A combined process for treating heavy metal content in biogas slurry for watering tea gardens

Abstract

The invention discloses a combined process for treating the heavy metal content of the biogas slurry for watering tea gardens. The heavy metal content in the biogas slurry is removed step by step by means of step-by-step implementation. Specifically, lead ions are removed by adding ferrous sulfate Subsequent addition of plant ash can not only adjust the pH value, make the pH gradually increase from acidity to the range of 7-9, gradually precipitate heavy metal ions such as nickel, chromium, zinc, etc., but also increase the potassium content in the biogas slurry, and promote the tea tree to potassium Absorption, and the plant ash in the biogas slurry is flocculent, after the sediment appears, it combines with the sediment, which is conducive to the deposition of the sediment and facilitates filtration; finally, quicklime is used to adjust the pH, which can further increase the pH value for the removal of Copper ions create conditions. After adjusting the pH several times, it is applied in the tea garden, which not only achieves the purpose of removing heavy metal ions, but also can initially improve the acidic soil of the tea garden, and prevent the tea garden soil from being too acidified to hinder the growth of tea trees.

Description

technical field [0001] The invention belongs to the technical field of resource and environment protection, and in particular relates to a combined process for treating heavy metal content in biogas slurry for watering tea gardens. Background technique [0002] With the development of the livestock and poultry breeding industry, my country's livestock and poultry breeding generally presents the characteristics of a large amount of breeding and a large amount of manure generated. Biogas projects have become the mainstream method for resourceful and harmless treatment of livestock and poultry breeding manure. As a high-quality and efficient organic fertilizer, biogas slurry is rich in organic matter, nitrogen, phosphorus, potassium and other beneficial mineral elements. Farmland utilization is the most economical and effective treatment method. [0003] In order to prevent livestock and poultry diseases, improve feed utilization and promote animal growth, a large number of hea...

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Problems solved by technology

[0005] However, using cheap and easy-to-obtain agricultural wastes to adsorb heavy metals in biogas slurry will reduce the content of heavy metals, but since the adsorbate itself has no selectivity, while adsorbing heavy metals in biogas slurry, due to multi-stage adsorption, the concentration of heavy metals in biogas slurry The organic matter content is also adsorbed, especially the organic matter content that contains a lot of nutrients but is insoluble in the biogas slurry. After repeated adsorption, it remains in the adsorbate, which cannot achieve effective recycling, resulting in a huge waste of resources.

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