生物法修复废弃钻井泥浆和含油污泥的研究进展

废弃钻井泥浆和含油污泥是石油工业产生最多的含油固体废弃物。它们是一种含有多种复杂成分的悬浊液,包括石油烃(PHCs)、水、重金属、化学处理剂和固体泥沙颗粒。由于其具有环境危害性,且产量逐渐增加,对其有效地处理和处置引起世界各国的广泛关注。综述了废弃钻井泥浆和含油污泥的性质、对环境的影响和生物修复方法,并介绍了生物修复PHCs的影响因素,同时初步探讨了两者中除PHCs之外其他污染物的处理方法。目前的生物修复方法都有不同的优势和局限性,未来应该进一步关注对现有处理技术的改进和不同技术的结合,使废弃钻井泥浆和含油污泥的处理既能达到无害化、资源化,又能节省处理成本。     

含铬钻井泥浆固化及影响因素

固化技术是含铬钻井泥浆无害化处理最有效的方法。以四川西部某钻井泥浆为研究对象,选取水泥、石灰、聚铝和水玻璃作为固化处理剂,运用正交试验研究了含铬钻井泥浆实验条件。最佳试验配方是：先将泥浆含水率调整为46%,水泥、聚铝、石灰和水玻璃的添加量分别为10%、1%、3%和0.5%。固化72 h,该试验配方对六价铬和总铬的固化率分别达到93%和95%,浸出六价铬浓度符合地下水三类水标准(GB/T14848-9),浸出总铬浓度符合国家污水综合排放标准（GB5085.3-1996）。     

市政污泥深度脱水药剂优化研究简

污泥含水率高影响污泥后续处置。利用化学药剂对污泥进行深度脱水处理可使污泥减量化、稳定化。为提高深度脱水效果,对添加剂进行了种类和添加量的优化研究（石灰、工业石灰、粉煤灰、硅藻土、十二烷基磺酸钠和飞灰;5%、10%、15%、20%、25%和30%）,另外,还进行了复合投加实验。研究结果表明,石灰、工业石灰、粉煤灰的深度脱水效果最好;复合添加中,25%石灰+5%粉煤灰,20%石灰+10%粉煤灰,10%石灰+20%粉煤灰的深度脱水效果最好。5%的石灰或者工业石灰的添加剂量使干化污泥pH值达到12.25,粉煤灰、硅藻土、十二烷基磺酸钠和飞灰的添加对干化污泥pH值影响相对要小。     

复合调理剂对废弃建筑泥浆脱水性能的影响

建筑泥浆具有高含水率、高碱性、脱水困难等特性,导致其环保处置困难.采用有机絮凝剂与酸性无机调理剂组成的复合调理剂对废弃建筑泥浆开展了絮凝调理实验,以探究不同药剂组合和用量对废弃建筑泥浆脱水性能的影响.结果表明,建筑泥浆中膨润土、高岭石等50μm以下细粒粘土颗粒占比达67％以上,颗粒之间相互排斥,难以自然沉淀脱水.使用P...     

采用配方均匀设计法利用脱水污泥制备陶粒的研究

长期以来,对城市污水处理后产生的污泥处置一直是环保的难题,传统的处理处置方法均存在诸多问题,寻求一种好的处理处置污泥方法迫在眉睫。针对目前的问题运用带约束条件的配方均匀设计方法对粉煤灰-脱水污泥陶粒配方进行实验设计,运用三叶回转窑进行小试。研究了陶粒组分中粉煤灰、污泥、黏土的比例对烧成陶粒堆积密度、颗粒强度的影响;确定了最佳物料配比,使陶粒的性能测试指标均符合GB/17431.2-1998标准的规定。实验结果表明:烧制陶粒湿比例下脱水污泥用量达45%,干比例污泥用量15.2%,污泥减量化和资源化效果显著;陶粒浸出毒性实验结果表明各项指标均低于浸出液中危害成分浓度限值,达到了污泥无害化的效果;粉煤灰、污泥和黏土的优化质量(干)比例为79%,15.2%,5.8%;陶粒的堆积密度为600 kg/m3,筒压强度2.2 MPa,1 h吸水率10.2%,粒型系数1.3。     

粉煤灰处理煤矿酸性废水的研究

采用石灰石中和沉淀，粉煤灰吸附处理煤矿酸性废水，取得了良好的效果。用石灰石调节pH至4.5，再用石灰中和至中性，并用粉煤灰吸附，粉煤灰用量为10g／L时处理效果较好。     

