氧化塘去除病毒效果的研究

本文采用加标方式对氧化塘去除病毒的能力进行研究.小型模拟氧化塘病毒去除率达99.99%.中试氧化塘冬季病毒去除率为80%,夏季病毒去除率为91%,春季适当增加停留时间(10天)和保温措施病毒去除率达99.76%.实验结果说明该氧化塘对病毒的去除相当于一般二级处理的效果.     

不同清洗法对空心菜中氧化乐果残留的去除效果

目的 研究不同清洗法对空心菜中氧化乐果残留的去除效果.方法 将氧化乐果污染的空心菜分别以自来水冲洗、温水浸泡、洗洁精溶液浸泡5、10和15 min,采用气相色谱法,测定不同清洗法对空心菜中氧化乐果的去除效果.结果 采用洗涤剂清洗,对于空心菜中氧化乐果残留去除效果最好,即使对高残留量样品(63.21 mg/kg)也具有较好的去除效果,去除率达55％;对低残留量的污染样品(0.68 mg/kg)去除率能达100％.采用流动的自来水冲洗,对于较低残留量的样品(0.68 mg/kg),去除效果较好,最高也能达100％;而对高残留量样品,去除效果则有限,去除率仅有20％.用温水浸泡,50℃温水比30℃温水去除效果好.结论 日常使用的清洗方式,均可降低空心菜中氧化乐果的残留量,但去除效果存在差异,洗涤剂对空心菜中的氧化乐果的去除效果最好.     

2种去除Vero细胞DNA工艺的研究

目的建立并比较2种去除Sabin株脊髓灰质炎疫苗Vero细胞DNA工艺方法。方法采用不同终浓度的鱼精蛋白和非限制性核酸内切酶在不同条件下分别处理Sabin株脊髓灰质炎病毒浓缩液,采用荧光染色法检测宿主细胞DNA、酶联免疫法检测D抗原和宿主残余蛋白含量。结果鱼精蛋白的终浓度为1 g/L~1.5 g/L,病毒浓缩液中Vero细胞DNA的去除率达98%以上,抗原回收率达85%以上,宿主细胞残余蛋白去除率可达30%左右;非限制性核酸内切酶的终浓度为100 U/ml~150 U/ml,37℃孵育2 h转入2℃~8℃孵育18 h~20 h,病毒浓缩液中Vero细胞DNA的去除率达95%以上,抗原回收率达98%以上,宿主细胞残余蛋白基本无去除。结论 2种工艺均可用于去除Sabin株脊髓灰质炎疫苗中Vero细胞残余DNA,非限制性核酸内切酶法操作更简便快捷。     

粉煤灰吸附-Fenton氧化联合处理高浓度有机实验室废水

采用粉煤灰-Fenton氧化法联合处理高浓度有机实验室废水.在粉煤灰吸附的最佳条件下对Fenton氧化的最佳条件进行研究,考察了pH、氧化时间、H202投加量、FeS04投加量以及H202投加方式等因素对COD去除的影响.结果表明:反映时间为2h、H202投加量为0.05mL/mL、c(H202):c(FeS04)为10:1、pH为3时是最佳实验条件,此时废水COD的去除率达90%以上,色度去除率这99%以上.     

湖南省室内空气净化产品甲醛净化效果对比研究

目的对湖南省内销售使用的各种类型的净化产品进行模拟现场甲醛净化效果实验，对比丁解其净化效果和各自的优缺点，探索科学有效的甲醛去除方法。方法20m^3密闭性良好的模拟现场空气试验室，采用人工模拟方式使试验间和对照问甲醛浓度达国家标准浓度的10～14倍，分别测定1h和12h各类空气净化产品对甲醛净化效果。结果静电吸附类净化产品A、B1h甲醛去除率分别为19％、15％，12h甲醛去除率分别为94％、66％；物理吸附类净化产品C和D1h甲醛去除率分别为15％、12％，12h甲醛去除率分别为84％、50％；化学消除类净化产品E和F1h甲醛去除率分别为12％、19％，12h甲醛去除率分别为44％、77％。结论不同的净化产品由于其作用原理和净化方式不同，对甲醛的去除效率和去除特征有所不同，去除甲醛应根据权威机构室内空气检测结果，采取综合、长期的科学治理方法，才能达到预期效果。     

