Forest Die-Back Modified Plankton Recovery from Acidic Stress

We examined long-term data on water chemistry of Lake Rachelsee (Germany) following the changes in acidic depositions in central Europe since 1980s. Despite gradual chemical recovery of Rachelsee, its biological recovery was delayed. In 1999, lake recovery was abruptly reversed by a coincident forest die-back, which resulted in elevated terrestrial export of nitrate and ionic aluminum lasting ~5 years. This re-acidification episode provided unique opportunity to study plankton recovery in the rapidly recovering lake water after the abrupt decline in nitrate leaching from the catchment. There were sudden changes both in lake water chemistry and in plankton biomass structure, such as decreased bacterial filaments, increased phytoplankton biomass, and rotifer abundance. The shift from dominance of heterotrophic to autotrophic organisms suggested their substantial release from severe phosphorus stress. Such a rapid change in plankton structure in a lake recovering from acidity has, to the best of our knowledge, not been previously documented.     

Enhanced electrokinetic remediation of lead-contaminated soil by complexing agents and approaching anodes

Optimizing process parameters that affect the remediation time and power consumption can improve the treatment efficiency of the electrokinetic remediation as well as determine the cost of a remediation action. Lab-scale electrokinetic remediation of Pb-contaminated soils was investigated for the effect of complexant ethylenediaminetetraacetic acid (EDTA) and acetic acid and approaching anode on the removal efficiency of Pb. When EDTA was added to the catholyte, EDTA dissolved insoluble Pb in soils to form soluble Pb–EDTA complexes, increasing Pb mobility and accordingly removal efficiency. The removal efficiency was enhanced from 47.8 to 61.5 % when the EDTA concentration was increased from 0.1 to 0.2 M, showing that EDTA played an important role in remediation. And the migration rate of Pb was increased to 72.3 % when both EDTA and acetic acid were used in the catholyte. The “approaching anode electrokinetic remediation” process in the presence of both EDTA and acetic acid had a higher Pb-removal efficiency with an average efficiency of 83.8 %. The efficiency of electrokinetic remediation was closely related to Pb speciation. Exchangeable and carbonate-bounded Pb were likely the forms which could be removed. All results indicate that the approaching anode method in the presence of EDTA and acetic acid is an advisable choice for electrokinetic remediation of Pb-contaminated soil.     

臭氧氧化—包埋菌流化床生物处理组合工艺深度处理煤气化废水

采用臭氧氧化—包埋菌流化床生物处理组合工艺对煤气化废水进行深度处理。实验结果表明：当臭氧的质量浓度20 mg/L、臭氧进气流量1.5 L/min、臭氧通气时间30 min、包埋菌流化床水力停留时间24 h时,臭氧氧化工序的COD去除率达到30.0%~40.0%,总酚去除率达到100.0%;包埋菌流化床工序的COD去除率达到60.0%以上,氨氮的去除率大于95.0%;经组合工艺处理后,出水COD<60 mg/L,ρ（氨氮）<1.0 mg/L,ρ（总酚）未检出,色度小于50倍,达到GB8978—1996《污水综合排放标准》中的一级排放标准。     

城市生活污水及二级处理水中手足口病病毒及肠道病毒的赋存状态

手足口病是由多种肠道病毒引起的传染病,其主要病原体有EV71、CVA16及CVA10。为了研究污水处理厂的生活原污水及二级处理水中此类病毒的存活情况,实验利用手足口病3种主要病毒的通用引物对其进行分型检测,同时使用肠道病毒通用引物检测所有肠道病毒,并对常规水质指标进行分析。结果表明,原污水及二级处理水的手足口病病毒阳性率分别为83.3%与36.7%,而肠道病毒阳性率更高达100%及93.3%。说明生活污水中的肠道病毒可以稳定存在,且若未进行有效消毒处理,可能存在于二级处理水中。在3种手足口病主要病毒中,CVA10检出率最高,达45.0%,CVA16及EV71检出率分别为8.3%及10.0%。可推断,CVA10为实验阶段该地区主要的手足口病病毒。通过相关性分析,肠道病毒的存活与水质条件密切相关。     

UV/Fenton技术处理某工厂高浓度乳化油废水

研究了UV/Fenton技术对高浓度金属清洗乳化油废水的处理效果,考察了亚铁与双氧水浓度、pH、反应时间和搅拌对COD去除效果的影响。实验结果表明,UV/Fenton技术对高浓度乳化油废水(COD平均浓度为35 000 mg/L)具有较高的去除效果,最佳工艺条件为:亚铁与双氧水浓度分别为2 400 mg/L和6 000 mg/L,pH为3,经过2 h反应,COD可降低至1 050 mg/L,去除率为97%。搅拌会降低COD的去除率。研究表明,UV/Fenton技术对高浓度乳化油废水具有很好的降解效果,且药品消耗较低,为目前此类高浓度有机废水的处理提供了技术参考。     

