造纸废水厌氧处理产沼气发电研究

以浙江某纸业企业利用造纸废水厌氧处理所产沼气发电工程为例,研究造纸废水厌氧处理产沼气发电系统工艺运行的稳定性和经济可行性。结果表明:(1)厌氧内循环(IC)反应器运行稳定,产沼气量基本在3000m3/d左右(测定点压强约为2×105Pa),平均产气率为0.38m3/kg,基本达到产气率设计要求。(2)经处理后沼气中硫化氢质量浓度始终处于20～50mg/m3,平均固体颗粒物质量浓度约为15mg/m3,平均湿度为66%,达到发电系统的要求。(3)运行期间平均日发电量为8600kW.h,回用的蒸汽量平均约为1.1t/d。(4)整个沼气发电系统总收支为6.0万元/a,实现收支平衡且略有盈余。(5)假设以煤炭替换沼气发电,以年发电258万kW.h计算,理论上沼气发电系统每年节省煤炭928.8t,减少2118t二氧化碳排放,节能减排成效显著。     

膜工艺在电镀废水处理工程中的应用

运用先进的膜分离技术,可以实现电镀废水的深度处理和资源化利用。基于近年内建成运行的3个工程实例,分析和讨论了膜技术在电镀废水处理中的应用及其效果。结果表明:结合常规废水处理工艺与膜生物反应器(MBR)组合工艺,电镀废水被处理后水质达到排放标准;电镀综合废水经超滤(UF)净化、反渗透(RO)和纳滤(NF)两段脱盐膜的集成工艺处理后,水质达到回用水标准,RO和NF产水水质电导率分别低于约100和1 000μS/cm,COD分别为约5和10 mg/L;镀镍漂洗废水通过RO膜后,镍的浓缩倍数高达25倍以上,实现镍的回收,RO产水水质达到回用标准。投资与运行费用分析表明:工程运行1年多即可收回RO浓缩镍的设备费用。此3项不同工艺处理电镀废水的工程实例,为进一步开展膜技术治理工业废水提供了成功案例。     

草制浆造纸中段废水处理及回用技术分析研究

中段废水是制浆造纸工业的主要污染源之一,从工程设计的角度出发,对草制浆造纸中段废水处理及回用提出一套可行适用的工艺方案;对主要工艺环节参数、设备备有说明,以供同行借鉴.     

Fenton氧化对制浆造纸废水分子量及可生化性变化的影响

以制浆造纸废水的初沉池出水为研究对象,对不同剂量的Fenton氧化试剂处理制浆造纸厂初沉废水的效果进行了研究,初沉废水中的分子量大于10 000的有机污染物含量占到83%,废水可生化性较差;在Fe2+与H2O2的摩尔比为1∶5,废水pH为3.5的条件下,H2O2(30%)投加量小于3.25 mL/L时,Fenton试剂的氧化效率更高;H2O2(30%)投加量为6.50 mL/L时,废水中污染物的去除率更高,其中废水COD的去除率为79.5%,AOX的去除率为75.3%,色度去除率为97.5%,同时处理后废水中分子量在500~3 000之间的有机物含量占到82.98%,废水的BOD5/COD值提高到0.56。Fenton氧化作为前置技术处理制浆造纸废水,可以降低废水中的有机物分子量,减少废水的生物毒性,增加废水生物降解性,有助于后续生物处理的正常运行。     

水资源的有效利用与污水的再循环使用

在人类生活中,水是最宝贵、最不可缺的资源。据日本国土厅“废水利用设施现状调查结果概要(1988年)”,现有废水再利用设施约850个,回用量为113000米~3/日,占生活用水总量的0.3％左右,关东、近畿、九州三个地区占到全国的80％左右(东京约为31％,福冈约为21％)。在回用废水中,冲洗厕所的用量最多,约占全部用量的70％,此外还可供洒水、冷却和冷气设备等用,最近用于美化环境的量也大为增加,如清扫、绿化、修景等。有35％的学校、办公楼利用了回用废水。在回用废水设施中,利用以     

