REMOVAL OF PROTEIN AND FAT

USING LIGNOSULFONIC A C I D FROM MEAT SLAUGHTERING AND PACKING WASTES

T . R . F o l t z , Jr.*, K. M. Ries**, a.nd J. W. Lee, Jr.***

INTRODUCTION

A physica, l -chemical p rocess i s desc r ibed h e r e i n t h a t i s designed t o remove t h e p r o t e i n and f a t from meat s l augh- t e r i n g and packing o p e r a t i o n s . The i n t e n t i s t o r ecove r t h e s e was tes m a t e r i a l s f o r t h e i r p o t e n t i a l feed v a l u e , o r a l t e r n a t e use , r a t h e r t h a n regard them a s p o l l u t a n t s t o be t r e a t e d i n a, waste wa te r t r e a t m e n t p l a n t .

The t e c h n i c a l l i t e r a t u r e d e s c r i b e s t h e n a t u r e of s l augh- t e r i n g o r a b a t t o i r was tes and meat packing was tes a s be ing h igh s t r e n g t h i n terms of BOD5, suspended s o l i d s , g r e a s e o r f a t , and n i t r o g e n ( 1 ) . The p r i n c i p a l m a t e r i a l s p r e s e n t a r e p r o t e i n s and fa t t h a t a r e animal body f l u i d s and t i s s u e l o s t i n t h e v a r i o u s o p e r a t i o n s necessa ry t o produce e d i b l e p roduc t s . A s t h e s e was tes are commonly warm, have a n a l - most n e u t r a l pH, c o n t a i n n u t r i e n t s and a r e r e a d i l y b iode - g radeab le , v a r i o u s systems of b i o l o g i c a l was te t r ea tmen t have been s u c c e s s f u l l y used t o produce a f i n a l e f f l u e n t low i n BOD, suspended s o l i d s , and g r e a s e ( 2 ) ( 3 ) ( 4 ) . Most p r e v i - o u s l y designed b i o l o g i c a l waste water t r e a t m e n t systems were not designed t o remove t h e n i t r o g e n p r e s e n t , b u t d i s - charge l i m i t a t i o m o n n i t r o g e n a r e expected t o be p laced on most d i s c h a r g e s i n t h e f u t u r e ( 5 ) . Ni t rogen removal r e p r e - s e n t s a s i g n i f i c a n t a d d i t i o n a l c o s t t o t h e meat i n d u s t r y i n a d d i t i o n t o t e c h n i c a l d i f f i c u l t i e s p r e s e n t i n c u r r e n t l y proposed n i t r o g e n removal r e s o l u t i o n s ( l ) ( 3 ) .

A p rocess designed f o r removal of p r o t e i n m a t t e r from r a w was tes has t h e p o t e n t i a l o f d i r e c t l y removing t h e n i t r o g e n i n i t s o r ig ina .1 s ta te , t h e r e b y reducing t h e need t o add-on a d d i t i o n a l wa,ste t r e a t m e n t o p e r a t i o n s s p e c i f i c a , l l y f o r n i t r o g e n c o n t r o l . A p rocess us ing l i g n o s u l f o n i c a c i d (LSA)

*Armour Food Company, Phoenix, Arizona **The Greyhound Corpora t ion , Phoenix, Arizona

***Cornell, Howland, Hayes & Merry f i e ld /Hi l l , C o r v a l l i s , Ore.

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t r ea tmen t of pro te inaceous wastes has a p o t e n t i a l f o r n i t r o g e n removal p l u s p o t e n t i a l recovery of waste water p r o t e i n f o r r e c y c l i n g as a.n animal feed i n g r e d i e n t .

BACKGROUND

The phys ica l -chemica l combining of l i g n o s u l f o n i c a c i d and p r o t e i n s i n an aqueous system has been known f o r over 30 y e a r s ( 6 ) ( 7 ) . covery of p r o t e i n s from d i l u t e s o l u t i o n s us ing spen t s u l - f i t e l i q u o r a t a pH of 2 t o 4. t h e s u l f i t e l i q u o r was i d e n t i f i e d as l i g n o s u l f o n i c a c i d and a r a t i o of 2 p a r t s l i g n i n t o 5 p a r t s p r o t e i n was observed t o be opt imal . P e a r l ( 9 ) d i scussed t h e u s e s of l i g n i n i n a survey paper i n 1957, and mentioned t h e r e a c t i o n of l i g n o - s u l f o n i c a c i d w i t h p r o t e i n s t o form i n s o l u b l e complexes and i n d i c a t e d t h i s r e a c t i o n was used t o remove p r o t e i n s from e f f l u e n t s of canne r i e s o r f i s h - p r o c e s s i n g p l a n t s .

I n 1968, a U.S. P a t e n t ( l 0 ) w a s i s sued t o Lei f J an tzen of Oslo, Norway, a s s i g n o r t o Arthur C. Trask and Sons, Chicago, t h a t descr ibed a, method of p u r i f y i n g a n aqueous pyo te in - con ta in ing l i q u i d by adding l i g n o s u l f o n i c a c i d s t o e f f e c t p r e c i p i t a t i o n of combined p r o t e i n - l i g n o s u l f o n i c a c i d s and s e p a r a t i n g t h e p r e c i p i t a t e .

~ a l l e r s t e i n ( 8 ) i n 1944, descr ibed the r e -

The p r e c i p i t a t i n g agent i n

I n a paper by Tdnseth & B e r r i d g e ( l l ) , l i g n o s u l f o n i c a c i d p r e c i p i t a t i o n of p r o t e i n s from v a r i o u s i n d u s t r i a l waste waters , i nc lud ing s laughterhouse wastes w a s reviewed. S u l - f i t e l y e ( spen t s u l f i t e l i q u o r ) , was compared t o l i g n o s u l - f o n i c a c i d as p r e c i p i t a t i n g agen t s on blood albumen solu- t i o n s , showing t h e l i g n o s u l f o n i c a c i d t o b e s u p e r i o r . F e r - r i c c h l o r i d e was a l s o compared, and performance was poorer t han w i t h l i g n o s u l f o n i c a c i d .

