大型UASB处理阿维菌素废水厌氧污泥颗粒化研究

采用大型UASB反应器处理阿维菌素废水,接种好氧絮状污泥,经过189 d运行,成功实现了厌氧污泥颗粒化.通过调节反应器进水水质控制进水中阿维菌素浓度和长时间培养驯化,阿维菌素对厌氧消化的抑制影响基本消除.UASB反应器进水pH值4～5、COD 8890～12 100 mg/L、容积负荷达到10.5 kg COD/m3·d,COD去除率稳定在85%以上,出水COD为1308～1670 mg/L.     

UASB处理甲醇废水的实验研究

利用升流式厌氧污泥床(UASB)反应器在中温条件下处理高COD浓度的甲醇废水。当反应器稳定运行,进水COD=36 000 mg/L时,容积负荷可达到70~74 kg COD/(m3.d),COD去除率可以达到95%以上,出水COD2 000 mg/L。通过实验取得的良好实验效果,为利用厌氧技术处理甲醇废水提供了设计依据。     

EGSB反应器处理丙烯酸废水的试验研究

采用厌氧颗粒污泥膨胀床（EGSB）进行丙烯酸废水的处理，考察了自制的EGSB反应器菌种驯化和容积负荷提高两阶段的一些运行参数，并对试验过程中出现的问题进行了探讨。为期96 d的试验表明，当进水COD在3 000 mg/L左右时，去除率可达90%以上；当进水COD在5 000 mg/L左右时，去除率可达85%以上，COD容积负荷可达到10 kg/m3·d以上，且出水可满足后续好氧工段处理的要求。     

不同容积负荷下有机废水发酵产酸和产乙醇特性

采用上流式厌氧污泥床(UASB)反应器,研究了反应器在不同的水力停留时间(HRT)和不同进水容积负荷(VLR)下,高浓度有机废水发酵时产酸产乙醇特性。结果表明,在厌氧反应初期,随着反应器水力停留时间的减少和进水容积负荷的增加,反应器内的p H值降低后稳定在3.81~4.55之间,氧化还原电位(ORP)一直处于波动状态。反应器发酵液中主要成分浓度随进水容积负荷的提高而变化,且乙醇的浓度一直很低。当VLR为9 kg COD/(m3·d)时,乙酸浓度最高,且最高值为961.40 mg/L,当VLR为48 kg COD/(m3·d),乙醇平均浓度升高,最大值为142.98 mg/L。在乙醇平均浓度最大时,反应器稳定的平均产氢速率为887 m L/d。反应器运行前后颗粒污表面泥都有杆状微生物存在,但具有产酸特性的污泥表面胞外聚合物含量相对较少。     

外循环式UASB反应器处理槟榔废水

在中温（35±2℃）条件下,利用外循环式UASB反应器处理中高有机浓度的槟榔加工废水,并着重探讨了水力停留时间（HRT）对厌氧消化的影响。研究表明,当反应器稳定运行,水力停留时间为1 d,进水COD浓度5 000 mg/L左右,容积负荷在2.53-5.25 kg COD/（m3·d）时,COD去除率在38%以上,出水COD〈3 000 mg/L,平均产气率为0.41 m3/kg COD;若水力停留时间延长至4 d,容积负荷为1.26-1.30 kg COD/（m3·d）,COD去除率可以达到79%,出水COD〈1 200 mg/L,出水可生化性下降,BOD5/COD平均为0.28,实验取得了良好的处理效果,为利用厌氧技术处理槟榔加工废水提供了设计依据。     

