Biogas slurry solid-liquid separation treatment method

Abstract

The invention discloses a biogas slurry solid-liquid separation treatment method. A conditioner is adopted to transfer part of polar insoluble substances in biogas slurry from a solid-liquid phase toan organic phase, so that the stability of an original colloid system of the biogas slurry is reduced, and the solid-liquid separation performance of sludge is improved. Furthermore, the conditioner is effectively recycled and cyclically utilized. The method comprises the following steps: mixing biogas slurry with a conditioner, and carrying out stirring extraction reaction; and carrying out solid-liquid separation on biogas slurry through mechanical centrifugation. Effective recovery of the conditioner in supernatant and biogas residues after centrifugation is achieved, and then cyclic utilization of the conditioner is completed while the solid content of the biogas residues is increased and the SS of effluent is reduced. Finally, the SS of the effluent is lower than 600mg/L, the solventrecovery rate is higher than 90%, and the moisture content of the mud cake is lower than 60%. According to the method, the consumption of a coagulation/flocculation conditioning agent in a traditionalbiogas slurry solid-liquid separation process is reduced, the energy consumption in the biogas residue incineration treatment process is also reduced, and the method has important social and environmental benefits and wide market application prospects.

Description

technical field [0001] The invention belongs to the technical field of environmental protection, and relates to a technical method for high-efficiency solid-liquid separation treatment of biogas slurry for recycling conditioners. Background technique [0002] Biogas slurry is an inevitable product of organic food waste fermentation and treatment. It carries a large number of pathogenic bacteria, heavy metals and toxic organic pollutants. If it is not properly disposed of, it will cause serious environmental pollution risks. With the vigorous promotion of the national garbage classification policy, wet garbage is collected separately. Due to its perishable and high water content, it is no longer possible to be sent to landfills with other garbage as before, or sent to Garbage incineration plant burning. Therefore, a large amount of wet garbage produced poses a serious challenge to the prevention and control of environmental pollution and the sustainable utilization of social...

AI Technical Summary

Problems solved by technology

Furthermore, incineration has gradually become the development direction of solid waste final disposal in my country due to its significant benefits of reduction, stabilization, and energy conversion. However, the addition of polyaluminum chloride (PAC) and polyferric chloride (PFC) to The introduction of a large amount of chloride ions into the sludge aggravates the risk of dioxin formation in the biogas residue incineration process, Fe 3+ The introduction of biogas slurry treatment equipment will cause corrosion. The above defects seriously limit the sustainable application of traditional mixing / flocculation conditioners in biogas slurry solid-liquid separation + incineration process

In addition, for the biogas slurry solid-liquid separation process, quicklime is widely used as a coagulation conditioning agent, but the dosage usually reaches 10-15wt.% of the wet weight of the sludge, and the dosage is high, the capacity increase ratio is large, Adjusting the pH value of biogas slurry to alkaline has become the main factor that restricts the subsequent resource utilization and treatment efficiency of biogas slurry by traditional coagulation conditioners

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