Monitoring of the Degradation Activities and the Diversity of the Microbial Community Degrading Refinery Waste Sludge

The biodegradation of n-alkanes and branched alkanes from waste sludge were observed in landfarming soils of Motor Oil Hellas (a petroleum refinery) and changes in the bacterial communities in the soils were monitored during the remediation. Bacterial 16S rRNA gene (rDNA)-based community fingerprint patterns were obtained from soil samples by terminal restriction fragment length polymorphism (T-RFLP) analysis. Changes in T-RFLP fingerprints, as well as in the petroleum contaminant composition of the polluted soil, correlated with degradation activities in field tests.     

Characterization of oily sludge from a wastewater treatment plant flocculation-flotation unit in a petroleum refinery and its treatment implications

Partly due to the complex and variable composition of oily sludge generated by the petroleum industry, cost-effective treatment and proper disposal pose considerable challenges worldwide. In this study, an extended component-based analysis of the oily sludge from a flocculation-flotation unit of a wastewater treatment system in a refinery in Sweden was carried out over 1 year. The heterogeneity of the oily sludge is illustrated by the wide ranges of concentrations found for different chemical components, particularly metals. Among the petroleum hydrocarbons, the most abundant compounds were nonpolar aliphatic hydrocarbons (63.7 ± 16.7 g kg⁻¹); from the benzene, toluene, ethylbenzene, and xylene group, xylenes (91–240 mg kg⁻¹) were most abundant; and among polycyclic aromatic hydrocarbons, naphthalene (25.7 ± 21.4), fluorene (27.25 ± 10.0), and phenanthrene (43.8 ± 18.4 mg kg⁻¹) were most abundant (all results in terms of dry matter). Based on the EU guidelines and the mean concentration values for metals found in the oily sludge, e.g., Pb (135.4 ± 125.8), Cu (105.2 ± 79.1), Hg (42.8 ± 31.3), Ni (320 ± 267.4), and Zn (1321.7 ± 529.9 mg kg⁻¹), disposal of oily sludge even in landfills for hazardous waste is not allowed. The organic content of the sludge can be reduced through biotreatment, but not the metal content. A multistep component-based treatment scheme is therefore needed.     

中和—絮凝法回收硝酸型退锡废水中的锡

将传统的中和法和絮凝法相结合,采用中和—絮凝法回收硝酸型褪锡废水中的锡,考察了反应终点体系pH、碱液浓度、絮凝剂浓度等因素对锡回收效果的影响。实验结果表明,在NaOH溶液浓度为6 mol/L、反应终点体系pH为0.8、聚丙烯酰胺溶液质量浓度为3 g/L的工艺条件下,可得到干基锡含量54.6%（w）的高品位锡泥。与传统的单一中和/絮凝法相比,采用中和—絮凝法不仅可以有效提高生产效率,而且减少了碱液和絮凝剂用量,回收锡之后体系中大量的硝酸可进一步回收利用。     

炼油废水污泥脱水工艺条件的优化

采用化学除油降黏—污泥调理—离心脱水工艺处理某炼油厂废水处理系统的混合污泥，并对工艺条件进行优化。实验结果表明，最佳的工艺条件为：化学除油降黏阶段处理体系的pH=4，反应温度35 ℃，H₂O₂加入量 2 g/L，m（H₂O₂）∶ m（Fe²⁺）=4，反应时间 60 min；污泥调理反应阶段的CaO加入量7.0 g/L；离心脱水阶段在分离因数为1 558时脱水5 min。在此条件下，得到的泥饼的含水率为70.0%~75.0%（w），含油率小于2%（w），污泥比阻约为3.0×10⁷ s²/g。     

炼油废水处理装置提标改造

对某炼油厂废水处理装置进行提标改造。在原炼油废水处理流程的基础上将接触氧化池改造为移动床生物膜反应器（MBBR）,将斜板沉淀池改换为高密度沉淀池,分别为新增曝气生物滤池（BAF）、催化臭氧氧化等深度处理工艺。改造后装置运行平稳,出水各项指标的6个月平均值：COD 25.2 mg/L,ρ（NH₃-N） 1.3 mg/L,TN 12.6 mg/L,TP 0.11 mg/L,满足《石油炼制工业污染物排放标准》（GB 31570—2015）的排放要求。改造后每年COD和NH₃-N消减分别约为240 t和44 t,环境效益显著。     

