Treatment of drilling wastewater from a sulfonated mud system

Treatment of drilling wastewater from a sulfonated drilling mud system in the Shengli Oilfield, East China, was studied. The wastewater was deeply treated by a chemical coagulationcentrifugal separation-ozone catalytic oxidation combined process. The factors （i.e. pH value, chemical dosage, reaction time, etc.） influencing the treatment effect were investigated, and pH = 7 was determined as optimal for the coagulation; polymeric aluminum chloride （PAC） was selected as the optimal coagulant with a dosage of 18 g/L; cationic polyacrylamide （CPAM） with molecular weight of 8 million was selected as the optimal coagulant aid with an optimum dosage of 8 mg/L; and the optimal condition of catalytic ozonation was found to be a pH of 12 and an oxidation time of 40 min. The results showed that the combined treatment process was effective. The oil content and suspended solids content of the effluent reached the first class discharge standard according to China＇s standard GB 8978-1996 （Integrated Wastewater Discharge Standard） and the chemical oxygen demand （COD） decreased to 195 mg/L from 2.34×10^4 mg/L after coagulation process and ozone oxidation at pH = 12 for 40 min.

Treatment of drilling wastewater using a weakly basic resin

Macroporous weak basic anion exchanger （D301R） was used to remove organic substances from drilling wastewater. The effect of pH, temperature and contact time on adsorption behavior was investigated in batch experiments, which indicated that the COD （Chemical Oxygen Demand） removal ratio of drilling wastewater was approximately 90%, and the COD of treated wastewater was below 70 mg/L under appropriate operating conditions. A mixed liquor of NaOH and NaCI was selected as desorbent because of its better elution performance. The results of column dynamic adsorption and regeneration showed that the COD of wastewater could be efficiently removed by D301R resin, and the resin was easily regenerated by the selected desorbent.

Occurrences of Glucocorticoids in Aquatic Environment and Their Removal during Wastewater Treatment

Glucocorticoids(GCs) are a group of endocrine-disrupting compounds(EDCs) frequently prescribed against various medical conditions.Recently,GCs have been shown to be effective in managing septic shock in patients infected with the 2019 novel coronavirus(COVID-19).Due to colossal consumption and potential risks to aquatic organisms,GCs have immensely attracted the focus of the scientific research community as a water pollutant.Therefore,the aim of this paper is to review the current knowledge on the occurrence of various GCs in the aquatic environment and their removal during wastewater treatment.A variety of GCs are ubiquitous in surface water,hospital wastewater,and sewage water worldwide.And the minimum concentration in volume is below 0.01 ng/L,and the maximum one is 10 000 ng/L,and enter the environment through hospital and urban wastewater discharging.Compared with natural GCs,higher risks to aquatic environments could be induced by synthetic GCs.The current activated sludge processes used in wastewater treatment plants(WWTPs) are not fully effective in eliminating GCs,some of which may further increase the risk of GC in the environment.In comparison with the aerobic process in WWTPs,the anaerobic and anoxic processes were found to be more efficient for GC degradation.Of the studied GCs,fluticasone propionate,clobetasol propionate,fluocinolone acetonide,and triamcinolone acetonide need more attention due to their low removal efficiencies and strong toxicity.Among the advanced treatment processes,reverse osmosis,ultraviolet irradiation,CaO_(2),and plasma could achieve significant GC activity removal while micro/ultra-filtration,chlorination,and ozonation were less efficient.

Treatment of pharmaceutical wastewater containing recalcitrant compounds in a Fenton-coagulation process

The advanced treatment using integrated Fenton＇s reaction and coagulation process was investigated in this study. Before the advancement, the pharmaceutical wastewater containing lincomycin hydrochloride was pretreated by UASB （upflow anaerobic sludge bed） and a SBR （sequencing batch reactor） process. The residual recalcitrant compounds, measured by gas chromatographymass spectrometry （GC-MS）, mainly consisted of alcohols, phenols, and nitrogenous and sulfur compounds. The experimental results indicated that when the Fenton＇s reaction was conducted at pH=3.0, H2O2CODOcr=0.27, H2O2/Fe^2＋=3：1 and 30 min of reaction time, and the coagulation process operated at a sulfate aluminum concentration of 800 mg/L and pH value of 5.0, the color and COD in the wastewater decreased by 94% and 73%, respectively; with a finale COD concentration of 267 mg/L and color level of 40 units, meeting the secondary standard of GB8978-1996 for industrial wastewater.