P i l o t p l a n t t r i a l s on p o u l t r y wastes were descr ibed by Rosen( 12) us ing p i l o t p l a n t equipment developed by Alwatech A/S, a n Oslo, Norway based f i r m of water t r ea tmen t eng inee r s . BOD removals ranging from 60 t o 95 pe rcen t were r e p o r t e d , and economic a s p e c t s were a l s o d i scussed .

J d r g e n s e n ( l 3 ) i n Denmark, i n a. s e r i e s of l a b o r a t o r y sca , le t e s t s compa.red p r o t e i n p r e c i p i t a t i o n w i t h t h e fo l lowing chemical a g e n t s :

Control (no a.gent u sed ) S u l f u r i c Acid Aluminum Sul fa . te Gluc o s e T r i s u 1 f a.t e S u l f i t e Liquor

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Lignin Su l fon ic Acid (LSA) Glucose T r i s u l f a t e p l u s Azoprotein

He observed t h a t l i g n i n s u l f o n i c a c i d was more e f f e c t i v e i n p r o t e i n remova.1 than t h e o t h e r chemicals . The p r o t e i n p r e - c i p i t a . t i o n w i t h g lucose t r i s u l f a t e p l u s azopro te in gave a lower r e s idua , l BOD and t h e recovered p r o t e i n had b e t t e r feed va lue than w i t h l i g n i n s u l f o n i c a c i d . Aluminum s u l - f a t e whi le l e s s e f f e c t i v e on n i t r o g e n removal, w a s found e f f e c t i v e for phosphate removal.

Hopwood and Rosen( 14) r epor t ed f u r t h e r developments by Alwatech A / S , a,nd descr ibed t h e "Alwatech p rocess" wherein p u r i f i e d sodivm l i g n o s u l f o n a t e c a l l e d "Alprecin" can be used a t p H 3 t o recover p r o t e i n and f a t from va.r ious indus- t r i a l wastes . P i l o t p l a n t data w a s reviewed, from s t u d i e s us ing Alwatech d i s s o l v e d - a i r f l o t a t i o n equipment.

S ince 1970 Alwatech A/S has marketed equipment and t e c h - nology i n Europe f o r recovery of p r o t e i n s from waste water on a n i n d u s t r i a l s c a l e . To d a t e , s e v e r a l p l a n t s c a l e i n s t a l l a t i o n s of Alwatech equipment have been completed and a r e i n o p e r a t i o n i n Sweden and England. There a r e c u r r e n t l y no p l a n t s c a l e i n s t a l l a t i o n s i n o p e r a t i o n i n t h e United S ta , t e s .

TKEORY

The p r e c i p i t a t i o n of s o l u b l e p r o t e i n wi th s o l u b l e l i g n o s u l - f o n i c a c i d i n an a c i d i c a.queous system i s be l i eved t o be a n e a r l y in s t an taneous r e a c t i o n involv ing t h e n e g a t i v e l y cha,rged s u l f o n a t e groups on LSA molecules and p o s i t i v e l y charged amine groups p r e s e n t on t h e p r o t e i n molecules . The complexing of t h e s e l a r g e molecules r e s u l t s i n a g e l a t i n o u s suspended m a t e r i a l t h a t can be removed by a s u i t a b l e phys i - c a l l i q u i d s - s o l i d s s e p a r a t i o n technique .

P r o t e i n molecules conta.in bo th p o s i t i v e l y cha.rged amine groups and n e g a t i v e l y charged carboxyl groups when t h e s o l u - t i o n i s a t p H va.lues near 7. A c i d i f i c a t i o n of pro te inaceous was te water t o p H va lues below t h e i s o e l e c t r i c p o i n t w i l l r e s u l t i n p r o t e i n s c a r r y i n g a, n e t p o s i t i v e charge. I s o e l e c - t r i c va lues va ry wi th d i f f e r e n t p r o t e i n s , bu t a c i d i f i c a t i o n t o 3.5 o r below norma.1ly i n s u r e s a p H below t h e i s o e l e c t r i c f o r most p r o t e i n s o l u t i o n s .

L ignosul fonic a c i d when i n s o l u t i o n has the s u l f o n a t e group e s s e n t i a l l y completely ion ized , r e s u l t i n g i n a n e t nega t ive charge on the LSA molecule . With a c i d i f i c a t i o n , t h e s t r o n g a c i d group of t h e s u l f o n a t e con t inues t o c a r r y a n e g a t i v e

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charge even a t pH v a l u e s of 2 t o 3. At extremely low p H va lues below 1, t h e s u l f o n a t e group begins l o s i n g i t s charge.

Table I summarizes t h e r e s p e c t i v e n e t charges on LSA and p r o t e i n molecules a t v a r i o u s pH ranges , no t ing t h e r e - s u l t i n g p r e c i p i t a t i o n potent ia .1 .

Ta.ble I. In f luence of pH on LSA-Protein P r e c i p i t a t i o n

PH R a.ng e P r o t e i n U A P r e c i p i t a k i o n Poor 0-1 P o s i t i v e Charge Weak Negative

Charge

2-3 P o s i t i v e Charge Nega.tive Charge Good

3.5-4.5 I s o e l e c t r i c Negative Charge Poor (no n e t charge)

Above 4.5 Negative Charge Negative Charge None

This t a b l e r e v e a l s tha. t t h e pH must b e i n range of 2 t o 3 t o o b t a i n e f f e c t i v e p r e c i p i t a t i o n . ActuaJ experimental evidence confirms t h a t t h i s i s t h e opt imal pH range f o r p r e c i p i t a t i o n of t h e maximum amount of p r o t e i n .

