A sludge volume index (SVI) model based on the multivariate local quadratic polynomial regression method

In this study, a multivariate local quadratic polynomial regression(MLQPR) method is proposed to design a model for the sludge volume index(SVI). In MLQPR, a quadratic polynomial regression function is established to describe the relationship between SVI and the relative variables, and the important terms of the quadratic polynomial regression function are determined by the significant test of the corresponding coefficients. Moreover, a local estimation method is introduced to adjust the weights of the quadratic polynomial regression function to improve the model accuracy. Finally, the proposed method is applied to predict the SVI values in a real wastewater treatment process(WWTP). The experimental results demonstrate that the proposed MLQPR method has faster testing speed and more accurate results than some existing methods.

Characteristics of microfauna and their relationships with the performance of an activated sludge plant in China

The occurrence and abundance of the microfauna groups were compared with the physico-chemical and operational parameters of the Baoding Lugang Sewage Treatment Plant in China. Attached and crawling ciliates were the dominant groups of ciliates. Crawling ciliates and testate amoebae showed a strong association with effluent BOD5 （biochemical oxygen demand）. Therefore, these two groups are likely to be useful bioindicators since their number decreased as the process produced poor quality effluent. Testate amoebae also had significant negative correlations with effluent TN （total nitrogen）, NH4^＋-N, SS （suspended solids） and SVI （sludge volumetric index）, which means that this group of ciliates may be indicators of good performance of the activated sludge system. Carnivorous ciliates and flagellates had significant positive correlations with SVI, suggesting that these two groups may be indicators of bad settlement conditions of sludge. As identification of the microfauna species is difficult and time-consuming, we recommend using microfauna functional groups to evaluate the performance of the activated sludge system.

Pollution characteristics of polycyclic aromatic hydrocarbons (PAHs) in oily sludge from the Zhongyuan Oilfield and its peripheral soils

The purpose of this study is to determine the degree of contamination caused by polycyclic aromatic hydrocarbons (PAHs) in oily sludge and soils around it in the Zhongyuan Oilfield. The contents of polycyclic aro-matic hydrocarbons in oily sludge samples were determined with HPLC. The contents of PAHs of oily sludge from three different oil production plants vary from high to low in the order of the Wenming oily sludge dumping site of No. 3 Oil Production Plant (3W)>the Mazhai oily sludge dumping site of No. 3 Oil Production Plant (3M)>the Wen'er oily sludge dumping site of No. 4 Oil Production Plant (4W). Naphthalene, acenaphthylene, acenaphthene, fluorine and phenanthrene are the major pollutants of PAHs in oily sludge. The contents of PAHs in soil samples around the oily sludge dumping sites vary widely from 434.49 to 2408.8 ng/g. Naphthalene, acenaphthene, fluorine, phenanthrene and pyrene are the characteristic factors of PAHs in soil samples of 3M and 3W, and naphthalene, acenaphthene, fluorine and phenanthrene are the characteristic factors of PAHs in soil samples of 4W. According to these data and the ratios of Fl/Py, PAHs in oily sludge samples come mainly from petrogenic sources, and soil samples are divided into petrogenic soil samples and mixed-source soil samples, and both petrogenic and pyrogenic soil samples in terms of the sources of PAHs. The classification by Nemero index P indicates that soils around the oily sludge dumping sites have been seriously polluted.

Effects of sludge on germination and initial growth performance of Leucaena leucocephala seedlings in the nursery

研究被执行决定污泥的不同类型的影响(市政，工业；居住) 在地萌芽上，生长；L 的生节。在托儿所的 leucocephala 幼苗。在种子播种前，污泥的不同联合与滋养的缺乏的自然森林土被合并。领域萌芽，生节地位；幼苗的物理生长参数(射击；根长度，活力索引，领子直径，叶数字，新鲜；弄干射击的重量；根；全部的干燥生物资源增长) 在三以后被记录；六月种子播种。地萌芽，生节地位；生长参数在与控制相比与污泥修改的土壤显著地被改变。小瘤的最高的数字从与居住污泥(1:1 ) 修改的土壤被记录；最高新鲜；干燥小瘤重量也在三从一样的联合被发现；六个月旧的幼苗。在生长参数的情况下，最高的生长从土壤被记录；与控制相比的居住污泥(1:1 ) 联合。从学习，与居住污泥(1:1 ) 修改的土壤提供更好的地萌芽，这能被推荐，生长；L 的小瘤形成。在降级的土壤的 leucocephala。

Effect of Deionization on Activated Sludge Characteristics: A Case Study of Activated Sludge Culture with Tap Water and Distilled Water