气井废弃泥浆微生物-固化复合处理技术

废弃泥浆的无害化处理对于油气田开发的可持续发展具有重要意义。针对废弃泥浆的特性,以浸出液重金属含量及COD等为考核指标,通过固化剂配方优选、微生物菌种优选与复配,对废弃泥浆进行了微生物-固化复合处理。结果表明,固化剂加量为20%、复合菌液4.0 m L,处理15 d后,废弃泥浆固化后的含水率为45%以下,浸出液的pH为7.2~9.0,Cu、Cd和Pb等重金属离子含量分别为17、0.28和8.7μg/L以下,COD低于100 mg/L,浸出液成分均符合GB 8978-1996Ⅰ级排放标准。     

改善环保疏浚底泥脱水干化效能的实验研究

采用以硫酸亚铁(FeSO4)为主要成分的复合脱水剂作为疏浚泥浆脱水剂(以下简称脱水剂),黄沙、炉渣、煤灰、石灰和粉煤灰分别作为疏浚底泥干化改良剂进行实验研究。结果表明,在脱水剂投加量为100 mg/L条件下,可以提高沉淀效率约20%;在投加脱水剂及5%石灰、粉煤灰、炉渣改良剂的条件下,底泥比阻值下降50%～70%;初期渗水速率提高6%～68%;与原泥相比,以黄沙、炉渣、煤灰为改良剂的底泥,经过4个月干化期后,承载力提高了30%～150%。本研究为疏浚底泥快速脱水干化提供了一种可行的技术途径。     

絮凝剂对工程废弃泥浆脱水性能的影响

为了提高工程废弃泥浆的脱水效率,以毛细吸水时间(CST)为评价指标,研究了添加不同种类及不同用量的絮凝剂对废弃泥浆脱水性能的影响。结果表明,絮凝剂存在最适添加量,添加不足或过量的絮凝剂均会使絮凝效果下降。阴离子聚丙烯酰胺(APAM)具有较强的吸附架桥能力,脱水效果最好,絮体粒径大,脱水效果改善明显且添加量最少。原泥浆稀释至80%含水率后,APAM的最适添加量为60 mg·L~(-1),对应的CST值为23.4 s。CST法可作为泥浆调理沉降快速筛选絮凝剂的分析方法。     

废弃油基钻井液提取柴油剩余废弃物无害化处理研究

针对废弃油基钻井液中柴油回收过程产生的泥渣、废水、废白土和酸碱废渣具有高色度、高pH、高COD和高石油类的特点,通过优化实验得出了一步法无害化处理废弃混合物的最佳固化配方:水泥和粉煤灰加量分别为12.5%,激活剂SG加量1.5%,促凝剂LSL加量1.5%,石灰加量1%。在最佳固化配方下,固化体浸出液的各主要污染指标都符合《污水综合排放标准》(GB 8978-1996)一级标准,固化成本约100元/m3,与分别处理废渣、废液相比,其处理成本可降低约20%。     

油气田环境保护与控制技术

如何控制和减少钻井、采油等作业过程中对环境的危害，一直是国内外众多科学家所研究的问题。介绍了一种从根本上解决和消除钻井、采油过程中对环境污染的油气田环境污染控制技术和各种废钻井液、钻屑、钻井废水及采油污水的处理方法。     

Groundwater contamination mechanism in a geothermal field: a case study of Balcova, Turkey

The Balcova Geothermal Field (BGF) located in Izmir, Turkey is situated on an east-west directed graben plain within which the hot waters surface from a fault zone that cuts the Mesozoic aged Bornova Flysch. Due to the low permeability and porosity of the Bornova Flysch, the geothermal water cycles along the immediate vicinity of the Agamemnon fault and mixes with cold waters at different depths of this fractured zone. Within the scope of this study, the mixing patterns and the groundwater contamination mechanisms are analyzed by, hydrogeological and hydrogeochemical methods. Based on the results of this research, it has been found out that the hot geothermal water and the cold regional groundwater resources of the surficial aquifer mix within the fractured zone in Bornova Flysch and within the Quaternary alluvium aquifer due to natural and anthropogenic activities including (i) the natural upward movement of geothermal fluid along the fault line, (ii) the accelerated upward seepage of geothermal fluid from faulty constructed boreholes drilled in the area, (iii) the faulty reinjection applications; and, (iv) the uncontrolled discharge of waste geothermal fluid to the natural drainage network. As a result of these activities, the cold groundwater reserves of the alluvial aquifer are contaminated thermally and chemically in such a way that various toxic chemicals including arsenic, antimony and boron are introduced to the heavily used surficial aquifer waters hindering their use for human consumption and agricultural irrigation. Furthermore, the excessive pumping from the surficial aquifer as well as the reduced surface water inflow into BGF due to the dam constructed on Ilica Creek intensify the detrimental effects of this contamination. Based on the results of this study, it can be concluded that the groundwater pollution in BGF will expand and reach to the levels of no return unless a series of preventive measures is taken immediately.     

