摘要
The study was carried out to evaluate the airborne gases and suspended particulate matter concentrations in the pig barns of a commercial pig farm situated in the peri-urban area of Beijing,China.The measurements followed the natural pig life-stages namely:gestation,farrowing,weaning,and fattening.In order to accomplish these objectives,three different measurement devices were employed:(i)color diffusion tubes,(ii)a portable gas measuring device,and(iii)a dust measuring instrument.Due to the rotation of the devices in the different sampling places,the measurements were performed at different time periods during the months of the summer and winter season in Beijing.The pig farm had a capacity of 15000 pigs per year and the manurial system was identified as“gan qing fen”or dry cleaning of the manure.The main by-products generated by the farm were irrigation water and small-scale biogas production.High dust concentrations were identified in the pig barns,especially during the feeding and manure cleaning events inside the farrowing and weaning barns with slatted floors.Inhalable dust ranged from 0 mg/m3 to 12.45 mg/m3,while the allowable dust ranged from 0 mg/m3 to 9.62 mg/m3.Ammonia concentration ranged from 0 ppm to 20 ppm(1 ppm=1 cm3/m3),and the carbon dioxide concentration ranged from 300 ppm to 8000 ppm.The highest ammonia concentration was recorded in the fattening barn during the summer season,while the highest carbon dioxide concentration was reported in the weaning barn during the summer season.The results of this study were similar to the results of studies performed on pig farms under natural and mechanical ventilation systems.On the other hand,the problems encountered during the gas measurements on the pig farm were directly related to the inadequate housing layout due to the obstruction of windows,fans and air channels for indoor ventilation,and thus the measurement devices faced harsh working conditions.Therefore,it is recommended that the housing system should be improved with repaired windows and curtains especially for the winter season;similarly,the repair of the fans should be attempted in order to improve the ventilation,especially in the gestation barns.
基金
The authors would like to thank the International Research Training Group of the University of Hohenheim and the China Agricultural University for their supports
This study is part of the Sub Project 1.4“Evaluation of nutrient and pollutant cycles of livestock production systems and manure management systems in the North China Plain”
The project is funded by the German Research Foundation(GRK 1070)
the Ministry of Education(MOE)of the People’s Republic of China
The authors also thank the fruitful cooperation with the Sino German Project:“Recycling of Organic Residues from Agricultural and Municipal Origin in China”,Sub Project 1:“Farm gate balance for animal production,”granted by the BMBF(FKZ 0330847A-H).