Because t h e p r e c i p i t a t i o n involves ba lanc ing of o p p o s i t e i o n i c c h a r g e s , i t fo l lows t h a t an optima.1 r a t i o e x i s t s between LSA and p r o t e i n s i n o r d e r t o ma,ximize p r o t e i n r e - moval w i t h t h e least amount of LSA. Experimental evidence a l s o confirms t h a t t r ea tmen t of pro te inaceous wastes w i t h LSA i s q u a n t i t a t i v e , making LSA dose c o n t r o l i m p o r t a n t ( l 5 ) .

I n p r e c i p i t a t i n g and removing t h e LSA and p r o t e i n complex, fa t and f a t t y ma.teria1 ( a s determined by hexane s o l u b l e e x t r a c t i o n ) a r e a l s o l a r g e l y removed. I n r a w waste , f a t i s p r i m a r i l y p a r t i c u l a , t e and emuls i f ied m a t t e r w i t h a f r e e f a t t y a c i d con ten t ranging from 5 t o over 50 pe rcen t of t h e t o t a l fa t con ten t . A c i d i f i c a t i o n of ra,w wastes e l i m i n a t e s t h e s t r o n g nega t ive charge on t h e f r e e a c i d carboxyl groups r e s u l t i n g i n a loss of water s o l u b i l i t y . Therefore , a t p r o t e i n p r e c i p i t a t i n g pH va lues , most of t h e f a t m a t e r i a l t ends to s e p a r a t e from t h e water and f l o a t t o t h e s u r f a c e . The presence of LSA would no t be expected t o enhance fa . t removal i f p r o t e i n m a t t e r w a s absen t from t h e r a w wastes.

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With p r o t e i n p r e s e n t and forming a n i n s o l u b l e m a t e r i a l w i th LSA, t h e fa t t e n d s t o be comingled w i t h t h e protein-LSA m a t e r i a l .

LIGNOSULFONIC A C I D (LSA)

Lignosul fonic a c i d i s a by-product from t h e s u l f i t e wood pu lp ing i n d u s t r y and i s commercially a v a i l a b l e i n a v a r i e t y of forms and q u a l i t y .

Spent s u l f i t e l i q u o r c o n t a i n s wood l i g n i n t h a t has been made s o l u b l e by t h e i n t r o d u c t i o n of s u l f o n a t e groups i n t h e l i g n i n . Sulfona,ted l i g n i n s are la . rge molecules made up of r e p e a t i n g u n i t s of polymerized c o n i f e r y l a l c o h o l , t o g e t h e r w i t h l e s s e r amounts of s i n a p y l and p-coumaryl a l c o h o l s . (S inapy l a.lcoho1 c o n t a i n s two aromat ic methoxyl groups whi le p-coumaryl a.lcoho1 has none . ) Approximately h a l f t h e c o n i - f e r y l u n i t s a r e s u l f o n a t e d , p r i m a r i l y on t h e a l i p h a t i c c a r - bon a , t tached t o t h e a romat ic r i n g ( l 6 ) . F igu re 1 i l l u s - t rates a t y p i c a l segment of su l fona ted l i g n i n . The term " l i g n o s u l f o n i c a c i d , " o r LSA, i s h e r e i n used t o d e s c r i b e t h e s u l f o n a t e d l i g n i n matter as p r e s e n t i n an aqueous system, which i s ion ized as shown i n F igu re 1.

The molecular weight of l i g n o s u l f o n i c a c i d i s n o t a de f ined q u a n t i t y a s t h e commercially a .va i la ,b le m a t e r i a l s are a c t u a l l y mix tu res of v a r i o u s molecular weight l i g n i n s . J a n t z e n ( l 7 ) desc r ibed t h e d e s i r a b i l i t y and method of sepa- r a t i n g l i g n o s u l f o n a t e s i n t o two molecula,r weight f r a c t i o n s and def ined them as fo l lows :

Name of LSA F r a c t i o n pvera,ae Molecular Weight

Alpha. a.cid Beta. a c i d

14,620 5,180

I n p r o t e i n p r e c i p i t a t i o n , t h e h i g h e r molecular weight f r a c - t i o n i s more s u i t a . b l e t h a n low molecular weight LSA(18).

Spent s u l f i t e l i q u o r i s over 50 p e r c e n t LSA on a d r y weight basis, and i s f u n c t i o n a l l y capable of p r e c i p i t a t i n g p r o - t e i n s . However, spen t s u l f i t e l i q u o r conta , ins carbohydra te matter tha , t c o n t r i b u t e s s o l u b l e BOD t o t h e p r o t e i n s o l u t i o n be ing t r e a t e d , and i s a n u n d e s i r a b l e p r e c i p i t a n t f o r t h i s reason .

Desugared su l fona ted l i g n i n s a r e commercially a v a i l a b l e from s e v e r a l m i l l s t h a t a r e b e t t e r cand ida te p r e c i p i t a n t s f o r waste water p r o t e i n than s p e n t s u l f i t e l i q u o r . More h i g h l y p u r i f i e d l i g n o s u l f o n i c a c i d i s t h e most s u i t a b l e

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H

I H C-SOj-

C=O H I

H COH HCH I

I 6 . . {-CH

\ /

$ H OH

HCOH I

CH30 0 CH

0 CH I

H H -c-so~- I

Figure 1. Typical Segment of Sulfonated.Lignin Molecule

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m a t e r i a l t o u s e as t h e n r e c i p i t a t i n g chemical, e s p e c i a l l y products t h a t h a v e m a i n l y h i g h molecular weight LSA.

