f the feed m a t e r i a l s i n the plasma zone. Quartz Raschig r i n g s were t e s t e d t o evaluate throughput under d i f f e r e n t packed bed c o n d i t i o n s . For PMA-30, maximum throughput was defined as the feed r a t e which showed no methanol component i n the plasma e f f l u e n t as determined by mass spectrometer. For the Kepone runs, a commercial m i x t u r e , A l l i e d Chemical 80% powder c o n c e n t r a t e , was used as a s t a r t i n g m a t e r i a l . A p p r o x i mately 200 g was converted i n t o aqueous s l u r r i e s , methanol s o l u t i o n s , and presscakes. The s o l i d presscakes were prepared by compress i n g 2-3 g batches i n a d i e under 1,000 p s i p r e s s u r e . The d i s c s , which r e q u i r e d a s t r o n g f i n g e r pressure t o f r a c t u r e , were p l a c e d at the top o f the Raschig r i n g area i n the plasma r e a c t o r tube before the plasma was i n i t i a t e d . I t was observed v i s u a l l y t h a t 2


63

Wastes

2

2

f

2

2

2

2

2

2



64

breakdown and decomposition o f the s o l i d s occurred w i t h i n 10 t o 30 seconds, depending on the flow of oxygen and the pressure w i t h i n the r e a c t o r . S o l u t i o n s of 20% Kepone-methanol a f t e r f i l t r a t i o n to remove the c l a y p a r t i c l e s , were g r a v i t y f e d i n t o the plasma from a 250 cm buret needle-valve feed system i n which atmospheric pressure i n s t e a d o f reduced pressure was maintained over the s o l u t i o n . D i s p e r s i o n s of Kepone formed r e a d i l y and were f e d unf i l t e r e d from the same system. The gaseous r e a c t i o n products from the s o l v e n t and s l u r r y mixtures were C0 , CO, H C l , and H 0; phosgene o r c h l o r i n a t e d hydrocarbons were not detected by MS. Because o f the short 10 to 30-sec r e a c t i o n times f o r the s o l i d Kepone presscakes, mass s p e c t r o m e t r i c a n a l y s i s o f the gaseous e f f l u e n t s were not performed. Instead, the c l a y support powders which passed through the r e a c t o r were c o l l e c t e d from the r e c e i v e r and analyzed by i n f r a r e d spectroscopy. No Kepone or hexachlorobenzene was detected i n the s o l i d r e s i d u e s . Percentage conversions were estimated at b e t t e r than 99%. Because of the l i m i t e d q u a n t i t y o f the s t a r t i n g m a t e r i a l , the r e a c t i o n s were not maximized w i t h respect t o throughput. A p o l y a r o m a t i c dye composition comprised of two polyaromatic dyes, sucrose, carbon b l a c k , and s i l i c a , which make up U. S. Navy MK 13 Mod 0 Marine Smoke and I l l u m i n a t i o n S i g n a l , was introduced i n t o the plasma as a s o l v e n t s o l u t i o n and as an aqueous d i s p e r s i o n . The dye components were 55.4% xylene azo-ft-naphthol and 18.9% 1-methylaminoanthraquinone. The KC10 oxidant was o m i t t e d from the e v a l u a t i o n i n t h i s s e r i e s . For the dye-solvent s o l u t i o n , a 15% s o l i d s methyl e t h y l ketone (MEK) mixture was decomposed. A f t e r the r e a c t i o n , there-were no red coloration© o r r e s i d u e s v i s i b l e below the r e a c t o r . However, because the MEK oxygen demand would prevent development o f a h i g h throughput, an aqueous v e h i c l e was t e s t e d f o r use as part of the feed system. A l s o , s i n c e the red dye components as a mixture were e s s e n t i a l l y hydrophobic, an ethylene oxide nonylphenol s u r f a c t a n t , TEC 1216E (TEC Chemical Co., Monterey Park, CA) was u t i l i z e d to y i e l d a f t e r f i l t r a t i o n , a 15.5% h y d r o p h i l i c s l u r r y , d e n s i t y 1.03 g/cm . The s l u r r y was added at r a t e s from 2 to 8 cm /min. The r e a c t i o n s were not maximized because, o f l i m i t a t i o n s i n s t a r t i n g m a t e r i a l supply, as was the case f o r Kepone. Based on wt%, the s o l i d r e s i d u e measured l e s s than 0.2% i n the r e c e i v e r t r a p s , or >99.8% convers i o n to gaseous products. Based on wt% of s t a r t i n g m a t e r i a l , l e s s than 0.2% s o l i d r e s i due passed through the r e a c t o r , or 99.8% conversion t o gaseous products. S p e c t r o p h o t o m e t r y comparisons i n the v i s i b l e r e g i o n o f a methylene d i c h l o r i d e s o l u t i o n of the unknown s o l i d , and known concentrations of the i n i t i a l dye mixture i n the same s o l v e n t i n d i c a t e d t h a t not more than 5 ppm of the dyes had passed through the plasma. P o l y a r o m a t i c hydrocarbons were not detected above 2 ppm u s i n g UV f l u o r e s c e n c e , i n f r a r e d and UV a b s o r p t i o n s p e c t r o photometry, and GC/MS. The )

Electrical and Oxygen Costs for PMA-30 Oxygen Plasma Reactions

$0.02AWh,

(a) O2, $0.012/SCF

4.6

31-88

Run No.

