内循环（IC）厌氧反应器处理糖蜜酒精废水的研究

糖蜜酒精废水由于含有高浓度的COD和硫酸盐,一般厌氧反应器无法有效处理.研究了IC反应器处理糖蜜酒精废水的效果.考察其COD及硫酸盐的去除率、沼气的产量和组分等.结果表明,反应器对于COD为5000～10 000 mg/L的中、高浓度废水去除效果良好,当COD在20 000～30 000 mg/L时,在适应了1～2个停留时间后,去除效果达到稳定,去除率在90%左右.实验中最高容积负荷提升至40 kg COD/m3·d左右.本研究中所用的糖蜜酒精废水的COD/SO24-的平均值为61.9,未对反应器的处理效果及产气量产生影响.     

电-Fenton法预处理糖蜜酒精废液厌氧发酵出水

糖蜜酒精废液厌氧发酵出水(以下简称厌氧发酵出水)有机物浓度高、色度大、可生化性差,是一种典型的难降解有机工业废水。为提高废水的可生化性,采用电Fenton工艺预处理糖蜜酒精废液厌氧发酵出水,研究了电Fenton反应中影响因子对废水COD去除速率和BOD5/COD(B/C)值的影响。结果表明,当初始pH调至3,电流密度0.6 m A·cm-2、H_2O_2(w/w,30%)投加量20 m L·L~(-1)、极间距2 cm、反应90 min后,废水COD去除率达75%,B/C由0.113增大为0.479,废水可生化性得到显著改善。同时发现,分步投加H_2O_2效果优于反应初始时刻一次性投加,反应的前30 min内结束投加效果最好。为探索糖蜜酒精废液厌氧发酵出水的高效处理方法提供了有意的参考。     

催化臭氧氧化降解糖蜜酒精废水的研究

以SnO2为催化剂,研究糖蜜酒精废水在臭氧条件下的氧化降解反应,为糖蜜酒精废水的治理提供一种新的处理方法.研究表明,SnO2加速了臭氧氧化反应,使糖蜜酒精废水的氧化降解加快.影响糖蜜酒精废水氧化降解的主要因素有臭氧流量、废水的初始pH和催化剂用量等.加大臭氧流量及增加催化剂用量,均有利于糖蜜酒精废水的降解.适宜的反应条件是:糖蜜酒精废水的稀释倍数为10倍,臭氧流量为130 mg/h,催化剂用量为2.500 g/L,废水的初始pH为4.25,温度为30 ℃.在该条件下反应60 min,废水的脱色率为60.2%,COD去除率为44.5%.动力学分析表明,单独臭氧氧化降解糖蜜酒精废水和SnO2催化臭氧氧化降解糖蜜酒精废水均为拟一级反应.     

厌氧滤池处理纺织印染废水的中试研究

对厌氧滤池反应器处理难降解印染废水进行中试研究。结果表明,厌氧滤池反应器水力停留时间(HRT)在8.1～14.6 h之间,进水COD浓度波动较大(500～1 000 mg/L)时,对COD平均去除率为20%。印染废水的BOD5/COD由0.23提高到0.35,废水可生化性明显改善。印染废水中硫酸根浓度略有下降,去除浓度为70 mg/L左右。厌氧滤池进出水颜色明显变化,由紫红色变为蓝黑色,紫外可见光谱分析表明废水中的有机物结构发生变化。     

猪场废水的厌氧消化除磷机制

采用批式厌氧消化实验,研究了猪场废水厌氧消化过程中生物、物理和化学作用对磷去除的贡献。结果表明,厌氧消化6 d,灭菌的混合液几乎没有磷被去除;未灭菌的混合液,上清液总磷去除率为57.3%,且随着混合液总磷的减少,吸收液的磷逐渐增多,说明废水中的部分磷被转化成气态磷化合物并释放。将原水在4℃、厌氧条件下静置6 d,废水TP去除率为70.7%,说明物理沉降的除磷作用显著。对厌氧消化前后的污泥进行浸提,发现没有灭菌、灭菌混合液的污泥的Ca、Mg-RP(HCl-RP)含量分别增加93.4%和50.5%。由于没有灭菌的混合液的pH不断升高,灭菌的混合液的pH不断下降,说明生物的新陈代谢活动使得环境条件改变(pH增加)而有利于磷化合物沉淀的形成。实验表明,猪场废水厌氧消化过程中磷的去除是物理、化学及生物过程共同作用的结果。     

厌氧折流板反应器处理低浓度废水的运行特性研究

接种厌氧絮状污泥,采用厌氧折流板反应器在中温下进行了处理低浓度废水的试验研究.结果表明,厌氧折流板反应器有效去除了废水中的有机物,平均去除率稳定在80%以上;启动迅速,在35 d内完成,启动性能较EGSB优;水力负荷起着重要的作用;在提高负荷阶段的初期,反应器COD去除率有较大波动,随着负荷的加大,这一现象逐渐消失;在容积负荷小于2.15 kg COD/m3·d时,进水容积负荷与基质去除负荷率之间具有明显的线性正比关系;反应器的前面隔室对有机物的去除起到主要作用;在长期运行的处理低浓度废水的ABR反应器中存在产酸相和产甲烷相的自然分离现象.     

