微电解技术处理钻井污水的试验研究

采用铁屑/活性炭微电解法,对化学混凝处理后的钻井污水进行试验研究,得出最佳工艺条件:起始pH为1.0、铁/炭质量比为10、反应时间3h,宜选择活性炭、铸铁作为微电解法的材料。多因素正交试验表明:对CODCr去除能力的影响顺序为:起始pH>液固比>铁/炭质量比,对两种有代表性的活性炭分别确定了最佳工艺条件。在四川普光气田普光A-2井现场试验表明,化学混凝——铁屑/活性炭微电解处理钻井污水,能够达到《污水综合排放标准》(GB8978—1996)一级标准要求。     

硫化物对厌氧生化作用的影响及解救措施

本文介绍了厌氧生化的两个过程及其特征,分析了S~(2-)对厌氧生化的影响过程,重点研究了影响厌氧微生物活性环境中S~(2-)浓度,强调了环境中S~(2-)浓度与进水中S~(2-)浓度的区别。研究结果表明:厌氧生化过程中,S~(2-)的安全环境浓度为80mg/L,当环境中S~(2-)浓度大于80mg/L时,对厌氧生化有明显的抑制作用。将此研究结果在UASB反应器上进行了试验,取得了良好效果。同时,分析了S~(2-)使UASB反应器中污泥失活的过程,提出厌氧生化S~(2-)中毒的解救方法。     

中、小型制革企业生产废水处理设计及运行结果

介绍了根据制革工业废水污染物浓度高，水质水量多变的特点。从企业的实际出发，采用微电解——二级斜管沉淀工艺路线处理制革生产废水。工程运行表明：4r进水CODCr、BOD5、SS平均浓度分别为1973mg／L、787mg／L、1049mg／L的情况下，排水中CODCr、BOD5和SS平均浓度分别为206mg／L、89mg／L和102mg／L，处理后的水质达到了《污水综合排放标准》（GB8978—1996）中的二级标准。该工程具有投资少，运行费用低，处理效果好，启动速度快的特点，并受气温影响小。因此，特别适合北方寒冷地区的中、小型制革企业的废水治理。     

混凝沉降-微电解-催化氧化法处理钻井废水

采用混凝沉降-微电解-催化氧化法对钻井废水进行处理,筛选出最佳的工艺条件。实验结果表明,该法可使原水的CODCr从5846 mg/L降至150 mg/L以下,色度去除率达到100%,出水达到排放标准。混凝沉降-微电解-催化氧化法对于处理高CODCr、高色度钻井废水是行之有效的,具有广阔的应用前景。     

川西北气矿中坝须二气田水处理方法

介绍了川西北气矿中坝气田须二气藏水质情况,论述了气田水四种处理方法的特点和适用性。为了维持生产和减少环境污染,在该气藏中引入了预处理装置,对气田水进行处理后再进行异层回注。介绍了该工艺的流程,处理后气田水中SS和石油类含量分别为15mg/L和5.3mg/L,达到了设计要求。对处理成本及四种地层水处理方案的经济效益进行了对比,分析了该技术的经济可行性,并根据其应用情况提出了建议,供生产决策部门参考。     

气田产出水回注问题探讨

气田开采进入中、后期,随着气藏压力下降,地层水逐渐浸入气藏,流向气井,随天然气一道流到地面,即气田产出水。气田产出水中含大量氯离子,矿化度高,还含有油、S~(2-)等其他污染物,这些污染物随着气田产出水外排对环境将构成危害。产出水量大,又无外排条件时,一般应回注。为保证回注顺利进行,本文探讨了回注层位的选择,气田回注水的预处理,回注工艺的选择,注水效果监测以及气田注水中所存在的问题。最后,作者为提高气田注水技术,保护安全作业,提出了建议。     

普光高含硫气田水中H2S去除技术研究

文章探讨了通常用于水中H2S去除的方法,对比方法的优缺点,提出以NaClO为主要脱硫剂的处理方法。通过对采出水的脱硫氧化剂优选试验、NaClO连续脱硫试验,并将试验研究结果应用于普光高含硫气田水脱硫处理。试验证明:采用NaClO可以安全、高效地去除采出水中的H2S,处理后的气田水中硫化物的含量小于1mg/L。     

