兼氧接触工艺处理造纸中段废水中间试验的研究

采用中试规律的兼氧接触工艺处理造纸中段废水，当处理水量为４．８ｍ＾３／ｄ，水力停留时间３～４ｈ，气水比３：１，进水ＰＨ８～９．５，平均ＣＯＤ浓度为１６４１．６ｍｇ／ｌ，ＢＯＤ５５１６．１ｍｇ／ｌ，ＳＳ６８８．４ｍｇ／ｌ的条件下，处理后出水ｐＨ７．５左右，平均ＣＯＤ浓度为１０５９．８ｍｇ／ｌ，去除率３４．９％，ＢＯＤ５２４６．５ｍｇ／ｌ，去除率５２．１％，ＳＳ１６１．９ｍｇ／ｌ，去除率为７７．１％。     

碱解─A/A/0─生物炭处理有机磷农药废水

通过对有机磷农药废水成份及其机理的分析，提出了碱解－Ａ／Ａ／０－生物炭处理工艺。在适当的污泥回流比、混合液回流比条件下，控制曝气池中Ｎ_（ＴＯＣ）≤０．１０ ｋｇ·ＢＯＤ_５／ｋｇＭＬＳＳ·ｄ、ＮＨ_３≤０．０８ ｋｇＮＨ_３－Ｎ／ｋｇＭＬＳＳ·ｄ，厌氧池中Ｎ_（Ｔｏｃ）≤（０．１０．２５）ｋｇ ＢＯＤ_5／ｋｇＭＬＳＳ·ｄ及兼氧池中Ｎ_（ＮＤ）_３≤０．０８ ｋｇＮＯ_３－Ｎ／ ｋｇＭＬＬＳＳ·ｄ时，可同时获得最高的ＴＮ、ＴＰ及ＴＯＣ的去除效果，并使出水达一级排入标准。     

SBR法处理印染废水的研究

应用ＳＢＲ法、ＰＡＣ－ＳＢＲ法，微电解－ＳＢＲ法对印染废水进行了对比处理试验研究。试验结果表明：微电解－ＳＢＲ法处理效果优于其它两种方法，当进水ＣＯＤ＝１０００～１６００ｍｇ／Ｌ，色度＝２００～８００倍，ＢＯＤ５＝２５０～４００ｍｇ／Ｌ时．ＣＯＤ去除率在８５％左右，ＢＯＤ５去除率和脱色率均在９０％以上，出水达到排放标准。     

液相色谱测定土壤中氟磺胺草醚残留量方法研究

采用甲醇／浓盐酸浸渍振荡提取，二氯甲烷萃取，经弗罗里硅土柱层析净化，用液相色谱法测定。方法的最低检出含量为０．０２ｍｇ／ｋｇ，添加回收率在９５．８％￣９６．６％之间。     

污泥与高浓度有机废物厌氧消化反应中的产气量

研究了高温／中温两相厌氧消化反应器系用以同时处理污泥与不同高浓度有机废物时产气及产甲烷的变化特性。结果表明，气体及甲烷主要是在第二段的中温消化反应器内产生。当中温消化反应器的有机负荷ＶＳ为１．６５￣３．１０ｋｇ／ｍ＾３ｄ时，稳态条件下的平均产气量为１．９５８￣４．０２０ｍ＾３／ｄ，气体中甲烷的平均组成为６５％￣７３％，甲烷的比产率为０．３９７￣０．５１１ｍ＾３／ｋｇＶＳ。     

含莠去津和乙草胺河水灌溉对苗期水稻危害的研究

本文以１９８８、１９９２和１９９３年洋河流域张家口市部分水稻田污染受害事故为背景，通过事故现场调查资料分析、洋河水质监测、宣化区污染源调查、水稻的药害暴露实验和模型计算，研究了含有除草剂莠去津和乙草胺的河水灌溉对苗期水稻的危害。结果显示，河水中莠去津和乙草胺对水稻苗期的安全灌溉浓度分别为０．０１ｍｇ／Ｌ和０．０５ｍｇ／Ｌ；河水中莠去津对水稻的致死浓度是０．１ｍｇ／Ｌ；ｐＨ、ＮＨ３－Ｎ和表面活性剂对这种危害作用具有一定的协同效应；为了满足河水对水稻的灌溉水质要求，污染源允许排放的莠去津和乙草胺分别为１．０ｋｇ／ｄ和２．０ｋｇ／ｄ。     

动力学光度法测定环境水样中痕量钒（V）

在柠檬酸介质中，Ｖ＾５＋对ＫＢｒＯ３氧化甲基紫的反应有催化作用，研究了其催化动力学条件，由此建立了痕量Ｖ＾５＋的测定方法。方法检出限为１．８μｇ／Ｌ，线性范围为０－０．３２０μｇ／２５ｍｌ，对水环境样品进行精密度试验和加标回收实验。相对偏差为７．２％，加标回收率为９０．６－９７．５％。     

