Effects of effluent organic matters on endocrine disrupting chemical removal by ultrafiltration and ozonation in synthetic secondary effluent

Endocrine disrupting chemicals(EDCs) in the secondary effluent discharged from wastewater treatment plants are of great concern when water reuse is intended. Ozonation and ultrafiltration(UF) are powerful technologies reported to eliminate EDCs. Due to the importance of effluent organic matters(EfOMs) in secondary effluent, the effects of three kinds of EfOM on the treatment of five EDCs using ozonation and UF were investigated. The three kinds of EfOM studied were humic acid sodium salt(NaAH), bovine serum albumin(BSA)and sodium alginate(NaAg); and the five EDCs were estrone, 17β-estradiol, estriol, 17α-ethynyl estradiol and bisphenol A. The results showed that EfOM accelerated the decay rate of ozone and inhibited the degradation efficiency of EDCs by ozonation in the order NaAH BSA NaAg.The ultraviolet absorbance at 280 nm(UVA_(280)) has potential for use as a surrogate indicator to assess EDC removal via ozonation without conducting difficult EDC analyses. When the decline in UVA_(280) exceeded 18%, the five EDCs had been completely removed. The UF behavior of NaAH,BSA and NaAg was found to follow the cake filtration law. The fouling potential of EfOM followed the order NaAg NaAH BSA; while EfOM on the membrane surface enhanced EDC removal in the order NaAH BSA NaAg. The mean retention rate of the membrane was increased by 24%, 10% and 8%, respectively. The properties of EDCs and EfOM cakes both influenced the EDC removal rates due to adsorption, size exclusion and charge attraction.     

The effect of low-molecular-weight organic-acids (LMWOAs) on treatment of chromium-contaminated soils by compost-phytoremediation: Kinetics of the chromium release and fractionation

A soil–plant biological system was developed from chromium(Cr) polluted soil treated by the compost-phytoremediation method. The transformation and migration of the Cr in this system is comprehensively studied in this research. The results illustrated that the co-composting treatment can reduce the Cr availability from 39%(F1 was about 31% of total, F2 was about 8% of total) to less than 2% by stabilizing the Cr. However, herbaceous plants can accumulate the concentrations of Cr from 113.8 to 265.2 mg/kg in the two crops,even though the concentration of soluble Cr in the substrate soil was below 0.1 mg/L.Cr can be assimilated and easily transferred in the tissues of plants because the lowmolecular-weight organic-acids(LMWOAs) derived from the plant root increase the bioavailability of Cr. The amount of extracted Cr dramatically increased when the organic acids were substituted in this order: citric acid malic acid tartaric acid oxalic acid acetic acid. On average the maximum(147.4 mg/kg) and the minimum(78.75 mg/kg) Cr were extracted by 20 mmol/L citric acid and acetic acid, respectively. The desorption of Cr in different acid solutions can be predicted by the pseudo second-order kinetics. The exchangeable Cr, carbonate-bound Cr, and residual Cr decreased, while Fe–Mn oxide bound Cr and organic bound Cr increased in the soil solid phase. According to the experimental results, the organic acids will promote the desorption and chelation processes of Cr, leading to the remobilization of Cr in the soil.     

不同材料包埋固定化厌氧氨氧化混培物

为探寻一条维持反应器中厌氧氨氧化混培物生物量的新途径,采用CMC、PVA、SA以及PVA.SA混合液等为包埋材料.对厌氧氨氧化混培物进行包埋固定,制成固定化小球.结果表明,4种包埋固定化小球均表现出较高的厌氧氨氧化活性,氨氮和亚硝酸盐氮的去除率分别达到100%和96%～98%,其中氨氯、亚硝酸盐氮去除量和硝酸盐氮生成量的比值在1:(1.142～1.252):(0.200～0.365)之间.4种包埋固定化小球的厌氧氨氧化活性排序为CMC小球>SA小球>PVA-SA小球>PVA小球.机械性能排序为PVA-SA小球>PVA小球>SA小球>CMC小球.PVA小球粘连现象严重,成球效果最差.综合评价PVA-SA为最佳的固定化材料.     

