Pretreatment effect of wastewater from cattle farm before its resource utilization

Solid-liquid separation，precipitation，ultrasonic oscillation and bio-chemical treatment methods were used to treat wastewater in cattle farm before its utilization. Wastewater were separated before entered precipitation tank and reduced 7.14% suspended solids，97.27% fecal coliform numbers and 82.51% COD contents. Effects of agent addition（ CaO and CaCN2） and ultra-sonic oscillation treatment were compared and discussed. The results showed that the increase of agent addition ratios to wastewater increased the transmittance，shortened the time to clarification，and increased the electric conductivity，decreased the total phosphorus content，but had little influence on potassium content. Addition of CaO 5 g/kg decreased fecal coliform number to 0，and increased the transmittance to over 90% after 2 days. Addition of CaCN2 5 g/kg decreased fecal coliform number to 0，and increased the transmittance to over 95% after 1 day，and increased total nitrogen content to 600 mg/kg after 3 days. While ultrasonic oscillation treatment had little influence on these detection indexes. The study suggested that wastewater from cattle farm could be resource utilization through integrative pipes of water and fertilizer locally after separated from solid wastes，treatment in precipitation tank，and addition of proper ration agent. It provided a basis for quick treatment of cattle farm wastewater before its safely resource utilization.