Performance of an industrial biofilter from a composting plant in the removal of ammonia and VOCs after material replacement

BACKGROUND: Biofiltration is a suitable odor reduction technique for the treatment of gaseous emissions from composting processes, but little is known about the start‐up of full‐scale biofilters after material replacement and their performance after several years of operation. RESULTS: Biofilter material (wood chips used previously as bulking agent in a composting process) can effectively remove ammonia and most of the volatile organic compounds (VOCs) content, achieving removal efficiencies greater than 70% for VOCs and near 90% for ammonia immediately after material replacement. These removal efficiencies were maintained for several months after material replacement. In the studied full‐scale biofilter no lag phase was observed in the removal of ammonia whereas in the case of VOCs different patterns were detected during biofilter start‐up. For the old biofilter material, after 4 years of operation, a statistically significant decrease of removal efficiency for ammonia in comparison with the new material was detected. No statistically significant differences were found in the case of VOCs. CONCLUSIONS: Data on the emissions of several pollutants from biofilters treating composting exhaust gases have been systematically obtained. The tested filtering media presented adequate properties for biofiltration of gases emitted during the composting process. Copyright © 2009 Society of Chemical Industry     

反硝化除磷工艺影响因素研究进展

概述了反硝化除磷工艺原理，介绍了关于碳源、硝酸盐和亚硝酸、温度、pH值、HRT、SRT等影响因素的研究进展，并分析了该反硝化除磷技术的发展前景，建议开展关于反硝化除磷工艺厌氧阶段、以NO3^--N和NO2^--N为电子受体的缺氧阶段各影响因素的多因素正交试验研究。     

Influence of filter media depth and vegetation on Faecal Coliform removal by stormwater biofilters

Biofilters are promising technologies that widely applied in the treatment of urban stormwater. However, the microbial removal capacity performance depends greatly on the design of biofilters. Hence, this laboratory study attempts to investigate the influence of filter media depths (i.e. 150, 250, 350 and 450 mm) and the variation of native plants, that is, Cow Grass (Axonopus compressus) and Pearl Grass (Axonopus compressus, dwarf) in removing stormwater microorganism particularly Faecal Coliform (FC). Findings showed that a minimum media depth of 300 mm was required to achieve >1 log FC removal. The mean removal of FC at 450 mm depth filter exceeded 2 log for both Cow and Pearl grass biofilter columns. Results showed that there was no statistically significant difference in vegetation type on the performance of FC removal, however, Cow grass biofilter column revealed higher FC mean log removal compared to Pearl grass biofilter column.     

不同碳源驯化聚糖菌反硝化及N2O释放特性

为了确定反硝化聚糖菌(DGAOs)的脱氮性能及N₂O释放特性,采用序批式生物反应器,分别以乙酸钠和葡萄糖为碳源(反应器分别记作SBRAc和SBRGl),考察其脱氮过程中的碳源变化以及N₂O释放特性。结果表明,SBRAc和SBRGl的总氮去除率分别为(80.2±2.8)%和(63.4±3.5)%,N₂O产率分别为(7.16±1.43)%和(13.35±2.46)%。以乙酸钠为碳源时,聚糖菌厌氧阶段吸收的有机物主要以胞内聚-β-羟基烷酸(PHA)形式储存;以葡萄糖为碳源时,部分有机物用于胞内糖原(Gly)的积累,PHA合成量减少。聚糖菌内源反硝化过程中,依次利用胞内PHA和Gly作为内碳源,且PHA提供电子的速率远大于Gly,导致SBRGl内NO₂^-大量积累、N₂O释放量增加。NO₂^-对氧化亚氮还原酶活性的抑制效应是导致聚糖菌内源反硝化过程释放N₂O的主要因素。与葡萄糖相比,乙酸钠更易被反硝化聚糖菌吸收为易利用的内碳源PHA,并降低反硝化过程中N₂O的释放量。     

未来科技城再生水厂一期工程工艺设计方案

该文介绍了未来科技城再生水厂一期工程的工艺流程和设计情况。根据水厂进出水水质特征,生物处理工艺采用A/A/O底曝氧化沟,深度处理工艺采用生物滤池+滤布滤池+超滤膜,出水经二氧化氯消毒后供再生水管网。对各处理构筑物的选择和设计参数的选用进行了重点说明,以期为同类水厂的设计提供经验借鉴。     

Performance of Granular Activated Carbon (GAC) Adsorption and Biofiltration in the Treatment of Biologically Treated Sewage Effluent