Microwave Power (kW)

Table V.


0.08

0.10

0.27

Total Cost ($/lb)

5.

BAILIN ET AL.


69

V a r i a b l e Costs Operating Labor Oxygen Electricity Maintenance (4% o f Investment)

$71,280 20,028 19,008 8,000


F i x e d Costs C a p i t a l Recovery (10 yr-7%) Taxes and Insurance (2%) T o t a l Annual Costs Cost p e r Pound Treated

28,480 4,000 150,796 $0.19

Based on recovery and s a l e o f the m e t a l l i c mercury, a net p r o f i t of $0.085/lb i s d e r i v e d . Process Development As the r e s u l t o f accomplishments i n t h e i n i t i a l s c a l e u p , the design and c o n s t r u c t i o n o f h i g h e r c a p a c i t y equipment and components has been continued. This i n c l u d e s p o s i t i v e displacement feed techniques f o r s o l i d s as w e l l as l i q u i d s and s l u r r i e s , a d d i t i o n a l microwave power, up t o 15 kW, to generate an estimated throughput of 10 t o 30 l b s / h r , and a high-power a p p l i c a t o r f o r t r a n s f e r o f the i n c r e a s e d microwave energy t o the r e a c t o r tube. C o o l i n g traps are r e q u i r e d , e s p e c i a l l y f o r product s e p a r a t i o n and condensation. Based i n p a r t on i t s c o m p a t i b i l i t y w i t h wet gases, a water r i n g s e a l vacuum pump system has been designed. A n a l y t i c a l instrumentat i o n has been extended t o i n c l u d e an automatic gas chromatographic mass spectrometer-data system f o r d e t e c t i o n o f t r a c e s of p o t e n t i a l l y t o x i c m a t e r i a l s i n the ppm range. As part o f the e v a l u a t i o n , data w i l l be c o l l e c t e d on e l e c t r i c a l power and oxygen consumed, percent conversion, and mass throughput f o r oxygen plasma systems. These w i l l be obtained i n order to prepare an economic comparison between the microwave plasma process, i n c i n e r a t i o n , and o t h e r conventional technologies. Future U t i l i z a t i o n The microwave plasma system, as now e n v i s i o n e d , w i l l be p o r t able t o , o r may be s i t u a t e d a t , s i t e s where h i g h l y t o x i c m a t e r i a l s are consumed, s t o r e d , o r manufactured, i n c l u d i n g h o s p i t a l s , u n i v e r s i t i e s , research f a c i l i t i e s , a g r i c u l t u r a l s t a t i o n s , as w e l l as chemical and i n d u s t r i a l areas. The p e s t i c i d e s and hazardous wastes which can be t r e a t e d by microwave plasma p r o c e s s i n g i n c l u d e gases, pure organic l i q u i d s , s o l u t i o n s , s l u r r i e s , pure s o l i d s , and s o l i d s mixed w i t h i n o r g a n i c components. These a r e s t o r e d i n drums, c a n n i s t e r s , b o t t l e s , i n d i s p e r s i o n , and i n s e t t l e d - o u t form, both pumpaMe and i n d i f f i c u L t - t o - p u m p c o n s i s t e n c y , and t h e r e f o r e cover the f u l l range o f m a t e r i a l s and m a t e r i a l s h a n d l i n g t e c h n o l o g i e s . R e l a t i v e t o l a r g e i n c i n e r a t o r equipment, such as on t h e s h i p Vulcanus, the microwave system i s , o f course, s m a l l . I t should be


70


noted, however, that t r a n s p o r t a t i o n o f hazardous wastes across s t a t e l i n e s may i n v o l v e l e g a l , p o l i t i c a l , and s c i e n t i f i c questions which have yet t o be r e s o l v e d .


CONCLUSIONS Microwave plasma technology has been shown t o be h i g h l y e f f e c t i v e f o r the d e t o x i f i c a t i o n / d e s t r u c t i o n o f hazardous o r g a n i c wastes. T o x i c compounds and wastes o f current i n t e r e s t were decomposed, and the r e a c t i o n products i d e n t i f i e d t o estimate t h e i r t o x i c i t y , and t o determine the p o t e n t i a l f o r recovery o f u s e f u l m a t e r i a l s . The study r e s u l t e d i n an expansion from 1 - 5 g up t o 3 kg (7 l b ) per h r i n throughput. With regard to oxygen plasma r e a c t i o n s i n the expanded s c a l e system, the products were g e n e r a l l y p r e d i c t a b l e , and no unexpected t o x i c by-products were formed which could not be t r e a t e d w i t h c a u s t i c . Of the systems t o which h i g h s e n s i t i v i t y a n a l y t i c a l techniques were a p p l i e d , e.g., malathion and polyaromatic dyes, very l i t t l e o r no s t a r t i n g m a t e r i a l was detected i n the r e s i d u e s , and no s i g n i f i c a n t t o x i c / c a r c i n o g e n i c substances were found i n the e f f l u e n t s . The p o t e n t i a l f o r resource recovery was demonstrated f o r a phenylmercuric acetate p e s t i c i d e which y i e l d e d m e t a l l i c mercury as a s a l a b l e product. The process may permit the recovery o f chemical feedstocks when a p p l i e d to other o r g a n o m e t a l l i c p e s t i cides o r wastes, which would otherwise be permanently l o s t . I n the f u t u r e , u t i l i z i n g h i g h e r power f o r the r e a c t o r , scaleup t o a p i l o t l e v e l throughput o f 10 to 30 l b s / h r w i l l be t e s t e d . Further expansion t o 50 - 100 l b s / h r i s e n v i s i o n e d as f e a s i b l e w i t h c u r rent technology.

