Pollution generation and its harm
In recent years, driven by the strong promotion of the animal husbandry doubling project, the animal husbandry industry in various countries has entered a stage of rapid development, and its main characteristics are: significant improvement in comprehensive production capacity, gradual optimization of the livestock and poultry industry structure, regionalization, specialization, and large-scale production development. Rapidly, but at the same time it brings serious environmental pollution risks.
• Production of livestock and poultry manure
1.solid fecal contamination
The amount of solid manure produced by livestock and poultry is related to the types of livestock and poultry, the nature of the farm, the management model, etc. The determination of the scale of solid manure treatment should be based on the actual production volume. Livestock and poultry manure contains a large amount of sodium and potassium salts. If it directly acts on farmland, excess sodium and potassium will reduce the micropores of some soils through reverse polymerization, reduce the permeability of the soil, and destroy the soil structure. Harm plants.The amount and properties of major solid pollutants produced by livestock and poultry breeding are shown in Table 1：
|
Types of livestock and poultry |
Daily excretion (kg/head) | COD(mg/kg) | NH3-N(mg/kg) | TP(mg/kg) | TN(mg/kg) | TS(mg/kg) |
| pig | 2.0-3.0 | 52000 | 3100 | 3400 | 5900 | 9400 |
| dairy cow | 20-30 | 31000 | 1700 | 1200 | 4400 | 4700 |
| beef cattle | 15-20 | 31000 | 1700 | 1200 | 4400 | 4700 |
| chicken | 0.1-0.15 | 45000 | 4800 | 5400 | 9800 | 16300 |
Note: The data in the table are statistical averages
2.wastewater pollution
Farm wastewater usually mainly consists of urine, litter (straw powder or sawdust, etc.), some or all of the remaining feces and feed residues, flushing water, and sometimes a small amount of wastewater generated during the workers' daily life and production. Excessive application in livestock and poultry breeding will cause nitrogen, phosphorus and other elements left in the soil to seep into the groundwater, which will lead to an increase in the concentration of NO2, N, and NO3 in the groundwater. If humans use it for a long time or in large quantities, it may induce cancer. Livestock and poultry breeding wastewater mainly includes urine, flushing water and a small amount of domestic sewage. The amount and properties of the main water pollutants produced by livestock and poultry breeding are shown in the following table 2:
|
Types of livestock and poultry |
Ways to clean up feces | Daily production volume (kg/head) | CODcr(mg/L) | NH3-N(mg/L) | TP(mg/L) | TN(mg/L) | PH |
| pig | Flush with water | 18 | 15600-46800 | 130-1780 | 30-290 | 140-1970 | 6.3-7.5 |
| beef cattle | Dry and clear manure | 20 | 890 | 22 | 40 | 5 | 7.1-7.5 |
| dairy cow | Dry and clear manure | 50 | 920-1050 | 40-60 | 16-20 | 57-80 | 7.1-7.5 |
| chicken | Dry and clear manure | 0.25 | 2740-10500 | 70-600 | 13-60 | 100-750 | 6.5-8.5 |
3.Air Pollution
In addition to solid feces and sewage pollution in livestock and poultry farms, air pollution within the farms cannot be ignored. The odor emitted by livestock and poultry houses mainly comes from the anaerobic decomposition of protein-containing waste. Since these gases are asphyxiating, irritating, and toxic, they will have harmful effects when they reach a certain concentration. There are many odors and harmful gases emitted by livestock and poultry farms, but the main ones are ammonia, hydrogen sulfide, phosphostin, and mercaptans. They pollute the air, causing a relative decrease in oxygen content in the air, lowering the immunity of animals and people, causing frequent respiratory diseases, and affecting the quality of livestock and poultry products.
Principles of manure treatment
1.The basic principle
a. The principles of reduction, harmlessness, resource utilization and ecology should be followed
b.The prevention of pollution from livestock and poultry breeding should follow the overall development strategy of developing circular economy, low-carbon economy, ecological agriculture and comprehensive utilization of resources.
c. The prevention and control of pollution from livestock and poultry breeding should focus on prevention, combine prevention with control, combine economy with practicality, and combine management measures with technical measures.
2.Technical principles
a.Scientific planning and rational layout
b. Develop clean breeding.
c. Comprehensive utilization of resources.
d. Combination of planting and breeding, ecological cycle.
e. Strict environmental supervision.
Contact Person: Richard
Tel: 86-18239972076
Fax: 86-371-65002168
