During years of drought, the significance of irrigating fields with water becomes evident in enhancing crop yields. The sustainable development of agricultural production relies on the vigorous development of irrigation. In recent years, Shuangcheng City has focused on promoting water-saving micro-irrigation to improve agricultural production conditions and ecological environment. It has developed “two high and one excellent” agriculture and water-saving agriculture, improved land utilization rates and replanting indices, adjusted agricultural planting structures, enhanced the overall quality and efficiency of agriculture, and increased farmers’ income.
This initiative has strengthened collective economic strength, increased fiscal revenue, laid a foundation for a new leap forward in agricultural economy, promoted the transformation of traditional agriculture into modern agriculture, and accelerated the pace of agricultural modernization. The application of sand media filters in micro-irrigation engineering helps improve the efficiency of micro-irrigation projects and ensures stable and increased agricultural yields.
I. Structure and Working Principle of Filters
Structure: Sand media filters utilize sand and gravel as a medium for filtration. They mainly consist of tank inlet, outlet, drain outlet, sand bed, and auxiliary components such as inlet pressure regulating valve, drain valve, flush valve, and pressure gauge.
Working Principle: The sand media filter is designed with a steel cylindrical tank and a graded sand bed with particle sizes ranging from 1.5 to 4.0 mm. Water containing impurities enters the tank and passes through the sand bed, where the filtration process occurs through the tortuous pores between the filtration media layers. Sediments are trapped within the sand bed filter unit, while filtered water passes through the sand bed filter unit into the secondary screen mesh filter. During operation, manual cleaning or backwashing is required when the pressure difference exceeds the allowable maximum pressure drop.
II. Performance of Sand Media Filters
Sand media filters are primarily used for filtering water sources such as reservoirs, ponds, canals, and rivers containing organic matter and sediments, especially suitable for handling algae, floating debris, and other impurities. Depending on the type of irrigation equipment chosen, sand media filters are generally used in series with screen mesh filters or disc filters.
III. Advantages of Micro-Irrigation Sand Media Filters
- Dry Field Crop Micro-Irrigation: This method involves connecting low-pressure hoses to sand media filter tanks for micro-irrigation in dry field crops. Micro-irrigation holes are spaced every 30 cm along the hose, and irrigation is conducted while the equipment moves. This method is cost-effective, with each set costing less than 42,000 yuan. It is convenient to use, simple to operate, saves water by 23% compared to furrow irrigation, eliminates the need for canal repairs and ridge construction, increases land utilization, and saves labor and time. It is suitable for hilly and sloping land. With an investment of 1.5 million yuan, purchasing 28 sets of micro-irrigation equipment can cover an area of 280 hectares.
- Vegetable Micro-Irrigation: Micro-irrigation for vegetables can increase greenhouse temperatures by 1°C to 3°C, reduce the occurrence of pests and diseases, and improve vegetable yield and quality. It is currently the best water-saving and efficient irrigation method and has great development prospects with increased investment.