Evaluation of Mixing Efficiency in Coagulation-Flocculation Process in Wastewater Treatment

Fluid flow and mixing phenomenon have a significant impact on coagulation and flocculation processes. Particles dissipating the turbulent kinetic energy increase the efficiency of collision, grow in size and incorporate phosphate from the wastewater Only certain flocks can be separated depending on their stability, size, density, etc.. According to the literature the velocity gradient of the flow （G-value） is the main design parameter of the flocculators, but there is a need to take into account at least the flocks age, too. In this paper, it presents a novel approach to determine the efficiency of flocculators using local mean age theory, residence time distribution and dimensional analysis. Calculations were performed for two constructions of cascade reactors---one with small baffles and one without these; hydraulical performance and the achievable conversion were compared. As a result, the flocculator with small baffles proved to be more efficient than the traditional construction.

OKRA (HIBISCUS ESCULENTUS) AND FENUGREEK (TRIGONELLA FOENUM GRACEUM) MUCILAGE:CHARACTERIZATION AND APPLICATION AS FLOCCULANTS FOR TEXTILE EFFLUENT TREATMENTS

The use of new food grade polysaccharides (mucilage) obtained from Hibiscus esculentus and Trigonella foenum graceum,commonly called Okra and Fenugreek,respectively,as flocculants was described.These polysaccharides were used for removal of solids (suspended solids (SS) and total dissolved solids (TDS)) and dyes from real textile effluents and aqueous solutions of different class of synthetic dyes.Influences of varying polysaccharide concentration,contact time and pH on removal of pollutant from the textile...

Sludge Density Prediction in a Wastewater Chemical Coagulation Process

This paper reports an approach to estimate the sludge density in a physicochemical treatment of municipal wastewater, experiments considered 4 coagulants (aluminum sulfate SAl, iron sulfate SFe, aluminum polychloride PAX, iron polychloride PIX), and 2 flocculant products (cationic CP and anionic AP polymers). Experimental approach is based on running a set of jar tests at different coagulant concentrations. After the stirring and resting times took place, pH and conductivity were registered finding that SAl and SFe either with or without polymers are the coagulants producing the higher pH drop. Conductivity measures also establish two kind of data since higher conductivity (about 2000 ) was observed for SAl, and PIX, PIX + CP, PIX + AP;otherwise a conductivity about 1300 was observed for SAl + PC, SFe and PAX alone and with CP or AP. Settleable solids (SST) determined with an Imhoff cone were similar for sulfates and polychlorides, but dry sludge (DS) clearly set up two groups the one with higher sludge content corresponds to sulfates group. The quotient of DS divided by the SST provided an estimation of the apparent sludge density, in this way it was observed that higher densities were obtained for sludge from sulfates at lower coagulant concentrations;also sludge from SFe was heavier than the one from SAl. Otherwise, polychlorides produced a lighter sludge in respect to the one obtained with sulfates, and between them the PIX coagulant provided a heavier sludge than the PAX coagulant.

赤泥用于酸性含锰废水中锰的净化研究

采用还原焙烧-磁选预处理赤泥,得到非磁性物;非磁性物经煅烧、盐酸溶出后加入饱和偏铝酸钠聚合剂聚合后过滤、熟化制备聚合氯化铝(PAC)基液;使用该PAC基液,在沉降时间5 h、PAC基液与废水体积比1∶120、搅拌转速140 r/min、pH值8、反应温度30℃、聚丙烯酰胺(PAM)投加量20 mg/L条件下处理含锰酸性废水,处理后液中锰质量浓度由325.3 mg/L降至1.5 mg/L,锰去除率达99.5%,净化后液中锰质量浓度达到国家一级排放标准。

铝电极电絮凝法处理机械加工含乳化液废水技术研究

采用铝电极电絮凝法处理机械加工含乳化液废水.实验结果表明,最佳的电解工艺条件为:电解电压=35V,反应时间=60min,电解质NaCl投加量=0.10g/L,pH值=3,破乳剂CaCl_(2)投加量=10g/L.在此条件下,废水COD去除率可以达到956%,出水COD可以达到500mg/L以下.此方法具有处理效果好、反应时间短等优点,在含乳化液废水处理领域具有良好的应用前景.

