【摘要】：DHA是一種對(duì)人體心血管系統(tǒng)、神經(jīng)系統(tǒng)及抗炎免疫系統(tǒng)非常有益的不飽和脂肪酸,也是人類(lèi)健康不可或缺的營(yíng)養(yǎng)要素。江蘇某生物科技有限公司采用發(fā)酵工藝生產(chǎn)DHA系列產(chǎn)品,生產(chǎn)過(guò)程中產(chǎn)生一定量高濃度難降解有機(jī)廢水,廢水中COD濃度為53000~54000mg/L,BOD5/COD為0.09~0.1,可生化性能極差,為此試驗(yàn)采用“鐵炭微電解—UASB—MBR”組合工藝,考察各系統(tǒng)及組合工藝對(duì)COD濃度的去除變化,獲取DHA廢水處理的最佳運(yùn)行參數(shù)。試驗(yàn)采用鐵炭微電解法對(duì)DHA廢水進(jìn)行預(yù)處理。由正交試驗(yàn)可得,影響鐵炭微電解反應(yīng)COD去除效率的因素為鐵炭比pH值反應(yīng)時(shí)間攪拌強(qiáng)度。根據(jù)單因素優(yōu)化試驗(yàn)可得,反應(yīng)最佳運(yùn)行條件為:pH為3,反應(yīng)時(shí)間為4h,鐵炭比為3:1,攪拌強(qiáng)度為300r/min。在最佳運(yùn)行條件下,鐵炭微電解對(duì)DHA廢水的COD去除率為45%左右,BOD5/COD值由0.1提升至0.31,很大程度提高了DHA廢水的生化性,為后續(xù)的生化處理創(chuàng)造了良好條件。試驗(yàn)采用UASB反應(yīng)器對(duì)DHA廢水進(jìn)行厭氧處理。經(jīng)過(guò)67天的調(diào)試運(yùn)行,反應(yīng)器容積負(fù)荷達(dá)到8kgCOD/(m3·d),并可保持穩(wěn)定運(yùn)行,出水COD濃度為1500mg/L左右,COD去除率為81%左右。試驗(yàn)研究了不同容積負(fù)荷對(duì)COD去除效率的影響。研究發(fā)現(xiàn),當(dāng)容積負(fù)荷大于8kgCOD/(m3·d),COD去除率明顯下降,出水水質(zhì)極不穩(wěn)定。此外,考慮到實(shí)際工程中因溫控裝置損壞導(dǎo)致反應(yīng)器內(nèi)水溫降低,本試驗(yàn)還研究了UASB反應(yīng)器內(nèi)水溫驟降對(duì)COD去除率的影響。研究發(fā)現(xiàn),當(dāng)反應(yīng)器內(nèi)水溫由37℃驟降至30℃時(shí),COD去除率逐漸降低,但隨著反應(yīng)時(shí)間的增長(zhǎng),COD去除率有上升趨勢(shì)。水溫由驟降30℃至20℃時(shí),出水水質(zhì)較差,COD去除率僅為60%左右。故采用UASB反應(yīng)器處理DHA廢水時(shí),應(yīng)控制容積負(fù)荷為8kgCOD/(m3·d),并保證反應(yīng)器水溫為30℃以上。試驗(yàn)采用MBR系統(tǒng)對(duì)DHA廢水進(jìn)行好氧處理。經(jīng)調(diào)試,好氧生物系統(tǒng)容積負(fù)荷可達(dá)1.5kgCOD/(m3·d)。在容積負(fù)荷為1.5kgCOD/(m3·d),HRT為24h時(shí),MBR膜出水水質(zhì)良好,COD濃度為80mg/L左右,去除率大于94%;氨氮濃度為5mg/L以下,去除率為96%以上。通過(guò)實(shí)驗(yàn)室小試結(jié)果可知,采用“鐵炭微電解—UASB—MBR”組合工藝可有效去除DHA廢水中有機(jī)物濃度,出水水質(zhì)穩(wěn)定,滿足《污水排入城鎮(zhèn)下水道水質(zhì)標(biāo)準(zhǔn)》(CJ 343-2010),可為DHA廢水處理實(shí)際工程提供借鑒。
[Abstract]:DHA is a very beneficial unsaturated fatty acid to human cardiovascular system, nervous system and anti-inflammatory immune system. It is also an indispensable nutritional element for human health. A certain amount of high concentration refractory organic wastewater was produced in a series of DHA products produced by a certain biotechnology company in Jiangsu Province. The concentration of COD in the wastewater was 53000,54000mg / L Bod / L = 0.09 / 0. 1, and the biodegradability was extremely poor. In order to obtain the best operation parameters of DHA wastewater treatment, the combined process of "iron-carbon micro-electrolysis-UASB-MBR" was adopted to investigate the removal and variation of COD concentration in each system and combination process. Iron-carbon micro-electrolysis was used to pretreat DHA wastewater. According to the orthogonal test, the factors influencing the removal efficiency of COD in iron-carbon microelectrolysis reaction are the stirring intensity of reaction time at the pH value of iron-carbon ratio. According to the single factor optimization test, the optimum operating conditions were as follows: ph 3, reaction time 4 h, ratio of iron to carbon 3: 1, stirring intensity 300 r / min. Under the optimum operating conditions, the removal rate of COD from DHA wastewater by iron-carbon microelectrolysis is about 45%, the value of BOD5 / COD is increased from 0.1 to 0.31, which greatly improves the biochemical properties of DHA wastewater and creates good conditions for subsequent biochemical treatment. UASB reactor was used for anaerobic treatment of DHA wastewater. After 67 days of commissioning, the volumetric load of the reactor reached 8kgCOD/ (m ~ 3 d),) and maintained stable operation, and the COD removal rate of effluent was about 81% when 1500mg/L concentration was about. The effect of different volume loading on the removal efficiency of COD was studied. It was found that when the volumetric load was greater than 8kgCOD/ (m3 d), the removal rate of COD decreased obviously, and the effluent quality was very unstable. In addition, the effect of sudden drop of water temperature in UASB reactor on the removal rate of COD was also studied in view of the decrease of water temperature in the reactor due to the damage of temperature control device in practical engineering. It was found that the COD removal rate decreased gradually when the water temperature in the reactor dropped from 37 鈩，

本文編號(hào)：2166890