It is urgent to cultivate and control pollution. The cost of the method is very important.

Recently, Yan Junfang, chairman of Yangling Benxiang Agricultural Industry Group, has had a headache. Due to problems left over from history, a farm under the group that can hold 200000 pigs at full capacity has encountered thorny environmental problems. It is reported that the pig farm is only 170 meters away from the surrounding villages. it is hot in summer and the stench of the pig farm directly affects the daily life of the villagers.

"I have to take care of the environment of the pig farm no matter what the cost." Yan Junfang made up her mind.

It is urgent to control the pollution of livestock and poultry breeding.

In recent years, with the rapid improvement of the level of livestock and poultry breeding in China, the breeding scale continues to expand, and the problem of livestock and poultry pollution is becoming more and more prominent. In order to effectively solve this problem, the State Council also issued the regulations on the Prevention and Control of pollution in large-scale breeding of Livestock and Poultry, so that there are laws to abide by in the treatment of pollution in livestock and poultry.

Aquaculture enterprises plagued by environmental pollution are by no means the only one of the above-mentioned groups. It is understood that at present, many farms across the country are in the same predicament and anxiety, and many of them.

"if many enterprises do not pay attention to the problem of aquaculture environment, it will not only slow down the speed of development, but will face the risk of being closed." He Cheng, a professor and doctoral supervisor of the School of Zoology of China Agricultural University, who has paid close attention to the environmental problems of livestock and poultry breeding for a long time, told reporters that "the pollution control of livestock and poultry farming Brooks no delay."

Common pollution control methods in foreign countries

In order to find a good way to solve the problem of livestock and poultry manure, he Cheng has specially visited a number of countries to learn from the advanced experience of other countries in controlling livestock and poultry environmental pollution. In the interview, he Cheng introduced in detail the common methods abroad.

One is the method of microbial fermentation. Put the solid and liquid waste of the farm into the biogas tank, add anaerobic fermentation bacteria, ferment for 4 days to form biogas, and finally transport it to residents' homes or enterprises in the form of gas. In summer, excess fermentation gas can also drive power generation for lighting by residents. The remaining solids after fermentation can be made into organic fertilizer after microbial fermentation, which can be used for flower cultivation.

The second is composting. According to a certain proportion, livestock and poultry manure was mixed with straw and sawdust, and suitable bacteria were added. After full stirring, organic fertilizer was made after 7 ~ 8 days of fermentation. In order to ensure the treatment effect, a shed can be built on top of the compost, which can not only protect the rain but also promote fermentation by heating.

The third is the method of coal chemical industry. That is, humic acid and fulvic acid are extracted from lignite and added to livestock and poultry feed in order to reduce the odor emission of livestock and poultry feces. Or spraying humic acid and fulvic acid on the surface of feces, on the one hand, can play an adsorption role; on the other hand, it is equivalent to covering the feces with a film to prevent the release of odor.

Fourth, the addition of microecological agents to feed can inhibit harmful bacteria in the intestinal tract of livestock and poultry, produce beneficial bacteria, and reduce harmful gas emissions in the process of fecal formation.

The cost of pollution control is a factor that cannot be ignored.

Which method has the best effect on pollution control and is the most suitable to be widely popularized in China? He Cheng believes that every method has its advantages and disadvantages. "for example, microbial fermentation has the advantage of high overall efficiency, but it has more stringent requirements on temperature. If in the cold season, it is relatively difficult to operate. The construction cost of the composting method is very low and the operation is simple, but after all, it is carried out in an open environment, and there will still be some peculiar smell in the process. " According to he Cheng, "the method of coal chemical industry is simple and easy, and is not limited by the season, but the treatment efficiency is about 60% to 80%, and the treatment efficiency is low for wastes with high liquid content." Although the addition of microecological agents to feed can promote animal growth, improve animal immunity and increase animal disease resistance, it is still inefficient in terms of the effect of livestock and poultry manure treatment. "

With such a dialectical analysis, how should the farm be chosen?

"cost is an important measure." He Cheng said that if the cost of pollution control is too high, the enthusiasm of enterprises will be discouraged. "like microbial fermentation, biogas tanks are essential, although the treatment efficiency is very good, but the cost of maintenance is high. In our country, composting treatment mode can be considered at present. For example, a dairy company in Tianjin uses composting to transport cow manure to a treatment plant, which is covered with a shed. This cost is the lowest. "

He Cheng also pointed out that the transportation cost of waste such as feces is also an issue to be considered. "We have discussed with German experts that waste water can be discharged through pipelines at a low cost. But chicken manure, pig manure and so on must be transported by car, which is more than the money subsidized by the state. This is the biggest problem we are facing at present, and there is no better alternative. " He Cheng said frankly.