Effect on Particulate 



The relationship between weight loss rate 

 strikingly different between the two chemi- 

 cals. Figure 10 presents the total accumulated 

 particulate produced from several fires. Ob- 

 viously, the AS treatment had little effect on 

 particulate production, while DAP produced 

 substantial increases in particulate; about 20 

 times more than that produced by the un- 

 treated at the 14.8 percent treatment level. 

 The rate of particulate is increased and the 

 peak rate occurs further from the point of ig- 

 nition as the amount of DAP increases (fig. 

 11). The range of particulate produced per 

 unit of weight consumed was 8 to 94 lb. ton" 1 

 for DAP, 3.8 to 7.2 lb.ton- 1 for AS, and 

 about 5.5 lb.ton" 1 for the controls, as shown 

 in table 1 . 



The relationship between weight loss rate 

 and particulate production rate is clearly 

 shown in figures 12 and 13. As can be seen, 

 intensity is decreased by both chemicals. 



However, there is little change in particulate 

 production by AS. 



The range in tetrahydrofuran soluble tar 

 was 41 to 56 percent (dry weight of total 

 particulate) for DAP treatment, 15 to 58 per- 

 cent for AS treatment, and 40 percent for 

 controls. The amount of tar was apparently 

 directly correlated with DAP treatment and 

 inversely correlated with AS treatment level. 

 The phosphorus content of the DAP particu- 

 late was 11 to 17 percent, depending on treat- 

 ment level. Preliminary estimates show that 

 about 30 percent of the phosphorus added by 

 treatment is emitted by the fire and can be 

 collected with the particulate. 



The particulate matter from the AS treated 

 fires was found to contain 33 to 57 percent 

 sulfate, depending on treatment level. How- 

 ever, this did not amount to over 10 percent 

 of the sulfate added by treatment at the high- 

 est level. 





800 







14.8% DAP 





82.0 





700 













(grams) 



600 







8.4%DAP 





61.5 



~o 



aj 



500 













E 















ulate i 



400 







5.6% DAP 





410 



1 partic 



300 













o 







>— 



200 







2.3% DAP 





205 











.,1.3% DAP 









100 



i i "\ 



'3^7 



1 1 1 1 1 1 1 1 1 



.11.9% AS 

 :::::::::£ 6.8% AS - 

 >1.9% AS 



Control 

 Untreated 













4 8 12 



16 20 24 28 32 36 40 44 48 52 

 Time (min.) 



56 60 









Figure 10.— 



The total particulate produced from fires at several treatment levels. 



12 