同步脱氮除磷复配菌剂对河流水质净化效果研究

通过选择培养基、溴麝香草酚蓝（Bromothymol Blue,BTB）培养基筛选及脱氮除磷性能检测,从城市河道中成功筛选出6株异养硝化-好氧反硝化菌株,分别属于假单胞菌属（Pseudomonas）、产碱杆菌属（Alcaligenes）、无色杆菌属（Achromobacter）和陶厄氏菌属（Thauera）,其中3株菌株兼具硝化、反硝化和聚磷能力,菌株MC-5除磷能力最优.在此基础上,将筛选出的6株单菌株进行复配,考察了复配菌剂在不同COD/TN下的脱氮除磷性能.根据群落结构变化分析,发现复配菌剂中的产碱杆菌属在脱氮除磷中发挥了更为关键的作用.水中碳源耗尽时补加碳源能显著提升复配菌剂的脱氮除磷性能,氨氮和总磷去除率分别由55.87%和50.48%提高到100%和98.89%,而水中COD/TN高于20会对微生物产生抑制作用.探究复配菌剂处理受污染河水最佳投加量的试验结果表明,投加量为1.69 g·m-3时,总磷指标能够从地表水劣Ⅴ类提高至Ⅲ类水质标准,氮类指标能够提升至接近地表水Ⅴ类水质标准.适当提高菌剂投加量能提高氮、磷元素降解速率,缩短河道水质修复时间.这说明本研究中的同步脱氮除磷...     

Simultaneous removal of chromium and arsenate from contaminated groundwater by ferrous sulfate: Batch uptake behavior

Chromium and/or arsenate removal by Fe(II) as a function of pH, Fe(II) dosage and initial Cr(VI)/As(V) ratio were examined in batch tests. The presence of arsenate reduced the removal e ciency of chromium by Fe(II), while the presence of chromate significantly increased the removal e ciency of arsenate by Fe(II) at pH 6–8. In the absence of arsenate, chromium removal by Fe(II) increased to a maximum with increasing pH from 4 to 7 and then decreased with a further increase in pH. The increment in Fe(II) dosage resulted in an improvement in chromium removal and the improvement was more remarkable under alkaline conditions than that under acidic conditions. Chromium removal by Fe(II) was reduced to a larger extent under neutral and alkaline conditions than that under acidic conditions due to the presence of 10 mol/L arsenate. The presence of 20 mol/L arsenate slightly improved chromium removal by Fe(II) at pH 3.9–5.8, but had detrimental e ects at pH 6.7–9.8. Arsenate removal was improved significantly at pH 4–9 due to the presence of 10 mol/L chromate at Fe(II) dosages of 20–60 mol/L. Elevating the chromate concentration from 10 to 20 mol/L resulted in a further improvement in arsenate removal at pH 4.0–4.6 when Fe(II) was dosed at 30–60 mol/L.     

电晕-催化技术治理甲苯废气的实验研究

利用脉冲电源供能,在有、无催化剂存在的２类电晕反应器中,对甲苯的去除效果进行了实验对比,并考察了影响甲苯去除率的主要因素。结果表明,对于线－筒式对反应器,在４２ＫＶ的峰值电压下,使用Ｍｎ或Ｆｅ催化剂使甲苯的去除率分别提高了２７％和２３％,去除率均在８０％以上,能量利用率约为３０Ｗ．ｈ／ｍ＾３。     

磁聚去除淡水藻华的研究

研究了磁场作用下壳聚糖与Fe₃O⁴复配去除淡水藻华.结果表明,在壳聚糖用量1.6mg/L,Fe₃O⁴用量4mg/L的情况下,通过0.5T的外磁场富集可使藻个数由4.80×10⁶个/mL降为2.80×10³个/mL;叶绿素a去除率达100%.藻液浊度、COD、总N、总P含量的去除率分别为99.6%、85.0%、73.9%、28.7%,并初步探讨了磁聚除藻的机理.     

