本文選題：濕污泥 + 燒結(jié)��； 參考：《西北農(nóng)林科技大學(xué)》2015年碩士論文

【摘要】：城市污水處理廠的興建對(duì)于水污染控制有積極的作用,但如何處理處置大量的污水污泥的問(wèn)題也隨之而來(lái)。以前由于受到技術(shù)、資金等因素的影響,我國(guó)長(zhǎng)期以來(lái)只重視污水的處理,而忽視了污泥的處置。如今,國(guó)家加大了對(duì)污泥處理處置的投資力度,為我們研究新的污泥資源化利用方法提供了政策保障和資金支持。污泥建材利用尤其是污泥制磚是長(zhǎng)期以來(lái)污泥資源化研究及應(yīng)用的重點(diǎn)。但是總結(jié)發(fā)現(xiàn),眾多研究是利用干化污泥和污泥焚燒灰制磚,而污泥干化和焚燒需要消耗大量的能量。本研究的思路,就是利用濕污泥高含水率的特點(diǎn),直接將濕污泥與粘土等材料混合陳化,使混合料達(dá)到一定的濕度,成型時(shí)不需要添加或只需少量的水,采用燒結(jié)工藝制磚,固化重金屬,消滅病原微生物,同時(shí)達(dá)到減少能耗,節(jié)約水資源,無(wú)害化處置污泥的目的。我們通過(guò)對(duì)西安市四個(gè)污水處理廠脫水污泥理化性質(zhì)的檢測(cè)發(fā)現(xiàn),個(gè)別污水處理廠污泥中Cd、Zn含量較高,超過(guò)了農(nóng)用標(biāo)準(zhǔn),可以通過(guò)制作園林綠化肥和燒結(jié)制磚來(lái)進(jìn)行處置。我們以粘土和濕污泥為主體材料,結(jié)合試驗(yàn)結(jié)果,選取工程砂和煤粉為輔助摻料,其比例分別為8%和3%。在輔助摻料比例確定的情況下,我們以污泥摻量、燒成溫度、保溫時(shí)間、和成型壓力為主要因素,每個(gè)因素三個(gè)水平,進(jìn)行了正交試驗(yàn)。正交試驗(yàn)結(jié)果表明:污泥摻量對(duì)磚體抗壓強(qiáng)度、吸水率的影響遠(yuǎn)大于其他三個(gè)因素,保溫時(shí)間的影響最弱。污泥摻量20%時(shí),磚還能保持一定的抗壓強(qiáng)度和吸水性,可以作為行道磚用于人行道。通過(guò)單因素分析發(fā)現(xiàn),同一試驗(yàn)條件下,隨著污泥摻量增加,磚體抗壓強(qiáng)度逐漸減小,燒成密度逐漸降低,吸水率逐漸升高。提高成型壓力和燒成溫度有利于改善磚的抗壓性能。泛霜試驗(yàn)結(jié)果顯示,在潮濕環(huán)境下,污泥燒結(jié)磚表面沒(méi)有出現(xiàn)泛霜。凍融試驗(yàn)結(jié)果表明,污泥摻量小于24%時(shí),污泥燒結(jié)磚具有一定的抗凍性,凍融質(zhì)量損失率可以控制在2%以內(nèi)。對(duì)污泥磚燒結(jié)前后浸出液中Pb、Cd、Cr等6種重金屬濃度進(jìn)行了檢測(cè),結(jié)果說(shuō)明污泥燒結(jié)制磚具有顯著的重金屬固化作用,用作行道磚是是可行的。最終確定,當(dāng)濕污泥摻量小于24%,燒成溫度控制在1050℃左右,成型壓力20MPa,可以使污泥行道磚強(qiáng)度達(dá)到10-20 MPa,滿足國(guó)家標(biāo)準(zhǔn)《燒結(jié)普通磚》(GB5101——2003)MU10強(qiáng)度的要求。利用濕污泥制備燒結(jié)行道磚,可以消納污泥,節(jié)能環(huán)保,節(jié)約水資源和土地資源,具有良好的社會(huì)經(jīng)濟(jì)效益。污泥處置需要多元化的資源化利用方式。
[Abstract]:The construction of municipal sewage treatment plant plays a positive role in water pollution control, but the problem of how to deal with a large amount of sewage sludge is followed.In the past, due to the influence of technology, capital and other factors, our country only attached importance to the treatment of sewage for a long time, but neglected the disposal of sludge.Nowadays, the government has increased the investment in sludge treatment and disposal, which provides policy guarantee and financial support for us to study new sludge resource utilization methods.The utilization of sludge building materials, especially sludge brick making, has long been the focus of sludge resource research and application.However, it is found that drying sludge and sludge incineration ash are used to make bricks, and sludge drying and incineration require a lot of energy consumption.The idea of this study is to make use of the characteristics of high moisture content of wet sludge, directly mix wet sludge with clay and other materials, so that the mixture can reach a certain humidity, and no or only a small amount of water is needed in the molding process, and the brick is made by sintering process.Solidify heavy metals, eliminate pathogenic microorganisms, reduce energy consumption, save water resources and dispose sludge innocuously.The physical and chemical properties of dewatered sludge from four sewage treatment plants in Xi'an were examined. It was found that the content of CD ~ (2 +) Zn in the sludge of several sewage treatment plants was higher than the agricultural standard, and could be disposed of by making garden fertilizer and sintered brick.With clay and wet sludge as main materials and combined with the test results, engineering sand and pulverized coal are selected as auxiliary admixtures, the proportions of which are 8% and 3% respectively.Under the condition that the proportion of auxiliary admixture is determined, the orthogonal experiments are carried out with the sludge content, sintering temperature, holding time and molding pressure as the main factors, three levels of each factor.The results of orthogonal test show that the influence of sludge content on the compressive strength and water absorption of brick is much greater than that of the other three factors, and the influence of holding time is the weakest.The brick can maintain a certain compressive strength and water absorption when the sludge content is 20 and can be used as the pavement brick.Through single factor analysis, it was found that under the same experimental conditions, with the increase of sludge content, the compressive strength of brick body gradually decreased, the firing density gradually decreased, and the water absorption rate gradually increased.Increasing the forming pressure and sintering temperature can improve the compressive performance of brick.The results of frosting test showed that there was no frosting on the surface of sintered brick in wet environment.The results of freeze-thaw test show that when the sludge content is less than 24%, the sludge sintered brick has a certain frost resistance, and the loss rate of freeze-thaw quality can be controlled within 2%.The concentration of six heavy metals, such as Pb, CD, Cr, etc. in leachate of sludge brick before and after sintering were detected. The results showed that the sludge sintered brick had remarkable solidification effect of heavy metal, and it was feasible to use it as a walking brick.Finally, when the wet sludge content is less than 24, the sintering temperature is controlled at about 1050 鈩，

本文編號(hào)：1759145