BLR厌氧反应器处理垃圾焚烧厂渗滤液工程运行效能

采用1 100 m3BLR(biogas-lift reactor)厌氧反应器对垃圾焚烧厂渗滤液进行工程化处置,接种污泥为消化污泥,正常运行温度控制在(33±2)℃,启动负荷为1 kg COD/(m3·d),120 d后容积负荷达到10 kg/(m3·d)并稳定运行,出水COD浓度为4 500~6 500 mg/L,COD去除率为88%~92%,出水VFA含量为200~600 mg/L,p H值稳定在7.4~7.7,出水SS含量为1 000 mg/L左右,并可观察到沉降性较好的颗粒化污泥。反应器运行初期将VFA/ALK控制在1.6以内,系统并未因VFA积累而酸化崩溃,运行后期VFA/ALK值小于0.3,系统稳定运行。运行过程中进水氨氮浓度从400 mg/L升高到2 200 mg/L,未发现氨氮对厌氧生物处理的明显抑制现象。垃圾渗滤液中平均每去除1 kg COD产生沼气量为0.32 m3。     

厌氧折流板反应器处理屠宰废水的实验研究

采用厌氧折流板反应器(ABR)处理屠宰废水,采用低负荷的方法驯化污泥,结果表明:其启动过程比较快,易培养出颗粒化的活性污泥;在常温下,当HRT=20 h,有机容积负荷为2.5 kg COD/m3·d时,COD的最佳去除率为94%;当进水浓度由1 500 mg/L提高到3 200 mg/L时,COD的去除率从91%降到86%,仅降低5%,表明厌氧折流板反应器对冲击负荷的适应能力较强.     

中试螺旋式自循环厌氧反应器处理安乃近制药废水的稳定性能简

以制药废水实验了50 m³螺旋式厌氧反应器（SPAC反应器）的稳定性。采用Augmented Dickey-Fuller（ADF）单位根检验表明，螺旋式反应器具有良好的启动和运行稳定性。负荷冲击实验显示，SPAC反应器具有较好的耐浓度冲击能力和耐水力冲击能力，所能耐受的最大浓度冲击强度大于60 000 （mg·h）/L（进水浓度提升2倍），所能耐受的最大水力冲击强度为300（m³·h）/d（进水流量提升50%）。SPAC反应器还具备受扰恢复能力。在反应液pH低于5.74，出水浓度、COD去除率和容积COD去除速率（VRR）分别为3 500 mg/L、22.30%和2.52 kg/（m³·d）的工况下，经过30 d恢复，出水浓度、COD去除率和VRR的恢复程度达到80%~90%。     

HRT对固定床厌氧反应器运行效果的影响

为了考察水力停留时间(HRT)对炭纤维载体固定床厌氧反应器运行效果的影响,在进水COD分别为20 000~25 000 mg/L和40 000~45 000 mg/L2个浓度范围下,研究了不同HRT对反应器运行效果的影响。结果表明,通过HRT的调整,在达到相同有机负荷(OLR)下,进水COD为20 000~25 000 mg/L的COD去除率和产气量,明显比进水COD为40 000~45 000 mg/L的运行效果好;进水COD为20 000~25 000 mg/L,HRT为14 h,相应的OLR为41.09 kgCOD/(m3.d)时,COD去除率仍然维持在68%以上,沼气容积产气率达到14.55 m3/(m3.d)。炭纤维载体固定床厌氧反应器具有较高的COD去除率、产气效率以及抵抗低pH、高负荷冲击的能力,运行过程中没有发生反应器堵塞的现象。     

IC厌氧反应器处理垃圾渗滤液

在(35±1)℃条件下,采用IC厌氧反应器对天津大港垃圾焚烧厂垃圾渗滤液进行处理,研究了COD的去除效果、容积负荷、沼气产量和污泥的颗粒化,分析了循环比、上升流速对反应器的影响.结果表明,厌氧反应器经60 d的启动运行后,达到300 m3/d的设计水量,进水容积负荷达到17.7 kg COD/(m3·d),水力停留时间3.7d,COD去除率高于80％,出水挥发酸(VFA)低于l 500 mg/L,平均每去除1 kg COD产沼气0.42 m3,适宜的上升流速和循环比为2.0 ～5.0 m/h、8∶1 ～20∶1.启动结束后,厌氧消化污泥明显出现颗粒化,颗粒污泥的沉降速度达到了67.5 ～ 96.0 m/h,0.3～1.0 mm的颗粒污泥量占有74％.     

