sm踩踏调教免费调教视频_久久福利无码少妇被窝av_欧美日韩激情视频_欧美日韩精品在线国产_亚洲AV永久无码精品导航_免费观看的A 级毛片的网站_2020国产特级黄色自拍_先锋影音资源亚洲天堂_中韩欧美视频二区_91精产国品一二三区在线

  • 2021年8月10日
    vch11602707
      導(dǎo)  讀     在污水處理過程中,總會遇到各種各樣的污水問題,比如:COD、氨氮、TP等指標(biāo)不達(dá)標(biāo),污泥膨脹、浮泥、活性微生物死亡等,當(dāng)我們遇上這些問題的時候,不妨拿出這篇文章進(jìn)行對照解決問題。     一、出水水質(zhì)   1、有機物   影響有機物處理效果的因素主要有:   (1)營養(yǎng)物 一般污水中的氮磷等營養(yǎng)元素都能夠滿足微生物需要,且過剩很多。但工業(yè)廢水所占比例較大時,應(yīng)注意核算碳、氮、磷的比例是否滿足100:5:1。如果污水中缺氮,通??赏都愉@鹽。如果污水中缺磷,通常可投加磷酸或磷酸鹽。   (2)pH 污水的pH值是呈中性,一般為6.5~7.5。pH值的微小降低可能是由于污水輸送管道中的厭氧發(fā)酵。雨季時較大的pH降低往往是城市酸雨造成的,這種情況在合流制系統(tǒng)中尤為突出。pH的突然大幅度變化,不論是升高還是降低,通常都是由工業(yè)廢水的大量排入造成的。調(diào)節(jié)污水pH值,通常是投加氫氧化鈉或硫酸,但這將大大增加污水處理成本。   (3)油脂 當(dāng)污水中油類物質(zhì)含量較高時,會使曝氣設(shè)備的曝...
  • 2021年8月9日
    vch11602707
    1、為什么需要預(yù)過濾器? 除病毒過濾在生物制藥的過程中是一個關(guān)鍵步驟。然而即使是層析純化后的樣品,蛋白聚體和雜質(zhì)也會限制除病毒過濾器的載量,導(dǎo)致過濾膜面積增加。 除病毒濾器堵塞主要是基于以下原因: 除病毒膜孔需要透過蛋白攔截病毒,對膜孔徑要求較高。 細(xì)小病毒直徑約為18-24nm,單抗分子約為8-12nm。聚體將導(dǎo)致膜孔堵塞。 隨著蛋白濃度提高,蛋白單體產(chǎn)生聚體的幾率變大,增加了堵塞除病毒濾器的風(fēng)險。 蛋白不穩(wěn)定導(dǎo)致結(jié)構(gòu)改變或碎片,以及其他未分離雜質(zhì),也有可能導(dǎo)致堵塞。 對樣品進(jìn)行預(yù)過濾處理能夠有效的去除這些堵膜因素,因此許多工藝會加入預(yù)過濾器來提高除病毒過濾器的載量從而降低工藝成本。通過研究和大量實踐表明,增加預(yù)過濾器后的除病毒濾器的平均載量能比未增加提高2倍以上。 2、如何選擇預(yù)過濾器 預(yù)濾器的選擇需要根據(jù)樣品特性和工藝需求來決定。一般對于去除單抗工藝中的聚體來說,吸附比基于分子大小的尺寸排阻的預(yù)過濾方式更有效。 默克提供了表面改性膜和吸附型深層濾器這兩種預(yù)過濾器,針對于不同的需求,達(dá)成穩(wěn)健的工藝目的。 Vire...
  • 2021年8月6日
    vch11602707
    Recently, local cases have been confirmed in many places. As of 24:00 on August 3, 2021, 31 provinces (autonomous regions, municipalities directly under the Central Government) and the Xinjiang Production and Construction Corps reported 71 new local confirmed cases and 15 new asymptomatic infections.The General Office of the National Health Commission released the Technical Guidelines for the Prevention and Control of Novel Coronavirus Infection (Second Edition). What guiding significance does it have for the current normalized epidemic prevention and control? Lan Guaping, the infection control plus operation team, brought "A look at the current normalized prevention and control of the epidemic from the second edition of prevention and control guidelines."...
  • 2021年8月5日
    vch11602707
    Viral filtration is a common step in the production of many biologics, and viral contaminants of different particle sizes can be removed depending on the pore size of the filter. Integrity Testing (IT) is a way to confirm the retention capacity of a filter. Integrity testing before use can confirm whether the filter has been damaged during transportation and whether the filtration system is set up correctly. Post-use testing can confirm the integrity of the membrane cassette to confirm the effectiveness of the virus removal process. This article supplements the Viresolve® Pro Solution User Guide and is designed to minimize the risk of integrity test failure. Describes the key influencing factors of using automated integrity testers, troubleshooting methods and corresponding measures after test failure. The pre-filters Viresolve® Pro Shield and Viresolve® P...
  • 2021年8月4日
    vch11602707
    The popularity of paper bags is not the result of environmental protectionFriends, the "plastic restriction order" has been implemented in China for 12 years. Are you surprised? After 12 years of hard work, plastic bags are no longer flying blatantly on the streets.The author believes that everyone has a common understanding: plastic bags pollute the environment, and most people think that using paper bags is to protect the environment. For breakfast, people subconsciously feel that paper bags are more environmentally friendly than plastic bags. So are paper bags really as environmentally friendly as people think? Beautified paper bag Paper bags are considered environmentally friendly because of their reputation for being highly recyclable and easy to decompose. But if we look at the life cycle of paper bags, you will find that it is not that beautiful.Life cycle: the entire ...
  • 2021年8月4日
    vch11602707
    簡介 水處理廠在為消費者生產(chǎn)安全飲用水的過程中,需要監(jiān)測多種水質(zhì)參數(shù),包括水中的pH值、總有機碳TOC、UV 254吸光度。TOC和UV 254吸光度是評估水中有機物(OM,Organic Matter)含量和質(zhì)量的重要參數(shù)。   TOC和紫外吸光度都取決于水中的有機物。正確了解兩者的關(guān)系,就能避免錯誤解讀水質(zhì)監(jiān)測數(shù)據(jù)。本文討論了這兩個參數(shù)間的關(guān)系,以及它們在水處理工藝和合規(guī)性方面的應(yīng)用。文中使用的Sievers® M5310 C分析儀為TOC分析提供了最佳解決方案,實際樣品數(shù)據(jù)也證明了此款分析儀的實用性。   技術(shù)比較 有機物  有機物是指水中的各種化合物的混合,包括自然物質(zhì)(即植物、動物、微生物)降解后產(chǎn)生的天然有機物(NOM,Natural Organic Matter),以及生活污水帶來的有機物1。盡管有機物本身對人體健康無害,但它會與氯反應(yīng)產(chǎn)生消毒副產(chǎn)物(DBP,Disinfection Byproducts)。消毒副產(chǎn)物對人體健康有害,因此法規(guī)要求水處理廠在處理水時控制有機物的濃度2,3。   TOC和紫外吸光度在有機物分析中的應(yīng)用 TO...