ABSTRACT
Concerning the agricultural waste water treatment, adsorption removal of cresol which is one of disinfectants by commercial activated carbon was investigated.<BR>It was not found the significant correlation between amount of cresol adsorbed and physical properties of eight kinds of activated carbon. The intraparticle diffusivity of cresol onto the pores of activated carbon was significantly related to the mesopore volume.<BR>In the treatment of agricultural waste water, it is concluded that the activated carbon which is rich in mesopore volume is suitable for the adsorption removal of cresol from the standpoint of adsorption rate.
ABSTRACT
For the security of water quality in rural areas, adsorption removal of phenol which is one of disinfectants for excretions by six kinds of commercial activated carbon was investigated.<BR>At equilibrium concentration of 1 and 10 ppm, activated carbon indicated pH 10.19 adsorbed phenol as much as 2.17 and 1.84 times compared with activated carbon indicated pH 3.06, respectively. At low equilibrium concentration of phenol, the amount adsorbed was significantly influenced by surface pH of activated carbon (p <0.05).<BR>These results suggest that the difference in amount of phenol adsorbed onto activated carbon is due to the interaction between phenol and surface oxygen groups on the adsorbent. Therefore, it is concluded that the activated carbon of which surface is basic suitable for the adsorption removal of phenol in the agricultural waste waters.
ABSTRACT
This paper reports on studies carried out regarding noise and vibration on a tractor and a binder which are the most commonly used for agricultural purposes. 1) The sound levels on both of a tractor and a binder were over 100 dBA, and the level on binder was larger about 6 dB than that on tractor. The 1/3 octave band sound pressure levels on a tractor exceeded the permissible criteria for 8 hr in the frequency range of 315 Hz and those on a binder exceeded it for 2 hr in the range of 630 Hz. 2) The vibration level on the handlebars of a tractor was the highest in the Y direction (117. 5 dB) and that under the seat was the highest in the vertical direction (97.5dB). The 1/3 octave band vibration acceleration levels for a tractor in the Y direction exceeded the exposure guideline for 4 hr in the frequency range of 16 to 50 Hz and those under the seat in the vertical direction exceeded the permissible criteria for 8 hr in the frequency range of 31.5 Hz. 3) The vibration level on the handlebars of a binder was the highest in the Z direction (114.1 dB) for the metal handlebars and (112. 1 dB) for the rubber grips. The band levels on a binder in the Z direction exceeded the guideline for 4 hr in the frequency range of 50 Hz and from 16 to 25 Hz. 4) We confirmed that there was sufficient danger of to hearing due to noise and vibration hazards in using both a tractor and a binder continuously for long periods of time in comparison with the exposure guideline and permissible criteria.