基于框架模型的煤层气开发生态效应评价

针对山西煤层气生态系统特征,运用"压力-状态-响应"(PSR)评价模型,构建了煤层气生态系统评价框架和评价指标体系,采用层次法对其进行了评价。评价结果表明:煤层气开发排放的煤层采出水和钻井废液、建设过程产生的废弃土方、植被破坏对生态环境影响较大。应及时采取有效措施保护煤层气开发的生态环境。     

油田采出水组分及其对环境的影响

油田采出水中含有多种组分，有油类（分散油和溶解油）、放射性元素、重金属和化学处理剂等。当采出水外排时，这些组分对环境有着不同的影响。现以海洋为对象，介绍采出水的化学特性及其对环境的作用，认为在一般情况下，采出水不致对海洋环境产生不良影响。讨论内容对陆上环境影响也具有参考价值。     

美国油气田采出水的处置与利用

美国油气田采出水除回注外,主要还有地下灌注、地表排放、农业灌溉等方式,多途径实现采出水的资源化利用,但同时也带来了地下处置可能引发地震、浅层处置可能影响含水层、浅层处置导致地层压力增大的风险。通过对美国油气田采出水管理方式的研究,为国内油气田采出水的处置及资源化利用提供借鉴。     

电絮凝＋电氧化法处理山西某区块煤层气采出水研究与实践

山西省某区块煤层气采出水水质均值为COD 170 mg/L,BOD₅29.7 mg/L,氨氮5.36 mg/L,氟化物6.59 mg/L,4个污染物指标超过GB 3838—2002《地表水环境质量标准》Ⅳ类水质限值要求。文章针对该地区煤层气采出水的可生化性差(BOD₅/COD≤20%)、氯离子含量较高等特点,采用“电絮凝+电氧化”法进行中试试验,处理后水质COD≤17 mg/L,氨氮≤0.1 mg/L,氟化物≤1.0 mg/L,试验结果表明:采用该方法可以有效降低COD、氨氮、氟化物等主要污染物指标,使该区块煤层气采出水达到GB 3838—2002标准Ⅳ类水质要求(COD≤30 mg/L、氨氮≤1 mg/L、氟化物≤1 mg/L)。应用中试试验研究成果,采用“双电+保障(过滤)”工艺在该区块建成了煤层气采出水处理示范工程,水处理站建成投运后出水水质稳定,始终满足GB 3838—2002《地表水环境质量标准》Ⅳ类水质要求。     

石西油田采出水资源合理化利用研究与应用

针对石西油田各区块采出液水质成分复杂、自结垢趋势严重、水质不配伍等情况,开展采出水稳定性控制等问题的攻关研究,采用预催化—强化絮凝水处理技术思路,评价药剂体系,复配除硫型净水剂,消耗水中还原性物质,使采出水稳定性提高。并通过对采出水走向进行合理调配,实现了石南采出水100%有效回注,达到了采出水资源合理化利用的目的。     

页岩气采出水处理及回用现状分析

介绍了页岩气采出水的产排特征,国内页岩气采出水的处理及回用现状,并总结出3项采出水处理技术,即:回注、简单处理后回用及处理至SY/T 6596—2004《气田水回注方法》达标,进行回注,以采出水复配压裂液为主要污水。这3种处理方式可以处理页岩气采出水,为污水达到GB 8978—1996《污水综合排放标准》做技术储备,并降低采出水对土壤、地表水等可能造成的环境污染风险。     

煤层气采出水达标排放处理工艺试验

文章探讨了一些常规的及新兴煤层气采出水处理方法,并在鄂东区块某公司开展了曝气生物滤池处理方法试验。结果表明:处理后满足GB 3838—2002《地表水环境质量标准》Ⅴ类标准,DB 61/224—2011《黄河流域(陕西段)污水综合排放标准》(一级标准),CODCr去除率为50%～60%,NH3-N可降低到检出限0.04mg/L以下;最佳水力停留时间为6.7h(流量23L/h),处理成本可降到3元/m3以下。建议场站建设应早期规划集水设施敷设,以保证后续采出水集中处理,降低处理成本。     