LSA products a r e a v a i l a b l e i n t h e s a l t form such a s sodium, calcium, o r ammonium l i g n o s u l f o n a t e . A s t he c a t i o n i s not involved i n p r e c i p i t a t i o n , t h e choice of sa l t form i s d i c t a t e d by reasons o t h e r t h a n p r e c i p i t a t i o n performance. Ammonium l i g n o s u l f o n a t e would be c l e a r l y u n s u i t a b l e i n a p p l i c a t i o n s where n i t r o g e n removal was an o b j e c t i v e .

LSA i s a v a i l a b l e as a d r y powder bagged i n 50 l b . bags o r a s a b u l k l i q u i d a t about 50 pe rcen t t o t a l s o l i d s .

It i s impor tan t t o n o t e t h a t LSA i s no t a s tandard chemical, b u t r a t h e r a complex mixture of su l fona ted l i g n i n s p l u s minor wood e x t r a c t i m p u r i t i e s . D i f f e rences i n t h e woods used, method of cooking, and subsequent handl ing w i l l a f f e c t t h e p r o p e r t i e s of LSA.

I n a p p l i c a t i o n LSA i s used as a s t o c k s o l u t i o n a t about 10 pe rcen t t o t a l s o l i d s , which makes a blackish-brown l i q u i d t h a t i s e a s i l y handled and pumped.

Lignin s u l f o n a t e s a r e FDA approved f o r u se i n animal feed a s descr ibed i n t h e Code of Fede ra l Regulat ion, 21CFR121.234.

PILOT PLANT TESTS - GREFN BAY

A b r i e f p i l o t p l a n t s tudy was conducted a t a beef a b a t t o i r i n Green Bay, Wisconsin, t o e v a l u a t e t h e LSA p r e c i p i t a t i o n and removal of p r o t e i n and f a t under a c t u a l p l a n t cond i t ions . Arrangements were made through t h e Arthur C . Trask Corpora- t i o n i n Chicago t o have Alwatech A/S of Oslo, Norway, d e l i - v e r and o p e r a t e a s m a l l p i l o t p l a n t f o r a per-iod of s e v e r a l ' weeks. The t e s t program w a s designed t o demonstrate t h e optimum p o l l u t a n t removal c a p a b i l i t y of LSA and t o cha rac - t e r i z e t h e p r o t e i n m a t t e r s epa ra t ed .

The p l a n t o p e r a t i o n s c o n t r i b u t i n g waste wa te r s cons i s t ed of t y p i c a l beef k i l l f l o o r o p e r a t i o n s , paunch manure sc reen ing , i n e d i b l e d r y render ing , blood dry ing , and h ide cu r ing . S a n i t a r y wastes , l i v e s t o c k pen was tes , and r e f r i g e r a t i o n cool ing water flows were handled s e p a r a t e l y and were no t p r e s e n t i n t h e r a w p l a n t wastes. The f r e s h r a w wastes were p r e t r e a t e d by sc reen ing i n a North Screen. A 20-ga l lon p e r minute s i d e s t ream from t h e sc reen e f f l u e n t was pumped t o t h e p i l o t u n i t a s t h e r a w waste t o be t r e a t e d .

The p i l o t p l a n t cons i s t ed of a n i n f l u e n t pump, p a r t i a l

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i n f l u e n t p r e s s u r i z a t i o n t o 75 p s i g , chemical feed systems f o r s u l f u r i c a c i d and LSA, and a c i r c u l a r d i s s o l v e d - a i r f l o t a t i o n t a n k having a 60-minute t h e o r e t i c a l d e t e n t i o n t ime. F igure 2 i l l u s t r a t e s a schematic of t h e p i l o t p l a n t equipment. A i r was provided by a, small compressor t o p rov ide a , i r f o r d i s s o l v i n g i n t o t h e p r e s s u r i z e d i n f l u e n t . Sludge s c r a p e r s were p r e s e n t f o r f l o a t i n g s o l i d s removal from t h e f l o t a t i o n c e l l . The f l o t a . t i o n u n i t e f f l u e n t w a s no t neu t r a , l i zed and w a s considered t h e e f f l u e n t from t h e p i l o t u n i t .

S u l f u r i c a c i d , t e c h n i c a l gra,de, w a s metered as a 1 pe rcen t s o l u t i o n and powdered LSA was made up as a 10 pe rcen t f eed s o l u t i o n f o r meter ing i n t o t h e p rocess . F igure 2 i l l u s - t r a . t e s a schematic of t h e p i l o t equipment employed.

Beaker t e s t s were f i r s t performed t o e s t a . b l i s h a n t i c i p a t e d pH and LSA dose ranges t o be s t u d i e d i n t h e p i l o t o p e r a t i o n .

Actual p i l o t p l a n t runs f o r sampling were conducted a f t e r a minimum of one-ha,lf hour of cont inuous normal o p e r a t i o n , w i t h t h e f l o t a t i o n t ank a l r e a d y f i l l e d w i t h chemica l ly t r e a t e d raw waste water remaining from t h e previous run. The p i l o t runs l a s t e d a minimum of f o u r hours p e r run, and a l l sampling w a s on a composite b a s i s .

Nine r epor t ed runs were conducted us ing a powder LSA c a l l e d "Na-Peri tan" which w a s suppl ied by Arthur C. T r a s k Corpor- a t i o n from sources i n Norway. T h i s product w a s a p u r i f i e d sodium sa l t of l i g n o s u l f o n i c a c i d t h a t conta.ined v e r y l i t t l e r e s i d u a l wood sugar and w a s a h igh molecular weight f r a c t i o n of LSA. Tab le I1 summa,rizes t h e data from t h e s e n i n e runs .

