餐厨垃圾高温厌氧消化产沼气的试验研究

探究了温度、含固率、pH及接种率对餐厨垃圾厌氧消化产沼量的影响,并设计L9(34)正交试验进行厌氧发酵工艺优化研究。结果表明,在温度为55℃、含固率为8%(质量分数)、pH为7.00、接种率为90%(质量分数)时,厌氧发酵累积产沼量为809.0mL/g(以挥发性固体计);各影响因素对产沼量的影响大小为温度pH接种率含固率。     

污泥预处理强化厌氧水解与产甲烷实验研究

污泥传统厌氧消化因水解瓶颈而导致有机物转化甲烷产率低下.选择适当工况对污泥实施预处理可同时实现对污泥中木质纤维素破稳和污泥微生物细胞破壁,从而释放出较多溶解性COD(SCOD),使有机物水解变得容易进行,最终导致甲烷产率大幅提高.本研究通过热水解(T=150℃,t=30 min)、超声波(P =500 W,t=2 h)、碱解(pH =13,t=2h)和酸解(pH =2,t=2 h)等4种预处理方式对原污泥实施最优工况预处理,分别获得了50.9％、39.1％、31.0％和22.4％的COD溶出率.对预处理后污泥进行传统条件下(SRT =20 d)厌氧消化,分别获得了53.6％、40％、26.8％和24％的甲烷产率(mL/g VSS)增量.同时,预处理后污泥中木质纤维素类物质降解率亦大大增加.缩短SRT(10 d)会导致传统厌氧消化甲烷产率急剧减少,但是,污泥预处理却非常有利于甲烷产率的提高,因此可通过外在预处理方式来逾越内在厌氧水解的瓶颈.     

固相餐厨垃圾厌氧发酵特性

为了研究固相餐厨垃圾厌氧发酵产甲烷特性,对固相餐厨垃圾进行批式厌氧发酵实验,主要考察了pH、VFA、COD以及纤维素酶活的变化情况,并运用修正Gompertz模型对其产气模型进行动力学拟合.实验结果表明,缓冲溶液的添加可明显促进厌氧发酵产甲烷.在添加缓冲溶液条件下,污泥与餐厨垃圾比例为2∶1,1∶1,2∶3和1∶2时,餐厨垃圾都能很好地进行厌氧发酵产甲烷,最大产甲烷产量分别为594.66、449.74、392.93和333.36 mL/g TS.采用修正Gompertz模型分别对2∶1、1∶1、2∶3和1∶2实验组产甲烷曲线进行拟合,得到产甲烷潜力分别为567.57、437.89、381.12和305.60 mL/g TS,最大产甲烷速率分别为89.38、59.81、47.26和25.80 mL/(d·g VS).对厌氧发酵过程中纤维素酶活的变化进行了研究,结果表明,CMC酶活性在提高餐厨垃圾厌氧发酵过程中纤维素的降解起重要作用.     

味精浓废水生物处理优化工艺

本文阐述两相厌氧消化法与缺氧—厌氧消化法处理味精浓废水的比较试验.进水为6×10~4mg/L～8×10~4mg/L时,两相厌氧消化法COD去除率为78%,产气率为0.15m~3/kgCOD,CH_4含量为50%.缺氧—厌氧消化法COD去除率为82.2%,产气率为0.23m~3/kgCOD,CH.含量达65%.两种方法均可使出水pH值由3.2上升至7.0以上.氯离子和氨氮的去除不明显.综合上述结果与运行管理的稳定程度均是缺氧——厌氧消化法优于两相厌氧消化法.     

污泥超声破解效应及厌氧消化性能研究

针对超声破解污泥的可行性进行了实验研究,重点考察了超声频率、比能耗、作用时间等因素对破解效应的影响,探讨了破解污泥的厌氧消化性能。结果表明,超声作用的施加可使污泥固体有效破解,污泥细胞内的活性有机物被释放至水相并形成溶解性有机物,表现为SCODCr的显著增加;采用低频、高比能耗及延长作用时间有利于获取高的SCODCr增加值;污泥在频率25kHz、比能耗2.0W/mL、作用时间30min条件下破解,其厌氧消化累计产气量可从破解前的268mL提高到473mL,相应TCODCr去除率、VS去除率分别从39.1%、33.5%提高至54.3%、61.7%。研究结果表明采用超声破解技术提高污泥的厌氧消化性是可行的。     

高浓度有机废水厌氧膜生物工艺处理的中试研究

高浓度有机废水ADUF工艺处理的中试研究结果表明 ,(1)厌氧池污泥SRT为 5 0d时 ,不仅COD去除率高 ,膜水通量也更稳定 ;(2 ) pH值宜采用在线控制为 7 0 ,温度则应在材质允许范围内尽可能高些 (本实验中为 39℃ ) ;(3)污泥负荷在1 0— 3 5kg/ (kg·d)之间时 ,污泥负荷对ADUF工艺的运行效果没有影响     