Fate of mutagenic chemicals in soil amended with petroleum and wood preserving sludges

A field study using monoliths (lysimeters) of a sandy clay loam soil was conducted to assess the fate of mutagenic chemicals after refinery and wood preserving bottom sediment sludges were land treated. The Ames Salmonella/microsome assay¹ was used to determine the direct (without metabolic activation, −S9) and indirect (with metabolic activation, + S9) mutagenicity of the wastes, unamended soil, waste amended soils, and leachate. Extracts having a mutagenic ratio (MR) (MR= No. colonies from sample extract/No. colonies from DMSO solvent control) of ⩾ 2 were considered positively mutagenic. Extracts of the wood preserving waste sludge without activation were non-mutagenic (MR < 2) but extracts with activation ( + S9) produced very strong indirect mutagenicity (MR = 7.9). After soil incorporation, the waste amended soil produced very strong direct (MR = 8.9) and indirect (MR = 11.9) mutagenicity by day 180 and remained mutagenic (MR = 5.7, −S9; MR = 3.95, + S9) through day 350. The amount of residue in leachate from the wood preserving waste amended lysimeters was significantly greater (P <0.05) than the unamended soil during the first 90 days after waste application, but was not different after 90 days. The leachate residue from wood preserving waste amended lysimeters in the 90–180-day period produced mutagenic responses both with (MR = 2.24 and 2.51) and without (MR = 2.29) activation. Polynuclear aromatic hydrocarbons were the main constituents identified in the leachate residues that produced a mutagenic response. Soil treatment of the refinery sludge reduced its weak indirect mutagenicity before soil incorporation (MR = 2) to non-mutagenic (MR = 1.4) immediately following soil treatment. The MR of the waste amended soil increased to 1.7 by day 180 but by day 350 decreased to a level equal to that observed at day 0 (MR = 1.4). Leachate from the refinery amended lysimeters had significantly greater (P < 0.05) amounts of organic residue than unamended lysimeters 180 to 350 days after waste application. The leachate from one refinery waste amended lysimeter (90–180 days after waste application) produced a mutagenic response (MR = 3.16). The refinery sludge was detoxified shortly after soil treatment, but the wood preserving sludge required > 350 days to detoxify in the soil environment. The possibility exists that mobile mutagenic chemicals may leach into underlying groundwater from the treatment zone of soils amended with refinery and wood preserving sludges.     

Use of rubber and bentonite added fly ash as a liner material

In many countries regulations require all hazardous waste disposal facilities to be lined with suitable impermeable barriers to protect against contamination. In this study, a series of laboratory tests on rubber and bentonite added fly ash were conducted. The aim of the tests was to evaluate the feasibility of utilizing fly ash, rubber and bentonite as a low hydraulic conductivity liner material. Type C fly ash was obtained from Soma thermal power plant in Turkey; rubber in pulverized form was waste from the retreading industry. To investigate the properties of rubber and bentonite added fly ash, hydraulic conductivity, leachate analysis, unconfined compression, split tensile strength, one-dimensional consolidation, swell and freeze/thaw cycle tests were performed. The overall evaluation of results have revealed that rubber and bentonite added fly ash showed good promise and a candidate for construction of a liner.     

Wood Residues as Raw Material for Biorefinery Systems: LCA Case Study on Bioethanol and Electricity Production