新型无机高分子絮凝剂在制革废水处理中的应用研究

介绍了一种新型无机高分子絮凝剂－硅钙复合型聚合氯化铝铁（ＳＣＰＡＦＣ）在制革废水处理中的应用。结果表明，该产品对废水的浊度去除率为９９％，ＳＳ去除率为９５％，ＣＯＤ去除率为９０％，Ｃｒ＾３＋的去除率为８５％左右。最佳使用ｐＨ值为６．０￣９．０，最佳投药量为０．３５￣０．４０ｇ／Ｌ，最佳混凝时间为１５￣２０ｍｉｎ，在同样条件下各项性能均优于ＰＡＣ２倍以上。同时该絮凝剂还可用于生活饮水、生产用水及其他     

絮凝—酸化法预处理腈纶纺丝生产废水的实验研究

研究采用絮凝－酸化法对腈纶纺丝废水进行预处理,考察了絮凝剂的选用及多种絮凝实验条件对实验结果的影响。结果表明,以ＰＦＳ作絮凝剂,絮凝ｐＨ６．０,ＰＦＳ 投加量为０．３ｍｌ,ＰＡＭ投加量为０．４ｍｌ时的ＣＯＤ,ＢＯＤ５和ＮＨ３－Ｎ及ＣＮ＾－去除率分别为３０％,３１％,８％及３２％。     

接种稀释水的空白对BOD5测定的影响

从接种液种类、空白ＢＯＤ５大小、接种液最佳添加范围等方面对ＢＯＤ５测定进行探讨，提出以接纳工业废水的河水作为最佳接种液，雨季时以土壤浸取液更适合。探讨了接种液空白值对ＢＯＤ５标液和工业废水的影响，结果表明，河水空白应控制在０．１－０．８ｍｇ／Ｌ土壤浸取液空白控制在０．０１－０．１０ｍｇ／Ｌ为宜。     

Subacute effects of a phosphorothionate pesticide on mixed function oxidases of Wistar rats

Subacute oral toxicity of a newly developed phosphorothionate insecticide (2-butenoic acid-3-(diethoxy-phosphinothioyl) methyl ester), coded as RPR-2, was studied in male rats by oral (multiple) intubation of low (0.014 mg kg(-1) day(-1)), medium (0.028 mg kg(-1) day(-1)), and high (0.042 mg kg(-1) day(-1)) dose for 90 days. The medium and high dose produced toxic symptoms along-with some mortality (20%) occurred in the high dose treated rats. The medium and high doses caused significant inhibition in cytochrome P-450 activity in liver, lung, kidney and brain tissues at 45 and 90 days. The high dose caused significant decrease in cyt.b5 activity of all the four tissues at 45 and 90 days. Whereas, medium dose brought such effect in liver and lung at 45 and 90 days. Kidney and brain cyt.b5 activity decreased significantly at 90th day due to medium dose. Low dose also caused inhibition in cyt.b5 activity in brain at 90th day. Cytochrome P-450 reductase activity was decreased significantly in liver,     

The toxicology of the three commercial polybrominated diphenyl oxide (ether) flame retardants

Three commercial polybrominated diphenyl oxide flame retardants (PBDPO, PBDE) are manufactured: decabromodiphenyl oxide (DBDPO), octabromodiphenyl oxide (OBDPO) and pentabromodiphenyl oxide (PeBDPO). The composition, production volumes, uses and toxicology of the three products differ. In 1999, DBDPO accounted for approximately 82% of the global PBDPO usage. DBDPO has been extensively tested. DBDPO was not acutely toxic, was not irritating to the skin or eye, and did not induce skin sensitization. No evidence of genotoxic effects was detected in the Ames Salmonella, chromosome aberration, mouse lymphoma, or sister chromatid exchange tests. No cytogenic changes were observed in the bone marrow of rats (parents and offspring) undergoing a one-generation reproduction test. DBDPO did not adversely affect development or reproduction in rats. DBDPO's no-adverse-effect-level (NOAEL) in repeated dose studies was > or = 1000 mg/kg body weight. No, equivocal, or some evidence of carcinogenicity, dependent on genus and sex, was found in mice and rats at 2.5% and 5% of the diet administered for 2 years. DBPDO was poorly absorbed from the gastrointestinal tract (< 0.3-2% oral dose), had a short half-life (< 24 h) compared to PCB 153 (only 2% of an oral dose eliminated by rats in 21 days), and was rapidly eliminated via the feces (> 99% in 72 h). In contrast, components of the PeBDPO product were well absorbed and slowly eliminated, OBDPO's effect level in a 90-day study was approximately 100 mg/kg, PeBDPO's no-effect-level (NOEL) in a 30-day study was 1 mg/kg, and OBDPO induced developmental toxicity in the rat. In aquatic species, neither DBDPO nor OBDPO were toxic to aquatic organisms or bioconcentrating. Components of the PeBDPO product bioconcentrated in fish but produced little evidence of adverse effects.     