丙烯酰胺改性壳聚糖絮凝剂处理焦化废水

合成了丙烯酰胺改性壳聚糖絮凝剂;用该絮凝剂处理了A/O工艺处理后的焦化废水.考察了pH值、絮凝剂用量及搅拌时间对去除污染物的影响.实验结果表明,当絮凝剂用量为50.0 mg·L-1,絮凝pH值为6.5,絮凝搅拌时间为12 min,COD、F-和色度的去除率分别达到64.7%、93.2%和75%;丙烯酰胺改性壳聚糖絮凝剂对焦化废水的深度处理效果优于聚合硫酸铁和聚合氯化铝絮凝剂.     

臭氧催化氧化处理化学镀镍废水

采用臭氧催化氧化工艺处理化学镀镍废水,以Fe2O3-TiO2-MnO2/A12O3作为臭氧催化剂,考察了不同反应条件下臭氧催化氧化对化学镀镍废水的影响。结果表明,在初始pH为9,臭氧投加量为300 mg·L-1,反应时间为60 min的最佳反应条件下,水中COD可从532 mg·L-1下降至285 mg·L-1,去除率达到46.4%。臭氧催化氧化对化学镍具有较好的破络效果,在初始pH为9,臭氧投加量为200 mg·L-1,反应为60 min后进行混凝过滤,水中镍的去除率可达到86.7%。紫外全波段扫描分析发现,经臭氧催化氧化后,各波段的吸收峰均有大幅度下降,位于254 nm和320 nm处的吸收峰基本消失,说明水中的苯环类物质和共轭结构被破坏。经臭氧催化氧化后,废水的生物毒性大幅降低,废水的可生化性提高,出水B/C由原来的0.12提高到0.36,为后续进一步生化处理提供了条件。     

不同泥源对厌氧氨氧化反应器启动的影响

采用2套上流式生物膜反应器,分别接种少量厌氧氨氧化污泥和大量硝化污泥,考察其对厌氧氨氧化反应器启动的影响。污泥接种入反应器后,测得接种厌氧氨氧化污泥的反应器(R1)内MLSS为0.22 g/L,另一个反应器(R2)MLSS为2.7 g/L。与直接接种厌氧氨氧化污泥相比,R1经过72 d的运行才显现出厌氧氨氧化特性。经过114 d的培养,前者氮去除速率由0.23 kg/(m3.d)提升到5.29 kg/(m3.d),总氮去除率大于89%;R2的氮去除速率由0.01 kg/(m3.d)提升到1.1 kg/(m3.d),总氮去除率大于84.6%。说明普通污泥启动需要一个较长的筛选过程,直接接种少量的厌氧氨氧化污泥比接种普通的污泥能够更快启动厌氧氨氧化反应器。     

厌氧折流板反应器处理有机农药废水的实验研究

介绍了采用厌氧折流板反应器(ABR)处理农药废水的实验研究情况.当进水COD负荷在2.0～4.5 kg/(m3·d),ABR反应器对COD去除率可保持在70%～80%.反应器的处理效果随温度下降而降低,当系统温度由35 ℃下降至25 ℃时,反应器的COD去除率下降30%.采用适量出水回流可提高系统的去除效率,回流比控制为50%比不回流COD平均去除率可提高近25%,回流比过高将导致系统COD去除率下降.     

Estimation of uncertainty of sampling for analysis of pesticide residues

Abstract

A computer model was used to take random samples from primary sample populations obtained from field trials to simulate the uncertainty of sampling for residue analysis of plant commodities and soil. The results indicate about 40%, 30% and 20% relative uncertainty when random samples of size 5, 10 and 25 are taken respectively, from a single lot. Therefore the sample size should be the same for establishing and enforcing legal limits.     

次氯酸钠发生器的研制

介绍了电解法生产次氯酸钠的原理 ,并在原有生产工艺的基础上进行了重新设计和对设备的重新选择、改造 ,得出了各个工艺参数的最佳值 ,生产出高品质的次氯酸钠     

An application of the theory of kinematics of mixing to the study of tropospheric dispersion

The most common technique used for numerical simulations of tracer mixing is that of the numerical solution of the advection–diffusion equation with the unresolved fluxes parameterized using the similarity theory. Despite correct predictions of the overall directions of transport, models based on a numerical solution of the advection–diffusion equation lack sufficient accuracy to correctly reproduce the coupling of mixing with small scale processes which are sensitive to the microstructure of the tracer distribution. The objective of this paper is to revisit the basic formalism employed in numerical models used to investigate atmospheric tracers. The main mathematical method proposed here is the theory of kinematics of mixing which could be applied effectively for simulations of atmospheric transport processes. At the beginning of the paper, we introduce simple mathematical transformations in order to demonstrate how complex topological structures are created by mixing processes. These idealistic flow systems are essential to explain transport properties of much more complex three-dimensional geophysical flows. An example of the application of the kinematics of mixing to the analysis of tracer transport on a planetary scale is presented in the following sections. The complex filamentary structures simulated in the numerical experiment are evaluated using some commonly applied statistical measures in order to compare the results with the data published in the literature. The results of the experiment are also analysed with the help of simple conceptual models of fluid filaments. The microstructure of the tracer distribution introduced in the paper is essential to increase our understanding of atmospheric transport and to develop more realistic parameterizations of small-scale mixing. The presented results could also be used to improve calculations of the coupling between microphysical processes and tracer mixing.     