Radionuclides and trace elements in fish collected upstream and downstream of Los Alamos national laboratory and the doses to humans from the consumption of muscle and bone

Abstract

The purpose of this study was to determine radionuclide and trace element concentrations in bottom‐feeding fish (catfish, carp, and suckers) collected from the confluences of some of the major canyons that cross Los Alamos National Laboratory (LANL) lands with the Rio Grande (RG) and the potential radiological doses from the ingestion of these fish. Samples of muscle and bone (and viscera in some cases) were analyzed for ³H, ⁹⁰Sr, ¹³⁷Cs, ^totU, ²³⁸Pu, ^239,240Pu, and ²⁴¹Am and Ag, As, Ba, Be, Cr, Cd, Cu, Hg, Ni, Pb, Sb, Se, and Tl. Most radionuclides, with the exception of ⁹⁰Sr, in the muscle plus bone portions of fish collected from LANL canyons/RG were not significantly (p<0.05) higher from fish collected upstream (San Ildefonso/background) of LANL. Strontium‐90 in fish muscle plus bone tissue significantly (p<0.05) increases in concentration starting from Los Alamos Canyon, the most upstream confluence (fish contained 3.4E‐02 pCi g^‐1 [126E‐02 Bq kg^‐1]), to Frijoles Canyon, the most downstream confluence (fish contained 14E‐02 pCi g^‐1 [518E‐02 Bq kg^‐1]). The differences in ⁹⁰Sr concentrations in fish collected downstream and upstream (background) of LANL, however, were very small. Based on the average concentrations (±2SD) of radionuclides in fish tissue from the four LANL confluences, the committed effective dose equivalent from the ingestion of 46 lb (21 kg) (maximum ingestion rate per person per year) of fish muscle plus bone, after the subtraction of background, was 0.1 ± 0.1 mrem y^‐1 (1.0 ± 1.0 μSv y^‐1), and was far below the International Commission on Radiological Protection (all pathway) permissible dose limit of 100 mrem y^‐1 (1000 μSv y^‐1). Of the trace elements that were found above the limits of detection (Ba, Cu, and Hg) in fish muscle collected from the confluences of canyons that cross LANL and the RG, none were in significantly higher (p<0.05) concentrations than in muscle of fish collected from background locations.     

Radionuclides in deer and elk from Los Alamos national laboratory and the doses to humans from the ingestion of muscle and bone

Abstract

This paper summarizes radionuclide concentrations (³H, ⁹⁰Sr, ¹³⁷Cs, ²³⁸Pu, ^239,240Pu, ²⁴¹Am, and ^totU) in muscle and bone tissue of mule deer (Odocoileus hemionus) and Rocky Mountain elk (Cervus elaphus) collected from Los Alamos National Laboratory (LANL), Los Alamos, New Mexico, lands from 1991 through 1998. Also, the committed effective dose equivalent (CEDE) and the risk of excess cancer fatalities (RECF) to people who ingest muscle and bone from deer and elk collected from LANL lands were estimated. Most radionuclide concentrations in muscle and bone from individual deer (n = 11) and elk (n = 22) collected from LANL lands were either at less than detectable quantities (where the analytical result was smaller than two counting uncertainties) and/or within upper (95%) level background (BG) concentrations. As a group, most radionuclides in muscle and bone of deer and elk from LANL lands were not significantly higher (p<0.10) than in similar tissues from deer (n = 3) and elk (n = 7) collected from BG locations. Also, elk that had been radio collared and tracked for two years and spent an average time of 50% on LANL lands were not significantly different in most radionuclides from road kill elk that have been collected as part of the environmental surveillance program. Overall, the upper (95%) level net CEDEs (the CEDE plus two sigma for each radioisotope minus background) at the most conservative ingestion rate (50 lbs of muscle and 13 lbs of bone) were as follows: deer muscle = 0.22 mrem y^‐1 (2.2 μSv y^‐1), deer bone = 3.8 mrem y^‐1 (38 μSv y^‐1), elk muscle = 0.12 mrem y^‐1 (1.2 μSv y^‐1), and elk bone = 1.7 mrem y^‐1 (17 μSv y^‐1). All CEDEs were far below the International Commission on Radiological Protection guideline of 100 mrem y^‐1 (1000 μSv y^‐1), and the highest muscle plus bone net CEDE corresponded to a RECF of 2E‐06, which is far below the Environmental Protection Agency upper level guideline of 1E‐04.     