Activated sludge dewaterability and settleability properties are of prime importance in sludge treatment and disposal. Herein, we have experimentally examined the effect of deionization on activated sludge characteristics taking a case study of activated sludge inoculated in tap water and distilled water. The quality of the effluent, both distilled water and tap water were analyzed to determine the characteristics of activated sludge. Results indicated the increasing of the sludge volume index from 51.67 ml/g to 146.9 ml/g leading to the sludge bulking for sludge inoculated in distilled water. The Capillary Suction Time (CST) of sludge cultivated in distilled water varied from 23.1 to 38.4 s, which suggests poor dewaterability. These are due to the growth of some filamentous bacteria in distilled water system. These have further confirmed by light microscope images that showed a significant difference between the sludge systems cultivated in tap water and those grown in distilled water. The present work indeed advances our understanding of activated sludge treatment and would serve as a handy reference for researchers or scholars who want to deal with sewage water treatment.

阴影植被指数SVI的构建及其在四种遥感影像中的应用效果

阴影是遥感影像中普遍存在的干扰因素,如何有效去除阴影已成为共识,寻找一个有效的阴影检测指标是实现影像阴影去除的基础工作。以Landsat TM,ALOS AVNIR-2,CBERS。02B CCD及HJ-1 CCD影像为试验数据,立足于进一步增大阴影区植被与明亮区植被、水体间的差异,实现影像阴影的有效检测,构建了一个新的植被指数——阴影植被指数SVI,该指数既可保证明亮区植被、阴影区植被、水体区在近红外波段的绝对差异,又能对NDVI进行放大,消除可能存在的混淆现象,改变NDVI直方图的"偏态"现象,使植被指数值更接近于正态分布,更符合地面实际;该指数适用于近红外波段辐射特征差异较大的地物。采用精度评估法验证SVI对明亮区植被、阴影区植被、水体区三类地物的识别效果,结果显示,四幅影像总分类精度依次高达98.89%,100%,97.78%,97.78%,总Kappa系数依次为0.983 3,1,0.966 7,0.966 7,说明SVI对明亮区植被、阴影区植被及水体区具有极好的检测效果;对子影像、SVI与NDVI的统计指标对比亦说明,SVI可靠、有效,可以将其应用于影像阴影去除。

SVI在生物铁MBR与普通MBR中的变化分析

污泥指数SVI可反映出污泥的凝聚和沉降性能,因此可通过分析系统的SVI值来分析和判断系统运行的情况。文章通过分析生物铁MBR与普通MBR中污泥SVI值的变化情况,得出:生物铁MBR系统的污泥沉降性能良好,且SVI值均低于普通MBR,不会随进水负荷的变化发生很大的波动,系统的净水头压差也没有发生很大的波动;而普通MBR系统污泥SVI值随进水负荷增加变化迅速,且容易发生污泥膨胀,系统的净水头压差迅速攀升,而为了保证处理流量,必须提升净水头压差,说明膜污染比较严重。

基于改进型PSO-BP神经网络的SVI软测量

针对曝气池污泥体积指数(SVI)难于在线测量的情况,提出了一种基于改进型的BP神经网络对SVI软测量的模型,该模型利用改进粒子群优化算法对BP神经网络进行权值调整。为了提高BP神经网络的学习性能,使粒子群的惯性权值按照对数规律变化,同时引入自适应变异算子对局部最优的粒子进行变异,然后利用粗糙集理论消除冗余信息,得到输入变量。该模型对实际污水厂的SVI值进行软测量预测,并与其它软测量模型进行比较,结果表明了该软测量模型具有较好的精度。

Cd^(2+)浓度对好氧颗粒污泥EPS各组分形成的影响

为探究重金属Cd^(2+)对好氧颗粒污泥系统运行的影响,采用紫外分析法和三维荧光光谱分析法研究了SBR反应器中不同浓度的重金属Cd^(2+)对好氧颗粒污泥EPS总量以及各组分(LB-EPS、SB-EPS、TB-EPS)的产生与组成成分的影响。试验结果表明:低浓度Cd^(2+)(小于0.1mg/L)促进EPS的产生,高浓度Cd^(2+)(大于3mg/L)抑制EPS的产生;SB-EPS随着Cd^(2+)浓度的增加逐渐减少,其中蛋白质含量增加,多糖、腐殖酸明显减少;当Cd^(2+)浓度小于0.1mg/L时TB-EPS显著增加,其中主要增加的成分是蛋白质;当Cd^(2+)浓度大于3mg/L时,TB-EPS的分泌受到抑制,但蛋白质含量仍高于空白对照组,多糖、腐殖酸含量显著降低;LB-EPS受到的影响因素较多,其含量变化不规律。采用扩展DLVO理论剖析了EPS各组分含量的变化对好氧颗粒污泥沉降性能的影响,以期为好氧颗粒化技术在工业废水处理中的应用提供有力的支持。