造纸废水混凝处理中SFT助凝替代性研究

中小造纸厂废水处理常用PAC作混凝剂 ,PAM作助凝剂。由于PAM成本很高 ,影响了处理设备的投运率。用超细滑石粉 (SFT)替代PAM助凝 ,与混凝剂PAC配合 ,其混凝处理效果基本相当 ,但是处理成本降低 0 .10元 /m3 。由于SFT属环境无害材料 ,不会给排泥带来二次污染     

活性炭三维电极法对印染废水的处理研究

对三维电极方法处理印染废水进行了实验研究,初步探讨了活性炭三维电极法处理印染废水的机理,对影响处理效果的各种要素,如反应时间、槽电压和pH值等进行了条件实验,得出了活性炭三维电极法处理印染废水的最佳运行条件为:停留时间120-180 min,槽电压25～30 V,进水pH值6.5～7.5。结果表明,该反应器能有效地降低废水色度,有较高的COD去除效率,并能提高印染废水的可生化性。     

红土吸附砷对其动电电位的影响

研究了遵义红土吸附砷对其动电电位的影响 ,从砷酸根浓度和体系pH对红土动电电位影响的角度作了探讨 ,结果表明 ,砷酸根离子浓度越大 ,Zata电位下降幅度越大 ,Zata电位也越低 ;随着体系pH的升高 ,氧化铁胶体动电电位逐渐下降 ,甚至改变了表面电位的符号。由此得出了红土吸附砷属于专性吸附的结论。     

生物质快速热裂解主要参数对生物油产率的影响

以松木木屑为原料,在自制的小型流化床上,开展了生物质热裂解温度、生物质粒径和进料速率对生物油产率的影响实验研究.结果表明,在热裂解温度分别为450、475、500、525和550℃条件下,当热裂解温度为500℃时,生物油产率最高,平均产率达到53.33%(质量百分比).反应温度越高,炭产量越低,不可冷凝气体产量越高,气体发热值越高;粒径＜1 mm的生物质其粒径对生物油产率影响不大;生物质进料速率增加时,生物油产率增加.本研究为生物能的利用提供了新的途径.     

Evaluation of the presence of drugs of abuse in tap waters

A total of seventy samples of drinking water were tested for non-controlled and illicit drugs. Of these, 43 were from Spanish cities, 15 from seven other European countries, three from Japan and nine from seven different Latin American countries. The most frequently detected compounds were caffeine, nicotine, cotinine, cocaine and its metabolite benzoylecgonine, methadone and its metabolite EDDP. The mean concentrations of non-controlled drugs were: for caffeine 50 and 19 ng L⁻¹, in Spanish and worldwide drinking water respectively and for nicotine 13 and 19 ng L⁻¹. Illicit drugs were sparsely present and usually at ultratrace level (<1 ng L⁻¹). For example, cocaine has mean values of 0.4 (Spain) and 0.3 ng L⁻¹ (worldwide), whereas for benzoylecgonine, these mean values were 0.4 and 1.8 ng L⁻¹, respectively. Higher concentrations of benzoylecgonine were found in Latin American samples (up to 15 ng L⁻¹). No opiates were identified in any sample but the presence of methadone and EDDP was frequently detected. Total mean values for EDDP were 0.4 ng L⁻¹ (Spain) and 0.3 ng L⁻¹ (worldwide). Very few samples tested positive for amphetamines, in line with the reactivity of chlorine with these compounds. No cannabinoids, LSD, ketamine, fentanyl and PCP were detected.     

Visualisation of the complexity of EUSES

The interdependencies of parameters applied in the models of EUSES are visualised in a directed connectivity graph. The parameters (inputs, defaults, state variables, outputs) are represented by boxes (nodes) and their relations by lines (edges). The visualisation, on the one hand, clarifies the complexity of the models in EUSES and, on the other hand, creates an overview and transparency. The parameters’ relations to each other can be recognised faster, and the models can be better understood. The complexity was quantified by the number (variety), kind (substance parameter, physico-chemical parameter, concentration, other parameters), and depth (dimension) of the parameter and the number of relations (connectivity). The variety of EUSES (without the modelsSimple Treat andSimple Box whose interior structure is not documented and without the effect and risk characterisation) amounts to 466, the connectivity to 961, and the maximal dimension is 21.