A method for pretreatment and strengthening anaerobic fermentation of excess sludge to produce acid
An anaerobic fermentation and residual sludge technology, which is applied in chemical instruments and methods, fermentation, biological sludge treatment, etc., can solve the problems of unsatisfactory dissolution and hydrolysis of organic matter, shorten the time of fermentation acid production, and save energy consumption for acid production and cost, the effect of improving the effect
Active Publication Date: 2019-11-08
HARBIN INST OF TECH
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Problems solved by technology
However, there is still a small amount of methanation reaction in anaerobic fermentation of sludge pretreated with free nitrous acid
Rhamnolipid is an efficient, environmentally friendly and cheap biosurfactant, which can effectively inhibit the activity of methanogens in anaerobic fermentation, but it is not satisfactory in promoting the dissolution and hydrolysis of organic matter
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[0021] In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, the following will describe in detail with reference to the drawings and specific embodiments.
[0022] The invention provides a method for pretreatment and strengthening the anaerobic fermentation of excess sludge to produce acid, which is characterized in that it is combined with free nitrous acid and rhamnolipid pretreatment, and the steps of the method are as follows:
[0023] Step 1. Wash the sludge three times with tap water, then remove the supernatant after standing still, and keep the sludge for later use;
[0024] Step 2, using free nitrous acid to pretreat the sludge; produced by the nitrosation reaction of anaerobic digestion liquid, it is a renewable and low-cost chemical substance, which can effectively promote the dissolution and hydrolysis of sludge;
[0025] Step 3, adding rhamnolipids to the sludge after free nitrous acid pretreatm...
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The invention provides a method for adopting pretreatment to reinforce anaerobic fermentation of excess sludge to produce acid. The pretreatment is jointly conducted by free nitrous acid and rhamnose. The method comprises the first step of using tap water to wash sludge for three times, conducing standing to remove supernatant liquid, and leaving the sludge for standby application; the second step of using free nitrous acid to conduct pretreatment on the sludge; the third step of adding rhamnose into the sludge which is pretreated by free nitrous acid to be subjected to anaerobic fermentation to produce volatile fatty acid. Time for optimal fermentation acid production is sharply shortened, and energy consumption and cost in acid production are greatly saved; the obtained volatile fatty acid mainly comprises propionic acid and acetic acid, fermentation liquor rich in acetic acid and propionic acid can be added into sewage as an additional carbon source so as to improve nitrogen and phosphorous removal effects, and thus the method has certain reference value in reducing cost in excess sludge resource utilization and in improving a returning rate.
Description
technical field [0001] The invention relates to the field of resource utilization of organic solid waste, in particular to a method for combined pretreatment of free nitrous acid and rhamnolipid to strengthen the anaerobic fermentation of excess sludge to produce acid. Background technique [0002] Sewage treatment plants at home and abroad mostly use activated sludge technology, but this technology will inevitably produce a large amount of excess sludge, and the cost of its stabilization and reduction has reached 60% of the operating cost of the entire sewage treatment plant. Improper treatment and disposal of excess sludge will cause serious environmental problems, such as polluting water, soil, air, etc., and thus threaten human health. Treating excess sludge through anaerobic fermentation can not only reduce the secondary pollution caused by sludge to the environment, but also realize the recovery of resources. The volatile fatty acids produced can be used as an excellen...
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IPC IPC(8): C02F11/04C12P7/52C12P7/54C02F3/34
CPCC02F3/34C02F11/04C02F2101/105C02F2101/16C02F2305/06C12P7/52C12P7/54
Inventor 郭婉茜吴清莲任南琪雒海潮杜鹃山郑禾山冯骁驰银仁莉
Owner HARBIN INST OF TECH