吹脱法去除采气废水中氨氮的影响因素研究

研究以四川地区采气废水经低温蒸馏处理后的水样作为研究对象,其氨氮的质量浓度为51.6mg/L,通过正交试验和单因素试验较为系统的探讨了曝气量、温度、pH值等相关因素对吹脱法去除采气废水中氨氮的影响。此外,在大量的试验数据中选取了较为适宜的处理条件,进行了一系列验证实验,试验结果表明在曝气量为2L/min、pH值为11、温度为80℃条件下,氨氮去除率可达90%以上,吹脱法处理采气废水中氨氮能够满足达标排放要求。     

石油化工废水的预处理试验研究

石油化工废水的浓度较高，其中某些组分可生化性低。采用空气吹脱法可去除其中定量低沸点有机溶剂，从而极大降低废水的有机物浓度，并可提高废水的可生化性。本文重点讨论了不同参数条件对废水预处理效果的影响，得出了最佳工艺参数。     

影响高浓度NH3-N废水吹脱-硝化过程的实验研究

废水中含氨氮过多，对人和动物的健康产生极大威胁，此外，水体中NH3-N浓度过高，也增加了废水生化的处理难度，为此，废水脱氮成为水处理领域的热点和难点。文章采取先用空气将高浓度NH3-N废水的中的一部分NH3-N吹脱，然后在适宜的氨氮剩余浓度下，采用活性污泥法对剩余NH3-N进行硝化处理。用空气吹脱NH3-N，碱度直接影响吹脱效果和最终的剩余氨氮浓度。在硝化反应时，pH值、温度、溶解氧对硝化反应影响十分大。文章通过大量实验，获得了NH3-N废水起始浓度为1000mg／L左右时的最佳吹脱碱度，获得了适宜的氨氮剩余浓度。同时得出了pH值、温度、溶解氧对硝化反应的影响规律。这些数据和规律对生产有一定的指导意义。     

气水比对废水吹脱除氮效果的影响

废水中含有的氨氮可通过游离氨的挥发作用加以去除。通过加碱提高废水的ＰＨ值。可将废水中绝大部分的氨氮转化为游离氨而被吹脱。化肥厂氨氮废水中的型吹脱试验表明,当废水的水温、ＰＨ值、布水负荷率以及及脱塔填料形式一定时,氨氮吹脱的气水比在所试验工况条件下均影响氨的去除效果,但其影响程度在不同的ＰＨ值和布水负荷率条件下也有所不同。     

页岩炼油高氨氮污水处理方法研究

针对抚顺页岩炼油污水中的高氨氮特点,结合现有生化系统,采用氧化钙作为碱源对传统吹脱法、间歇式曝气吹脱法、二级循环吹脱法、膜法及生化法处理页岩炼油厂高氨氮废水的效果进行了对比。结果表明,传统筛板吹脱系统处理效率最低,仅为84%。最高效率99.8%是现有SDN生化法实现的,但处理量低。RANS膜法处理效率达到了96%。     

胜利油田井下压裂废水处理实验研究

井下压裂施工工艺复杂,压裂废液对环境会造成污染。针对压裂废水特点,采用絮凝-隔油法对其进行预处理,再用次氯酸钠结合紫外光对废水进行深度处理,可氧化降解难处理的部分高分子有机化合物。结果表明,在适宜的处理条件下,该法可有效去除水中CODCr和石油类,去除率分别为98.6%、98.1%,达到《污水综合排放标准》(GB8978—1996)二级标准。     

电絮凝法处理电脱盐废水的实验研究

采用曝气和温度调节对电脱盐废水进行预处理,并通过电絮凝方法对电脱盐废水进行破乳除油。实验结果表明:一定的曝气可以起到均质调节作用,曝气15min时不稳定指数最大,而此时TOC也最大,说明通过曝气改变了体系的稳定状态;反应过程中一定的升温和曝气作用都可以有效提高处理效率,电絮凝处理电脱盐废水的过程中,最佳电流密度为5mA/cm2;从紫外三维荧光谱图可以看出,电絮凝过程破坏了物质的结构;采用电絮凝法处理电脱盐废水,可以有效去除废水的COD和浊度。     