Assessment of teratogenic potential of trichlorfon in mice and rats

Trichlorfon was evaluated for its teratogenic potential in the CD-1 mouse at doses of 200, 300 or 400 mg/kg/day administered by gavage on days 7-16 of gestation. In the CD-1 mouse, TCF was teratogenic, fetotoxic and lethal at the two highest dose levels which were also maternally lethal. At the lowest dose level which was not maternally lethal, there was a significant decrease in the number of calcified centers in the forepaws and hindpaws indicating fetotoxicity and a delay in maturation. TCF was administered at doses of 50, 100 or 200 mg/kg/day to CD rats by gavage on gestational days 7-19 (study I) or 8-20 (study II). In the CD rat in body study I and II, the highest dose level was maternally lethal. In study I, TCF was teratogenic with a shift in rib profile. In study II, TCF was teratogenic with an increased incidence in malformations of the urinary system. Additionally, TCF was fetotoxic with reduced ossification of the skulls at the lowest and highest dose levels.     

Effect of manganese on the concentration of amino acids in different regions of the rat brain

The present study was designed to determine if chronic exposure of weanlings and adult rats to Mn produces significant alterations in amino acid concentrations in different regions of the rat brain. Weanling (30 day old) and adult (90 day old) male rats were exposed to 10 and 20 mg Mn/kg body weight per day, by gavage, for 30 days. Forty-eight hours after the last dose, animals were sacrificed by decapitation and brains were dissected into different regions to determine the concentration of amino acids by HPLC/EC. A dose dependent decrease in body weight gain was found in the adult, but not in the weanling rats. Significant increases occurred in concentrations of aspartate, glutamate, glutamine, taurine and gamma-aminobutyric acid (GABA) in the cerebellum of the adult rats dosed with 20 mg/kg per day, Mn. A significant decrease in the concentration of glutamine was observed in caudate nucleus and hippocampus of weanling rats dosed with 10 mg/kg, Mn. These data suggest that chronic Mn exposure can produce a decrease in body weight gain in adult rats and alterations in amino acids in different regions of weanling and adult rat brains.     

Effect of manganese on the concentration of amino acids in different regions of the rat brain

Abstract

The present study was designed to determine if chronic exposure of weanlings and adult rats to Mn produces significant alterations in amino acid concentrations in different regions of the rat brain. Weanling (30 day old) and adult (90 day old) male rats were exposed to 10 and 20 mg Mn/kg body weight per day, by gavage, for 30 days. Forty‐ eight hours after the last dose, animals were sacrificed by decapitation and brains were dissected into different regions to determine the concentration of amino acids by HPLC/EC. A dose dependent decrease in body weight gain was found in the adult, but not in the weanling rats. Significant increases occurred in concentrations of aspartate, glutamate, glutamine, taurine and y‐aminobutyric acid (GABA) in the cerebellum of the adult rats dosed with 20 mg/kg per day, Mn. A significant decrease in the concentration of glutamine was observed in caudate nucleus and hippocampus of weanling rats dosed with 10 mg/kg, Mn. These data suggest that chronic Mn exposure can produce a decrease in body weight gain in adult rats and alterations in amino acids in different regions of weanling and adult rat brains.     

Fate of ochratoxin A in goats.

The fate of ochratoxin A (OA) was studied in goats given a single oral dose of 3H-OA (0.5 mg/kg). More than 90% of the radioactivity was found to be excreted in 7 days and the majority (53%) was found in feces. Thirty-eight percent, 6% and 2.26% of the activity was found in urine, milk and serum, respectively. The radioactivity in the liver and kidney 6 hours after feeding amounted to 1.5 and 0.5% of the total dose administered, respectively. Subsequent fractionation of liver and kidney homogenates revealed that microsomes, ribosomes and post-ribosomal supernatant fractions contained most radioactivity. Thin layer chromatographic analyses revealed two additional radioactive spots with Rf values and fluorescent characteristics different from OA, Oalpha and 4-OH-OA. Whereas OA was found as the unaltered molecule in feces, the metabolites were primarily found in urine and milk. Less than 0.03% of free OA was found in milk during the 7-day period.     