运用模糊层次分析法优选制浆造纸废水深度处理方案

制浆造纸废水最适深度处理方案的选择是一个多准则决策问题,本文通过建立评价指标体系,从经济费用、技术性能、管理效果和社会效益4个方面,对混凝沉淀（气浮）＋过滤、Fenton氧化和生态法3种深度处理方案进行分析;采用层次分析法确定指标体系权重,其中技术性能（0.5333）权重最高;结合模糊数学法开展综合评判,评估各方案的优缺点,最后通过方案总排序确定工程优选方案。同时,针对2个具有代表意义的制浆造纸企业废水深度处理工程案例,在方案隶属度的确定时增加了决策者的期望值和企业的实际情况,分别选取了最适的制浆造纸废水深度处理方案：混凝沉淀（气浮）＋过滤法（A企业）和生态法（B企业）,这样可以更客观地指导决策者选取最合适的制浆造纸废水深度处理方案。     

铁炭微电解法深度处理燃料乙醇生产废水

采用铁炭微电解法深度处理燃料乙醇生产废水,考察了初始pH、水力停留时间、铁炭质量比和曝气量对废水处理效果的影响,并对该技术应用于燃料乙醇废水深度处理的经济性进行了评价。结果表明,在初始pH值3.5、水力停留时间40 min、铁炭质量比2∶1、曝气量为1 m3/h时,获得了较好的处理效果,废水经处理后,COD均值为37.8 mg/L,BOD5为13.9 mg/L,色度为10.1倍,浊度为1.2 NTU,达到工业用水回用的标准(GB/T 19923-2005)。将此工艺应用于燃料乙醇生产废水的处理,处理费用约为1.46元/t,具有较好的社会、经济和环保效益。     

未来25至30年间水回用量将剧增

联合国最近若干报告书对人类面临的水资源短缺情况作了分析。称,未来25至30年间,全球人口将达到90亿,至2025年,全球2/3人口将生活在水紧缺的条件下(参见联合国环境计划淡水网页,freshwater unep.net)。美国水回用协会建议采用3种措施解决21世纪用水问题:实施多种废水回用和脱盐     

反渗透处理稀土氨氮废水试验研究

根据稀土冶炼厂排放的碳铵沉淀洗涤废水的水质情况，采用NH4Cl和 NaCl模拟废水进行了反渗透可行性对比实验。模拟实验发现，在相同条件下反渗透对NaCl 较NH₄Cl 有着更高的去除率，而NH₄Cl 相对NaCl则有着更高的产水速率。实际废水试验结果表明，在恒定操作压力范围内回收率为65%的条件下，NH₄Cl浓度为2.85 g/L的碳铵沉淀洗涤废水经反渗透处理其NH₄Cl去除率为77.3%，可作为氨氮废水的预处理。对该废水处理成本进行了分析，得出其约为2.7元/m³，比相近浓度氨氮废水的氨吹脱处理成本节省约26%。     

蜡染废水在线处理回用及热能回收工程实例

采用絮凝沉淀-ClO2脱色-砂滤-微波无极紫外光催化氧化工艺对青岛凤凰印染有限公司蜡染印花水洗废水进行处理,详细论述了该工艺的运行特点、处理及回用效果。结果表明,在进水COD及色度波动很大的情况下,处理后废水水质长期稳定达到COD100 mg/L,色度10倍,其他各项水质指标均可满足蜡染水洗工序的生产回用要求,并回收了水中的热能。废水回用率达80%,日节水200 t,节约热能折合成标准煤约为1 t,为印染行业完成节能20%,减排20%的总体目标提供了新的思路。     