吹脱法处理化肥厂氨氮废水的研究

在实验的基础上选用塔滤吹脱——接触氧化工艺处理化肥厂氨氨废水,使出水浓度低于10mg/l;井提出实验室最佳运行参数及工艺流程;采用空气预热的方法较好地解决了严寒地区结冰期吹脱塔运行的问题,通过控制 pH 值和选用塑料条板填料克服了塔内结垢的弊端。     

重金属废水生物制剂深度处理与回用技术在锌冶炼废水处理中的运用

目前锌冶炼重金属废水处理最常用的方法是化学沉淀法(石灰或硫化中和),它能快速去除废水中的金属离子,但净化水硬度高而无法实现大规模回用,制约了对废水的综合利用.重金属废水生物制剂法深度处理与回用技术可同时实现对镉、砷、铅、锌、汞、铜等重金属离子的高效去除,同时生物制剂兼有高效絮凝、协同脱钙作用,处理后的低钙净化水可以实现大规模回用.文章通过对重金属废水生物制剂深度处理与回用技术在西部矿业股份有限公司锌业分公司锌冶炼废水深度治理工程的运用进行分析,阐述了重金属废水生物制剂法深度处理与回用技术的技术特点、处理效果.     

吹扫捕集/气相色谱-质谱法测定水中丙烯腈

建立了吹扫捕集/气相色谱-质谱联用仪(GC-MS)测定水中丙烯腈的分析方法,探讨了吹扫温度、吹扫时间、脱附温度和脱附时间对吹扫捕集效率的影响情况,同时对线性范围、方法检出限、准确度和精密度进行实验。在确定的最佳条件下,丙烯腈的线性相关系数为0.9998,平均加标回收率为96.9%,相对标准偏差为4.0%;方法检出限为0.18μg/L。结果表明,该方法简单易操作、检出限低、灵敏度高、准确度及精密度高。     

模拟油田采出水中硫化氢的脱除研究

硫化氢是油气田伴生气中的有害组分。在含硫油气田的采出水中,硫化氢的存在对于安全生产和和油田环境均会产生危害。采出水经处理后通常需作为地层回注水使用,由于油气生产的特殊性,常用的硫化氢脱除方法在使用中受到限制,探索适合于油气田生产的水处理方法十分必要。本文探讨了通常可用于油田水中硫化氢脱除的各种方法,对比了各类方法的优缺点,提出以次氯酸钠为主要脱硫剂的水处理方法,通过对模拟采出水的室内试验,证明次氯酸法可以快速有效地去除采出水中的硫化氢,并提出了消除过量氧化剂的后续处理方法。实验表明经处理后的水质可以达到油气田回注水质要求,处理成本较低。     

模拟油田采出水中H2S的脱除

采出水经处理后通常需作为地层回注水使用,由于油气生产的特殊性,常用的H2S脱除方法在使用中受到限制,探索适合于油气田生产的水处理方法十分必要。文章探讨了通常可用于油田采出水中H2S脱除的各种方法,对比了各类方法的优缺点,提出以NaClO为主要脱硫剂的水处理方法,通过对模拟采出水的室内实验,证明次氯酸法可以快速有效地去除采出水中的H2S,使H2S残留量低于1 mg/L。实验表明:经处理后的水质可以达到SY/T 5329-2012《碎屑岩油藏注水水质指标及分析方法》要求,处理成本较低。     

Remediation of saturated soil contaminated with petroleum products using air sparging with thermal enhancement