Two o t h e r LSA products were a l s o eva lua ted dru ing t h e p i l o t t r i a l s ; a n ammonium sa l t of LSA and a sodium sa l t of LSA, bo th experimental p roducts from S c o t t Paper Company. Typica l runs f o r t h e s e products produced roughly s i m i l a r r e s u l t s except t o t a l n i t r o g e n removal w a s poor f o r t h e ammonium LSA.

Acid a d d i t i o n and LSA dose were v a r i e d by t h e Alwatech ope ra - t o r t o ach ieve good v i s u a l performance wi thout regard to a r r i v i n g a t t h e economically minimum chemical requirement . While a p r e c i p i t a t i n g pH of 3 .4 w a s exper imenta l ly found t o b e s u i t a b l e f o r e f f e c t i v e p r e c i p i t a t i o n , t h e average pH f o r all runs w a s 2 .6 , w i t h one run a s low a s 2.0. Good p r e c i p i - t a t i o n w a s found a t t h i s pH range, b u t excess a c i d was used t h a t would not b e r e p r e s e n t a t i v e of f u l l p l a n t s c a l e opera- t i o n .

The LSA dose range t e s t e d w a s 244 t o 537 mg/l, which r e p r e - sen ted a range of e f f e c t i v e p r e c i p i t a t i o n r a t h e r t han a

92

n

a Q

) k 0

Qi

m ,I

Q) k

5A

mc

ma

U

E-l

k

pc

k

vi

4

p-1 u

-c, c cd

93

Table 11: Summary Data, LSA P r e c i p i t a t i o n wi th Alwatech P i l o t P l an t Armour and Company Beef Aba.t toir , Green Bay, Wisconsin

T e s t No. ~~

LSA, mg/l ~2~04, mg/l

pH: i n f ef f

BOD: i n f , mg/l e f f . mg/l % Rem.

\o TSS: i n f . mg/l e f f . mg/l e

% Rem.-

FOG: i n f . mg/l e f f , mg/l % Rem.

TKN: i n f , mg/l e f f . mg/l % Rem.

P r o t e i n % of TI Hex.Sol.% of TI

I I1 I11 m VI1 VI11 IX X XI

244 -

6.5 2.9 1260 180 85

760 71 91

254 19 93 448 46 90

5.8 76 34

355 405 298 506 750 1000

6.8 6.4 6.5

920 1700 960

82 94 82

82 35 39 95 98 97 526 744 473 17 9 6 97 99 99 220 126 182 24 21 24 89 83 87

3.0 2.3 2.1

180 90 170

1770 1470 1310

7.2 8.0 9.2 8 66 36 17 34 48

537 516 663 671

7.0 6.6 2.7 2.6

267 223 77 78

560 666

94 96 296 749 35 38 88 95

22 18 79 87

7.5 5.5 28 36 42 41

1160 1040

33 24

105 138

484 534 428 917 910 850 6.8 6.8 7.8

1070 1160 2130 178 156 360 83 86 83

684 658 1220 20 28 23 97 96 98 252 243 370 18 21 30 93 91 92

2.4 2.4 3.4

175 175 129 21 18 21 88 go 84

5.0 5.1 6.9 40 42 44 34 41 17

Average

422 784 6.8 2.6 1258 208 84

960 41 96

435 22 95 188 24 87

6.7 42 34

BOD denotes Biochemical Oxygen Demand, 5-dayY 2OoC, seeded TSS denotes Tota,l Suspended S o l i d s FOG denotes F a t , O i l , and Grease (hexane s o l u b l e s ) TKN denotes To ta l Kjeldahl Nitrogen, a s N

range of minimum dose to achieve adequate precipitation.

As Table I1 illustrates, effective pollutant removal was accomplished in terms of BOD, suspended solids, fat or grease, and total Kjeldahl nitrogen. The pilot plant out- performed the existing plant scale dissolved-air f lotazion unit in service at the abattoir as summarized in Figure 3. Samples of the recovered raw sludge were withdrawn and ana- lyzed by the Armour and Company Food Research Laboratory in Oakbrook, Illinois. Table I11 summarizes the analytical values for the LSA sludge, and Table IV compares the amino acid profile of the LSA sludge as compared to soybean oil meal and casein. These analyses reflect raw sludge solids characteristics and are not necessarily representative of a final product as produced on a plant scale.

PLANT SCALE OPERATION - SUTTON BFNGER

A one-day visit was ma,de to observe the operation of a plant scale installation of Alwatech equipment at a poultry plant in Engknd in November, 1972. This plant wa.s designed for approximately 75,000 broilers per day, and was located at Sutton-Benger, near Chippenham, in Wiltshire, England.

Typical of broiler plants in the United States, this plant had rotating screens on each of the offal flow-away waste water and feather flow-away waste water sewers. This plant had an older industrial waste treatment facility consisting of primary clarification, trickling filters, final clarifiers and humus ta_vks prior to final river discharge.

The newer Alwatech equipment consisted of the following:

1. Balancing tank to receive screened raw wastes. 2. Precipitation and flotation system, designed

3. Neutralization svstem. for &OO gallons per minute flow.

4. High rate trickling filters with plastic media. 5. Final clarifiers.

The Alwatech system provided primary waste wa,ter treatment and the effluent was then subsequently treated in the existing older secondary trea,tment plant final to river dis- charge.

After balancing the flow to dampen fluctuations in flow and waste water strength, the raw waste was initially dosed with approximately 140 mg/l of Alprecin (LSA). Once the dosa.ge was set, this dose was held constant and no changes in LSA dosewereneeded from day-to-day or hour-to-hour.. The flow

95

Carcass Beef I 680 hd/day BEEF ABATTOIR Without Stock Pen Wastes

With Dry Rendering

TSS 960 mg/l ..............................................