Fossil energy and chemical sources are depleting. There is a critical need to change the current industry and human civilization to a sustainable manner, assuring that our way of life actual continues on the path of improvement after the depletion of fossil energy sources. The utilization of agricultural residues as raw materials in a biorefinery is a promising alternative to fossil resources for production of energy carriers and chemicals, thus mitigating climate change and enhancing energy security. Biorefinery is a concept of converting lignocellulosic biomass or grains (such as corn) to chemicals, materials and energy on which human civilization runs, replacing the need for petroleum, coal, natural gas, and other nonrenewable energy and chemical sources. Lignocellulosic biomass is renewable, that is plant synthesizes chemicals (by drawing energy from the sun and carbon dioxide) and water from the environment, while releasing oxygen. Combustion of biomass releases energy, carbon dioxide and water. Therefore, biorefinery plays a key role in satisfying human needs for energy and chemicals by using the biomass production and consumption cycle. This paper focuses on a biorefinery concept and in particular on the bioethanol production from wood residues. In order to evaluate the environmental reliability of the system under study, the biorefinery plant (producing bioethanol and electricity from wood residues) was compared, by using the LCA methodology, to both conventional refinery system (producing light fuel oil and electricity from petroleum) and biorefinery plant based on corn feedstock producing the same goods. Interesting considerations about LUC emissions effect on biorefinery sustainability are also reported. The obtained results show that by assigning reasonable values to the three damage categories used in the eco-indicator 99 methodology the biorefinery system is preferable, from an environmental point of view, to the conventional refinery system analysed. This finding confirms the high potentials of this innovative plant technology.     

厌氧折流板污泥对偶氮染料酸性大红GR的生物降解性能研究

研究了厌氧折流板反应器（ABR）活性厌氧污泥对偶氮染料酸性大红GR的吸附与生物降解性能，并与失活污泥进行了对比。试验结果表明，35℃时厌氧活性污泥2h、12h、6d的脱色率分别为78.2%、86.0%、98.9%。无论在反应初始阶段还是稳定阶段，ABR活性厌氧污泥对染料的去除效果都明显优于失活污泥。而且在初始COD为1152mg/L的，由于非有效吸附位置染料脱落等原因，反应期间，失活污泥混合液中染料浓度还会升高。情况下，活性厌氧污泥混合液出水COD为86.0mg/L，去除率约为92.5%。这说明ABR厌氧污泥微生物在短时间内便可以得到驯化，一旦厌氧微生物适应生长环境，生物降解便开始对染料发挥作用。     

Enhanced Macroporous Cationic Chitosan Hydrogel by Freezing and Thawing Method with Superadsorption Capacity for Anionic Dyes

Journal of Polymers and the Environment - In this study, we have developed a simple technique to prepare cationic chitosan hydrogel with interconnected porous structure using freeze–thaw...     

Biodegradation of Aliphatic and Aromatic Hydrocarbons: Specificity among Bacteria Isolated from Refinery Waste Sludge

Indigenous microorganisms, enriched and isolated from refinery waste sludge, were observed to possess a broad range of metabolic activities for mixtures of several classes of substrates of petroleum hydrocarbons, such as monoaromatic and polycyclic aromatic hydrocarbons (PAHs) and n- and branched alkanes. Three of the best-growing bacterial isolates selectively enriched with these compounds were identified by 16S rDNA sequencing as belonging to the genera Enterobacter and Ochrobactrum. Two of them, Enterobacter sp. strain EK3.1 and Ochrobactrum sp. strain EK6 utilise a hydrocarbon mixture of the branched alkane 2,6,10,14-tetramethylpentadecane and the PAHs acenaphthylene and acenaphthene. Enterobacter sp. strain EK4 can grow with a mixture of 2,6,10,14-tetramethylpentadecane, toluene, acenaphthylene and acenaphthene as carbon sources. Nucleic acid fingerprint analysis, by terminal restriction fragment length polymorphism (T-RFLP) of the PCR-amplified 16S rRNA genes, of the autochthonous bacterial community in contaminated soil samples showed complex and different community structures under different treatments of refinery waste sludge in landfarm areas. The characteristic peaks of the T-RFLP profiles of the individual, isolated degrading bacteria Enterobacter spp. and Ochrobactrum sp. were detected in the T-RFLP fingerprint of the bacterial community of the four months old treated landfarm soil, suggesting the enrichment of bacteria belonging to the same operational taxonomic units, as well as their importance in degrading activity.     