Pollutants in the form of non-aqueous phase liquids (NAPLs), such as petroleum products, pose a serious threat to the soil and groundwater. A mathematical model was derived to study the unsteady pollutant concentrations through water saturated contaminated soil under air sparging conditions for different NAPLs and soil properties. The comparison between the numerical model results and the published experimental results showed acceptable agreement. Furthermore, an experimental study was conducted to remove NAPLs from the contaminated soil using the sparging air technique, considering the sparging air velocity, air temperature, soil grain size and different contaminant properties. This study showed that sparging air at ambient temperature through the contaminated soil can remove NAPLs, however, employing hot air sparging can provide higher contaminant removal efficiency, by about 9%. An empirical correlation for the volatilization mass transfer coefficient was developed from the experimental results. The dimensionless numbers used were Sherwood number (Sh), Peclet number (Pe), Schmidt number (Sc) and several physical-chemical properties of VOCs and porous media. Finally, the estimated volatilization mass transfer coefficient was used for calculation of the influence of heated sparging air on the spreading of the NAPL plume through the contaminated soil.     

土壤中污染物迁移模型在油田环境影响评价中的应用

在石油的生产、运输、贮存以及炼制等过程中都存在泄油、漏油风险,各生产过程中的废弃物,如油类、重金属等各种化学物质也会危害水土环境,进而危及当地地下水源。文章分析了油田企业污染物对土壤及地下水的主要污染途径,提出了将污染物在土壤中的迁移模型用于预测污染物浓度的方法。建立了污染物由土壤迁至室内空气、地下水、农作物及由地下水转移到地表水的迁移数学模型,该模型可以运用于油田环境影响评价。     

Air‐Water Temperature Relationships in the Trout Streams of Southeastern Minnesota's Carbonate‐Sandstone Landscape

Carbonate‐sandstone geology in southeastern Minnesota creates a heterogeneous landscape of springs, seeps, and sinkholes that supply groundwater into streams. Air temperatures are effective predictors of water temperature in surface‐water dominated streams. However, no published work investigates the relationship between air and water temperatures in groundwater‐fed streams (GWFS) across watersheds. We used simple linear regressions to examine weekly air‐water temperature relationships for 40 GWFS in southeastern Minnesota. A 40‐stream, composite linear regression model has a slope of 0.38, an intercept of 6.63, and R² of 0.83. The regression models for GWFS have lower slopes and higher intercepts in comparison to surface‐water dominated streams. Regression models for streams with high R² values offer promise for use as predictive tools for future climate conditions. Climate change is expected to alter the thermal regime of groundwater‐fed systems, but will do so at a slower rate than surface‐water dominated systems. A regression model of intercept vs. slope can be used to identify streams for which water temperatures are more meteorologically than groundwater controlled, and thus more vulnerable to climate change. Such relationships can be used to guide restoration vs. management strategies to protect trout streams.     

A STUDY OF WATER RESOURCES IN THE CANBERRA AREA AND THE QUEANBEYAN RIVER WATERSHED (GOOGONG DAM CATCHMENT)1

Data provided by the Australian Commonwealth Bureaus of Meteorology and Mineral Resources are used in this water budget study of the Queanbeyan River watershed. Air and soil temperatures show close correlation from month to month during the five-year period. A close parallel also exists for the air temperature values and the seasonal variations in the Nett-Moisture (rainfall minus evaporation) plots. Ground-water levels appear to be influenced by drought periods and by under groundwater storage conditions such as “nick-points” in the sub-surface migration conditions. The groundwater levels were unusually high early in the drought year of 1964-65. The annual rainfall totals for 1962, 1963, and 1966 were all exceeded by the evaporation totals. In 1964 and in 1965 (the drought year) the evaporation total exceeded the rainfall total. The minimum annual water discharge values for the Queanbeyan River ranged from 4.9″ in 1963 to 1.4′ in 1965.     

Effects of Groundwater-Flow Paths On Nitrate Concentrations Across Two Riparian Forest Corridors1