ABSTRACT Detoxification of pesticides and hazardous wastes has been performed successfully in a microwave-induced oxygen plasma. Materials were passed through a laboratory-size reactor to determine conversion efficiencies and product identities. Construction of an expanded-volume system followed which resulted in an increase in throughput from 1 - 5 g/hr for the laboratory unit to 450 3200 g (1 to 7 lb) per hr in the larger system. Substances treated were PCB's, phenylmercuric acetate (PMA) solution, methyl bromide, malathion, a polyaromatic dye mixture, and Kepone. Detoxification of PMA yielded metallic mercury as a salable by-product. Treatment costs were computed which included electricity, oxygen, capital equipment, and labor.


5.

BATON ET AL.


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ACKNOWLEDGMENT The work upon which t h i s p u b l i c a t i o n i s based was performed pursuant t o Contract 68-03-2190 w i t h the U. S. Environmental Pro t e c t i o n Agency, C i n c i n n a t i , Ohio. A d d i t i o n a l support was obtained from the Lockheed Independent Research Program. A p p r e c i a t i o n i s tendered t o Dr. Ernest L. L i t t a u e r , Lockheed P a l o A l t o Research Laboratory, and P r o f e s s o r A l e x i s T. B e l l , U n i v e r s i t y o f C a l i f o r n i a , Berkeley, f o r guidance and many v a l u a b l e suggestions.

LITERATURE CITED 1.

"Disposal of Hazardous Wastes," U.S. Environmental Protection Agency, Report to Congress, Publication SW-115, 1974.

2.

Bailin, L. J., "Microwave Plasma Detoxification Process for Hazardous Wastes, Phase II, Systems Application Evaluation," Lockheed Missiles & Space Company, Inc., Contract EPA 68-032190, Cincinnati, Ohio, October 1977.

3.

McTaggart, F. Κ., "Plasma Chemistry in Chemical Discharges," Elsevier, New York, 1967.

4.

Bailin, Lionel J., Sibert, Merle Ε., Jonas, Lonard Α., and Bell, Alexis Τ., "Microwave Decomposition of Toxic Vapor Simu lants," Envir. Sci. & Technology, 9(3), 254-258 (1975).

5.

Bailin, L. J. and Hertzler, Barry L . , "Development of Micro wave Plasma Detoxification Process for Hazardous Wastes, Phase I," Lockheed Missiles & Space Company, Inc., Contract EPA 68-03-2190, Final Report, U. S. EPA-600/2-77-030, Apr 77.

6.

Millard, Μ., "Synthesis of Organic Polymer Films in Plasmas," Chapter 5, "Techniques and Application of Plasma Chemistry," Hollahan, John R., and Bell, Alexis T., Eds. 192-193, John Wiley, New York, 1975

7.

Norris, M. V., Vail, W. Α., and Averill, P. R., "Colorimetric Estimation of Malathion Residues," Agricultural and Food Chemistry., 2(11), 570-573 (1954).

8.

Brown, Lloyd C. and Bell, Alexis T., "Kinetics of the Oxida tion of Carbon Monoxide and the Decomposition of Carbon Diox ide in a Radiofrequency Electric Discharge," Ind. Eng. Chem. Fund, 13(3), 203-218 (1974).

9.

Renard, J. J. and Boker, H. I., "Chemistry of Chlorine Monox ide," Chem. Rev., 76, 487-508 (1976).



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10. Remy, Η., "Treatise of Inorganic Chemistry," I, 449, Elsevier, Amsterdam, 1956. 11. Ibid., 810.


12. Ibid., II, 464. 13. Kaufman, F., "Production of Atoms and Simple Radicals in Glow Discharges," in "Chemical Reactions in Electrical Discharges," Advances in Chemistry Series No. 80, 45-46, American Chemical Society, Washington, D. C., 1969. 14. Owens, E. J., and Ward, D. Μ., "A Review of the Toxicology of Colored Chemical Smokes and Colored Smoke Dyes, EB-TR74064, Edgewood Arsenal, Aberdeen Proving Ground, MD, Dec. 1964; available as DDC-AD-A003827. MARCH 24, 1978


Detoxification of Pesticides and Hazardous Wastes by the Microwave

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