Sorption and desorption of Cu and Cd by macroalgae and microalgae

The sorption and desorption of Cu and Cd by two species of brown macroalgae and five species of microalgae were studied. The two brown macroalgae, Laminaria japonica and Sargassum kjellmanianum, were found to have high capacities at pHs between 4.0 and 5.0 while for microalgae, optimum pH lay at 6.7. The presence of other cations in solution was found to reduce the sorption of the target cation, suggesting a competition for sorption sites on organisms. Sorption isotherms obeyed the Freundlich equation, suggesting involvement of a multiplicity of mechanisms and sorption sites. For the microalgae tested, Spirulina platensis had the highest capacity for Cd, followed by Nannochloropsis oculata, Phaeodactylum tricornutum, Platymonas cordifolia and Chaetoceros minutissimus. The reversibility of metal sorption by macroalgae was examined and the results show that both HCl and EDTA solutions were very effective in desorbing sorbed metal ions from macroalgae, with up to 99.5% of metals being recovered. The regenerated biomass showed undiminished sorption performance for the two metals studied, suggesting the potential of such material for use in water and wastewater treatment.     

Persistence and dissipation kinetics of trifloxystrobin and tebuconazole in onion and soil

The persistence and dissipation kinetics of trifloxystrobin and tebuconazole on onion were studied after application of their combination formulation at a standard and double dose of 75 + 150 and 150 + 300 g a.i. ha^?1. The fungicides were extracted with acetone, cleaned-up using activated charcoal (trifloxystrobin) and neutral alumina (tebuconazole). Analysis was carried out by gas chromatograph (GC) and confirmed by gas chromatograph mass spectrometry (GC-MS). The recovery was above 80% and limit of quantification (LOQ) 0.05 mg kg^?1 for both fungicides. Initial residue deposits of trifloxystrobin were 0.68 and 1.01 mg kg^?1 and tebuconazole 0.673 and 1.95 mg kg^?1 from standard and double dose treatments, respectively. Dissipation of the fungicides followed first-order kinetics and the half life of degradation was 6–6.6 days. Matured onion bulb (and field soil) harvested after 30 days was free from fungicide residues. These findings suggest recommended safe pre-harvest interval (PHI) of 14 and 25 days for spring onion consumption after treatment of Nativo 75 WG at the standard and double doses, respectively. Matured onion bulbs at harvest were free from fungicide residues.     

Kinetic and structural relationships of transition monomeric and oligomeric carboxyl- and choline-esterases

The kinetic and structural relationships of eight electrophoretically pure mammalian serum and liver serine carboxylesterases (CE) and cholinesterases (ChE) have been studied. Eight CE's and ChE's, which were fully resolved but only partially purified, provided additional information. Five of the electrophoretically pure esterases were monomeric, and of these, four belonged to a new and widely distributed class. These four monomeric esterases hydrolyzed choline esters, but at widely differing rates. Thus two were termed monomeric butyrylcholinesterases, mBuChE I and II, and two were monomeric CE's (mCE). The rabbit liver mCE was not a subunit of the oligomeric CE (oCE), although the oCE also hydrolyzed choline esters at a very low rate. The complex kinetics of the mCE's, mBuChE's, oCE's, and of the oligomeric BuChE's of horse and human serum could be interpreted according to a single reaction scheme involving an allosteric site and the equation derived from it. Thus activation and inhibition at high substrate concentrations, together with sigmoidal activity versus substrate concentration plots, all of which characterize the reactions of these esterases, could be interpreted by a single scheme and equation. Structural and kinetic comparisons showed a progressive transition of properties from the oCE's through the mCE's to the oBuChE's. One of the purified mCE's was from horse serum, and it exhibited physical and kinetic properties unlike those of the liver mCE's or oCE's.     