煤层气采出水达标排放处理技术研究

以鄂东区块采出水为研究对象，在对其水质特征充分分析的基础上，研究提出了“固定化微生物”曝气生物滤池的采出水COD和NH3-N的去除工艺，开展了3个阶段的现场试验进行COD和NH3-N去除效果的验证，同时采用GC-MS分析方法探究采出水中有机物氧化降解情况。试验数据显示：最终出水的COD、NH3-N均低于40，2mg/L排放指标要求，难降解有机物种类和数量大幅减少。其中，COD去除率从70％逐步提升至880％，且随水力停留时间（HRT）增加而不断提升；NH3-N去除率可稳定达到99％以上，远低于标准设定值2mg/L，且对HRT的调整不敏感。研究结果表明，以“固定化微生物-曝气生物滤池＋活性炭吸附”为主体的工艺的处理技术，对鄂东区块采出水中的COD，NH3-N和难降解有机物均具有明显的去除效果，将HRT调整至8h左右时，出水仍可稳定达标，此时的直接运行费用将降至1.40元/m3以下，较化学处理工艺处理费用低70％以上，实现了鄂东区块煤层气采出水的“低成本、 稳定达标排放”处理。     

回用锅炉的热采稠油采出水软化工艺

针对我国热采稠油油田所面临的采出水处理难的问题，对国内外热采稠油采出水的处理方法进行了广泛、深入、全面的调查研究。着重介绍了热采采出水作注汽锅炉给水的各种软化工艺及处理方法。     

高矿化度稠油采出水处理实验

为解决稠油采出水合格、有序排放问题,针对稠油采出水高矿化度、可生物性差,完全采用好氧工艺处理污水难度较大的水质特点,通过对车510稠油采出水进行分析,提出了实现采出水达标排放的技术路线,并开展稠油采出水达标处理的现场实验。结果表明采用"混凝沉降+水解酸化—接触氧化"工艺处理该采出水,其出水水质中COD_(Cr)≤120mg/L、石油类≤10mg/L、挥发酚≤0.5mg/L,可达到GB 8978—1996《污水综合排放标准》中二级指标。     

煤层气勘探开发和利用的环境影响分析

煤层气是煤层中自生自储的一种非常规天然气，其成分主要是甲烷。与煤和石油比较，煤层气是一种清洁能源，因此加快煤层气的开发和利用，能改善能源结构，缓和能源紧张状况，减少环境污染。根据煤层气的特点，详细分析了其对于大气环境、水环境以及土壤、植物的影响因素后指出：开发利用煤层气对大气环境的影响利大于弊，而对水体、土壤、农作物等则产生一系列不利影响。     

Formulation of criteria for pollution control on cement products produced from solid wastes in China

The process of producing cement products from solid waste can increase the level of pollutants in the cement products. Therefore, it is very important to establish a pollution control standard for cement products to protect the environment and human health. This paper presents acceptance limits for the availability of heavy metals in cement products which have been produced from solid wastes and explains how the limits have been calculated. The approach and method used to formulate these criteria were based on EN 12920. The typical exposure scenarios used in this paper involve concrete being used for drinking water supply pipelines and concrete pavements and are based on an analysis of typical applications of cement in China, and the potential for contact with water. The parameters of a tank test which was based on NEN 7375 were set in accordance with the environmental conditions of typical scenarios in China. Mechanisms controlling the release of heavy metals in concrete and a model for that release were obtained using the leaching test. Finally, based on acceptance criteria for drinking water and groundwater quality in China, limit values for the availability of heavy metals in concrete were calculated.     