Preparation and characterisation of activated carbon from waste tea by physical activation using steam

ABSTRACT

In this study, the feasibility of preparing activated carbon from waste tea by physical activation using steam was investigated. The effects of activation temperature on yield and pore properties of the prepared activated carbon were studied. The yield decreased with increased activation temperature owing to the decomposition of cellulose and hemicellulose. The specific surface area and pore volume of the activated carbon were estimated using the Brunauer–Emmett–Teller method, Langmuir equation, and t-plot method. The specific surface area and micropore volume increased with increases in activation temperature, as additional volatile materials were released. The specific surface area significantly decreased at first but slightly increased with increasing activation time. The maximum specific surface area reached 995 m²/g at an activation temperature of 800 °C with a water flow rate of 0.075 g/min and a constant hold time of 0.5 hr. According to the nitrogen adsorption isotherms, micropores mainly developed when the activation temperature was below 800 °C, and both micropores and mesopores developed when it was above 800 °C. The results showed that activation temperature significantly affected micropore and mesopore volumes, as well as the specific surface area of the activated carbon. Overall, waste tea was found to be an attractive raw material for producing low-cost activated carbon.

Implications: Every year, a large amount of waste tea is generated after extraction. The high carbon content of waste tea showed that it can be used as raw material to produce activated carbon. This study investigated the feasibility of preparing activated carbon from waste tea by physical activation using steam. Temperature and time were found to have clear effects on pore properties. Our proposed method and raw material are more environmentally friendly and involve low cost. Furthermore, this offers a potential solution to the problems of waste tea disposal and low-cost activated carbon production.     

Preparation of sulfurized powdered activated carbon from waste tires using an innovative compositive impregnation process

The objective of this study is to develop an innovative compositive impregnation process for preparing sulfurized powdered activated carbon (PAC) from waste tires. An experimental apparatus, including a pyrolysis and activation system and a sulfur (S) impregnation system, was designed and applied to produce sulfurized PAC with a high specific surface area. Experimental tests involved the pyrolysis, activation, and sulfurization of waste tires. Waste-tire-derived PAC (WPAC) was initially produced in the pyrolysis and activation system. Experimental results indicated that the Brunauer-Emmett-Teller (BET) surface area of WPAC increased, and the average pore radius of WPAC decreased, as water feed rate and activation time increased. In this study, a conventional direct impregnation process was used to prepare the sulfurized PAC by impregnating WPAC with sodium sulfide (Na2S) solution. Furthermore, an innovative compositive impregnation process was developed and then compared with the conventional direct impregnation process. Experimental results showed that the compositive impregnation process produced the sulfurized WPAC with high BET surface area and a high S content. A maximum BET surface area of 886 m2/g and the S content of 2.61% by mass were obtained at 900 degrees C and at the S feed ratio of 2160 mg Na2S/g C. However, the direct impregnation process led to a BET surface area of sulfurized WPAC that decreased significantly as the S content increased.     

Preparation of Sulfurized Powdered Activated Carbon from Waste Tires Using an Innovative Compositive Impregnation Process

Abstract

The objective of this study is to develop an innovative compositive impregnation process for preparing sulfurized powdered activated carbon (PAC) from waste tires. An experimental apparatus, including a pyrolysis and activation system and a sulfur (S) impregnation system, was designed and applied to produce sulfurized PAC with a high specific surface area. Experimental tests involved the pyrolysis, activation, and sulfurization of waste tires. Waste-tire-derived PAC (WPAC) was initially produced in the pyrolysis and activation system. Experimental results indicated that the Brunauer-Emmett-Teller (BET) surface area of WPAC increased, and the average pore radius of WPAC decreased, as water feed rate and activation time increased. In this study, a conventional direct impregnation process was used to prepare the sulfurized PAC by impregnating WPAC with sodium sulfide (Na₂S) solution. Furthermore, an innovative compositive impregnation process was developed and then compared with the conventional direct impregnation process. Experimental results showed that the compositive impregnation process produced the sulfurized WPAC with high BET surface area and a high S content. A maximum BET surface area of 886 m²/g and the S content of 2.61% by mass were obtained at 900°C and at the S feed ratio of 2160 mg Na₂S/g C. However, the direct impregnation process led to a BET surface area of sulfurized WPAC that decreased significantly as the S content increased.     