活性陶瓷球为载体的生物氧化池对污水中CODcr、BOD_5影响的观察

目的 :了解活性陶瓷球为载体的生物氧化池对污水中CODcr,BOD5浓度的影响情况。方法 :在生物氧化池 (1 )及生物氧化池 (2 )处理医院污水、生活污水的前后 ,分别取水样测定水中CODcr,BOD5的含量 ,后进行各组间浓度差异的显著性检验及分析。结果 :使用活性陶瓷球为载体的生物氧化池污水中CODcr ,的去除率达 93 2 0～ 99 45 % ,BOD5去除率为 98 63～ 98 68%。结论 :活性陶瓷球为载体的生物氧化池对医院污水及生活污水中的有机物均有非常好的去除作用     

甲苯废气吸收液的Fenton氧化处理条件优化研究

目的探讨甲苯废气吸收液的Fenton氧化处理条件优化。方法以吸收了甲苯气体的水基BDO-甲苯溶液为处理对象,采用Fenton氧化处理方法,通过正交实验,优化Fenton氧化的pH、FeSO_4投加量、H_2O_2投加量和反应时间等反应条件。结果采用Fenton氧化技术对甲苯去除效果明显,最大去除率达83.5%。由正交试验得出最优化实验条件为FeSO_4投加量400 mg/L,30%H_2O_2投加量4 ml/L,pH为4,反应时间为30 min,其中pH的水平变化对实验效果影响最大。结论该方法可有效去除吸收液中的甲苯。     

催化-臭氧在游泳池水质处理的应用

目的:建立一种用催化-臭氧方法氧化游泳池水中尿素,以使得游泳池水中的尿素、细菌总数、大肠菌群指标符合国家标准。方法:用不同的方法,如改性沸石过滤试验;加氯试验;臭氧氧化试验;臭氧加入催化剂(催化剂为硫酸铜或五氧化二矾)等试验观察尿素的去除效果。结果:催化-臭氧方法去除尿素效果最好,臭氧加入以硫酸铜为催化剂的催化方法尿素去除率为76.3%,臭氧加入以五氧化二矾为催化剂的催化方法尿素去除率为76.8%,高浓度氯(有效氯含量5.0 mg/L)消毒剂效果次之,去除率为46.1%。结论:理想的去除游泳池水尿素及杀灭细菌的有效方法为臭氧发生器连接游泳池本身的循环水处理系统。     

饮用水中微囊藻毒素去除效果研究

目的 探讨高效、经济、可行的去除饮用水中藻毒素的水处理方法.方法 采用烧杯试验,研究不同水处理工艺[混凝沉淀(液态聚合氯化铝、固态聚合氯化铝、聚合硫酸铁、聚丙烯酰胺),氧化(高锰酸钾、二氧化氯、臭氧),吸附(粉末活性炭)]对微囊藻毒素的去除效果,并进行工艺优化组合和验证;藻毒素的检测采用酶联免疫法(ELISA).结果 混凝沉淀可少量去除水中微囊藻毒素(去除率为4.3%～29.7%),臭氧等氧化剂预处理工艺与混凝沉淀工艺组合后,对微囊藻毒素的去除率提高,达83.3%～91.9%;成本效益分析表明,所选臭氧预处理工艺及"氧化剂 吸附剂"预处理工艺使每吨水处理成本仅增加0.03～0.14元.结论 在常规水处理基础上进行臭氧、高锰酸钾氧化、二氧化氯、粉末活性炭等预处理,能较好地去除微囊藻毒素,且经济可行.     