基于改性凹凸棒土的强化混凝处理高藻低浊原水工艺

针对水厂低浊高藻水的处理难题,研究了改性凹凸棒土(改性凹土)联合聚合氯化铝(PAC)强化混凝的除藻除浊效果。设计实验原水条件为叶绿素a(chl-a)浓度为98.58~110.35μg/L,浊度(5.6±0.5)NTU。考察了PAC和改性凹土的复配投加量、混凝沉淀时间、pH、投加顺序、搅拌速率等工艺参数对Chl-a和浊度耦合去除效果的影响。结果表明,"PAC+改性凹土"对Chl-a和浊度的去除效果明显优于单投PAC的效果。当PAC投药量12 mg/L,改性凹土投药量10 mg/L,沉淀时间20 min时,对Chl-a和浊度的去除率可分别达到92.5%和89.2%,可至少减少40%的PAC投量,且形成的矾花密实,沉降速度快,去除效率高。最适pH范围为7~8。投加顺序应为先投加改性凹土,混合搅拌转数宜慢速,可控制为50 r/min。     

污泥淤砂分离器再分离底流污泥

研究了污泥淤砂分离器对分离原污泥所得的底流污泥进行再分离时,分离分流污泥的性质。实验结果表明,原污泥MLVSS/MLSS为0.372,1次分离后得到的底流污泥MLVSS/MLSS为0.222,2次分离后得到的底流污泥MLVSS/MLSS为0.126,表明通过底流污泥再分离,能够进一步降低底流污泥中生物有机质的含量,提高底流污泥中无机淤砂的含量。同时,原污泥CST为2.85(s·L)/g SS,1次分离后得到的底流污泥CST为0.98(s·L)/g SS,2次分离后得到的底流污泥CST为0.12(s·L)/g SS,表明底流污泥再分离进一步提高了底流污泥的脱水性能,最终得到的底流污泥脱水性能良好。     

Fate in soil of 14C-sulfadiazine residues contained in the manure of young pigs treated with a veterinary antibiotic

The fate of ¹⁴C-labeled sulfadiazine (¹⁴C-SDZ) residues was studied in time-course experiments for 218 days of incubation using two soils (A_p horizon of loamy sand, orthic luvisol; A_p horizon of silt loam, cambisol) amended with fresh and aged (6 months) ¹⁴C-manure [40 g kg^?1 of soil; 6.36 mg of sulfadiazine (SDZ) equivalents per kg of soil], which was derived from two shoats treated with ¹⁴C-SDZ. Mineralization of ¹⁴C-SDZ residues was below 2% after 218 days depending little on soil type. Portions of extractable ¹⁴C (ethanol-water, 9:1, v/v) decreased with time to 4–13% after 218 days of incubation with fresh and aged ¹⁴C-manure and both soils. Non-extractable residues were the main route of the fate of the ¹⁴C-SDZ residues (above 90% of total recovered ¹⁴C after 218 days). These residues were high immediately after amendment depending on soil type and aging of the ¹⁴C-manure, and were stable and not remobilized throughout 218 days of incubation. Bioavailable portions (extraction using CaCl₂ solution) also decreased with increasing incubation period (5–7% after 218 days). Due to thin-layer chromatography (TLC), 500 μg of ¹⁴C-SDZ per kg soil were found in the ethanol-water extracts immediately after amendment with fresh ¹⁴C-manure, and about 50 μg kg^?1 after 218 days. Bioavailable ¹⁴C-SDZ portions present in the CaCl₂ extracts were about 350 μg kg^?1 with amendment. Higher concentrations were initially detected with aged ¹⁴C-manure (ethanol-water extracts: 1,920 μg kg^?1; CaCl₂ extracts: 1,020 μg kg^?1), probably due to release of ¹⁴C-SDZ from bound forms during storage. Consistent results were obtained by extraction of the ¹⁴C-manure-soil samples with ethyl acetate; portions of N-acetylated SDZ were additionally determined. All soluble ¹⁴C-SDZ residues contained in ¹⁴C-manure contributed to the formation of non-extractable residues; a tendency for persistence or accumulation was not observed. SDZ's non-extractable soil residues were associated with the soluble HCl, fulvic acids and humic acids fractions, and the insoluble humin fraction. The majority of the non-extractable residues appeared to be due to stable covalent binding to soil organic matter.     

羧酸盐型双子表面活性剂的合成及性能研究

以月桂酰氯、乙二胺与丁二酸酐为原料合成了一种羧酸盐型双子(gemini)表面活性剂。采用IR、1 HNMR对中间产物和目标产物进行结构表征,并考察了合成所得羧酸盐型gemini表面活性剂的表面活性。结果表明:合成产物即为目标产物。合成产物的临界胶束浓度为0.027mmol/L,比普通单链表面活性剂低2～3个数量级,表面张力最低可降至29.5mN/m。     

中原油田开展清洁生产工作的几点体会

中原油田自2008年以来全面推行清洁生产工作,取得了丰硕的成果。文章结合中原油田实施清洁生产的实际,论述了中原油田有效开展清洁生产审核、建立清洁生产长效机制的一些经验和实际做法。中原油田经过努力,油区环境质量得到改善,为构建资源节约型、环境友好型企业奠定了基础。