Synthetic fibers as an indicator of land application of sludge

Synthetic fabric fibers have been proposed as indicators of past spreading of wastewater sludge. Synthetic fiber detectability was examined in sludges (dewatered, pelletized, composted, alkaline-stabilized) and in soils from experimental columns and field sites applied with those sludge products. Fibers (isolated by water extraction and examined using polarized light microscopy) were detectable in sludge products and in soil columns over 5 years after application, retaining characteristics observed in the applied sludge. Concentrations mirrored (within a factor of 2) predictions based on soil dilution. Fibers were detectable in field site soils up to 15 years after application, again retaining the characteristics seen in sludge products. Concentrations correlated with residual sludge metal concentration gradients in a well-characterized field site. Fibers found along preferential flow paths and/or in horizons largely below the mixed layer suggest some potential for translocation. Synthetic fibers were shown to be rapid and semi-quantitative indicators of past sludge application.     

连续施用城市污泥后林地土壤中重金属的含量变化及生态风险

将堆肥污泥施用于林地能够增加土壤肥力,促进林木增长,具有广阔的应用前景,但污泥中所含重金属进入土壤环境后的积累特征及所引起的生态风险问题亦备受关注.连续5年将污泥堆肥产品施用于林地并对相应林地土壤重金属含量进行了同步监测,采用单因子指数法和潜在生态危害指数法分析评价了污泥堆肥泥质、污泥堆肥不同施用比例以及是否连续施肥等...     

Properties of biochars from conventional and alternative feedstocks and their suitability for metal immobilization in industrial soil

In contaminated soils, excessive concentrations of metals and their high mobility pose a serious environmental risk. A suitable soil amendment can minimize the negative effect of metals in soil. This study investigated the effect of different biochars on metal (Cu, Pb, Zn) immobilization in industrial soil. Biochars produced at 300 and 600 °C from conventional (MS, maize silage; WP, wooden pellets) and alternative (SC, sewage sludge compost; DR, digestate residue) feedstocks were used as soil amendments at a dosage of 10 % (w/w). The type of feedstock and pyrolysis temperature affected the properties of the biochars and their ability to immobilize metal in soil. Compared to production at 300 °C, all biochars produced at 600 °C had higher pH (6.2–10.7), content of ash (7.2–69.0 %) and fixed carbon (21.1–56.7 %), but lower content of volatile matter (9.7–37.2 %). All biochars except DR biochar had lower dissolved organic carbon (DOC) content (1.4–2.3 g C/L) when made at 600 °C. Only MS and SC biochars had higher cation exchange capacity (25.2 and 44.7 cmol/kg, respectively) after charring at 600 °C. All biochars contained low concentrations of Cd, Cu, Ni, Pb and Zn; Cd was volatilized to the greatest extent during pyrolysis. Based on FTIR analysis and molar ratios of H/C and O/C, biochars had a greater degree of carbonization and aromaticity after charring at 600 °C. The efficiency of the biochars in metal immobilization depended mainly on their pH, ash content, and concentration of DOC. SC and DR biochars were more effective for Cu and Zn immobilization than MS and WP biochars, which makes them attractive options for large-scale soil amendment.     

Metal concentrations in edible mushrooms following municipal sludge application on forest land

In the context of biosolids utilisation in forestry, effects of sludge application on mushroom metal concentration were studied in six sites of maritime pine forests in the South-West of France. Municipal sludge were applied at a rate of 6 T dry matter per hectare. Edible mushrooms were collected two years after sludge application. As, Cd, Cu, Hg, Pb, Se and Zn concentrations were determined. Results showed a high variability for trace element concentrations in mushrooms collected from control areas. No significant correlation was found between soil parameters (pH and trace elements concentrations) and mushroom trace element concentrations. Even if the concentration of trace metals increased in the soils, sludge application did not affect As, Cu, Se and Zn concentrations in carpophores but slightly increased Cd, Pb and Hg concentrations on some sites. This effect is dependent on sludge type and sites.     

