Method for extracting ferroaluminum from chemical sludge for preparing polyaluminum ferric chloride flocculating agent

Abstract

The invention discloses a method for extracting a ferroaluminum component from chemical sludge for preparing a polyaluminum ferric chloride flocculating agent, which comprises the following steps of: diluting chemical coagulated sludge with water, heating and agitating, adding concentrated hydrochloric acid until the pH value of the solution is 3.0-4.0, standing at a normal temperature, adding H2O2, continuously agitating, conventionally filtering to obtain filter residue, drying at a constant temperature in a constant-temperature drying box and cooling to the normal temperature to obtain dried sludge ash; adding the pretreated dried sludge ash and hydrochloric acid to a four-neck flask, agitating, diluting with distilled waterg, heating, adding a sodium sulfide solution, agitating, ageing at a room temperature, adjusting the pH value of the reaction liquid by using a sodium hydroxide solution and filtering by using a microfilter to obtain a dark red and brown transparent liquid product. By the invention, environmental pollution can be controlled and treated from a source, the reduction and the harmless treatment of the sludge can be carried out during the resource utilization of the sludge, the purposes of the waste treatment by the waste and clean production are achieved, the gap of the resource utilization of the chemical sludge is filled, and obvious economic, social and environmental benefits can be generated.

Description

technical field [0001] The invention relates to a method for extracting aluminum and iron components from chemical sludge and using the same to prepare a polyaluminium-ferric chloride flocculant. Background technique [0002] With the rapid development of my country's social economy, the discharge of urban sewage and industrial wastewater has increased year by year, and the number of sewage treatment projects has doubled. At the same time, the sludge in sewage treatment plants has also doubled. Sludge from sewage treatment plants contains a large amount of flocs, which contain a large amount of water, rich organic matter and nutrients such as N, P, and K, as well as harmful substances such as heavy metals and pathogenic bacteria. Especially in the process of sewage chemical coagulation strengthening primary treatment, after adding composite polyaluminum iron inorganic polymer flocculant [such as polyaluminum ferric chloride (PAFC)], the chemical sludge produced also contains...

AI Technical Summary

Problems solved by technology

my country's sewage treatment is still in the stage of heavy water treatment and light sludge treatment. A large amount of untreated or unstabilized sludge is discharged randomly, which not only causes serious secondary pollution to the environment, but also is a serious waste of resources. Does not meet the requirements for clean production in industrial processes

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