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.     

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.     

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,...     

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...     

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...     

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.

     

Removal of organic contaminants in bioretention medium amended with activated carbon from sewage sludge

Bioretention, also known as rain garden, allows stormwater to soak into the ground through a soil-based medium, leading to removal of particulate and dissolved pollutants and reduced peak flows. Although soil organic matter (SOM) is efficient at sorbing many pollutants, amending the bioretention medium with highly effective adsorbents has been proposed to optimize pollutant removal and extend bioretention lifetime. The aim of this research was to investigate whether soil amended with activated carbon produced from sewage sludge increases the efficiency to remove hydrophobic organic compounds frequently detected in stormwater, compared to non-amended soil. Three lab-scale columns (520 cm³) were packed with soil (bulk density 1.22 g/cm³); activated carbon (0.5% w/w) was added to two of the columns. During 28 days, synthetic stormwater—ultrapure water spiked with seven hydrophobic organic pollutants and dissolved organic matter in the form of humic acids—was passed through the column beds using upward flow (45 mm/h). Pollutant concentrations in effluent water (collected every 12 h) and polluted soils, as well as desorbed amounts of pollutants from soils were determined using GC-MS. Compared to SOM, the activated carbon exhibited a significantly higher adsorption capacity for tested pollutants. The amended soil was most efficient for removing moderately hydrophobic compounds (log K _ow 4.0–4.4): as little as 0.5% (w/w), carbon addition may extend bioretention medium lifetime by approximately 10–20 years before saturation of these pollutants occurs. The column tests also indicated that released SOM sorb onto activated carbon, which may lead to early saturation of sorption sites on the carbon surface. The desorption test revealed that the pollutants are generally strongly sorbed to the soil particles, indicating low bioavailability and limited biodegradation.

     

去除污泥中重金属铬的生物淋滤反应器设计与应用

用微生物方法去除污泥中重金属（生物淋滤法）是近年来发展的新技术，探索工程化的条件有重要的应用价值。设计了一套容积为1m^3的生物淋滤反应器，由生物淋滤池、搅拌器、曝气器和空气压缩机等构成。其中，搅拌叶轮由平叶桨和斜叶桨组合而成。利用制革污泥进行了半连续的生物淋滤试验，结果表明，在反应器中污泥与菌体和营养物质能充分混匀，经过2-5d的处理，污泥pH持续下降到2．0以下，污泥中铬的溶出率达90％-99．5％。     

Biosolids management strategies: an evaluation of energy production as an alternative to land application

Currently, more than half of the biosolids produced within the USA are land applied. Land application of biosolids introduces organic contaminants into the environment. There are potential ecological and human health risks associated with land application of biosolids. Biosolids may be used as a renewable energy source. Nutrients may be recovered from biosolids used for energy generation for use as fertilizer. The by-products of biosolids energy generation may be used beneficially in construction materials. It is recommended that energy generation replace land application as the leading biosolids management strategy.     

脱水污泥制备含炭吸附剂及其应用研究

采用热解炭化法、物理活化法、化学活化法制备污泥含炭吸附剂,通过静态吸附实验研究各种影响污泥含炭吸附剂吸附性能的因素.实验结果表明,采用化学活化法制得的污泥含炭吸附剂吸附性能最好,在以ZnCl2为活化剂、锯末添加剂投加量为脱水污泥质量的1%、ZnCl2为3 mol/L、活化温度为450 ℃、活化时间为1.5 h、固液质量比(干污泥与活化剂溶液的质量比)为1:4的最佳制备条件下,制得的污泥含炭吸附剂碘吸附值在520 mg/g以上,产物收率>60%,比表面积>230 m2/g,总孔容积为0.35 mL/g,其中微孔容积为0.08 mL/g,中孔容积为0.23 mL/g.利用其处理城市污水,其对COD、色度、TP的去除率好于选定的商品颗粒活性炭.     

Complexation-flocculation of organic contaminants by the application of oxyhumolite-based humic organic matter

Control of hazardous organic micropollutants is a challenging water quality issue. Dissolved humic organic matter (DOM) isolated from oxyhumolite coal mined in Bohemia was investigated as a complexation agent to remove polycyclic aromatic hydrocarbons (PAHs) and functionalized phenols from water by a two-stage process involving complexation and flocculation. After the formation of humic-contaminant complexes, ferric salts were added resulting in the precipitation and flocculation of the DOM and the associated pollutants. Flocculation experiments with ferric ion coagulants indicated that precipitation of oxyhumolite DOM together with the complexed contaminants occurred at lower ferric ion concentrations than with the reference DOM in acidic environments (pH approximately 3.5). The complexation-flocculation removal rates for non-reactive PAHs characterized by small localization energies of pi-electrons correlated well with the complexation constants. On the other hand, the combined complexation-flocculation removal rates for activated PAHs including trans-stilbene, anthracene and 9-methyl anthracene, as well as functionalized polar phenols, were higher than predicted from the complexation coefficients. Methodological studies revealed for the first time that the ferric ion coagulant contributed to enhanced removal rates, most probably due to ferric ion-catalyzed pollutant degradation resulting in oxidized products.     