With Paunch Screen ‘4 - Sludge 1-1) w 20 gpa I

I S A Process

P i l o t P l a n t

I *

Flow 0.15 ngd

I

Dissolved - A i r F l o t a t i o n Unit

BOD 600 ag/l TSS 320 mg/l ,............... ............................

1 North 1 Screen

BOD 208 m g / l TSS 41 n g l .................................

b

Table 111: Analys is of LSA Sludge from P i l o t P l a n t S t u d i e s , Amour and Compa.ny, Green Eay, Wisconsin

It em p e r c e n t of Dry Matter

P r o t e i n Fa.t Crude F i b e r Lignin S u l f o n a t e

T o t a l S o l i d s

40.2 24.08 4.29 31.62 100.00

T o t a l Ni t rogen 6.43 T o t a l Non-prot e i n Ni t rogen 0 503

Sodium Pota.ssium Calcium Magne s ium Phosphorus S u l f u r I r o n Copper Mangan e s e Zinc

0 359 0.042 0.054 0.0083 0 398 1.55 0.169 0.0025 0.022 0.0066

Vitamin A ( i n c l u d i n g c a r o t e n e ) IU 5811

97

Table TV: Amino Acid P r o f i l e s f o r LSA Sludge (Green Bay P i l o t S tudy) , Soybean O i l Meal and Casein

Amino a .c ids

Lys i.ne Threonine Va l ine Methionine I s o l e u c i n e Leucine Phenylalanine T r yp t o p ha n H i s t i d i n e Arginine Aspa r t i c a c i d S e r i n e Glutamic a c i d P r o l i n e Glycine Alanine Cys t ine Tyrosine

LSA Sludge

gm of amino a c i d p e r 16 am of N

9.77 5.75 8.05 1.67 4.19 11.74 6.17 1.32 4.82

12.49 5.49 5.42 14.70

8.23 3.80 4.61

5.16 5.83

Soybean o i l mea 1

gm of amino a c i d p e r 16 pm of N

6.30 3.70 5.23 1.30 5.45 7.40 4.80 1.30 2.40 7.00 11.40 4.70 19.30 4.70 3.80 4.30 1.70 3.05

Casein g m of amino a c i d p e r 16 pm of N

8.5 4.2 6.5 3 - 4 7.8 9.0 5 .1 1.4 3.2 3.6 6.7 6.7 22.5 12.3 2.1 3.2 0.3 5.4

98

was t h e n s ~ l i t i n t o t h r e e f lows . Two equal main f lows were r egu la t ed by f low c o n t r o l l e r s f o r d e l i v e r y t o each of two d i s s o l v e d - a i r f l o t a t i o n u n i t s . The t h i r d f low, approximately 15 percen t of t h e incoming t o t a l f low, was p re s su r i zed t o 75 p s i g , s a t u r a t e d wi th a i r , and then s p l i t i n t o two equal f lows t o d e l i v e r d i s so lved a i r t o t h e two main i n f l u e n t s t reams.

. T u s t p r i o r t o e n t r y i n t o t h e f l o t a t i o n u n i t , t h e waste water was mixed w i t h t h e s i d e s t ream of waste water w i t h d i s so lved a i r , and a one percen t s o l u t i o n of s u l f u r i c a c i d was added t o dep res s t h e mixture from pH 7 t o p H 3. I n one f l o t a t i o n c e l l , t he raw waste pH was monitored, w i t h t h e e l e c t r o d e s be ing cleaned by a timed u l t r a s o n i c g e n e r a t o r . The p H was cont inuous ly recorded and a c o n t r o l f u n c t i o n a u t o m a t i c a l l y a c t u a t e d t h e s u l f u r i c a c i d feed pumps t o main ta in a ps-I 3.0 0.3. The normal s u l f u r i c a c i d dose was 250 mg/l.

The f l - o t a t i o n u n i t s were c i r c u l a r 18 f t . diameter f i b e r g l a s s t anks w i t h s u r f a c e s c r a p e r s c o n s i s t i n g of a vacuum s u c t i o n system f o r s ludge removal. The c l a r i f i e d e f f l u e n t from t h e 'iwo f l o t a t i o n u n i t s were combined and d e l i v e r e d t o a smal l n i x i n g t ank where hydrated l i m e was added a t t h e r a t e of about 180 mg/l, and a u t o m a t i c a l l y pH c o n t r o l l e d t o 7 .0 f 0.5. The n e u t r a l i z e d waste was t h e n sub jec t ed t o b i o l o g i c a l t r e a t - ment i n t h e subsequent t r i c k l i n g f i l t e r system.

Sludge from t h e two f l o t a t i o n c e l l s was accumulated i n an e x i s t i n g p i t and hauled away f o r land d i s p o s a l a s a temporary measure. It was understood t h a t s t u d i e s were then underway t o u t i l i z e t h e recovered s ludge a s an animal feed component.

The e n t i r e p r e c i p i t a t i o n and f l o t a t i o n system p l u s chemical handl ing was housed i n a b u i l d i n g t o reduce t h e i n f l u e n c e of weather on p l a n t o p e r a t i o n s .

P i l o t p l a n t d a t a i n e s t a b l i s h i n g t h e des ign of Alwatech equipment revea led t h a t on t h e raw wastes of 1,000 t o 1,500 mg/l BOD, t h e removals observed were a s fo l lows :

BOD removal 73 8$ COD removal 76.3% TSS removal 82.7%

64.3 t o 80.5 range 70.6 t o 86.8 range 75.6 t o 89.2 range

N o p l a n t o p e r a t i n g r e s u l t s were a v a i l a b l e f o r review a t t h e t ime of v i s i t , b u t v i s u a l performance i n producing a c l e a r e f f l u e n t a f t e r f l o t a t i o n suggested t h e p i l o t p l a n t d a t a was dun l i ca t ed i n t h e a c t u a l p l a n t s c a l e o p e r a t i o n .

