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本文对重庆地区沼气肥的基本性状、养分物质含量、毒性重金属及其污染状况进行了研究。结果表明,沼气肥的pH值范围为中性到微碱性。沼气肥养分和重金属含量及变异主要受发酵原料的影响。沼液全量和水溶性氮磷钾养分平均含量均以K>N>P,沼渣则以P高于N、K。沼液的中、微量元素平均含量为Ca>Mg>Fe>Zn>Cu>Mn,沼渣则为Ca>Fe、Mg、Mn>Cu、Zn。沼液毒性重金属的平均含量为全As>Cr>Cd>Pb>Hg,而沼渣则为全Cr>As>Pb>Cd>Hg。沼气肥重金属含量的变异很大,以猪粪发酵而成的沼气肥(沙坪坝区)毒性重金属含量(除As外)均低于以猪粪+农作物废弃物为发酵原料的沼气肥(涪陵区),且毒性重金属的变异也较小。除Pb外沼液毒性重金属均存在不同超标现象,并以As较严重。沼渣的毒性重金属含量均在允许范围内,农用安全性高。
In this paper, the basic characteristics of biogas fertilizer in Chongqing, nutrient content, toxic heavy metals and their pollution status were studied. The results show that the biogas fertilizer pH range from neutral to slightly alkaline. Biogas nutrient and heavy metal content and variation are mainly affected by the fermentation of raw materials. The total amount of biogas slurry and the average content of water-soluble NPK nutrients were K> N> P, while that of biogas residue was higher than that of N and K. The average content of trace elements in biogas slurry was Ca> Mg> Fe> Zn> Cu> Mn, while that of biogas residue was Ca> Fe, Mg and Mn> Cu and Zn. The average content of toxic heavy metals in biogas slurry was As> Cr> Cd> Pb> Hg, while biogas residue was Cr> As> Pb> Cd> Hg. The content of heavy metals in biogas fertilizer is very large. The content of toxic heavy metals (excluding As) of biogas fertilizer (Shapingba District) fermented by pig manure is lower than that of biogas fertilizer (Fuling District) using pig manure + crop wastes as raw materials for fermentation. , And the variation of toxic heavy metals is also small. In addition to Pb outside the biogas toxicity of heavy metals there are different over-standard phenomenon, and As more serious. Biogas residue toxic heavy metal content are within the allowable range, agricultural safety.