高分子絮凝剂在制革废水处理的实验研究

制革废水含有大量难降解的有机污染物及有毒有害物质,直接排放将严重影响生态环境与人类健康。文章以制革废水为研究对象,使用阳离子聚丙烯酰胺(C-PAM)絮凝剂处理制革废水,对处理工艺参数进行优化。通过试验,确定制革废水处理最佳工艺条件:阳离子聚丙烯酰胺(C-PAM)投加量为1.5 mg/L,调节废水的p H值为9,沉降时间约20 min,COD去除率最高为89.6%。

磁性Fe_(3)O_(4)纳米颗粒强化微藻废水处理及产油效果的研究

针对微藻规模化废水处理过程中污染物去除效果不稳定、采收困难及藻细胞油脂提取率低等问题,以磁性Fe_(3)O_(4)纳米颗粒作为强化剂和絮凝剂,考察其对微藻废水处理效果、藻细胞生物量和油脂含率及后续微藻采收的提升作用。结果表明,在20 mg/L浓度的Fe_(3)O_(4)NPs作用下,斜生栅藻对污水中COD、NH_(4)^(+)-N和TP的去除率分别达到98.82%、93.25%和78.22%,小球藻生物量增加49.91%,总脂产量增加66.92%;投加30 mg/L浓度的Fe_(3)O_(4)NPs可以在10 min内获得94%的小球藻收获率;当投加浓度增加到100 mg/L时,小球藻细胞的油脂含率由23.27%提升至38.66%,总脂产量增加68.38%。为制定集促进微藻净水效率提高、藻细胞生物量和油脂含率提升及藻细胞快速采收等多种功能于一体的Fe_(3)O_(4)NPs投加策略提供技术参考。

无机混凝剂的研究及应用进展

介绍了无机混凝剂的发展历程,其中主要包括铁盐混凝剂、铝盐混凝剂、钛盐混凝剂,重点论述了一种新型混凝剂(锆盐混凝剂)的作用机理以及研究进展,并在此基础上对锆盐混凝剂在未来研究及应用的方向做出了总结与展望。

强化混凝沉淀法处理生活垃圾渗滤液实验研究

采用Fenton和絮凝处理的结合方式处理广东垃圾填埋场的滤液。实验采用不同的Fenton处理条件,包括pH值、H_(2)O_(2)/Fe(Ⅱ)比例和用量以及反应时间,以确定最佳的处理条件。在最佳Fenton处理条件下,COD去除效率约为80%,进水质量浓度为624±80 mg·L^(-1),符合QCVN 25:2009/BTNMT的要求。同时去除了75%的色度、25%的氨和12%的悬浮物,为下一阶段的絮凝处理创造了有利条件。在絮凝方面,研究使用CaO和聚合氯化铝(PAC)顺序处理滤液。经过Ca O(6 g·L^(-1),180 min)、PAC(1 500 mg·L^(-1))和A101(2 mg·L^(-1))处理后,COD、色度、氨和悬浮物的去除率分别达到85%、99%、99%~99.5%和88%,出水可满足排放标准,毒性分析表明Fenton处理降低了垃圾填埋场渗滤液的毒性。

浙江某石矿废水高效净化试验研究

为解决石矿废水浊度大和固体悬浮物粒度细的问题,通过单一有机絮凝剂、无机絮凝剂、调整剂种类用量、药剂组合优化试验对该废水开展高效净化研究。结果表明,在调整剂CaO用量为200 g/m^(3),无机絮凝剂聚合氯化铝(PAC)用量为2.5 g/m^(3),有机絮凝剂PAM-新用量为12 g/m^(3)组合用药条件下,废水浊度为97.30 NTU,满足废水“零排放”生产回用要求和工业废水排放标准。

污水处理装置排放超标控制措施研究

针对目标污水处理装置采用加药絮凝的方式对污水进行处理,出现了出口系统水质污染物排放超标的现象,在分析进水系统和出水系统水样水质指标的基础上,考察了不同类型絮凝剂对污水处理效果的影响,优选出性能较好的复合絮凝剂FX-1,并考察了污水处理装置的长时间运行效果。结果表明:FX-1的使用能够有效降低目标污水处理装置出口端水样中的各项污染物浓度,且出水系统水样各项污染物浓度在12个月内均能得到有效控制,COD、悬浮物、氨氮、总氮、总磷和石油类含量均能达到GB 18918—2002中“一级A标准”要求,实现了目标污水处理装置高效稳定运行。

某氟化工生产废水处理工程设计实例

针对某氟化工生产废水的水质特点,采用分质处理的方法,对高氟废水采用钙盐沉淀-铝盐沉淀-三效蒸发预处理,对其他低氟废水采用钙盐沉淀-铝盐沉淀预处理,采用好氧生化-臭氧催化氧化-絮凝沉淀组合工艺处理经过预处理后的混合废水,介绍了该工程的处理工艺、设计参数、运行效果、投资及运行成本等。工程运行结果表明,pH值、COD及氟离子指标达到GB 3838—2002《地表水环境质量标准》中V类水标准,全盐量达到山东省DB37/3416.3—2018《流域水污染物综合排放标准第3部分:小清河流域》要求,满足下游污水厂纳管标准。