Preliminaries on pollution risk factors related to mining and ore processing in the Cu-rich pollymetallic belt of Eastern Carpathians, Romania

The present study focuses on the mineralogical and geochemical patterns of mining and ore-processing wastes from some occurrences in the Eastern Carpathians; its aim is to identify the main factors and processes that could lead to the pollution of the environment. In this respect, the following types of solid waste were investigated: efflorescent salts developed on the surface of rock blocks from a quarry, ore-processing waste from two tailings ponds, and salt crusts developed at the surface of a tailings pond. The potential risks emphasized by these preliminary investigations are the following: (1) the risk of wind-driven removal and transport of the waste from the surface of tailings ponds, given that fine grains prevail (up to 80 %); (2) the risk of tailings removal through mechanical transport by water, during heavy rainfall; (3) the appearance of hydrated sulfates on the rock fragments from the mining waste, sulfates which are highly susceptible to the generation of acid mine drainage (pH?<?4); (4) the high amount of toxic elements (Pb, Cd, Cu, Zn, As, etc.) that acid mine drainage leachates contain; and (5) the development of a salt crust on the flat, horizontal surfaces of the waste deposit, due to this very shape. Statistical data regarding the amount of both major and minor elements in the tailings have revealed two statistical populations for nearly all the toxic metals. This suggests that, beyond the effect that the tailings have upon the environment through their mere presence in a given area, there are alleged additional factors and processes which intensify the pollution: the location of the waste deposit relative to the topography of the area; the shape of the waste deposit; the development of low areas on the surface of the deposit, areas which favor the appearance of salt crusts; and the mineralogy of efflorescent aggregates.     

含油钻屑高效除油剂及除油机理研究

油基钻井液在复杂井、深井的钻井作业中受到越来越多的使用和重视,但相应也产生了大量的废弃含油钻屑,带来了环境污染问题。针对含油钻屑的特点,研制了一种高效除油剂HBS-6,在阴离子表面活性剂、非离子表面活性剂、溶剂和软水剂等组分的协同作用下,利用强化分离设备,实现了钻屑含油的去除与无害化处置,含油钻屑除油率达90%以上。同时,还采用红外光谱、气相色谱和液相色谱等分析手段,研究了除油剂HBS-6的作用机理。HBS-6含有HLB值高且能生物降解的阴离子表面活性剂,以保证除油剂的清洗能力和环保性,同时还采用HLB值低的非离子表面活性剂,以提高对油的乳化和除油能力,为含油钻屑的无害化处理拓展了一条新的技术途径。     

超临界流体技术在环境保护中的应用

简要介绍了超临界流体萃取和超临界水氧化的基本原理及优点 ,综述了超临界流体技术在废水处理、固体废物处理及污染监测中的开发和应用     

An environmental forensic investigation at a bio-medical waste treatment and disposal facility in Kerala,India

Indian statutes identify twelve different types of biomedical wastes and give the treatment and disposal options for each. Since it is not possible for every generator of biomedical waste to go for their own treatment and disposal facility, the small-scale generators take the service of centralized treatment and disposal facilities available to them on payment. In the state of Kerala in India, where the basic health indicators match those of many developed countries, the centralized biomedical waste treatment facility is run by Indian Medical Association (IMA), Kerala, under the banner IMAGE (IMA Goes Eco-Friendly) at a place called “Kanjikode” in the Palakkad District. The facility receives biomedical waste from around 4500 hospitals across the State and an equal number of medical laboratories. The plant incinerates the incinerable waste and the other kind of waste are disinfected and decontaminated. The residual ash and dried sludge are then moved to the landfill area. Recently, the facility was in the middle of a controversy due to the alleged health hazards it posed to the surrounding population. An environmental forensic investigation was carried out at the site to establish the merits of the allegation. The reported study is a part of the investigation where groundwater was analysed for the presence of heavy metals. As the biomedical waste contain heavy metals like Zn, Pb, Cd, Cr, and Hg, the presence of these were analysed to establish contamination of groundwater by the facility. The study area is bounded by Malampuzha dam and Korayar river. Groundwater contaminant transport modelling was done for a 3430 m × 3960 m area surrounding the waste treatment facility using Visual MODFLOW and MODPATH. Ground water flow direction and particle pathlines were computed to track the movement of contaminants. Groundwater samples were collected from the area shown to be polluted by the model, if metals were discharged by the facility, and also from outside this area. Water samples were collected conforming to the guidelines in the “Pollution Crime Forensic Investigation Manual” published by INTERPOL. The collected water samples were tested for heavy metal concentration using atomic absorption spectroscopy (AAS). The water sample analysis showed that the groundwater is not contaminated by heavy metal discharge from the biomedical treatment facility.