生物絮凝吸附+生物接触氧化除磷机理探讨

通过单因素试验研究了生物絮凝吸附+生物接触氧化组合式一体化工艺对城市污水悬浮物SS、化学需氧量COD、氨氮NH3-N、总氮TN、总磷TP的去除效能和机理。试验结果表明:在组合工艺的较优运行条件下,装置对SS、COD、NH3-N、TN、TP的平均去除率分别为88.7%、89.3%、87.9%、73.4%、58.8%。组合工艺对污染物的总体去除效果良好,且稳定可靠,其中生物絮凝吸附段对总磷的去除率为32.4%,生物接触氧化段对总磷的去除率为39.1%。     

Assessment of the waste stabilization pond performance, New Borg El-Arab City

New Borg Al-Arab city includes 9 residential areas and 4 industrial zones. The four industrial zones are occupied by 266 running factories belonging to different industrial sectors. All the domestic sewage as well as the industrial wastewater is treated at an oxidation pond treatment plant and the plant effluent is used in irrigation of silviculture areas. The plant consists of 2 pond complexes. Each complex comprises 9 facultative ponds, arranged in 3 parallel series. Raw wastewater is pre-treated through screens and grit removal before entering the primary ponds. The study aims at assessment of the performance of the waste stabilization ponds. The results revealed that pre-treatment units were not functioning properly. The retention time was calculated to be 6 days in each pond of the first complex and 3 days in each pond of the second complex. The mean BOD surface loading rate was calculated to be 676 kg/ha/d for the first complex and 1584 kg/ha/d for the second. The plant was hydraulically and organically overloaded. The percentage removal of BOD, COD, SS, and NH3-N had an annual mean of 57%, 56%, 44%, and 39%, respectively for the first complex and 21%, 42%, 39%, and 25%, respectively for the second. Faecal coliforms were reduced by about 1 log10 unit in both complexes. The final pond effluent was not complying with the Egyptian law for reuse in irrigation. The study proposed some recommendations which can improve the efficiency of the plant as well as the effluent quality.     

Enteroviruses in sewage: comparison of different technologies for wastewater treatment and reuse

Seven wastewater treatment plants were twice sampled to compare their different technologies for the removal of enteroviruses. These technologies are extended aeration, oxidation ditch, stabilization pond, aerated stabilization pond, submerged fixed film reactor, trickling filter and trickling filter followed by activated sludge in El-Serw, El-Rahamna, El-Adliya, Daqahla, El-Barashiya, Sohag and El-Fayoum wastewater treatment plants, respectively. Virus counts of raw sewage ranged between 2.7 x 10(3) and 20 x 10(3) PFU/L and for treated effluents was between 0 and 6 x 10(3). The percentage of virus removal was varied where trickling filter and tickling filter followed by activated sludge reduced virus counts by 95.7 and 99.9, respectively. Extended aeration removed 64.2%, oxidation ditch 66.5%, stabilization pond 44.9%, aerated stabilization pond 13.34%, and submerged fixed film reactor removed 53.4%. The neutralization test revealed five types of enteroviruses, poliovirus types 1,2 and 3 and Coxsackievirus types B4 and B5. The isolated polioviruses were vaccine strains. From the frequency distribution of the detected viruses, poliovirus type 2 was the most dominant.     

The efficiency of pilot plant stabilization pond treatment of wastewater

A pilot plant stabilization pond (SP) using Jerusalem wastewater primary effluent, was constructed to study the effect of hydraulic characteristics on treatment system performance. The system consists of six ponds: the first, 3 m3, and the remainder 1 m3 each. Two longitudinal baffles were installed in ponds 1 and 5, and two cross-sectional baffles in ponds 2 to 4. Pond 6 was without baffles. Two runs were made, using two theoretical detention times (TDT): 11 and 33 days. In each run, rhodamine water tracer (RWT) studies were conducted, biological oxygen demand (BOD) was determined, and physico-chemical and microbiological tests were carried out. According to the tracer study, the first pond had a flow pattern similar to an idealized completely mixed pattern. In the remaining series of ponds, the flow was similar to that of an idealized plug flow pattern, and with more efficient usage of pond volume as compared with that of a single SP. Thermal stratification occurred during the day in ponds with or without longitudinal baffles, causing hydraulic failures. However, ponds with cross-sectional baffles showed no thermal stratification, had higher microbial decay rates, and displayed improved treatment efficiency. The tested microorganisms at the exit of pond 6 were reduced by up to 1.8 logs after 11 days of TDT, and by 3.3 to 5.2 logs after 33 days of TDT. BOD was reduced by 79 and 93% respectively. In the baffled SP pilot plant, 27 days of TDT were required to achieve the WHO guidelines of 1000 F. coliforms/100 ml wastewater effluent for unrestricted irrigation.     