Cu／Fe内电解预处理焦化废水的研究

采用混凝沉淀一厌氧水解酸化一催化铁内电解（即Cu／Fe体系）一好氧组合工艺处理焦化废水，研究了催化铁内电解法用于焦化废水的预处理时，对焦化废水的COD、色度、总磷的去除率。结果表明，催化铁用于焦化废水的预处理，可以提高废水的可生化性，使好氧处理的COD去除率提高，达到80％-90％；催化铁对焦化废水有较好的脱色效果，色度去除率为77．7％-89．3％；催化铁能够去除部分总磷，但是由于微生物生长需要，需在厌氧段补充磷。试验证明，催化铁内电解法是一种有效的焦化废水预处理工艺。     

铁屑微电解法处理光致抗蚀剂废水的初步研究

初步研究了铁屑微电解法处理先致抗蚀剂废水；对废水pH值、曝气、铁屑和活性炭的用量等作了单因素影响试验。正交试验结果表明：当铁屑投加量50．0g／L，活性碳投加量5．0g／L，废水pH值2．0，反应时间60min时，CODCr去除率达42％。     

油田钻修井废水处理工艺技术研究及应用

在钻井、完井、井下作业等油气田开发生产过程中,会产生钻井泥浆压滤液、压井液、洗井液、压裂和酸化返排液等含油钻修井废水,这些废水组成复杂难处理,无法直接外排或回注。文章对冀东油田钻修井废水的水质特性及组成进行分析,开发了1套钻修井废水一体化处理技术,介绍了电催化、絮凝沉降、铁碳微电解、多级砂滤等核心工艺,开展了絮凝剂、助凝剂及pH值调节剂的最佳条件试验研究。研究结果表明:最佳药剂添加浓度分别为絮凝剂50 mg/L、助凝剂6 mg/L,最佳絮凝效果反应条件pH值为9。同时,现场试验应用结果表明:该工艺处理后的污水水质能够达到SY/T 5329—2012《碎屑岩油藏注水水质指标及分析方法》相关指标要求,实现了钻修井废水的合规化处置。     

国外油气田采出水处理新进展

对油气田采出水，国外普遍采用的处理方法是回注。但是在没有回注条件的地区必须将采出水处理后排放在地表水系，而对排放在地表水系的水有严格的规定，现在有些国家执行排放水含油量40mg／L的新标准，废止72mg／L的标准，原有污水处理设施需要改进。针对这个问题，文章介绍了国外在执行新标准后采用的新的油气田采出水处理工艺、设备以及新型澄清剂。     

催化电解法处理苯胺废水实验

在实验装置上对电化学法处理苯胺废水进行研究。根据不同电极材料对有机物降解机理的不同,对工业上应用较为广泛的几种电极材料进行筛选,并在此基础上考察了电流密度、投盐量、pH值、极间距、处理水量、电解时间等因素对处理结果的影响。结果表明:当用Ti/PbO2作电极,在电极间距为10mm,电流密度10mA/cm2,硫酸钠投加量1.5g/L,水板比8.3mL/cm2的条件下电解120min,废水中苯胺去除率可达94%以上,电解150min,溶液中的苯胺几乎完全降解。     

含硫低浊度采油污水絮凝处理技术的研究

中原油田明二污属含硫低浊度污水,处理后水主要用于回注。文章通过pH调节剂的优选、除硫剂优选并与絮凝药剂联合,对明二污含硫低浊度污水进行了絮凝处理。结果表明:当pH值为7.5、2#絮凝剂加量为50mg/L、有机絮凝剂加量为0.5mg/L、除硫剂加量为20mg/L时,处理后水中的悬浮物、总铁和含油量分别达到1.9mg/L、0.43mg/L和0mg/L;SRB、TGB均为102个/mL;腐蚀速率及结垢量分别降到0.062mm/a和1.9mg/L;污泥产生量降低到0.23～0.26mg/L;在90℃时的结垢量由地层水的23.3mg/L降低到1.9mg/L,处理后的水达到中原油田回注水的水质标准,并且水质稳定。     

间接电化学降解亚甲基蓝废水的可行性研究

研究以ClO^-／Cl^-作媒介，间接电化学降解亚甲基蓝模拟废水的可行性。结果表明，亚甲基蓝的电化学降解与电极材料、电流密度以及添加剂种类等因素有关。以石墨为阳极，不锈钢为阴极，在无隔膜的烧杯中放置50ml浓度为1000mg/L的亚甲基蓝模拟废水，在室温25℃，pH6．0－8．0，槽电压10V，电流密度30．0mA/cm^2，Cl^-加入量2g/L的条件下，电解60min后，亚甲基蓝溶液的平均消色率达到98．0％，CODcr降解率为97．0％，BOD5降解率为99．0％；用浸涂过MnO2薄膜的石墨棒作阳极可显著加快其消解速率，而用浸涂过CeO2薄膜的石墨棒作阳极对其消解速率无明显的影响。并初步讨论了其降解机理。     