Speiran, Gary K., 2010. Effects of Groundwater-Flow Paths on Nitrate Concentrations Across Two Riparian Forest Corridors. Journal of the American Water Resources Association (JAWRA) 46(2):246-260. DOI: 10.1111/j.1752-1688.2010.00427.x Abstract: Groundwater levels, apparent age, and chemistry from field sites and groundwater-flow modeling of hypothetical aquifers collectively indicate that groundwater-flow paths contribute to differences in nitrate concentrations across riparian corridors. At sites in Virginia (one coastal and one Piedmont), lowland forested wetlands separate upland fields from nearby surface waters (an estuary and a stream). At the coastal site, nitrate concentrations near the water table decreased from more than 10 mg/l beneath fields to 2 mg/l beneath a riparian forest buffer because recharge through the buffer forced water with concentrations greater than 5 mg/l to flow deeper beneath the buffer. Diurnal changes in groundwater levels up to 0.25 meters at the coastal site reflect flow from the water table into unsaturated soil where roots remove water and nitrate dissolved in it. Decreases in aquifer thickness caused by declines in the water table and decreases in horizontal hydraulic gradients from the uplands to the wetlands indicate that more than 95% of the groundwater discharged to the wetlands. Such discharge through organic soil can reduce nitrate concentrations by denitrification. Model simulations are consistent with field results, showing downward flow approaching toe slopes and surface waters to which groundwater discharges. These effects show the importance of buffer placement over use of fixed-width, streamside buffers to control nitrate concentrations.     

Estimating Current and Future Groundwater Resources of the Maldives

The water resources of the atolls of the Republic of Maldives are under continual threat from climatic and anthropogenic stresses, including land surface pollution, increasing population, drought, and sea‐level rise (SLR). These threats are particularly acute for groundwater resources due to the small land surface area and low elevation of each island. In this study, the groundwater resources, in terms of freshwater lens thickness, total volume of fresh groundwater, and safe yield are estimated for the 52 most populous islands of the Maldives for current conditions and for the year 2030, with the latter accounting for projected SLR and associated shoreline recession. An algebraic model, designed in previous studies to estimate the lens thickness of atoll islands, is expanded in this study to also estimate volume of groundwater. Results indicate that average current lens thickness, groundwater volume, and per capita safe yield are approximately 4.6 m, 1,300 million liters, and 300 l/day, and that these values will decrease by approximately 10, 11, and 34%, respectively, by the year 2030. Based on results, it is demonstrated that groundwater, in terms of quantity, is a viable source of water for the islands of the Maldives both now and in coming decades, particularly for islands with large surface area and low population. Study results can provide water resource managers and government officials with valuable data for consideration in water security measures.     

采油废水气浮-生物处理方法研究

针对采油废水外排水质超标现象,胜利油田孤岛采油厂在室内试验和现场小试的基础上,分别采用直接投加菌液方法和生物接触氧化方法对孤岛采油废水进行了现场中试对比研究。试验结果表明:两种方法都能有效地去除了采油废水中的超标污染物,处理后的水质指标全部达到GB8978-1996《污水综合排放标准》二类水质标准。相比较生物接触氧化法工序运行稳定,易于实施。     

CONTROL OF LAKE PHOSPHORUS WITH ALUMINUM SULFATE: DOSE DETERMINATION AND APPLICATION TECHNIQUES1

ABSTRACT: Nutrient diversion does not always bring about prompt and sufficient reduction in lake phosphorus concentration due to recycling from nutrient rich sediments. Certain lakes and reservoirs may continue to experience nuisance algal blooms and require additional restorative steps. The phosphorus precipitation/inactivation technique is a procedure to remove phosphorus from the water column and to control its release from sediments in order to achieve P-limiting conditions to algal growth. Aluminum salts have been used in advanced waste water treatment to remove phosphorus and this technology was extended to lake rehabilitation. Guidelines for dose calculation and application are generally lacking, and are provided in this report. The dose determination suggested here allows maximum application of aluminum to bottom sediments and thus emphasizes long term control of phosphorus recycling. Dose can be calculated directly from the alkalinity of the water to be treated. Titration of lake water samples of Varying alkalinity allows the establishment of the relationship between residual dissolved aluminum, alkalinity, and dose which can then be employed for lake scale applications of alum to lakes and reservoirs. Application equipment and procedures are described. These depend on site characteristics and treatment objectives and include lakeside stores, a distribution pipe, and an application barge and manifold. Alum may also be used to meet other restoration objectives including the treatment of problem flows and the reduction of particulate concentrations.