A Survey of Metal and Pesticide Levels in Stormwater Retention Pond Sediments in Coastal South Carolina

During the summer of 2007, sediment samples were collected from 16 stormwater detention ponds and 2 reference ponds located in coastal South Carolina. The sediments were analyzed for more than 30 pesticides with current and historical uses, six polybrominated diphenyl ethers (PBDEs), and seven metals. The results are compared with established screening assessment parameters, with copper found to be the contaminant of highest concern. Lead levels were found to correlate well with pond drainage area, while copper and zinc levels correlated with both pond drainage area and pond surface area. Chlorpyrifos levels were found to correlate with pond surface area. Our results also show that ponds draining commercial areas were likely to have higher levels of zinc and lead in the sediments compared to other pond classes.     

The toxicity of selenium in experimental freshwater ponds

Flue Gas Desulphurization equipment installed in coal-fired power stations to reduce sulphur dioxide emissions produces effluent containing several contaminants, including selenium. To assess the effects that this might have on fish reproduction and biological community richness, selenate and selenite were added to freshwater pond systems to achieve duplicated nominal concentrations of 0 (control), 2, 10 and 25 g Se/L. Perch (Perca fluviatilis), grass carp (Ctenopharyngodon idella Val.) and stickleback (Gasterosteus aculeatus) were placed in each pond in the early summer and left relatively undisturbed until the following spring. A spawning tray was then placed in each pond and monitored regularly for the appearance of perch egg ropes. When ropes were found, they were removed to the laboratory and either placed in uncontaminated well water or exposed to selenium. Almost half the perch exposed to 25 g Se/L died during the pond experiment, but there were no observed deaths at the lower concentrations. No grass carp were recovered from the 25 g Se/L ponds but all were recovered from the other ponds. Stickleback were missing from all treatments, presumably due to predation by the perch. Perch egg ropes were found in seven of the eight ponds, and all but one rope showed signs of successful fertilisation. Hatching success in the laboratory was highly variable for eggs obtained from the 0, 2, and 10 g Se/L ponds, but was always above zero. No eggs hatched from ropes obtained from the 25 g Se/L ponds. Effects of selenium on plants, macroinvertebrates and zooplankton in the ponds were generally limited. Accumulation of selenium in fish was dose-related and comparable with results reported from other contaminated systems. The results from this experiment suggest that mean environmental concentrations of approximately 25 g Se/L may seriously affect the reproductive capacity of perch, but no clear effects on reproduction are evident at mean concentrations of 10 g Se/L and below. Selenium-induced effects occur during gametogenesis, but only become evident between fertilization and hatching.     

Perturbation of the aquatic invertebrate community of acidic bog ponds by the insecticide fenitrothion

In forest areas receiving aerial application of pesticides, small bodies of water, which are often difficult to see from low-flying spray planes, are at risk of receiving high concentrations of contaminants. To determine the sensitivity of bog pond invertebrate communities, formulated fenitrothion was applied at ground level with a mist blower to four acidic bog ponds near Lake George, New Brunswick, Canada. Fenitrothion fate and persistence, insect emergence, gyrinid populations, and the invertebrate community inhabiting the floating sphagnum fringe of the ponds were sampled before and after treatment.The invertebrate community was sensitive to formulated fenitrothion. Concentrations of fenitrothion in bog pond water were in ranges that would be expected after a direct aerial application, with no buffer zone, of 2×210 g active-ingredient/ha, the operational emission rate used for spruce budworm. Insect emergence was reduced compared to control ponds for 6–12 weeks following fenitrothion treatment. The population densities of Chironomidae and Ceratopogonidae were reduced by more than 50% for 1 month after treatment. The densities of most other benthic insect taxa were also reduced. Some reductions in density lasted over winter into the next year. This contrasted with the usual small and transitory effects of fenitrothion on aquatic invertebrate communities in streams or large lakes.Insecticide-induced suppression of aquatic insects and adult insect emergence in the small bog ponds allowed Hydrachnellae, Oligochaeta, and Nematoda to dominate the aquatic invertebrate community. Export of energy and nutrients to the terrestrial system through insect emergence was thus reduced and cycling or retention within the aquatic system increased. Sustained suppression of insect emergence could result in nutrient accumulation in the ponds. Substantially reduced insect emergence would be expected to have effects on dependent predators in the bog ecosystem.     