高效生物滴滤塔处理化工污水含H2S恶臭气体实验研究

以化工污水水解酸化池收集的现场恶臭气体作为实验气体,以陶粒、半软性塑料作为生物滴滤塔的填料,探讨了生物滴滤塔挂膜过程阻力变化和H2S气体脱除率关系,并以生活污水为营养液进行了连续实验.实验研究表明：在所选实验条件下,为使H2S出口浓度达到0.06mg/m^3,生活污水COD应维持250mg/L以下,SO4^2-浓度＜1400mg/L.     

Aerobic treatment of palm oil mill effluent

In this study treatment of palm oil mill effluent (POME) was investigated using aerobic oxidation based on an activated sludge process. The effects of sludge volume index, scum index and mixed liquor suspended solids during the acclimatizing phase and biomass build-up phase were investigated in order to ascertain the reactor stability. The efficiency of the activated sludge process was evaluated by treating anaerobically digested and diluted raw POME obtained from Golden Hope Plantations, Malaysia. The treatment of POME was carried out at a fixed biomass concentration of 3900+/-200mg/L, whereas the corresponding sludge volume index was found to be around 105+/-5mL/g. The initial studies on the efficiency of the activated sludge reactor were carried out using diluted raw POME for varying the hydraulic retention time, viz: 18, 24, 30 and 36h and influent COD concentration, viz: 1000, 2000, 3000, 4000 and 5000mg/L, respectively. The results showed that at the end of 36h of hydraulic retention time for the above said influent COD, the COD removal efficiencies were found to be 83%, 72%, 64%, 54% and 42% whereas at 24h hydraulic retention time they were 57%, 45%, 38%, 30% and 27%, respectively. The effectiveness of aerobic oxidation was also compared between anaerobically digested and diluted raw POME having corresponding CODs of 3908 and 3925mg/L, for varying hydraulic retention time, viz: 18, 24, 30, 36, 42, 48, 54 and 60h. The dissolved oxygen concentration and pH in the activated sludge reactor were found to be 1.8-2.2mg/L and 7-8.5, respectively. The scum index was found to rise from 0.5% to 1.9% during the acclimatizing phase and biomass build-up phase.     

Photodegradation of selected herbicides in various natural waters and soils under environmental conditions

The photochemical degradation of herbicides belonging to different chemical groups has been investigated in different types of natural waters (ground, river, lake, marine) and distilled water as well as in soils with different texture and composition. Studied herbicides and chemical groups included atrazine, propazine, and prometryne (s-triazines); propachlor and propanil (acetanilides); and molinate (thiocarbamate). The degradation kinetics were monitored under natural conditions of sunlight and temperature. Photodegradation experiments were performed in May through July 1998 at low concentrations in water samples (2-10 mg/L) and soil samples (5-20 mg/kg), which are close to usual field dosage. The photodegradation rates of all studied herbicides in different natural waters followed a pseudo-first order kinetics. The half-lives of the selected herbicides varied from 26 to 73 calendar days in waters and from 12 to 40 d in soil surfaces, showing that the degradation process depends on the constitution of the irradiated media. The presence of humic substances in the lake, river, and marine water samples reduces degradation rates in comparison with the distilled and ground water. On the contrary, the degradation in soil is accelerated as the percentage of organic matter increases. Generally, the photodegradation process in soil is faster than in water. The major photodegradation products identified by using gas chromatography-mass spectrometry (GC-MS) techniques were the hydroxy and dealkylated derivatives for s-triazines, the dechlorinated and hydroxy derivative for the anilides, and the keto-derivative for the thiocarbamate, indicating a similar mode of degradation for each chemical category.     

Collateral geochemical impacts of agricultural nitrogen enrichment from 1963 to 1985: a southern Wisconsin ground water depth profile