Sorption and Desorption Behavior of Chloroanilines and Chlorophenols on Montmorillonite and Kaolinite

The bioavailability of pollutants, pesticides and/or their degradation products in soil depends on the strength of their sorption by the different soil components, particularly by the clay minerals. This study reports the sorption-desorption behavior of the environmentally hazardous industrial pollutants and certain pesticides degradation products, 3-chloroaniline, 3,4-dichloroaniline, 2,4,6-trichloroaniline, 4-chlorophenol, 2,4-dichlorophenol and 2,4,6-trichlorophenol on the reference clays kaolinite KGa-1 and Na-montmorillonite SWy-l. In batch studies, 2.0 g of clay were equilibrated with 100.0 mL solutions of each chemical at concentrations ranging from 10.0 to 200.0 mg/L. The uptake of the compounds was deduced from the results of HPLC-UV-Vis analysis. The lipophilic species were best retained by both clay materials. The most lipophilic chemical used in the study, 2,4,6-trichloroaniline, was also the most strongly retained, with sorption of up to 8 mg/g. In desorption experiments, which also relied on HPLC-UV-Vis technique, 2,4,6-trichloroaniline was the least desorbed from montmorillonite. However, on kaolinite all of the compounds under study were irreversibly retained. The experimental data have been modelled according to the Langmuir and Freundlich isotherms. A hypothesis is proposed concerning the sorption mechanism and potential applications of the findings in remediation strategies have been suggested.     

Sorption and desorption behavior of chloroanilines and chlorophenols on montmorillonite and kaolinite

The bioavailability of pollutants, pesticides and/or their degradation products in soil depends on the strength of their sorption by the different soil components, particularly by the clay minerals. This study reports the sorption-desorption behavior of the environmentally hazardous industrial pollutants and certain pesticides degradation products, 3-chloroaniline, 3,4-dichloroaniline, 2,4,6-trichloroaniline, 4-chlorophenol, 2,4-dichlorophenol and 2,4,6-trichlorophenol on the reference clays kaolinite KGa-1 and Na-montmorillonite SWy-l. In batch studies, 2.0 g of clay were equilibrated with 100.0 mL solutions of each chemical at concentrations ranging from 10.0 to 200.0 mg/L. The uptake of the compounds was deduced from the results of HPLC-UV-Vis analysis. The lipophilic species were best retained by both clay materials. The most lipophilic chemical used in the study, 2,4,6-trichloroaniline, was also the most strongly retained, with sorption of up to 8 mg/g. In desorption experiments, which also relied on HPLC-UV-Vis technique, 2,4,6-trichloroaniline was the least desorbed from montmorillonite. However, on kaolinite all of the compounds under study were irreversibly retained. The experimental data have been modelled according to the Langmuir and Freundlich isotherms. A hypothesis is proposed concerning the sorption mechanism and potential applications of the findings in remediation strategies have been suggested.     

Bacterial and archaeal diversity in oil fields and reservoirs and their potential role in hydrocarbon recovery and bioprospecting

Environmental Science and Pollution Research - Hydrocarbon is a primary source of energy in the current urbanized society. Considering the increasing demand, worldwide oil productions are declining...     

Sources and fate of PCDD and PCDF

PCDD and PCDF were found in urban air particulates from St. Louis and Washington, D.C., and in sediments from the Great Lakes and Siskiwit Lake, Isle Royale. The similarity between the PCDD and PCDF found in air particulates and sediment samples and the presence of PCDD and PCDF in sediment from Siskiwit Lake (a location which can receive only atmospheric inputs) suggest that these compounds are emitted to the atmosphere from combustion sources. The historical input of PCDD and PCDF to dated sediment cores shows a strong increase since 1940, and this suggests that the incineration of chlorinated organic compounds is an important source of PCDD and PCDF to the environment.     

畜禽养殖业污染与循环经济

解决畜禽养殖业的污染问题要以充分利用资源为根本出发点，通过对污染全过程控制及废物综合利用，达到畜禽粪便的减量化、无害化、资源化，走循环经济的发展道路。     

Synthesis and characterization of m- and p-methylbenzyl-mercapturic acids derived from m- and p-xylenes

Chemical synthesis and physical properties of two mercapturic acids suggested as urinary metabolites of m- and p-xylenes ace described. These compounds may be used for the identification and quantivative determination by high-performance liquid chromatography of the corresponding mercapturic acids in urine.