The Removement And Disposal Of The Heavy Metals From The Pig Manure

Our previous studies have found that pig manure is rich in nutrients such as N, P, and K, which can be used as organic fertilizer economically and practically. But now with the development of animal husbandry, some unscrupulous merchants began to add various additives to pig feed, which have heavy metals exceeding badly, thus directly use as organic fertilizer will cause heavy metal pollution to the farmland. If we want to use pig manure as organic fertilizer, and solve the problems of heavy metals pollution of land, the pig manure should be taken pollution-free processing before entering the field. Therefore, the removal and processing of heavy metals in pig manure is particularly important. Based on the study of removal and processing of heavy metals in pig manure, the main research results can be summarized as follows:the content of Cu、Zn and Cd in pig manure; the removal rate and influencing factors of Cu、Zn and Cd in the pig manure by inorganic acid;the removal rate and influencing factors of Cu、Zn and Cd in the pig manure by ultrasound; the removal rate of Cu、Zn and Cd in the pig manure by ultrasound combined with inorganic acid;subsequent wastewater recycling;different forms of heavy metals and the N, P, K content in pig manure before and after the processing is analyzed.The results show that inorganic acid could remove the Cu and Zn in the pig manure, and with the increase of the amount of inorganic acid and reaction time, the removal rate of Cu and Zn also increased. The inorganic acid was added to adjust pH to0.70, the removal rate of Cu can reach58.7%after3h; the removal rate of Zn can reach81.8%;the removal rate of Cd can reach43.5%. Ultrasound could also help remove the Cu and Zn in the pig manure, with the increase of ultrasonic frequency and time, the removal rate of Cu and Zn has increased; in40KHZ, the removal rate of Cu can reach87.4%after90min under ultrasound, the removal rate of Zn can reach76.4%,and the removal rate of Zn can reach85.3%. The removal rate of Cu and Zn in the pig manure by ultrasound combined with inorganic acid is higher than the single use of the two.The N, P, K content in pig manure after the processing is decrease. The decrease of N is under20%; the decrease of P and K is aboutr60%.