In this study, we used chlorofluorocarbon (CFC) age-dating to investigate the geochemistry of N enrichment within a bedrock aquifer depth profile beneath a south central Wisconsin agricultural landscape. Measurement of N(2)O and excess N(2) allowed us to reconstruct the total NO(3)(-) and total nitrogen (TN) leached to ground water and was essential for tracing the separate influences of soil nitrification and ground water denitrification in the collateral geochemical chronology. We identify four geochemical impacts due to a steady ground water N enrichment trajectory (39 +/- 2.2 micromol L(-1) yr(-1), r(2) = 0.96) over two decades (1963-1985) of rapidly escalating N use. First, as a by-product of soil nitrification, N(2)O entered ground water at a stable (r(2) = 0.99) mole ratio of 0.24 +/- 0.007 mole% (N(2)O-N/NO(3)-N). The gathering of excess N(2)O in ground water is a potential concern relative to greenhouse gas emissions and stratospheric ozone depletion after it discharges to surface water. Second, excess N(2) measurements revealed that NO(3)(-) was a prominent, mobile, labile electron acceptor comparable in importance to O(2.) Denitrification transformed 36 +/- 15 mole% (mol mol(-1) x 100) of the total N within the profile to N(2) gas, delaying exceedance of the NO(3)(-) drinking water standard by approximately 6 yr. Third, soil acids produced from nitrification substantially increased the concentrations of major, dolomitic ions (Ca, Mg, HCO(3)(-)) in ground water relative to pre-enrichment conditions. By 1985, concentrations approximately doubled; by 2006, CFC age-date projections suggest concentrations may have tripled. Finally, the nitrification induced mobilization of Ca may have caused a co-release of P from Ca-rich soil surfaces. Dissolved P increased from an approximate background value of 0.02 mg L(-1) in 1963 to 0.07 mg L(-1) in 1985. The CFC age-date projections suggest the concentration could have reached 0.11 mg L(-1) in ground water recharge by 2006. These results highlight an intersection of the N and P cycles potentially important for managing the quality of ground water discharged to surface water.     

GROUND WATER AS A SOURCE OF NUTRIENTS AND ATRAZINE TO STREAMS IN THE SOUTH PLATTE RIVER BASIN1

ABSTRACT: Concentrations of nitrite plus nitrate, ammonia, orthophosphate, and atrazine were measured in streams and ground water beneath the streams at 23 sites in the South Platte River basin of Colorado, Nebraska, and Wyoming to assess: (1) the role of ground water as a source of nutrients and atrazine to streams in the basin, and (2) the effect of land-use setting on this process. Concentrations of nitrite plus nitrate, ammonia, orthophosphate, and atrazine were higher in ground water than in the overlying streams at 2, 12, 12, and 3 of 19 sites, respectively, where there was not a measurable hydraulic gradient directed from the stream to the ground water. Orthophosphate was the only constituent that had a significantly higher (p ≤ 0.05) concentration in ground water than in surface water for a given land-use setting (range land). Redox conditions in ground water were more important than land-use setting in influencing whether ground water was a source of elevated nitrite plus nitrate concentrations to streams in the basin. The ratios of nitrite plus nitrate in ground water/surface were were significantly lower (p ≤ 0.05) at sites having concentrations of dissolved oxygen in ground water ≤ 0.5 mg/L than at sites having dissolved oxygen concentrations ≥ 0.5 mg/L. Elevated concentrations of ammonia or atrazine in ground water occurred at sites in close proximity to likely sources of ammonia or atrazine, regardless of land-use setting. These results indicate that land-use setting is not the only factor that influences whether ground water is a source of elevated nutrient and atrazine concentrations to streams in the South Platte River Basin.     

Controlling nitrate leaching in irrigated agriculture

The impact of improved irrigation and nutrient practices on ground water quality was assessed at the Nebraska Management System Evaluation Area using ground water quality data collected from 16 depths at 31 strategically located multilevel samplers three times annually from 1991 to 1996. The site was sectioned into four 13.4-ha management fields: (i) a conventional furrow-irrigated corn (Zea mays L.) field; (ii) a surge-irrigated corn field, which received 60% less water and 31% less N fertilizer than the conventional field; (iii) a center pivot-irrigated corn field, which received 66% less water and 37% less N fertilizer than the conventional field; and (iv) a center pivot-irrigated alfalfa (Medicago sativa L.) field. Dating (3H/3He) indicated that the uppermost ground water was <1 to 2 yr old and that the aquifer water was stratified with the deepest water approximately 20 yr old. Recharge during the wet growing season in 1993 reduced the average NO3-N concentration in the top 3 m 20 mg L(-1), effectively diluting and replacing the NO3-contaminated water. Nitrate concentrations in the shallow zone of the aquifer increased with depth to water. Beneath the conventional and surge-irrigated fields, shallow ground water concentrations returned to the initial 30 mg NO3-N L(-1) level by fall 1995; however, beneath the center pivot-irrigated corn field, concentrations remained at approximately 13 mg NO3-N L(-1) until fall 1996. A combination of sprinkler irrigation and N fertigation significantly reduced N leaching with only minor reductions (6%) in crop yield.