| 英文摘要 |
Because the swine farming industry has been complaining about the strict effluent standards, one of the main tasks is to review whether these standards are applicable by referring to the detailed collected information on livestock effluent controls in Japan, Korea, Malaysia, America, Denmark, and the Netherlands. Additionally, simplified information in some countries are collected for analysis, comparison and applicability study as well.
In a study about analyzing the effect of temperature on the three-stage wastewater treatment process, the result points out that the water quality discharged by 29 swine farms meet the effluent standards on the condition that the treatment facilities are under normal operation. However, if the hardware facilities or the operators failed to perform well, the effluent would exceed the standards by 2 to 30 times, which has nothing to do with temperature. It is estimated that although the lowered temperature of 10~15℃would influence the second stage of anaerobic digestion, the third stage of aerobic treatment could show a better process performance. Therefore, no significant differences in SS, BOD and COD concentrations of the final effluent were observed between a lowered temperature of 10~15℃ and an appropriate temperature of 25~30℃. From 2005 March to November, the values of SSave, BODave, and CODave were 35, 49 and 200mg/L and the values of SSP80, BODP80 and CODP80 were 49, 76 and 299mg/L respectively, which complied with the present standards. It is reported that the present maximum limit of COD is fairly lax.
To understand the effect of swine wastewater on the water bodies, the water quality of the source water protection zones in Kao-Ping Creek is to study, where approximately 466 thousands heads of swine had been cut down by 2000. After that, the NH3-N concentration fell under 0.3mg/L, greatly improving the compliance from 0% to 75~100%.
Finally, it is suggested that our livestock effluent standards should be tougher. The reasons are that our standards are less strict than those of other industries and of other countries. Moreover, our high swine density is ranked number three around the world (number one in Asia). To relieve the pressure of joining the WTO, our government should refer to some advanced countries as role model by adopting their performance standards. By devoting to source waste deduction measures, we can thus reduce the cost of swine wastewater treatment.
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