Research On The Technology Of Natural Biological Purity And Lime Flocculation Treatment With Sewage On Farms

In order to seek for a rapid and effective method for livestock and poultry industrial waste water treatment, two experiments were carried out to determine the optimal technological parameters of "natural biological treatment plus lime flocculation sedimentation", and to investigate the effectiveness of washing the pens by using the recycle water from this technological treatment.On the base of understanding of the properties of the livestock and poultry industrial waste water, the waste water of pig farm was chosen as the objective to illustrate the features of this kind of waste water, and then, the natural biological treatment plus lime jelling sedimentation method was adopted to process this kind of waste water. The optimal days of treatment and supplement level of lime were determined by detecting the change of pH, CODcr, TP, total bacterial count and the differences of treatment efficiency of different stages of waste water dealt with different supplement levels of lime. The effectiveness of washing the nursery by using the recycle water from natural biological treatment plus lime jelling sedimentation treatment was evaluated.1.The use of lime in waste water had a direct effect on water quality of recycle water, and the effect had something to do with the supplement level of lime,but the relationship is not linear. Lime supplemented at the level of 3‰in waste water (Fecal: urine = 1:1.5; waste: water =1:10) had good clearance effect of TP, but still had slight effect on CODcr, The lime additive had a certain effect in killing bacteria, but the effect is not obvious. When the supplement level of lime was 5‰, the pH of sewage was increased to over 12, and the clearance of CODcr, TP were 52.02%, 88.58%, and an obvious sterilizing effect was also observed. A dosage of 7‰in sewage had approached the threshold value of lime, and an increase of lime supplement in sewage had little improvement of the treatment efficiency. Thus, and the optimal dose was 5‰.2. The natural biological treatment had little effect on pH of the sewage. After natural biological treatment, a part of organics were decomposed and a number of phosphorus were used by microorganism, and resulted in decline of TP and organism in sewage. With the microbial decomposition effect, the nutrients and total bacterial count in sewage declined gradually.3. The effect of lime treatment was transient. Treated with lime in short time was effective, but the extension of liming had no notable improvement of treatment efficiency.4. The combination of both methods could lower the cost of sewage treatment and shorten the processing time, and better treatment efficiency was obtained.5. The recycle water can obviously improve the pH of the waste water, even make the pH up to about 12. And the recycle water can decrease the CODcr and TP further, the highest clearance can go up to 63.44% and 87.57% respectively. The higher the concentration is, the higher clearance will demonstrate.6. Different portion has little effect to pH and the total number of bacteria. When the concentration of the water is much lower, the CODcr and TP will be lower, but it's relative content will be much higher.The fast treatment of livestock and poultry industrial waste water by natural biological treatment plus lime sedimentation technology can get huge environmental and social benefits.