99

The subsequent b i o l o g i c a l t r ea tmen t of t h e p r e c i p i t a t i o n and f l o t a t i o n e f f l u e n t was r epor t ed s u c c e s s f u l i n meeting t h e f i n a l e f f l u e n t s t anda rds of 30 mg/l BOD and 40 mg/l SusDended S o l i d s .

N o d i f f i c u l t i e s i n o p e r a t i o n of t h e e n t i r e system were ob- served dur ing t h e v i s i t . P l an t o p e r a t o r f u n c t i o n s c o n s i s t e d of main ta in ing a l l equipment i n good working o r d e r and i n - s u r i n g adequate chemicals a r e a v a i l a b l e t o t h e chemical f eed systems.

PLANT SCALE OPEBATION - KALMAR

A b r i e f v i s i t was made t o ano the r i n s t a l l a t i o n of Alwatech equipment t h a t used LSA t r ea tmen t of meat i n d u s t r y was tes . A s i n t h e case of Sutton-Benger, t h e pr imary g o a l was BOD, g r e a s e , and suspended s o l i d s r educ t ion , w i t h t h e i n t e n t of recover ing a by-product . Nitrogen removal was n o t a s p e c i f i c ob j ec t i v e.

This f a c i l i t y was a complex packing p l a n t i n Kalmar, Sweden, t h a t s l augh te red b e e f , hogs, and a minor number of lambs, ho r ses , and e l k . A wide v a r i e t y of sausages , smoked meats, and o t h e r processed meat products were produced. Canning o p e r a t i o n s included canned meat products and some canning of vege tab le s , w i t h peas and c a r r o t s be ing processed a t t h e t i m e o f v i s i t a t i o n i n November, 1972.

The waste water t r ea tmen t system i n o p e r a t i o n c o n s i s t e d of t h e fo l lowing :

1. Grease skimming b a s i n converted i n t o a ba l anc ing

2. Rotary sc reen (1/8 i nch d iameter openings) p r e -

3. P r e c i p i t a t i o n and d i s s o l v e d - a i r f l o t a t i o n system. 4. N e u t r a l i z a t i o n system.

tank .

t r e a t m e n t .

The f i n a l t r e a t e d e f f l u e n t was t h e n d ischarged t o t h e Kalmar municipa.1 sewerage system f o r j o i n t t r ea tmen t w i t h domestic was tes .

The p r e c i p i t a t i o n and f l o t a t i o n p rocesses were o p e r a t i n g a t a des ign f low of about 400 g a l l o n s p e r minute on each of t h r e e o u t of t h e f i v e working days. On t h e remaining two working days, reduced o p e r a t i o n s produced a raw waste f low of about 265 gpm.

Screened waste was dosed w i t h a cons t an t dose of 220 mg/l Alprec in (LSA). A s a t t h e Sutton-Benger i n s t a l l a t i o n , man- u a l c o n t r o l of t h e LSA dose r a t e was found e f f e c t i v e i n

100

mainta in ing proper p r e c i p i t a t i o n . The LSA was f e d a s a t e n pe rcen t s t o c k s o l u t i o n w i t h t h e f eed r a t e p r o p o r t i o n a l to t h e t o t a l waste f low. Unusually h igh s t r e n g t h shock loads w i t h BOD v a l u e s w e l l above 2,000 mg/l d i d r e q u i r e upward adjustment of t h e LSA dose, bu t t h i s problem was considered i n f r e q u e n t , and one b e s t c o n t r o l l e d by improving i n p l a n t o p e r a t i o n s .

The LSA dosed screened waste was s p l i t i n t o t h e 15 percen t s i d e s t ream f o r i n f l u e n t p r e s s u r i z a t i o n and a i r d i s s o l v i n g , whi le t h e major f low was e q u a l l y s p l i t f o r d e l i v e r y t o t h e two 18 f t . diameter f i b e r g l a s s f l o t a t i o n c e l l s . S u l f u r i c a c i d a d d i t i o n and r e - e n t r y of t h e d i s s o l v e d - a i r s i d e s t ream took p l a c e j u s t p r i o r t o e n t r y i n t o t h e f l o t a t i o n t anks . The DH w a s monitored, recorded, and c o n t r o l l e d a t pH 3.0 by automatic adjustment of t h e s u l f u r i c a c i d feed pumps. Su l - f u r i c a c i d dose was t y p i c a l l y about 350 mg/l. The f l o t a t i o n e f f l u e n t flowed by g r a v i t y t o a n e u t r a l i z a t i o n t ank f o r adjustment of p H t o 7 .0 . A lime s l u r r y w a s pumped t o t h e n e u t r a l i z a t i o n t a n k and was manually s e t f o r about 180 mg/l hydrated 1-ime. With manual adjustment of n e u t r a l i z a t i o n , t h e recorded f i n a l p H f l u c t u a t e d between pH 6 and 8.

Sludge accumulating i n t h e f l o t a t i o n t a n k was scraped i n t o f o u r r a d i a l t roughs a t t h e s ludge s u r f a c e , u s ing a timed mDtorized s c r a p e r making two sweeps i n t h r e e minutes f o l - lowed by t h r e e minutes o f f - t i m e . The s ludge normally was about t e n pe rcen t t o t a l s o l i d s and was pumped t o a s t o r a g e t a n k .