暗管排水稻田中氮素淋失动态混合模型及应用

为研究淹灌稻田在排水条件下的氮素淋失规律,根据势能理论及溶质运移理论提出了流网法与动力学方法相结合的田间水氮动态混合模拟模型该模型在暗管排水出流计算中采用叠加原理,将SPAC系统中异常复杂的二维水氮运移问题的求解简化为对多个流带中一维问题的求解,方法简单、实用对方法及模型的正确性进行了田间试验验证,结果表明,水稻生长期间,试验田块中氮肥淋失量为4kgN/hm²占总施氮量的1.3％．氮肥淋失量与农田排水条件有关,地下排水强度增大,会增加氮肥淋失量。因此,应合理进行水位管理。     

固定化藻类脱氮除磷效果研究

藻类固定在活性炭上用于去除人工配制污水中的氮、磷等污染物。试验结果表明藻类对氮、磷和浊度的去除率分别达到50％、41．9％和98．2％,氮、磷和浊度相应达到较好去除效果的时间分别为12、60、60h。     

生物质-硫磺混合营养反硝化体系对尾水中 NO 3 - -N的去除效果

生活污水经二级处理工艺处理后排放,尾水 NO 3 - -N浓度仍较高。构建了生物质-硫磺混合营养反硝化体系,对其去除 NO 3 - -N的效果进行了研究。静态试验结果表明:木屑-硫磺混合营养反硝化体系能在较短的时间内去除 NO 3 - -N,反应速率常数为0.041 6 d-1,且 NO 2 - -N、 NH 4 + -N转化量低;初始pH为6~9、木屑与硫磺配比为0.5~2.0时,对反硝化过程影响不大,铁屑的添加对体系的pH具有一定的调控作用。动态试验结果表明:含有50 g硫磺和25 g木屑的混合营养反硝化体系,对初始浓度为15 mg/L的 NO 3 - -N有较好的去除效果,去除率接近90%;通过改变木屑与硫磺配比或加入铁屑能适当提高高浓度 NO 3 - -N的去除率,其中,50 g硫磺+50 g木屑的反硝化体系在 NO 3 - -N浓度为30 mg/L时,也能维持约90%的去除率。初始NO 　 3 - -N浓度会对反应柱内微生物群落的丰度产生一定影响,但对微生物群落的结构基本没有影响。     

Inhibition effect of magnetic field on nitrous oxide emission from sequencing batch reactor treating domestic wastewater at low temperature

This study aims to investigate the effect of a magnetic field on nitrous oxide(N₂O) emission from a sequencing batch reactor treating low-strength domestic wastewater at low temperature(10℃).After running for 124 days in parallel,results indicated that the conversion rate of N₂O for a magnetic field-sequencing batch reactor(MF-SBR) decreased by34.3% compared to that of a conventional SBR(C-SBR).Meanwhile,the removal efficiencies for total nitrogen(TN) and ammonia nitrogen(N...     

脉冲变频电磁场对水中藻类的抑制及去除效能

研究了脉冲变频电磁场对水华鱼腥藻的抑制及去除效果.结果显示,磁场对循环水样表现出很好的杀藻效果,水样在磁场中累积停留时间为6min时,杀藻率可以达到94%,累积停留时间为10min时,杀藻率可以达到96%.处理后的水样,藻细胞密度在120h内没有增加,生长受到抑制,经磁场处理的循环水样"磁记忆"时间可以达到120h.对于静置于磁场中的水样,处理1h后,藻的生长开始受到抑制.不同的处理方式会产生不同的效果,对于脉冲变频磁场,水以运动的形式通过磁场更有利于杀藻.     