Leaching of seven pesticides currently used in cotton crop in Mato Grosso State—Brazil

This study aimed to evaluate the leaching of pesticides and the applicability of the Attenuation Factor (AF) Model to predict their leaching. The leaching of carbofuran, carbendazim, diuron, metolachlor, α and β endosulfan and chlorpyrifos was studied in an Oxisol using a field experiment lysimeter located in Dom Aquino – Mato Grosso. The samples of percolated water were collected by rain event and analyzed. Chemical and physical soil attributes were determined before pesticide application to the plots. The results showed that carbofuran was the pesticide that presented a higher leaching rate in the studied soil, so was the one representing the highest contamination potential. From the total carbofuran applied in the soil surface, around 6 % leached below 50 cm. The other pesticides showed lower mobility in the studied soil. The calculated values to AF were 7.06E-12 (carbendazim), 5.08E-03 (carbofuran), 3.12E-17 (diuron), 6.66E-345 (α-endosulfan), 1.47E-162 (β-endosulfan), 1.50E-06 (metolachlor), 3.51E-155 (chlorpyrifos). AF Model was useful to classify the pesticides' potential for contamination; however, that model underestimated pesticide leaching.     

Endosulfan in China 2—emissions and residues

Background, aim, and scope  Endosulfan is one of the organochlorine pesticides (OCPs) and also a candidate to be included in a group of new persistent organic pollutants (UNEP 2007). The first national endosulfan usage inventories in China with 1/4° longitude by 1/6° latitude resolution has been reported in an accompanying paper. In the second part of the paper, we compiled the gridded historical emissions and soil residues of endosulfan in China from the usage inventories. Based on the residue/emission data, gridded concentrations of endosulfan in Chinese soil and air have been calculated. These inventories will provide valuable data for the further study of endosulfan. Methods  Emission and residue of endosulfan were calculated from endosulfan usage by using a simplified gridded pesticide emission and residue model—SGPERM, which is an integrated modeling system combining mathematical model, database management system, and geographic information system. By using the emission and residue inventories, annual air and soil concentrations of endosulfan in each cell were determined. Results and discussion  Historical gridded emission and residue inventories of α- and β-endosulfan in agricultural soil in China with 1/4° longitude by 1/6° latitude resolution have been created. Total emissions were around 10,800 t, with α-endosulfan at 7,400 t and β-endosulfan at 3,400 t from 1994 to 2004. The highest residues were 140 t for α-endosulfan and 390 t for β-endosulfan, and the lowest residues were 0.7 t for α-endosulfan and 170 t for β-endosulfan in 2004 in Chinese agricultural soil where endosulfan was applied. Based on the emission and residue inventories, concentrations of α- and β-endosulfan in Chinese air and agricultural surface soil were also calculated for each grid cell. We have estimated annual averaged air concentrations and the annual minimum and maximum soil concentrations across China. The real concentrations will be different from season to season. Although our model does not consider the transport of the insecticide in the atmosphere, which could be very important in some areas during some special time, the estimated concentrations of endosulfan in Chinese air and soil derived from the endosulfan emission and residue inventories are in general consistent with the published monitoring data. Conclusions  To our knowledge, this work is the first inventory of this kind for endosulfan published on a national scale. Concentrations of the chemical in Chinese air and agricultural surface soil were calculated for each grid cell. Results show that the estimated concentrations of endosulfan in Chinese air and soil agree reasonably well with the monitoring data in general. Recommendations and perspectives  The gridded endosulfan emission/residue inventories and also the air and soil concentration inventories created in this study will be updated upon availability of new information, including usage and monitoring data. The establishment of these inventories for the OCP is important for both scientific communities and policy makers.     