面向矿山废弃地复垦的炉渣污泥人工土壤的理化特性

通过添加不同比例的燃煤电厂粉煤灰和炉渣对城市污泥进行钝化,配制成不同灰渣比例的人工土壤,对人工土壤的pH、电导率、养分含量、重金属含量以及持水、渗水性能进行了研究。结果表明,污泥人工土壤pH介于7.5～8.0之间,属于弱碱性土壤;电导率变化范围为2.93～3.71 mS/cm,表明盐分含量较高。污泥人工土壤中有效态养分含量随炉渣比例提高而增加,所有配比人工土壤有机质和有效磷、速效钾的含量达到高肥力水平。人工土壤中Cd、Ni、Pb、Cu、Zn含量均明显低于国家农用标准(GB 4284-84、GB 8173-87)。粉煤灰渣对污泥中有效态Cd、Ni、Pb和Cu有钝化作用,使其向无效态转化,对Zn则有活化作用。炉渣对Cd、Ni的钝化作用要优于粉煤灰,而粉煤灰对Pb、Cu的钝化作用要优于炉渣。添加炉渣提高了污泥人工土壤水分的蒸发量,减弱了人工土壤的持水能力,但加入炉渣使人工土壤的渗透系数显著增加,提高了其渗水性能。     

两性高分子污泥脱水剂P(AM-DAC-AMPS)的表征与应用

采用三元自由基水溶液聚合法,以丙烯酰胺(AM)、丙烯酰氧乙基三甲基氯化铵(DAC)、2-丙烯酰胺基-2-甲基丙磺酸(AMPS)为原料,经过复合引发制备了两性高分子脱水剂P(AM-DAC-AMPS),简称为PADA).采用傅里叶变换红外光谱(FT-IR)、透射电镜(TEM)对结构进行了表征,结果证明聚合物为三元共聚物,并具有良好的直链结构.经过PA-DA、CPAM调理后的污泥最佳比阻(r)分别为1.58×109s2/g和1.8×109s2/g,离心后含水率分别为77.4％和78.1％;污泥沉降速度分别为0.3 mL/min和0.25 mL/min;污泥滤液中,多糖去除率分别为70.3％和40.7％,蛋白质去除率分别为31.5％和17.5％;表明PADA比CPAM具有更好的脱水性能.并且通过SEM观察,发现PADA的调理增强了污泥絮体的密实性.     

Removal and recovery of uranium (VI) from aqueous solutions by residual sludge and its biochars

Environmental Science and Pollution Research - The removal and recovery of uranium (VI) from water solutions are critical for energy and environmental security. In this study, hydrochar at 100,...     

新制备生物炭的特性表征及其对石油烃污染土壤的吸附效果

生物炭作为一种绿色环保的功能材料因其在污水处理和污染土壤修复方面具有显著效果而受到极大关注。采用红外光谱、元素分析仪及微孔分析对不同温度(200、300、400、500和600℃)条件下制备的木屑和麦秆生物炭进行特性表征,并采用制备的生物炭净化石油污染土壤,分别考察了污染物性质、生物质原料和热解温度对其净化效果的影响。结果表明,随着热解温度的增高,生物炭芳香化程度增加,极性降低,微孔结构逐渐发育,表面积增大。加入生物炭33 d后,污染土壤中总石油烃及其组分烷烃的浓度比对照略有降低,而PAHs浓度下降显著。随着热解温度升高,2种生物炭对PAHs的吸附强度均逐渐增大,芳香度增高、表面积增大是强吸附的主要原因。2种生物炭在400℃及以下温度制备时对PAHs的吸附强度为:木屑生物炭 > 麦秆生物炭;而400℃以上温度制备的生物炭吸附强度则相反,即麦秆生物炭 > 木屑生物炭,说明生物炭原料对其吸附强度也具有显著影响。     

剩余污泥生物干化处理及产物土地利用潜力

以昆明地区污水处理厂脱水污泥为对象进行生物干化处理,考察了典型工况条件下污泥干化处理效果,探究了微生物活性及其有机质代谢,并对干化处理产物的土地利用潜力进行了评价分析。结果表明,采用污水厂脱水污泥进行处理时,混合物料初始含水率以65%左右较为适宜,采用底部间歇曝气+顶部间歇抽风的通风方式,堆体自热升温至60 ℃以上,高温期持续时间长达30 h;干化处理120 h时,含水率降低至50%以下,水分净去除率达到16%。干化进程中,混合料中DOC质量浓度呈降低趋势,但SCFAs组分及其浓度波动明显。伴随着堆体温度的变化,常温、中温或嗜热微生物发生更替,微生物活性及其生化代谢差异明显。干化产物中可溶性磷以及氮钾质量分数均较高,重金属Cd、As、Hg满足GB4284-2018 B级标准限值,Cr、Pb等其他重金属质量浓度满足A级标准限值,种子发芽指数GI值高达90%,污泥干化产物具备园林绿化、矿山修复等方面土地利用前景。本研究结果可为污水厂污泥处理处置及资源化利用提供参考。     

An assessment of the risks associated with PCDDs and PCDFs following the application of sewage sludge to agricultural land in the UK