Comparison of mosquito control provided by the arroyo chub (Gila orcutti) and the mosquitofish (Gambusia affinis)

Two 6-wk trials were conducted in 28-m2 earthen ponds to compare the efficacy of the arroyo chub, Gila orcutti, to the mosquitofish, Gambusia affinis, as a biological control agent for mosquitoes and a possible replacement for the mosquitofish in sensitive watersheds of southern California. The mosquitofish population growth rate was 1.73 times greater than the arroyo chub population growth rate; however, greater reproduction by the mosquitofish did not result in significantly better reduction of mosquitoes than was provided by the comparatively small populations of arroyo chub. On average across a 6-wk study in the spring, both larvivorous fishes reduced the abundance of 3rd and 4th instars by 4- to 5-fold compared to that observed in the control ponds that lacked fish but contained few invertebrate predators. The abundance of nontarget microinvertebrates in ponds containing the mosquitofish was only 7% of that in ponds containing the arroyo chub during the summer, but did not differ significantly between the fish species treatments when zooplankton was comparatively more abundant during the spring. Even though the number of individuals produced by each fish species during 6 wk in the spring was greater than for fish stocked in the summer, species-specific population growth rates in the spring study (individuals/individual/d; mosquitofish, 0.077; arroyo chub, 0.044) were only slightly higher than in the summer (individuals/individual/d; mosquitofish, 0.068; arroyo chub, 0.039) indicating that differences in the number of fish stocked contributed primarily to the differences in final population size between spring and summer studies. The arroyo chub is native to the South Coastal drainages in California and should be considered as a viable alternative to the mosquitofish for integrated mosquito management programs in riverine wetlands and sensitive watersheds of southern California.     

Lethal and Sublethal Effects of Embryonic and Larval Exposure of Hyla versicolor to Stormwater Pond Sediments

Stormwater ponds are common features of modern stormwater management practices. Stormwater ponds often retain standing water for extended periods of time, develop vegetative characteristics similar to natural wetlands, and attract wildlife. However, because stormwater ponds are designed to capture pollutants, wildlife that utilize ponds might be exposed to pollutants and suffer toxicological effects. To investigate the toxicity of stormwater pond sediments to Hyla versicolor, an anuran commonly found using retention ponds for breeding, we exposed embryos and larvae to sediments in laboratory microcosms. Exposure to pond sediments reduced survival of embryos by ~50% but did not affect larval survival. Larvae exposed to stormwater pond sediment developed significantly faster ([`(x)] = 39 \bar{x} = 39 days compared to 42 days; p = 0.005) and were significantly larger at metamorphosis ([`(x)] =  0. 4 9 \bar{x} = \, 0. 4 9 g compared to 0.36 g; p < 0.001) than controls that were exposed to clean sand. Substantial amounts (712–2215 mg/l) of chloride leached from pond sediments into the water column of treatment microcosms; subsequently, survival of embryos was negatively correlated (r ² = 0.50; p < 0.001) with water conductivity during development. Our results, along with the limited number of other toxicological studies of stormwater ponds, suggest that road salt contributes to the degradation of stormwater pond habitat quality for amphibian reproduction and that future research should focus on understanding interactions among road salts and other pollutants and stressors characteristic of urban environments.