Impact of spiked concentrations of Cd,Pb, As and Zn in growth medium on elemental uptake of Nasturtium officinale (Watercress)

This study is aimed at investigating the impact of water quality on the uptake and distribution of three non-essential and toxic elements, namely, As, Cd and Pb in the watercress plant to assess for metal toxicity. The plant was hydroponically cultivated under greenhouse conditions, with the growth medium being spiked with varying concentrations of As, Cd and Pb. Plants that were harvested weekly for elemental analysis showed physiological and morphological symptoms of toxicity on exposure to high concentrations of Cd and Pb. Plants exposed to high concentrations of As did not survive and the threshold for As uptake in watercress was established at 5 ppm. Translocation factors were low in all cases as the toxic elements accumulated more in the roots of the plant than the edible leaves. The impact of Zn on the uptake of toxic elements was also evaluated and Zn was found to have an antagonistic effect on uptake of both Cd and Pb with no notable effect on uptake of As. The findings indicate that phytotoxicity or death of the watercress plant would prevent it from being a route of human exposure to high concentrations of As, Cd and Pb in the environment.     

Butyltin compounds in sediment and fish from the Polish Coast of the Baltic Sea

Concentrations of mono- (MBT), di- (DBT), and tri-(TBT) butyltin compounds were measured in eggs, liver, and muscle of nine species of fish from four regions of the Baltic Sea - the Firth of Vistula, the Gulf of Gdańsk, Puck Bay, and the mouth of the Vistula River. The overall concentration ranges among all the fish sampled from the four sites were: < 7 to 79 ng/g for MBT, 6 to 1100 ng/g for DBT, 7 to 3600 ng/g for TBT, and 16 to 4800 ng/g for total BTs, on a wet wt basis. The highest concentration of total BTs was found in herring liver from the Firth of Vistula (4800 ng/g, wet wt) and in roach muscle from Puck Bay (3300 ng/g, wet wt), while the least concentration was found in burbot eggs and liver from the Vistula River (39 and 32 ng/g, wet wt, respectively). TBT was the major form of BTs present in most samples analyzed. Sediment samples collected from shipyards in the Gulf of Gdańsk contained butyltin concentrations ranging from 1.2 to 46 μg/g (dry wt) for MBT, 2.0 to 42 μg/g for DBT, and 2.6 to 40 μg/g for TBT. As with the fish, the majority of the BTs in sediment were present as TBT, which suggested recent exposure of the aquatic environment of the region to TBT.     

Malathion-induced sublethal toxicity on the hematology of cricket frog (Fejervarya limnocharis)

The effect of malathion [diethyl(dimethoxythiophosphorylthio)succinate] at sublethal concentration (0.006 ppm) on hematological parameters of the cricket frog (Fejervarya limnocharis) was studied for 24 hrs to 240 hrs of exposure and remarkable hematological alterations were observed. The study on hematological parameters revealed a highly significant decrease (P < 0.01) in the total erythrocytes count in malathion-exposed animals from 24 hours to 96 hrs of exposure as compared to control. Significant decreases (P < 0.01) of hemoglobin and packed cell volume were also observed from 48 hrs to 240 hrs. A significant increase (P < 0.01) in leucocytes count was noted throughout the exposure period. Elevated numbers of lymphocytes and eosinophils as found in the present study revealed lymphocytosis as well as eosinophilia, suggesting that this was a result of direct stimulation of the immunological defense due to the presence of a toxic substance or may be associated with tissue damage. The cytomorphological and cytopathological study of erythrocytes and leucocytes in malathion-exposed frogs at 0.006 ppm concentration revealed various cytotoxic effects at different exposure times. It was noted that the size and the shape of the erythrocytes were subjected to variation in different blood disorders.     