A t t h i s p l a n t , e d i b l e blood was being recovered and used i n process ing . Res idua l c o l l e c t e d blood was mixed w i t h t h e LSA s ludge i n t g e s ludge s t o r a g e t ank and t h e mixture was heated t o about 50 C . The heated s ludge and blood mixture was t h e n sub jec t ed t o l i v e steam to coagu la t e t h e p r o t e i n m a t t e r . T h i s mixture was then dewatered by a s o l i d bowl c e n t r i f u g e which produced a g r a n u l a r s o l i d of about 40-50 percen t d r y m a t t e r . The c e n t r a t e was recyc led back t o t h e raw waste ba l anc ing tank . The recovered s o l i d was then added to t h e main p l a n t cont inuous i n e d i b l e render ing system f o r f i n a l d ry ing and recovery w i t h i n e d i b l e t a l l o w and c r a c k l i n g s .

Table V summarizes BOD7 removal based on i n f l u e n t samples p r i o r t o t h e raw wa,ste s c reen and e f f l u e n t samples a t t he f l o t a t i o n u n i t d i scha rge .

A t t h e t ime of v i s i t a t i o n , t h i s p l a n t had v e r y l i t t l e r e p r e - s e n t a t i v e d a t a on t h e n i t r o g e n removal achieved i n t h e p r e - c i p i t a t i o n and f l o t a t i o n equipment. Alwatech engineers con- ducted a b r i e f s tudy t o provide t h e da t a a s summarized i n Table VI(l8).

101

Table V: BOD Removal at Kalmar(l8)

1200 1500 1360

1290

1700 1600 2100 1950 1500 1700

1440

1100

i v t n

360 300 330 370 220

31co 312

70.0 80.0 75.8 74.3 86.0 82.0

83.0

80 .o 83.8

74.6 84.0 80.5

80,6 79.9

10 2

Ta,ble V I : BOD and Nitrogen Removal a. t Ka,lmar(l8)

Tes t Number 1 2 3 4 5 6 7 AVE . BOD: I n f . mg/l 1290 1100 1700 1600 2100 1950 1750 1622

Eff . mg/l 220 150 300 320 340 380 340 300

TKN: I n f . mg/l 91 77 119 112 147 136 122 114

% 'Rem. 83 86 82 80 84 81 81 82

E f f . mg/l 24 18 32 33 38 40 35 32 % Rem. 77 77 73 71 74 71 71 73

Ts: I n f . mg/l 3088 2855 2564 3607 3138 4129 3216 3117 E f f . mg/l 3174 2569 2605 3173 3140 4012 3094 2981

Notes: I n f l u e n t excluded rumen c l ean ing and g u t - c l e a n i n g waters , samples j u s t p r i o r t o f l o t a t i o n . E f f l u e n t downstream of n e u t r a l i z a , t i o n .

103

C ONCLUS I O N S

1.

2.

3 .

4.

5.

6.

7 .

Lignosul fonic a c i d t r ea tmen t of meat i n d u s t r y was te waters under a c i d i c c o n d i t i o n s , fol lowed by d i s s o l v e d - a i r f l o t a t i o n i s capable of removing s i g n i f i c a n t q u a n t i t i e s of BOD, suspended s o l i d s , g r e a s e , and n i t r o - gen from r a w wastes, a s demonstrated i n p i l o t p l a n t and p l a n t s c a l e i n s t a l l a t i o n s .

LSA t r ea tmen t appears s u i t a b l e a s a p re t r ea tmen t s t ep t o f i n a l b i o l o g i c a l t rea , tment . It i s t h e r e f o r e a can- d i d a t e p rocess f o r bo th meat i n d u s t r y p l a n t s u s i n g municipal sewerage systems a n d i n c a s e s where t h e i n - d u s t r y must t reat i t s own waste wa te r .

Removal of p r o t e i n and f a t w i t h LSA o f f e r s t h e poten- t i a l of a recovered by-product t h a t may have v a l u e a s a component i n animal f eed . T h i s would e l i m i n a t e a problem o f u l t i m a t e d i s p o s a l of t h e m a t e r i a l s removed.

The phys ica l -chemica l na. ture of t h e process makes it convenient t o r a p i d l y s t a r t - u p t h e process when needed, and t o s t o p p rocess ing when d e s i r e d .

The p rocess r e q u i r e s v e r y l i t t l e land a r e a , and i f housed, w i l l o p e r a t e indpendent of weather e f f e c t s .

The p rocess a,ppears b e s t app l i ed t o v e r y f r e s h r a w waste of h igh p r o t e i n con ten t a n d w h e r e i n e d i b l e r e n - de r ing o p e r a t i o n s can b e used t o handle t h e recovered dewa.tered s ludge . Waste waters having a low b u f f e r i n g c a p a c i t y a r e advantageous as a c i d and n e u t r a l i z a t i o n chemical requirements a r e reduced.

Various LSA products are commercially a v a i l a b l e from s e v e r a l s u p p l i e r s that a r e s u i t a b l e f o r p r o t e i n p r e - c i p i ta , t i on.

10 4

13. J(ZIRGENSEN, S . E. P r e c i p i t a , t i o n of P r o t e i n s i n Waste Water. Va t t en 1: 58 (1971).

14. HOPWOOD, A . P. and ROSEN, G . D . P r o t e i n s and Fa t Recovery from E f f l u e n t s . Process Biochemistry: 15 (March 1972).

15. CLAGGETT, F. G . and WONG, J. Salmon Canning Waste- Water C l a r i f i c a t i o n , P a r t 11. Circu1a.r N o . 42, F i s h e r i e s Research Board of Canada: (Feb. 1969).

16. BALL, F. J . Chemistry of Lignin and i t s App l i ca t ions . Presented at APPA-TAPPI Research Conference: (Oc t . 1965).

17. JANTZEN, L . Method of Sepa ra t ing Lignosul fonic Acids. U.S. Pa ten t No. 2 ,838 ,483 : (~une 10, 1958).

18. TdNSETH, E. I. Personal Communication (1972).

106

References

'7 -.

3 .

' 1 .

7.

0 ' i .

9.

10.

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