“第一类污染物”防治需求的紧迫性及其对策措施

"第一类污染物"是指会对人体健康产生长远不良影响的污染物,包括8种重金属和类金属。已经证实,工业源重金属超量排放严重,使水土及生态环境遭受到"第一类污染物"的严重污染,面临的"第一类污染物"防治形势更加紧迫。本文在重金属污染现状与治理需求分析的基础上,通过长期调研,针对重点行业提出了6项综合防治措施,建议从源头严格控制排放总量,对重点企业进行监管与治理,总结与创新重金属修复新技术等,旨在推动第一类污染物的污染防治。     

Evaluation of biogas production from seaweed in batch tests and in UASB reactors combined with the removal of heavy metals

Seaweed can be anaerobically digested for the production of energy-rich methane. However, the use of seaweed digestate as a fertilizer may be restricted because of the high heavy metal content especially cadmium. Reducing the concentration of heavy metals in the digestate will enable its use as a fertilizer. In this laboratory-scale study, the potential of seaweed and its leachate in the production of methane were evaluated in batch tests. The effect of removing the heavy metals from seaweed leachate was evaluated in both batch test and treatment in an upflow anaerobic sludge blanket (UASB) reactor. The heavy metals were removed from seaweed leachate using an imminodiacetic acid (IDA) polyacrylamide cryogel carrier. The methane yield obtained in the anaerobic digestion of seaweed was 0.12 N l CH₄/g VS_added. The same methane yield was obtained when the seaweed leachate was used for methane production. The IDA-cryogel carrier was efficient in removing Cd²⁺, Cu²⁺, Ni²⁺ and Zn²⁺ ions from seaweed leachate. The removal of heavy metals in the seaweed leachate led to a decrease in the methane yield. The maximum sustainable organic loading rate (OLR) attained in the UASB reactor was 20.6 g tCOD/l/day corresponding to a hydraulic retention time (HRT) of 12 h and with a total COD removal efficiency of about 81%. Hydrolysis and treatment with IDA cryogel reduced the heavy metals content in the seaweed leachate before methane production. This study also demonstrated the suitability of the treatment of seaweed leachate in a UASB reactor.     

Five-wheel framework for system-based monitoring of heavy metal pollution in rivers

Sectorial approach for monitoring heavy metal pollution in rivers has failed to report realistic pollution status and associated ecological and human health risks. The increasing spread of heavy metals from different sources and emerging risks to human and environmental health call for reexamining heavy metal pollution monitoring frameworks. Also, the sources, spread, and load of heavy metals in the environment have changed significantly over time, requiring consequent modification in the monitoring frameworks. Therefore, studies on heavy metal monitoring in rivers conducted in the last decade were evaluated for experimental designs, research frameworks, and data presentations. Most studies (∼99%) (i) lacked inclusiveness of all environmental compartments; (ii) focused on “one pollutant – one/two compartment” or sometimes “one pollutant – one compartment – one effect” approach; and (iii) remained “data-rich but information poor.” An ecological approach with integrative system thinking is proposed to develop a holistic approach for monitoring river pollution. It is visualized that heavy metal monitoring, risk analyses, and water management must incorporate tracking pollutants in different environmental compartments of a river (water, sediment, and floodplain/bank soil) and consider correlating it with riverbank land use. The systems-based pollution monitoring and assessment studies will reveal the critical factors that drive heavy metals pollutant movement in ecosystems and associated potential risks to the environment, wildlife, and humans. Also, water quality and pollution indexing tools would help better communicate complex pollution data and associated risks among all stakeholders. Therefore, integrating systems approaches in scientific- and policy-based tools would help sustainably manage the health of rivers, wildlife, and humans.     