大型城市污水处理厂处理工艺对微塑料的去除

污水处理厂出水是自然水体中微塑料(MPs)的重要来源.本文以上海市两个大型污水处理厂(WWTP)为研究对象,分析了进水及各处理工艺出水中MPs的数浓度、形态变化及相应的去除率差异,计算了MPs在污水处理厂的归趋.结果表明,WWTP1和WWTP2进水中MPs数浓度分别为(226. 27±83. 00)个·L-1和(171. 89±62. 98)个·L-1; WWTP1对MPs的去除效率为63. 25%,略大于WWTP2的处理效率(59. 84%);两个污水处理厂一级处理工艺对MPs的去除率占整个处理工艺的70%～80%.从污水处理厂的处理工艺来看,一级处理工艺和二级处理工艺分别将污水中(48. 10%±1. 62%)和(12. 97%±0. 05%)的MPs转移到污泥中.从整体来看,污水处理厂中的最终有(38. 82%±1. 55%)的MPs随出水进入到自然水体,剩余(61. 18%±1. 55%)的MPs进入到污泥中.本研究表明,上海市污水处理厂对MPs的去除率较低,即使在处理后依旧有大量的MPs随出水进入到自然水体,仍会对生态系统造成巨大的风险.本研究提供了平原河网地区大型城市污水处理厂MPs去除及归趋的基础数据,可为进一步的MPs去除工艺设计提供参考.     

Degradation of dissolved organic matter in effluent of municipal wastewater plant by a combined tidal and subsurface flow constructed wetland

Dissolved organic matter (DOM) is an important constituent of wastewater treatment plant (WWTP) effluent. A novel combined tidal and subsurface flow constructed wetland (TF-SSF-CW) of 90 L was constructed for a ten-month trial of advanced treatment of the WWTP effluent. Excitation emission matrix (EEM) fluorescence spectroscopy, parallel factor (PARAFAC) analysis and a two end-member mixing model were employed to characterize the composition and removal process of the effluent DOM (EfOM) from the WWTP. The results showed that the TF-SSF-CW performed an efficient EfOM removal with dissolved organic carbon (DOC) removal rate of 88% and dissolved organic nitrogen (DON) removal rate of 91%. Further analysis demonstrated that the EfOM consisted mainly of two protein moieties and two humic-like groups; protein moieties (76%) constituted the main content of EfOM in raw water and humic-like groups (57%) became the dominating contributor after treatment. The EfOM from the WWTP was mainly of aquatic bacterial origin and evolved to a higher proportion of terrigenous origin with higher humification in the TF-SSF-CW effluent. A common controlling treatment-related factor for determining the concentrations of the same kind of substances (protein groups or humic-like groups) was revealed to exist, and the ratio of removal rates between the same substances in treatment was calculated. Our study demonstrates that the TF-SSF-CW can be a novel and effective treatment method for the EfOM from WWTPs, and is helpful for understanding of the character of EfOM in wetland treatment.     

高效复合菌群JHD降解苯酚的特性及其动力学研究

为了获得能降解苯酚的高效微生物菌群,研究了不同条件(温度、pH、接种量、振荡速率及初始苯酚浓度等)对复合菌群JHD降酚性能的影响.结果表明,32℃、pH=7.0、接种量为10%和振荡速率为150 r·min-1,初始苯酚浓度为1000 mg·L-1时降解苯酚16 h,降酚率高达99.97%,残余苯酚浓度低于0.28 mg-L-1,远低于国家一级排放标准.采用Andrews方程对复合菌群JHD降解苯酚的过程进行拟合,其动力学参数为qmax=0.41 h-1,K=55.44 mg·L-1,Ki=970.06 mg·L-1,复合菌群JHD降解苯酚的最佳初始苯酚浓度为231.90 mg·L-1,实验数据与该动力学方程拟合较好.     

混菌接种条件下微生物燃料电池芯片的产电特性研究

微生物燃料电池(MFC)芯片因具有体积小、运行条件温和、产电稳定等优点而有可能成为一种新型的野外水环境监测系统中传感器供能方式.但目前采用纯菌种及贵重金属阳极构建的MFC芯片,不仅成本较高且纯菌种在复杂环境条件下不易存活和保持稳定.因此,本文通过采用混合菌群接种,以活性炭为阳极,构建了阳极体积为50μL的MFC芯片,发现其稳定运行最大输出电流为3.5μA,平均运行周期为8.0 h,最大输出功率约为160 nW,最大功率密度为10.2 mW·m-2.EIS分析结果表明,MFC芯片的总内阻约为35.6 kΩ,其中,阴阳极内阻占主要部分.本研究制备的MFC芯片产电性能达到了同类采用纯菌株及Au作阳极的MFC芯片的性能,表明采用低成本材料为阳极,接种混合菌液的MFC芯片是完全可行的.     