Reduction of oil in sludges from light petroleum separators

A flotation treatment for reducing the oil content of sludges accumulated in light petroleum separators and grit traps is described. Hydrocarbon content of the sludge can be reduced to less than 3% of the dry solids by air flotation assisted by appropriate surfactants. There is a corresponding reduction in Polychlorinated Biphenyls (PCBs) and Polyaromatic Hydrocarbons (PAHs). Air escaping from the flotation cells is scrubbed in a bio-filter and water is purified by activated sludge or a further flotation method. Recovered oil can be further dewatered to produce a useful fuel.     

Leaching of wood ash products aimed for spreading in forest floors--influence of method and L/S ratio

Use of biofuels in the form of logging residues is increasing in the European countries. This intensive forestry, where entire trees are removed from the felling sites, may contribute to a negative nutrient balance in the forest soil. Recycling of ash from the combustion of clean wood fuel, sometimes in combination with limestone or additives/binders, back into the forest soil could maintain the soil nutrient reservoir intact. Before spreading ash, it is important to determine its contents and, particularly, its decomposition pattern using reliable laboratory leaching tests. In this study, mineralogy and the leaching of Na, Ca, K, Mg, Mn, Al, Cu, Fe, P, and Zn from wood ash pellets and granules, produced both from green liquor sludge and fly ash, are examined by XRD and by subjecting these substances to three different laboratory leaching tests: upflow percolation (CEN/TS 14405), batch leaching (SS-EN12457), and a new Swedish leaching test using a magnetic stirrer. Mineral phases such as quartz, ettringite, calcite, gehlenite, and aphtitalite were identified in the ash granules and in the ash/green liquor sludge granules, by means of XRD. Six additional minerals were detected in the granules of ash only, and another six in the ash/green liquor sludge granules. At L/S 2, the batch leaching test resulted in the highest amounts of elements leached and the upflow percolation test the lowest. At L/S 10, both the batch leaching test and the upflow percolation test resulted in high amounts of elements leached. The batch leaching test at L/S 10 complies quite well with the percolation test and could be suitable for ash/green liquor sludge granule evaluation in daily practice. The magnetic stirrer test seems to underestimate the release potential of elements from granules. The batch test is simple to perform, and has the ability to dissolve 70-80% of the elements with the highest mobility from the materials under study.     

Mercury leaching characteristics of waste treatment residues generated from various sources in Korea

In this study, mercury (Hg) leaching characteristics of the waste treatment residues (fly ash, bottom ash, sludge, and phosphor powder) generated from various sources (municipal, industrial, medical waste incinerators, sewage sludge incinerator, oil refinery, coal-fired power plant, steel manufacturing plant, fluorescent lamp recycler, and cement kiln) in Korea were investigated. First, both Hg content analysis and toxicity characteristic leaching procedure (TCLP) testing was conducted for 31 collected residue samples. The Hg content analysis showed that fly ash from waste incinerators contained more Hg than the other residue samples. However, the TCLP values of fly ash samples with similar Hg content varied widely based on the residue type. Fly ash samples with low and high Hg leaching ratios (R_L) were further analyzed to identify the major factors that influence the Hg leaching potential. Buffering capacity of the low-R_L fly ash was higher than that of the high-R_L fly ash. The Hg speciation results suggest that the low-R_L fly ashes consisted primarily of low-solubility Hg compounds (Hg₂Cl₂, Hg⁰ or HgS), whereas the high-R_L fly ashes contain more than 20% high-solubility Hg compounds (HgCl₂ or HgSO₄).     

炼油厂"三泥"离心脱水处理研究

通过对目前炼油厂“三泥”性状的调查，利用已有污泥处理设施进行了炼油厂“三泥”离心分离的现场试验，并分析了影响“三泥”离心分离处理工艺的主要因素，发现了离心机转速和絮凝剂投加量对“三泥”离心分离的有关规律和最佳操作条件，在此基础上，提出了适合炼油厂“三泥”处理系统的优化方案。     