Recent advances in the application of magnetic Fe3O4 nanomaterials for the removal of emerging contaminants

Environmental Science and Pollution Research - Emerging contaminants (ECs) are widely distributed and potentially hazardous to human health and the ecological system. However, traditional...     

Model development and application for surfactant biodegradation in an acclimatising activated sludge system

A model for the biodegradation of non-ionic surfactants in an activated sludge system during acclimatisation was developed, based on respirometric and titrimetric experimental data. The data were obtained in a sequencing batch reactor (SBR) using a non-ionic surfactant as sole carbon source and sludge previously acclimatised to a different surfactant. The model was successfully applied to successive SBR-cycles of sludge acclimatisation processes subjected to two ethoxylated surfactants. The model was validated using the corresponding total organic carbon data. The evolution of the model parameters along the acclimatisation process was examined. An acclimatisation model was developed using the evolution of two of these parameters (affinity constant and inhibition constant), supported by two independently calculated acclimatisation indicators. This acclimatisation model was then applied to determine an optimal surfactant concentration sequence to feed non-acclimatised sludge during a period of 41 days, in order to induce pre-acclimatisation to this surfactant before it replaces another one in the wastewater. The model was also useful in the economical assessment of this and alternative procedures to cope with frequent changes in activated sludge feed composition.     

Butyltin accumulation in the marine clam Mya arenaria: an evaluation of its suitability for monitoring butyltin pollution

The use of Mya arenaria as a new sensitive biomonitor of butyltins pollution in the oceanic system was investigated. Field survey indicated that much higher levels of butyltin compounds were found in M. arenaria compared with the other species investigated. Using Mytilus edulis as a control organism, a 28 days exposure of tributyltin chloride (TBT) to M. arenaria for accumulation and subsequent 28 days breeding in clean seawater for elimination were conducted under laboratory conditions in order to confirm its high accumulation ability and characterize its kinetic behavior to TBT. Bioconcentration factor (BCF) of M. arenaria ranged from 15,538 to 91,800 after 28 days exposure. The rapid uptake and low rate to eliminate TBT of M. arenaria displayed first-order kinetics. M. arenaria shows potential as a new bioindicator to monitor TBT pollution in marine environment.     

基于CaO2的污泥处理应用技术研究进展

随着污水处理厂排泥量的剧增,污泥的处理处置成为当今急需解决的环境问题之一。基于目前污泥处理中CaO₂相关技术的研究现状,综述了CaO₂技术对于污泥减量化、无害化、资源化处理的促进作用,包括改善污泥脱水性能、实现污泥增溶减量、去除污泥中的有机污染物及重金属、促进污泥厌氧消化产酸产氢产甲烷等,展望了CaO₂相关技术的发展前景,以期为CaO₂相关污泥处理技术的研究与应用提供参考。     

粉煤灰/污泥烧结陶粒的研制与应用

以粉煤灰和工业污水处理站的剩余污泥为主要原材料,采用烧结法研制复合陶粒.分析了不同配方和不同烧结温度对陶粒性能的影响,以陶粒吸水率、容重为评价指标确定最佳配比和最佳烧结温度,并对陶粒用于铺设景观水底、治理城市水体进行了可行性分析.粉煤灰/污泥陶粒的容重为0.79～0.90 g/m3,吸水率为68.95%～80.01%.陶粒对水中氨氮和总磷吸附容量分别为0.03～0.05 mg/g和0.01～0.02 mg/g.     

微波辐照与碱联合处理污泥的试验研究

对采用微波辐照与碱联合(简写为微波辐照/碱)处理污泥过程中污泥性质的变化进行了研究.结果表明, 在相同NaOH投加量下, 达到相同污泥减少率(减量20%左右)时,用热碱处理需要0.5 h,而微波辐照/碱处理只需120 s.微波辐照/碱处理可以加剧污泥的溶胞作用,在微波辐照功率为800 W、辐照时间为120 s、每克悬浮固体(SS)NaOH投加量为0.16 g时,SS溶解率达到19.7%;处理后污泥中溶解性COD(SCOD)增至3 107 mg/L,比处理前增加了约11倍;TN增至59.9 mg/L,比处理前增加了约2.7倍;TP增至23.9 mg/L,比处理前增加了约0.9倍;NH+4\|N减至3 mg/L左右.NH+4\|N随着NaOH投加量的增加转变成NH3逸出.     

Observations on the suitability of the aethalometer for vehicular and workplace monitoring

A field study was undertaken to evaluate the suitability of the aethalometer, an instrument capable of performing near-real-time measurement of low-level (10-1,000 ng/m3) airborne combustion products, for vehicular and workplace monitoring. Several technical limitations were identified: (1) there was no ready means for external calibration of optical measurements; (2) airflow rates were unstable; (3) effective range of concentrations was limited; and (4) the aethalometer demonstrated sensitivity to movement and vibration. Unless addressed, these limitations will restrict future uses of the aethalometer for vehicular and workplace monitoring.