A model has been developed to describe the transfer of PCDDs and PCDFs from sludge-amended soils to the human foodchain. The model is conservative and assumes that all foods consumed by an individual are derived from sludge-amended soils. Predicted concentrations of PCDDs and PCDFs in potatoes, cereals, root vegetables and leafy vegetables were in close agreement with mean concentrations reported in the food survey conducted by MAFF in the UK. Predicted concentrations in milk were well below the Maximum Tolerable Concentration adopted by MAFF. Assuming a half-life of ten years in sludge-amended soils, the maximum estimated incremental daily intake (IDI) predicted by the model following ten applications of sludge to agricultural land was 0.80 pg I-TEQ kg⁻¹ day⁻¹, representing an increase of approximately 45% on current levels of background exposure. For an individual whose diet is solely derived from sludge-amended soils, the total exposure is predicted to be approximately 181 pg I-TEQ day⁻¹ or 2.6 pg I-TEQ kg⁻¹ day⁻¹. This compares with an average background exposure of approximately 2 pg I-TEQ kg⁻¹ day⁻¹, well within the TDI of 10 pg I-TEQ kg⁻¹ day⁻¹ and indicates that the application of sewage sludge to agricultural land under the conditions assumed would not appear to present a significant health risk under the conservative scenarios considered in this assessment.     

不同性状城市污水污泥在草坪生产中的应用研究

将城市污水污泥的生污泥和腐熟污泥施用于土壤,对该土壤上生长的高羊茅的生物量、土壤的理化特性等进行测定,并将污泥肥效与鸡粪进行了对照.结果表明,腐熟污泥对高羊茅生长的抑制作用主要表现在地上部分,对于其地下部分的生长存在着促进作用,而生污泥对高羊茅生长的促进作用主要表现在地上部分,施用量较大时会对其地下部分的生长产生轻微的...     

城市污泥堆肥产品施用对沙荒地土壤理化性质及高羊茅生长的影响

通过盆栽实验研究了城市污泥堆肥产品4种施用比例（0、10%、25%和50%）对沙荒地土壤理化性质及高羊茅生长的影响,结果表明：污泥堆肥产品的施加使混配土壤pH值向更利于高羊茅生长的pH范围（6.0~7.0）变化,土壤电导率随着施肥比例的增大有显著的增加,当施肥比例为10%、25%、50%时,土壤电导率分别为不施肥沙土的11.93、12.66和19.81倍;城市污泥堆肥产品施用后可显著提高沙荒地土壤中全氮、全磷、全钾及有机质含量,施肥比例为10%、25%和50%的沙土中有机质含量分别是不施肥沙土的3.69、4.22和5.65倍。污泥堆肥产品的施入有利于高羊茅对营养元素氮、磷和钾的吸收,进而促进了高羊茅的生长,但是这种促进作用在实验初期较为缓慢,直到实验后期方才显现出来。当施肥比例为25%时,高羊茅对营养物质的利用率达到最高,确定其为沙荒地土壤改良较为适宜的施肥比例。     

不同热解温度污泥生物炭对Pb2+、Cd2+的吸附特性

采用剩余污泥为原料,分别于300、400、500℃缺氧条件下制备污泥生物炭,利用X射线能谱仪（EDS）、环境扫描电镜（SEM）、红外光谱（FTIR）对其进行表征,并探究不同吸附时间,不同pH和不同Pb2+、Cd2+浓度下污泥生物炭对Pb2+、Cd2+的吸附特性,以期拓展污泥资源化利用途径。结果表明,准二级动力学方程能更好地描述污泥生物炭对Pb2+、Cd2+的吸附过程,约30 h达到平衡,其吸附主要受化学吸附控制。随溶液初始pH的升高,重金属的吸附量呈先增高后降低趋势,在pH 4.5时对Pb2+的吸附量最大,而Cd2+在pH 6.5时最大。在25℃时,低温热解制备的污泥生物炭对Pb2+、Cd2+的吸附量为RC500 > RC400 > RC300,RC500的饱和吸附量分别为Pb2+（14.39 mg·g-1）>Cd2+（1.45 mg·g-1）,污泥生物炭对重金属离子的吸附量与其水合离子半径呈负相关。     

New biopolymer from biomass for conditioning and dehydration of sewage sludge: application on the sludge of Bouira WWTP

Environmental Science and Pollution Research - Sewage treatment plants in Algeria produce huge quantities of sludge expressed in tons annually. This sludge produced is unfortunately contaminated...     