添加剩余活性污泥无害化处理含油钻屑

采用剩余活性污泥对废弃含油钻屑进行无害化处理。考察了加入剩余活性污泥后混合物料中微生物浓度、碱解氮含量、有效磷含量、总石油烃(TPH)含量和组分的变化,并对降解后混合物料的生物毒性进行了评价。实验结果表明:加入剩余活性污泥后,总细菌浓度保持在较高水平;碱解氮含量逐渐减少后保持稳定,有效磷含量在一定范围内波动,整体略有增加;剩余活性污泥的加入量为20%～60%(w)时, TPH去除率均达到74%以上,远高于未添加剩余活性污泥的对照组(28.8%);剩余活性污泥的添加能有效促进微生物对含油钻屑中TPH的降解及氮元素的转化,添加50%(w)以上的剩余活性污泥能使处理后含油钻屑的生物毒性更低,更有利于含油钻屑的无害化处理。     

用CO_2改性碱渣废水强化炼油废水的硝化效能

针对炼油废水缺乏碱度而硝化效能受限问题,以CO_2曝气处理后的改性碱渣废水为碱度补充剂,按一定配比加入炼油废水好氧阶段以强化硝化效能。实验结果表明:经流量为1 L/min的CO_2连续曝气处理5 h后,碱渣废水p H可降至7.2~7.8,钙元素质量浓度可降低90.65%,并去除了部分汞、砷等有毒重金属;将该改性碱渣废水以1∶99的体积比加入炼油废水并进行生化处理,COD去除率可达90.2%;相较于未补充碱渣的炼油废水,出水ρ(NO3--N)提高25%~30%,硝化细菌菌群密度增加52%,污泥絮体形态结构未发生改变。     

Evaluation of bangkok sewage sludge for possible agricultural use.

Bangkok (Thailand) covers more than 1500 km2 and has 10 million inhabitants. The disposal of wastewater is creating huge problems of pollution. The estimated amount of sewage sludge was estimated to be around 108 tonnes dry matter (DM) per day in 2005. In order to find a lasting way of disposal for this sewage sludge, the suitability of the sludge produced from three waste-water treatment plants for use as fertilizing material was investigated. Monthly samplings and analysis of sewage sludge from each plant showed that the composition of sludge varied according to the area of collection and period of sampling, and there was no link to rainfall cycle. Plant nutrient content was high (i.e. total N from 19 to 38 g kg(-1) DM) whereas organic matter content was low. The concentrations of heavy metals varied between sludge samples, and were sometimes higher than the E.U. or U.S. regulations for sewage sludge use in agriculture. Faecal coliforms were present in the sludge from one of the plants, indicating a possible contamination by night soil. In order to decrease this potentially pathogenic population the sewage sludge should be heated by composting. As the C/N ratio of sewage sludge was low (around 6) some organic by-products with high carbon content could be added as structural material to enhance the composting.     

Life cycle assessment of sewage sludge co-incineration in a coal-based power station

A life cycle assessment was conducted to evaluate the environmental and economic effects of sewage sludge co-incineration in a coal-fired power plant. The general approach employed by a coal-fired power plant was also assessed as control. Sewage sludge co-incineration technology causes greater environmental burden than does coal-based energy production technology because of the additional electricity consumption and wastewater treatment required for the pretreatment of sewage sludge, direct emissions from sludge incineration, and incinerated ash disposal processes. However, sewage sludge co-incineration presents higher economic benefits because of electricity subsidies and the income generating potential of sludge. Environmental assessment results indicate that sewage sludge co-incineration is unsuitable for mitigating the increasing pressure brought on by sewage sludge pollution. Reducing the overall environmental effect of sludge co-incineration power stations necessitates increasing net coal consumption efficiency, incinerated ash reuse rate, dedust system efficiency, and sludge water content rate.     

多组分电镀污泥酸浸出液中铁的分离

研究了采用Ｐ５０７－煤油－Ｈ２ＳＯ４萃取体系分离电镀污泥酸浸出液中Ｆｅ＾３＋的工艺，确定了从含有多种上金属组分的硫酸溶液中萃取铁的最佳工艺条件以及负载有机相反萃取较优工艺条件，研究结果表明，以Ｐ５０７为萃取剂，硫酸为洗涤剂，经３级萃取、２级洗涤的分馏萃取后，可以从含有多种金属组分的硫酸溶液中分离出９９．９％的铁，其他金属的流失量小于１％，不影响后者的回收，铁在工艺过程中以ＦｅＣｌ３·６Ｈ２Ｏ的形式