生物陶粒——硅藻土联合工艺脱氮除磷

试验采用硅藻土和生物接触氧化组合工艺处理污水处理厂出水,氨氮从10mg／L下降到0．5mg／L以下,去除率70～95％;硅藻土澄清池对总磷的去除率高于95％;且对浊度、色度均有良好的去除效果。     

臭氧/活性炭协同作用去除二级出水中DON

为探讨臭氧氧化和活性炭吸附对城市污水厂二级出水中溶解性有机氮(DON)的去除机制,首先测定二级出水DON、溶解性有机炭(DOC)、UV254、pH值等指标.接着通过臭氧氧化试验和活性炭吸附试验来考察二级出水中DON、DOC和UV254变化,以及DON分子量分布和DON亲疏水性变化,并应用三维荧光光谱对二级出水中DON变化进行表征.结果表明,当臭氧投加量为8mg/L,DON的去除率大约为33.9%,DOC和UV254去除率约21.2%、66.7%;当活性炭投加量为2.0g/L,DON、DOC和UV254的去除率大约为43.4%、27.6%、92.2%;臭氧氧化和活性炭吸附组合试验时,对DON的去除率大约为83.3%和81.5%;臭氧氧化提高小分子量( 20kDa)的DON所占比例;活性炭吸附降低小分子量( 20kDa)DON所占比例为;臭氧氧化和活性炭吸附都提高亲水性DON所占比例,而降低疏水性和过渡性DON所占比例;三维荧光光谱证实,二级出水中DON变化与3个主要峰有关,分别代表物质为色氨酸类蛋白质、芳香族类蛋白质和富里酸类物质.     

Removal of phenol by activated alumina bed in pulsed high-voltage electric field

A new process for removing the pollutants in aqueous solution-activated alumina bed in pulsed high-voltage electric field was investigated for the removal of phenol under different conditions. The experimental results indicated the increase in removal rate with increasing applied voltage, increasing pH value of the solution, aeration, and adding Fe^2＋. The removal rate of phenol could reach 72.1% when air aeration flow rate was 1200 ml/min, and 88.2% when 0.05 mmol/L Fe^2＋ was added into the solution under the conditions of applied voltage 25 kV, initial phenol concentration of 5 mg/L, and initial pH value 5.5. The addition of sodium carbonate reduced the phenol removal rate. In the pulsed high-voltage electric field, local discharge occurred at the surface of activated alumina, which promoted phenol degradation in the thin water film. At the same time, the space-time distribution of gas-liquid phases was more uniform and the contact areas of the activated species generated from the discharge and the pollutant molecules were much wider due to the effect of the activated alumina bed. The synthetical effects of the pulsed high-voltage electric field and the activated alumina particles accelerated phenol degradation.     

An advanced anaerobic biofilter with effluent recirculation for phenol removal and methane production in treatment of coal gasification wastewater

An advanced anaerobic biofilter (AF) was introduced for the treatment of coal gasification wastewater (CGW), and effluent recirculation was adopted to enhance phenol removal and methane production. The results indicated that AF was reliable in treating diluted CGW, while its efficiency and stability were seriously reduced when directly treating raw CGW. However, its performance could be greatly enhanced by effluent recirculation. Under optimal effluent recirculation of 0.5 to the influent, concentrations of chemical oxygen demand (COD) and total phenol in the effluent could reach as low as 234.0 and 14.2 mg/L, respectively. Also, the rate of methane production reached 169.0 mL CH₄/L/day. Though CGW seemed to restrain the growth of anaerobic microorganisms, especially methanogens, the inhibition was temporary and reversible, and anaerobic bacteria presented strong tolerance. The activities of methanogens cultivated in CGW could quickly recover on feeding with glucose wastewater (GW). However, the adaptability of anaerobic bacteria to the CGW was very poor and the activity of methanogens could not be improved by long-term domestication. By analysis using the Haldane model, it was further confirmed that high effluent recirculation could result in high activity for hydrolytic bacteria and substrate affinity for toxic matters, but only suitable effluent recirculation could result in high methanogenic activity.