污泥干化焚烧技术经济评估指标体系研究

干化焚烧可集约、高效地实现污泥的减量化、稳定化和无害化,是目前污泥处理处置的主流技术之一。干化焚烧工艺构成相对复杂、设备仪表众多,客观评估工程设计和运行情况难度较大。结合我国污泥干化焚烧主流工艺“间接干化+流化床焚烧”的特点和评估需求,研究提出了适用于污泥干化焚烧工程状态表征、问题识别、优化方向辨识和优化空间预估的技术经济评估指标体系,并以某污泥干化焚烧工程为例对该指标体系用于其不同时间的运行状态评估进行了简要解析。

SVI在Orbal氧化沟运行管理中的指导作用

在污水处理厂的实际运行管理中,影响活性污泥处理工艺运行效果的因素很多,在缺乏经验数据的情况下,运行管理人员常以污泥容积指数(SVI)作为指导运行的主要参数。通过对西安市第三污水处理厂Orbal氧化沟工艺在运行中的实测结果进行统计分析,归纳出了SVI与污泥负荷NS、溶解氧DO及出水SS之间的相关关系,提出以SVI值指导Orbal氧化沟的工艺运行。

SVI简便快速测定法

详细介绍了ＳＶＩ快速测定法的原理和方法，并对实验数据进行了统计分析。结果表明，该方法准确、简便、快速且实用，可以替代传统方法。

Mapping Spatial and Temporal Variations of Leaf Area Index for Winter Wheat in North China

Leaf area index （LAI） is an important parameter in a number of models related to ecosystem functioning, carbon budgets, climate, hydrology, and crop growth simulation. Mapping and monitoring the spatial and temporal variations of LAI are necessary for understanding crop growth and development at regional level. In this study, the relationships between LAI of winter wheat and Landsat TM spectral vegetation indices （SVIs） were analyzed by using the curve estimation procedure in North China Plain. The series of LAI maps retrieved by the best regression model were used to assess the spatial and temporal variations of winter wheat LAI. The results indicated that the general relationships between LAI and SVIs were curvilinear, and that the exponential model gave a better fit than the linear model or other nonlinear models for most SVIs. The best regression model was constructed using an exponential model between surface-reflectance-derived difference vegetation index （DVI） and LAI, with the adjusted R2 （0.82） and the RMSE （0.77）. The TM LAI maps retrieved from DVILAI model showed the significant spatial and temporal variations. The mean TM LAI value （30 m） for winter wheat of the study area increased from 1.29 （March 7, 2004） to 3.43 （April 8, 2004）, with standard deviations of 0.22 and 1.17, respectively. In conclusion, spectral vegetation indices from multi-temporal Landsat TM images can be used to produce fine-resolution LAI maps for winter wheat in North China Plain.

Switching variability index based multiple strategy CFAR detector

A switching variability index （SVl） constant false alarm rate （CFAR） detector is proposed for improving the detection performance of VI-CFAR detectors in multiple targets backgrounds. When the presence of non-homogeneity in CFAR reference windows is indicated by a VI-CFAR detector, a switching- CFAR detector is introduced to optimize the performance of the VI-CFAR detector in homogeneous, multiple targets and clutter edge backgrounds. The structure and parameters selection method of the SVI-CFAR detector is presented. Comparisons with classic CFAR detectors and recently proposed detectors are also given. Theoretical analysis and simulation results show that SVICFAR detector maintains the good performance of the VI-CFAR detector in homogeneous and clutter edge backgrounds, while greatly improving the capacity of anti-multi targets.

污泥基充填膏体重金属浸出机理及风险评价研究

以污水污泥替代部分煤矸石,与水泥、粉煤灰制备污泥基充填膏体材料,可以妥善处置污水污泥,同时解决矿井充填材料短缺问题。为保障地下水环境安全,研究了污泥含量10%的污泥基充填膏体的重金属浸出机理,利用熵权质量指数对污泥及污泥基充填膏体浸出液进行水质评价,并利用支持向量机构建水质评价预测分类模型。结果表明:结合浸出动力学分析重金属离子浸出规律,重金属离子质量浓度上升阶段,其质量浓度变化符合扩散作用控制的收缩核模型;污泥基充填膏体重金属浸出机理是水分子与充填膏体中游离重金属离子结合形成水合金属离子,在浓度梯度力的作用下浸出至外部水中;污泥基充填膏体浸出液水质等级整体为2级,满足Ⅲ类水质量标准。根据EWQI结果以支持向量机算法为核心,建立了水质评价模型,模型效果较好,且具有较高的统一性。