Abstract

In this study, the performance of GAC adsorption and biofiltration systems in treating biological treated sewage effluent (BTSE) was evaluated in terms of organic removal efficiency, organic fractions, and molecular weight distribution (MW) of organic matter (OM) removed. The GAC biofilter removed 23.5% and 61% of the hydrophobic fractions and hydrophilic fractions of OM in the BTSE respectively. MW distribution studies of GAC filter and GAC adsorption revealed the following: Hydrophobic fraction of the effluent showed a peak at 345 dalton after GAC biofiltration and 256 dalton after GAC adsorption, whereas, with hydrophilic fractions, peaks at 46,178 and 345 daltons were observed after GAC biofiltration and peaks at 46,178 and 256 daltons after GAC adsorption. Transphilic fraction showed the peaks at 12,783 dalton with GAC biofiltration, and 1,463 dalton with GAC adsorption. The performance of the GAC biofilter was successfully mathematically modelled.     

臭氧-活性炭-反硝化生物滤池在污水再生回用中的应用

在酒仙桥污水处理厂建立200m3/d的示范工程进行高品质再生水的生产,在二级出水强化脱氮除磷的基础上,采用臭氧(O3)-活性炭(GAC)-反硝化生物滤池(DNBF)工艺进行试验研究。经过13个月的试验证明,该工艺由于O3在脱色除臭基础上,能够强化活性炭滤池的生物多样性及活性,从而使出水CODCr能够长期稳定在30mg/L以下,NH3-N小于1mg/L。在外加碳源CH3COONa条件下,系统经DNBF后出水TN小于2mg/L。同时试验发现,为了实现经济节能及良好的污水再生效果,DNBF和O3单元在流程中的位置设置非常关键,有别于污水二级处理工艺。     

人工神经网络模拟生物膜滴滤塔废气处理过程

在生物滴滤塔处理有机废气过程中，参数非线性度大，其处理过程适合用人工神经网络(ANN)模拟。通过建立神经网络模拟生物滴滤塔处理有机废气的过程，对遗传算法的改进能够提高其收敛速度，并采用改进遗传算法(MGA)与LMBP算法相结合(MGA—LMBP)，利用已有的实验数据样本训练神经网络，取得了较好的效果。     

反硝化聚磷体系中颗粒污泥的特性生研究

为了考察反峭化聚磷颗粒污泥的形成过程,利用SBR在厌氧/好氧/缺氧(A/0/A)运行方式下、以人工配水培养驯化颗粒污泥,研究了颗粒污泥在形成过程中的特性变化.结果表明,在培养初期污泥呈褐色絮体,结构松散,污泥活性较差;在第二阶段,颗粒污泥开始出现,粒径范围为0.13～1.63 mm,沉降速率逐渐变大,SVI值下降,MLSS值上升;至第三阶段末,颗粒污泥呈致密的球形或椭球形,粒径范围为0.6～3.0 mm,沉降速率基本在0.5～1.5 cm/s,沉降速率与粒径的关系大致符合斯托克斯定律,MLSS值达到2 500 mg/L,SVI值约为90 mL/g,此时的颗粒污泥沉降性能良好、活性较强、生物量较大.     

不同类型稻田亚硝酸型CH4厌氧氧化潜力的比较研究

甲烷(CH₄)厌氧氧化是稻田土壤中消减温室气体排放的重要过程.本试验选择内陆性南京稻田和滨海性上海崇明岛围垦稻田,比较研究稻田耕层(0~10 cm)和深层(50~60 cm)土壤中亚硝酸盐型CH₄厌氧氧化(n-DAMO)潜力的差异及其微生物驱动机制.结果表明,南京稻田耕层土壤的n-DAMO速率为3.51 nmol·g^-1·d^-1(以¹³CO₂计),显著高于围垦稻田耕层土壤(1.43 nmol·g^-1·d^-1).两种类型稻田耕层土壤的n-DAMO速率均显著高于深层土壤.南京稻田和围垦稻田M.oxyfera-like细菌的16S rRNA基因拷贝数分别为(2.31~4.82)×10⁷和(0.89~2.12)×10⁷ copies·g^-1,与亚硝酸盐型CH₄厌氧氧化速率显著正相关.相关性分析发现,土壤有机碳、总氮、无机态氮是稻田n-DAMO速率分异的重要原因.综上所述,内陆性稻田土壤n-DAMO氧化潜力较高,其主要由较高的土壤本底碳、氮水平和功能微生物丰度所致.