微波密封消解法快速测定CODcr

标准法──重铬酸钾法测定ＣＯＤＣｒ的缺点是测定时间长，氯离子干扰大。微波密封消解法对此进行了改进。实验结果表明，该法具有消解时间短，减轻了二次污染，准确度高，精密度好等优点，可同标准回流法等效使用。     

二相厌氧-混凝法处理制浆造纸综合废水的工艺设计及调试

湖南某造纸厂采用二相厌氧 混凝法处理制浆造纸综合废水取得了显著效果 ,CODCr排放总量削减率达 80 % ,水体水质明显改善。本文介绍了该工程的工艺设计及调试。     

Fate of ah receptor agonists during biological treatment of an industrial sludge containing explosives and pharmaceutical residues

GOAL, SCOPE AND BACKGROUND: Sweden is meeting prohibition for deposition of organic waste from 2005. Since 1 million tons of sludge is produced every year in Sweden and the capacity for incineration does not fill the demands, other methods of sludge management have to be introduced to a higher degree. Two biological treatment alternatives are anaerobic digestion and composting. Different oxygen concentrations result in different microbial degradation pathways and, consequently, in a different quality of the digestion or composting residue, It is therefore necessary to study sludge treatment during different oxygen regimes in order to follow both degradation of compounds and change in toxicity. In this study, an industrial sludge containing explosives and pharmaceutical residues was treated with anaerobic digestion or composting, and the change in toxicity was studied. Nitroaromatic compounds, which are the main ingredients of both pharmaceutical and explosives, are well known to cause cytotoxicity and genotoxicity. However, little data are available concerning sludge with nitroaromatics and any associated dioxin-like activity. Therefore, we studied the sludge before and after the treatments in order to detect any changes in levels of Ah receptor (AhR) agonists using two bioassays for dioxin-like compounds. METHODS: An industrial sludge was treated with anaerobic digestion or composting in small reactors in a semi-continuous manner. The same volume as the feeding volume was taken out daily and stored at -20 degrees C. Sample preparation for the bioassays was done by extraction using organic solvents, followed by clean up with silica gel or sulphuric acid, yielding two fractions. The fractions were dissolved in DMSO and tested in the bioassays. The dioxin-like activity was measured using the DR-CALUX assay with transfected H4IIE rat hepatoma pGudluc cells and an EROD induction assay with RTL-W1 rainbow trout liver cells. RESULTS AND DISCUSSION: The bioassays showed that the sludge contained AhR agonists at levels of TCDD equivalents (TEQs) higher than other sludge types in Sweden. In addition, the TEQ values for the acid resistant fractions increased considerably after anaerobic digestion, resulting in an apparent formation of acid resistant TEQs in the anaerobic reactors. Similar results have been reported from studies of fermented household waste. There was a large difference in effects between the two bioassays, with higher TEQ levels in the RTL-W1 EROD assay than in the DR-CALUX assay. This is possibly due to a more rapid metabolism in rat hepatocytes than in trout hepatocytes or to differences in sensitivities for the AhR agonists in the sludge. It was also demonstrated by GC/FID analysis that the sludge contained high concentrations of nitroaromatics. It is suggested that nitroaromatic metabolites, such as aromatic amines and nitroanilines, are possible candidates for the observed bioassay effects. It was also found that the AhR agonists in the sludge samples were volatile. CONCLUSIONS: The sludge contained fairly high concentrations of volatile AhR agonists. The increase of acid resistant AhR agonist after anaerobic digestion warrants further investigations of the chemical and toxic properties of these compounds and of the mechanisms behind this observation. RECOMMENDATION AND OUTLOOK: This study has pointed out the benefits of using different types of mechanism-specific bioassays when evaluating the change in toxicity by sludge treatment, in which measurement of dioxin-like activity can be a valuable tool. In order to study the recalcitrant properties of the compounds in the sludge using the DR-CALUX assay, the exposure time can be varied between 6 and 24 hours. The properties of the acid-resistant AhR agonists formed in the anaerobic treatment have to be investigated in order to choose the most appropriate method for sludge management.     

农业蔬菜废物处理方法研究进展和探讨

目前我国农业蔬菜废物污染问题正日益加重 ,蔬菜废物和其他固体废物相比具有高含水率、高营养成分和基本无毒害的特性 ,适宜于单独收集处理。本文介绍了国内外蔬菜废物处理方法的研究进展 ,包括好氧堆肥法、厌氧消化法、好氧 -厌氧联合处理法 ,并对这些方法的适用条件进行了论述。同时 ,探讨了接种微生物自然堆沤法的初步研究结果