Relation between forest vegetation, atmospheric deposition and site conditions at regional and European scales

Several monitoring programs have been set up to assess effects of atmospheric deposition on forest ecosystems. The aim of the present study was to evaluate effects on the understorey vegetation, based on the first round of a regional (the Netherlands) and a European forest monitoring program. A multivariate statistical analysis showed surprisingly similar results for both data sets; the vegetation appeared to be largely determined by the ‘traditional’ factors soil, climate, and tree species, but there was a small but statistically significant effect of atmospheric deposition. The effects of deposition include a slight shift towards nitrophytic species at high N deposition in the European network, and towards acidophytic species at high S-deposition in the Dutch network. The relatively small effect of atmospheric deposition is understandable in view of the very large natural variation in environmental conditions. Time series of both vegetation and environment are needed to assess deposition effects in detail.     

Influence of crop residues on trifluralin mineralization in a silty clay loam soil

Trifluralin is typically applied onto crop residues (trash, stubble) at the soil surface, or onto the bare soil surface after the incorporation of crop residues into the soil. The objective of this study was to quantify the effect of the type and amount of crop residues in soil on trifluralin mineralization in a Wellwood silty clay loam soil. Leaves and stubble of Potato (Solanum tuberosum) (P); Canola (Brassica napus) (C), Wheat (Triticum aestivum) (W), Oats (Avena sativa), (O), and Alfalfa (Medicago sativa) (A) were added to soil microcosms at rates of 2%, 4%, 8% and 16% of the total soil weight (25 g). The type and amount of crop residues in soil had little influence on the trifluralin first-order mineralization rate constant, which ranged from 3.57E-03 day^?1 in soil with 16% A to 2.89E-02 day^?1 in soil with 8% W. The cumulative trifluralin mineralization at 113 days ranged from 1.15% in soil with 16% P to 3.21% in soil with 4% C, again demonstrating that the observed differences across the treatments are not of agronomic or environmental importance.     

Concurrent nitrate and Fe(III) reduction during anaerobic biodegradation of phenols in a sandstone aquifer

The biodegradation of phenols (5, 60, 600 mg l⁻¹) under anaerobic conditions (nitrate enriched and unamended) was studied in laboratory microcosms with sandstone material and groundwater from within an anaerobic ammonium plume in an aquifer. The aqueous phase was sampled and analyzed for phenols and selected redox sensitive parameters on a regular basis. An experiment with sandstone material from specific depth intervals from a vertical profile across the ammonium plume was also conducted. The miniature microcosms used in this experiment were sacrificed for sampling for phenols and selected redox sensitive parameters at the end of the experiment. The sandstone material was characterized with respect to oxidation and reduction potential and Fe(II) and Fe(III) speciation prior to use for all microcosms and at the end of the experiments for selected microcosms.The redox conditions in the anaerobic microcosms were mixed nitrate and Fe(III) reducing. Nitrate and Fe(III) were apparently the dominant electron acceptors at high and low nitrate concentrations, respectively. When biomass growth is taken into account, nitrate and Fe(III) reduction constituted sufficient electron acceptor capacity for the mineralization of the phenols observed to be degraded even at an initial phenols concentration of 60 mg l⁻¹ (high) in an unamended microcosm, whereas nitrate reduction alone is unlikely to have provided sufficient electron acceptor capacity for the observed degradation of the phenols in the unamended microcosm.For microcosm systems, with solid aquifer materials, dissolution of organic substances from the solid material may occur. A quantitative determination of the speciation (mineral types and quantity) of electron acceptors associated with the solids, at levels relevant for degradation of specific organic compounds in aquifers, cannot always be obtained. Hence, complete mass balances of electron acceptor consumption for specific organic compounds degradation are difficult to confine. For aquifer materials with low initial Fe(II) content, Fe(II) determinations on solids and in aqueous phase samples may provide valuable information on Fe(III) reduction. However, in microcosms with natural sediments and where electron acceptors are associated with the sediments, complete mass-balances for substrates and electron acceptors are not likely to be obtained.