规模化沼气工程总挥发酸与碳酸氢盐自动滴定装置

为及时有效地监测和预警厌氧发酵系统的运行稳定性,根据Nordmann滴定法的原理,设计了一种沼气工程厌氧发酵液总挥发酸(VFA)质量浓度和碳酸氢盐(TIC)质量浓度自动滴定装置。本装置以Lab VIEW为平台,可精确测定厌氧发酵液的VFA质量浓度和TIC质量浓度,并能够实现p H计自动标定、自动滴定与补液、生成实时滴定曲线、数据处理与存储等功能。利用该装置对人工配制的混合模拟样品溶液和实际沼气工程的猪粪厌氧发酵液进行滴定试验,结果表明:测定混合模拟样品溶液和实际厌氧发酵液VFA质量浓度和TIC质量浓度的相对标准偏差均在5%以内,结果重复性好,准确度和精密度均比手动滴定法高,可有效避免手动滴定人为误差,提高工作效率,降低劳动强度;装置在连续运行15 h条件下测定结果稳定,运行性能良好,该装置在沼气工程监测和预警方面具有推广价值。     

纤维填料在上流式厌氧污泥床过滤器中的作用及特点

合成纤维填料一种孔隙率大，比表面积大，价廉耐用的新型填料。它作为不同规模的上流式厌氧污泥床过滤器（ＵＡＳＢ＋ＡＦ）的滤层填料，在处理高浓度有机废水的试验和生产运行过程中均显出突出的优点，纤维填料挂膜性能好，膜活性较高，并具有阻截污泥的作用，纤维填料的设置还改善了反应区上部的水流状态，因而，从整体上提高了反应器的性能。     

高硫废水厌氧消化中硫酸盐抑制解除方法的研究

本文采用物理化学和砂氧消化等手段，对含以有机废水厌氧消化中硫酸盐抑制的解除方法进行了研究。采用投加以铁盐为主手复合脱硫剂ＨＳ－１，糖蜜酒精废水厌氧处理小试运行结果为，有朵负荷稳定在８．０ｇＣＯＤ／（Ｌ．ｄ）以上，容积产气率在３Ｌ／Ｌ．ｄ）以上，ＣＯＤ去除率为７５－７８％，达到稳定运行的效果。沿气中Ｈ２Ｓ含量在１０ｍｇ／ｍ＾２以下，低于城市用煤气标准（２０ｍｇ／ｍ＾２）。     

厌氧同时反硝化产甲烷工艺研究进展

近年来,厌氧废水处理工艺的功能在原有单纯去除有机物的基础上,得到了进一步的扩展。本文介绍了厌氧同时反硝化/产甲烷工艺的原理、技术开发与应用实践,并对其应用前景进行了展望。根据我国现阶段国情,高效低耗、操作简单、易于管理的厌氧同时反硝化/产甲烷工艺是今后高含氮有机废水处理的发展方向。     

厌氧颗粒污泥膨胀床(EGSB)反应器处理生活污水中试研究

采用规模为240 m3.d-1的厌氧颗粒污泥膨胀床(EGSB)反应器对生活污水进行研究。试验结果表明:采用此系统处理生活污水,出水水质良好。COD的去除率在73%~90%之间,出水的COD值小于70 mg.L-1,SS的去除率在70%~95%之间,停留时间为2 h的产气率在1.26 m3.m-3d-1,出水的氨氮、乙酸值比进水的高;硝酸根离子出水值比进水值低。     

薯干酒精废醪厌氧消化添加剂的研究

本试验采用正交试验法,研究了薯干酒废酸醪厌氧消化添加剂的组分和浓度范围。在批量发酵中,这种复合添加剂使产甲烷量增加12.65％,氢化酶活力提高40.11％.2.5升UASB—AF消化器的半连续运行中,有机负荷在4.60～19.60gCOD/L·d范围内,该添加剂使池容产气率增加31.53％～70.40%,COD去除率增加30.75％～89.33％,甲烷含量增加13.12％～29.07％。出水碱度与总酸之比值,试验柱为2.68～12.50,对照柱为1.03～4.78。两个有效容积各400m~3UASB—AF沼气池,相同条件下并列运行,试验池优于对照池,运行11天和25天的氢化酶活力分别提高13.84％和25.87％,一次性启动成功。     