河湖疏浚淤泥的表征、絮凝和脱水

以无锡锡山湿地公园河道淤泥及太湖贡湖湾疏浚底泥为研究对象,对比分析了两种淤泥的矿物组成、粒径分布及泥微粒表面基团、ζ电位等理化特性。以聚丙烯酰胺类聚合物(polyacrylamide,PAM)为絮凝剂,对比分析了其在2种底泥絮凝分离、真空抽滤脱水过程中的作用特征,并对相关影响因素进行了探讨。结果表明,两种淤泥样具有相近的主体矿物组分、有机基团及ζ电位值,但有机质含量稍高的淤泥样中大颗粒所占比例相对较高。相比阳离子型PAM,阴离子型PAM在较少用量下即可获得较大絮团,但上清液浊度较高。絮凝泥在抽滤过程受絮团尺寸影响较大, PAM不同类型基团间的差异对其影响较小,但对趋于平衡后的泥饼含水率略有影响。     

铁基污泥炭活化过硫酸盐调理污泥脱水

利用给水厂含铁污泥和污水厂污泥混合热解制备铁基污泥炭 (Iron-SBC) ,作为过硫酸盐活化剂,用于调理污泥脱水。研究了Iron-SBC的最佳制备条件及其活化PDS调理污泥脱水的效果,并探究其活化机制。结果表明,Iron-SBC最佳制备条件为给水厂含铁污泥和污水厂污泥比例3∶1、热解温度800 ℃、热解时间1 h。XRD、FT-IR及BET分析结果表明,与原混合污泥相比,Iron-SBC比表面积和孔容增大,表面负载了Fe⁰和FeO、Fe₂O₃、Fe₃O₄等铁的氧化物,并含有大量官能团。在活化PDS过程中,Iron-SBC表面的Fe⁰、铁的氧化物及官能团等均能有效活化PDS,产生SO₄⁻·和·OH自由基。XPS分析结果表明,Iron-SBC表面部分Fe²⁺被氧化为Fe³⁺,官能团C-C、C-OH和C=O等被氧化,并有Fe-O键生成。经Iron-SBC/PDS调理污泥后,CST、SRF和W_c分别由原泥的19.1 s、14.9×10¹² m·kg⁻¹和85.06%下降到8.4 s、5.4×10¹² m·kg⁻¹和73.48%。本研究结果可为含铁污泥和剩余污泥资源化及污泥深度脱水提供参考。     

Risk assessment of land-use suitability and application to Tangshan City

Risk assessment for suitability is one of the main problems in city landuse planning for disaster prevention. Decision-making strategy using GIS-based Ordered Weighted Averaging (OWA) method is discussed through analysing OWA evaluation procedure. Data of geological disaster in Tangshan City are used to calculate the distances from dangerous areas or safety area to yield evaluation criteria for all disaster factors of land-use suitability.     

A review of the application of different treatment processes for oily sludge

Oily sludge contains high concentrations of total petroleum hydrocarbons and heavy metals, which seriously impact the environment and human health. How to dispose of and use the oily sludge has attracted an increasing amount of attention. This study introduces harmless and resource-based oily sludge treatment technologies. It summarizes the technologies from various aspects, such as the process principle, influencing factors, advantages, and disadvantages, and analyzes and summarizes the status quo of the development of the technologies. In comparison, the direction of processing technology development is discussed to provide reference for processing technology improvements, optimization, and efficiency improvements.

     

高负荷活性污泥法中污水有机组分表征

污水有机组分表征是高负荷活性污泥法(HRAS)模型建立的基础。针对经典活性污泥1号模型不适用于HRAS这一问题,提出了相应的双水解模型,即将污水有机组分中水解型有机物分为快速水解型与慢速水解型2种,发现两者水解动力学参数具有明显差异。对原水氧利用速率进行参数拟合,通过灵敏度和共线性分析,估计了快速生物降解型有机物、快速水解型有机物、慢速水解型有机物以及异养菌等4种污水有机组分,探讨了污水有机组分与增加HRAS碳源捕获率的关系。结果表明：以上4种有机组分均可被准确识别,共线性指数γ_K低于经验限值,各组分比例分别为13.9%、11.6%、12.6%和12.8%;从污水组分角度来说,提高HRAS碳源捕获率的3个方向分别为：反应器中的异养菌尽可能将快速生物降解型有机物和快速水解型有机物同化生成细胞物质;避免絮体污泥中的慢速水解型有机物过量水解;抑制异养菌衰减,减少内源呼吸产物的产生。双水解模型对污水有机组分成功表征有助于HRAS的设计、运行及优化。