厌氧污泥微生物作用对微塑料表面性质的影响

污水处理剩余污泥是微塑料的潜在储存库。为了考察污泥微生物对微塑料分解作用的影响特征,以聚丙烯、聚乙烯、聚氯乙烯和丁苯橡胶轮胎颗粒微塑料为研究对象,研究其表面性质在厌氧污泥微生物作用过程中的变化情况。结果表明:随着厌氧污泥微生物作用时间的延长,微塑料表面羰基和羟基等含氧官能团吸收峰强度呈增大趋势,接触角测试结果进一步证实微塑料表面亲水性增强。通过相关性分析可知,微塑料的羰基指数可较好地反映厌氧污泥微生物对聚乙烯和聚氯乙烯微塑料表面性质的作用,而聚丙烯和丁苯橡胶轮胎颗粒微塑料可通过1300~1500 cm^(-1)处的峰面积表征其表面性质的变化过程。该研究可为进一步研究污泥微生物驱动的微塑料的分解和反应行为提供理论依据。

药物和个人护理用品对地下水污染的风险评价

为进一步明确污泥土地利用过程中新型有机污染物—药物和个人护理用品(PPCPs)对地下水污染的风险,采用数学模型初步预测和评价了29种PPCPs在砂土和壤土2种介质条件下对地下水污染的风险。结果表明:砂土条件下,环丙沙星、氧氟沙星、土霉素、诺氟沙星和咖啡因等5种PPCPs的风险指数大于1,具有高地下水污染风险,其中,除咖啡因外,其余4种PPCPs均为抗生素类药物,应加强其在地下水中的监测和防控。壤土条件下,29种PPCPs对地下水均表现为低污染风险。吸附强度是影响PPCPs对地下水污染风险的最主要因素。PPCPs在包气带中的半衰期、有机碳-水分配系数、土壤密度、有机碳含量、含有机质的上层土壤层厚度是模型主要的敏感参数。不确定性分析显示,PPCPs的有机碳-水分配系数和其在包气带中的半衰期的改变对地下水污染风险评价结果影响较大。验证表明,地下水污染风险指数越大的PPCPs在地下水中的检出率也越高,说明评价结果具有一定的合理性。今后应加强对PPCPs降解产物、地下水中安全浓度值、共存PPCPs相互作用及介质非均质性影响等方面的研究,以便更加精确地评价PPCPs对地下水污染的风险。

鄱阳湖生态经济区污水处理厂污泥重金属污染特征、来源及潜在生态风险评价

鄱阳湖生态经济区是我国南部市场经济最活跃区域之一,为了解该区域城市污水处理厂污泥重金属的来源及污染情况,为污泥处理和资源化开发再利用提供科学依据,收集环鄱阳湖生态经济区主要城市污水处理厂脱水污泥,得到污泥中8种主要重金属含量,并分析重金属污染特征、来源和风险评价。结果表明:①研究区域污泥重金属含量高低依次为Zn、Cu、Pb、Cr、Ni、As、Cd和Hg,其中Cu、Zn、Pb、Cd和Cr变异程度较高,属于强变异。②主成分分析结果显示,研究区域污泥中重金属主要来源有2个,其中Cu、Zn、Pb、Cd、Cr和As来源主要为生活清洁和工业部门,Ni和Hg来源主要为电镀化工行业和医疗。③内梅罗综合污染指数为1.615,污泥重金属为轻度污染。④Cd元素地累积指数平均值最高,污染达强-极强污染级别。⑤Cd、Hg生态风险为严重风险,且Cd元素对研究区域生态风险影响最大,研究区域综合生态风险指数为467.43,区域潜在生态风险程度属于重风险。研究显示,鄱阳湖生态经济区污水处理厂脱水污泥中重金属污染程度中等,但Cd元素潜在生态风险值得关注。

淋洗后污泥对3种蔬菜种子萌发的影响

以2种污泥(SA、SB)为材料,研究皂角苷和柠檬酸联合淋洗后污泥(LSA、LSB)对萝卜、白菜和生菜种子的发芽率、发芽指数和根伸长抑制率的影响。结果表明,淋洗后污泥(LSA、LSB)中的重金属(Cd、Cu、Ni、Cr、Pb和Zn)和养分(有机质、N、P)均降低。随污泥添加量(总干质量的5%~50%)的增加,3种蔬菜种子的发芽率减小;而淋洗后污泥提高了种子的发芽率,淋洗后污泥添加量为50%时,3种蔬菜种子的发芽率均在90%以上。3种蔬菜种子的发芽指数随淋洗污泥(LSA、LSB)添加量的增加呈上升趋势。与SA、SB相比,添加淋洗污泥后,3种蔬菜种子的根伸长抑制率增大,小白菜根伸长抑制率增加了32%~35%。