先进实用的污水生物处理新技术研究

随着我国城市化进程加快,未经处理的小城镇污水排放量急剧增加,构成对水环境的严重威胁。以厌氧生物处理为主流工艺(HABR)、好氧生物处理为后续工艺的新技术,投资省、运行费用低、处理效果好、便于管理,适合在小城镇推广应用。本文概述了污水处理技术现状,介绍了组合式折流板厌氧反应池(HABR)及其中试研究。     

Effect of organic manure on organic phosphorus fractions in two paddy soils

We investigated the transformation of the organic P fractions from organic manure in two paddy soils (Ultisol, Entisol) and the influence of organic manure or cellulose on organic P under anaerobic conditions. The results obtained from the P fractionation experiment indicated that during the incubation labile and moderately labile organic P fractions increased in the Ultisol and decreased in the Entisol, which might be related to the difference in the organic matter content of both soils. Immediately after the application of organic manure, a large part of labile and moderately labile organic P supplied with the manure was transformed into moderately resistant organic P, possibly Ca- or Mg-inositol P were transformed into Fe-inositol P. During anaerobic incubation, the labile forms of organic P in the soils treated with organic manure were increased along with the incubation period in the first 4 weeks. The change in the moderately labile fraction was dramatic. It increased sharply in the first 2 weeks, then decreased, which was more pronounced in the soils treated with pig faeces. The moderately resistant fraction decreased during the whole incubation period. This indicated that under anaerobic conditions, the moderately resistant fraction can be transformed into labile and moderately labile organic P fractions, perhaps as Fe³⁺-inositol P is reduced to Fe⁺²-inositol P. Cellulose as an organic substrate had an increasing effect on organic P, especially when it was combined with inorganic P. Therefore, it is suggested that the application of inorganic P fertilizer combined with organic manure may be an effective way of protecting inorganic P against intensive sorption in soils.     

Anaerobic reoxidation of Mn2+, Fe2+, S0 and S2– in submerged paddy soils

Anaerobic reoxidation of reduced products in paddy soils was investigated. Ferrous iron (Fe²⁺) and monosulfide ion (S^2–) added to the soil chemically reduced MnO₂ to Mn²⁺, and MnO₂ and Fe(OH)₃ to Mn²⁺ and Fe²⁺, respectively, where Fe²⁺ and S^2– were considered to be oxidized to Fe³⁺ and S⁰. Elemental sulfur was oxidized to sulfate by anaerobic incubation with NO₃ ^– MnO₂ and Fe(OH)₃. A new conceptual model for the reduction processes in submerged paddy soil including the reoxidation processes of reduced products, in which soil heterogeneity in paddy fields was taken into consideration, was proposed based on the results. Received: 20 October 1996     

Implications of iron solubilization on soil phosphorus release in seasonally flooded forests of the lower Orinoco River, Venezuela

The microbial reduction of Fe oxides is thought to contribute with the release of P in sedimentary environments. However, secondary reactions of the bioproduced Fe(II) with P in solution, can lead to a decrease in the soluble P concentration. In this study, we examined how the reduction of Fe(III) affects the soluble P concentration, when the soils of a seasonally flooded forest gradient are subjected to anaerobic conditions. Soil samples were collected during the dry season from two zones subjected to different flooding intensity: MAX and MIN zones that were inundated 8 and 2 months per year, respectively. When anaerobic conditions were applied to soils from both zones, a clear stimulatory effect on the Fe(III) reduction was observed. However, bioproduced Fe(II) underwent secondary chemical reactions, masking the extend of Fe(III) reduction of these soils. Iron was reduced mainly during the first 15 days of the anaerobic incubation and it was stimulated by a pulse of labile carbon. Iron dissolution did not lead to an increase of the soluble P content. However, in both zones P was high and positively correlated with Fe(II), implying that soil P mobilization was linked to Fe dissolution. In the MIN zone, soluble P concentration decreased, probably as a consequence of the secondary reactions of solubilized P with other non-redox sensitive soils elements. Fe solubilization also had an effect on the activity of acid phosphatase and consequently in the solubilization of P from the organic pool. In conclusion, the P cycle in these soils is strongly coupled to C and Fe cycles.