我国煤炭开采和燃烧过程中的硫污染对土壤环境的影响

我国煤炭在开采和燃烧过程中形成的硫污染物主要是酸性矿井水和二氧化硫,由煤炭燃烧造成的硫的干湿沉降以及煤炭开采过程中形成的酸性矿井水使土壤的物理化学性质发生变化,从而对土壤造成严重的破坏。主要表现在造成土壤中可溶性硫酸盐的大幅度升高;引起土壤的pH值下降;植物营养元素特别是K、Na、Ca、Mg等产生淋失;活性铝溶出量增加;有毒重金属活化;抑制土壤酶的活性等方面。可以通过脱硫除尘、加强绿化、建立合理的工业布局、加入土壤改良剂等措施来减少硫污染物的排放量和改善其对土壤环境的影响,但总量控制是关键,是最根本的途径。     

西湖和东苕溪沉积物重金属化学形态分析

不同赋存形态重金属的环境行为和生态效应不同,水体沉积物中重金属的迁移转化及其潜在环境危害更大程度上取决于其赋存形态。本研究在西湖和东苕溪设置12个采样点采集沉积物样品,采用改进BCR分步提取法,提取了重金属污染物的4种化学形态,分别为弱酸提取态、可还原态、可氧化态及残渣态。结果表明:沉积物中Cd以弱酸提取态为主,对外界环境的变化极其敏感,并易于发生迁移转化,生态风险较高。Cu离子对有机质表现出极强的亲和力导致Cu的可氧化态含量较高也有一定的生态风险。Pb会被Fe-Mn氧化物所吸附导致Pb的可还原态含量较高,存在较高的潜在生态危害。Mn的弱酸提取态、可还原态和残渣态含量都较高,在迁移的过程中变化地较快,能够逐渐降低Mn对自然环境的危害。其他各重金属(As、Cr、Zn)则都以残渣态为主,潜在危害较低。     

QUALITY OF WATER AND BOTTOM SEDIMENTS IN THE TRINITY RIVER1

ABSTRACT: Data were developed to determine the quality of water and bottom sediments in the Trinity River, and the mobility of various contaminants when bottom sediments were mixed with the river water under simulated dredging conditions. Thirteen sampling sites were selected. A number of chemical tests including heavy metals and pesticides were conducted on river water, elutriates, and bottom sediments. Statis bioassays using Daphnia magna were conducted on river water and elutriates. Results indicated that the river in the upper reach is grossly polluted due to discharge of waste water effluents from several large treatment plants. High concentrations of nitrogen, phosphorus, organic carbon, COD, heavy metals, and pesticides were found in water and bottom sediments. The concentrations of most of these pollutants exceeded the EPA recommended limits. Elutriation gave no consistent results, perhaps because of release or uptake of contaminants from the sediments. High mortality of D. magna were also recorded in the upper reach of the river. The quality of water and bottom sediments gradually improved in lower reaches.     

Application of membrane bioreactor technology for wastewater treatment and reuse in the Mediterranean region: Focusing on removal efficiency of non-conventional pollutants

The Mediterranean Region is a semi-arid area whose land is facing serious erosion, causing adverse impacts on agriculture. To improve the water availability, researchers have proposed the reclamation and reuse of treated wastewater. In this paper, we report the main findings of 10 years of research on the efficiencies of a conventional activated sludge process and a submerged membrane bioreactor, with particular emphasis on the removal of non-conventional pollutants. The studies showed that the membrane bioreactor produced a virtually solids-free, high-quality permeate: most nutrients, heavy metals, and persistent organic pollutants were removed, and in particular, dioxins, furans, and polychlorinated biphenyls were typically present at concentrations below the detection limit. Moreover, the total coliforms count decreased by 4–5 log and Escherichia coli was absent from the membrane bioreactor permeate. These results, combined with the continuing reduction of the capital and operating costs for this approach, suggest that membrane bioreactors are an increasingly cost-effective technology to produce treated effluents that are suitable for reuse.     

植物-微生物联合修复石油-重金属复合污染土壤的研究

植物及微生物联合修复石油-重金属复合污染土壤具有很大的潜力。但重金属以不同形态存在关系到石油-重金属复合污染土壤生物修复过程中,植物、微生物的修复效率以及是否需要增加辅助工程解决重金属污染等问题,因此石油-重金属复合污染土壤修复过程中就必须考虑重金属有效态及形态的变化特征。