电解法处理废水中有机物的试验研究

电解法是一种新型的废水处理技术,由于其无须添加药剂,不产生二次污染,越来越受到人们的关注。试验使用电解法来降解废水中的有机物,分别研究pH、反应时间、电流和电压对化学需氧量(COD)去除率的影响,从而确定合适的反应条件,更好地将电解法应用于废水处理中。

微气泡O_(3)/H_(2)O_(2)深度处理某树脂厂二级出水效果与机制

针对传统生物降解对树脂废水中苯系物、聚乙烯醇等大分子有机物降解效果不好、达不到排放标准的问题,构建微气泡O_(3)/H_(2)O_(2)体系,对某树脂厂二级出水进行深度处理。对比了微气泡O_(3)曝气与普通O_(3)曝气的化学需氧量(COD)降解效果,考察了进气O_(3)浓度、H_(2)O_(2)浓度、初始pH对微气泡O_(3)/H_(2)O_(2)体系降解COD效果的影响,通过总有机碳验证体系的矿化效果,通过电子顺磁共振谱仪(EPR)检测微气泡O_(3)/H_(2)O_(2)体系中的活性物质,最后通过气相色谱质谱联用仪(GC-MS)分析降解前后废水中主要有机物的种类,并对微气泡O_(3)/H_(2)O_(2)体系降解COD的机制与路径进行分析。结果表明:1)微气泡O_(3)/H_(2)O_(2)体系中微气泡粒径主要分布在10~50μm,平均粒径为32.82μm;与普通O_(3)曝气方式进行对比,微气泡O_(3)体系对COD降解率更高,说明微气泡可以延长O_(3)气泡上升时间,增加O_(3)气泡比表面积,提高O_(3)传质系数和利用率。2)微气泡O_(3)/H_(2)O_(2)体系降解COD,当O_(3)浓度为60 mg/L、H_(2)O_(2)浓度为29.37 mmol/L、pH为7时,反应60 min后,微气泡O_(3)/H_(2)O_(2)体系对树脂厂二级出水的COD降解率为89.53%,处理后出水COD为15.05 mg/L,可达到GB 31572—2015《合成树脂工业污染物排放标准》。3)EPR试验表明,H_(2)O_(2)可以促进微气泡O_(3)体系产生更多的超氧自由基(·O_(2)^(-))和羟基自由基(·OH),从而提高体系的氧化能力和对COD的降解效果。根据GC-MS结果推断O_(3)/H_(2)O_(2)体系降解COD的可能路径,即树脂厂二级出水以长链烷烃和环烷烃类为主的大分子物质在O_(3)的作用下断链、开环,在·OH等自由基的作用下矿化或降解为以小分子有机酸为主的小分子物质。

絮凝剂在废水处理中的应用

絮凝是工业上常用的实现固液分离的技术。在此过程中,絮凝剂通过范德华力作用、电中和作用、吸附架桥作用或网捕卷扫作用聚集胶体颗粒,调节分散体系的稳定性和絮凝性能。文中介绍了絮凝剂的分类,主要包括无机絮凝剂、有机絮凝剂、微生物絮凝剂和复合絮凝剂四大类,其中复合絮凝剂又包括无机复合絮凝剂、有机复合絮凝剂、无机与有机复合絮凝剂、微生物絮凝剂和复合磁性絮凝剂。讨论了废水浊度、废水温度、废水pH、共存杂质、絮凝剂种类、用量、加药顺序和搅拌速率、搅拌时间等因素对絮凝效果的影响。介绍了絮凝剂在工业废水处理中的应用情况,并对絮凝剂的发展方向做了展望。

废水污泥用功能复合型脱水剂制备及应用研究

针对复杂废水污泥高效脱水,开发应用复合型絮凝脱水剂尤为重要。以天然钠基膨润土、2-丙烯酰胺-2-甲基丙磺酸、对苯乙烯磺酸钠、交联复合乳液为主要原料,调节不同配比,辅以引发剂,采用共聚反应方式制备功能复合型絮凝脱水剂AW。通过污泥脱水去除率及脱水速率提升效果确定最佳质量比,可发挥各组分结构的独特作用,实现高效污泥脱水。结果表明:该絮凝脱水剂较常规絮凝脱水剂综合脱水率提高5%~10%,脱水速率提高3倍以上,性能优异。