Effect of nonylphenol on steroidogenesis of rat Leydig cells

Nonylphenol is the primary final biodegradation product of nonylphenol polyethoxylate (NPE), a non-ionic surfactant that is frequently incorporated into pesticide and detergent formulation. Recent researchers have hypothesized that environmental/ occupational exposure to nonylphenol poses adverse effects on reproductive system of humans and wildlife species. During our study, in vivo and in vitro experiments were performed to examine the effect of nonylphenol on testosterone biosynthesis of rat Leydig cells. In experiment in vivo, serum testosterone (T) as well as luteinizing hormone (LH) levels were detected after animals had been treated with different doses (0 mg/kg/day, 125 mg/kg/day, and 250 mg/kg/day) of nonylphenol for 50 days by gavage, and the final result revealed that testosterone level dramatically declined at the dose of 250 mg/kg/day, while LH level ascended at the dose of 125 mg/kg/day and 250 mg/kg/day. In experiment in vitro, primary cultured Leydig cells were exposed to nonylphenol for 48 h, including low concentrations (0 mg/L, 0.0011 mg/L, 0.0033 mg/L, 0.0055 mg/L, 0.011 mg/L, 0.022 mg/L) and higher concentrations (0.11 mg/L, 0.55 mg/L, 1.1 mg/L, 1.65 mg/L, 2.2 mg/L, 2.75 mg/L, 3.3 mg/L, 5.5 mg/L). Increase of testosterone levels was observed at low concentrations of nonylphenol while reduction was detected at higher concentrations.     

Effect of Nonylphenol on Steroidogenesis of Rat Leydig Cells

Nonylphenol is the primary final biodegradation product of nonylphenol polyethoxylate (NPE), a non-ionic surfactant that is frequently incorporated into pesticide and detergent formulation. Recent researchers have hypothesized that environmental/ occupational exposure to nonylphenol poses adverse effects on reproductive system of humans and wildlife species. During our study, in vivo and in vitro experiments were performed to examine the effect of nonylphenol on testosterone biosynthesis of rat Leydig cells. In experiment in vivo, serum testosterone (T) as well as luteinizing hormone (LH) levels were detected after animals had been treated with different doses (0 mg/kg/day, 125 mg/kg/day, and 250 mg/kg/day) of nonylphenol for 50 days by gavage, and the final result revealed that testosterone level dramatically declined at the dose of 250 mg/kg/day, while LH level ascended at the dose of 125 mg/kg/day and 250 mg/kg/day. In experiment in vitro, primary cultured Leydig cells were exposed to nonylphenol for 48 h, including low concentrations (0 mg/L, 0.0011 mg/L, 0.0033 mg/L, 0.0055 mg/L, 0.011 mg/L, 0.022 mg/L) and higher concentrations (0.11 mg/L, 0.55 mg/L, 1.1 mg/L, 1.65 mg/L, 2.2 mg/L, 2.75 mg/L, 3.3 mg/L, 5.5 mg/L). Increase of testosterone levels was observed at low concentrations of nonylphenol while reduction was detected at higher concentrations.     

Neurotoxicity of diallate and triallate when administered orally or topically to hens

Two allylthiocarbamate herbicides, diallate and triallate, were evaluated for neurotoxicity by oral and topical dosing studies with mature white leghorn hens. Diallate was tolerated for 90 days at topical doses of 40 mg/kg/day and oral doses of 20 mg/kg/day. Reversible ataxia and narcosis occurred at diallate doses of 80 mg/kg/day and higher by either route of administration. Triallate did not elicit signs of neurotoxicity at 300 mg/kg/day topically or 400 mg/kg/day orally. The oral dose, however, resulted in gastrointestinal irritation and severe weight loss, such that dosing was terminated after 25 days. Triallate was tolerated at oral dosages of 90 mg/kg/day and topical doses up to 330 mg/kg/day.     

Behavior of the organophosphorus insecticide fenitrothion in stored faba beans and its biological effects towards experimental animals

Sound whole-seed faba beans were treated with (methyl-(14)C) fenitrothion [O, O-dimethyl-O-(3-methyl-4-nitrophenyl) phosphorothioate] at 5 and 10 mg insecticide/kg seeds, a dose normally used in practice. During the 30 weeks of storage period, the penetration and distribution of insecticide residues were studied. The amount of surface residues, internal residues and bound insecticide residues was estimated. Surface residues were found to decrease with the increase in time of storage, whereas internal residues showed a gradual increase with time apparently not dose dependent. Grain-bound residues increased with time and reached to its maximum (14-18%) after 24 weeks of storage. Chromatographic analysis of the internal extracts revealed the presence of the parent compound together with three main metabolites which were found in both free and conjugated form. Feeding mice for 90 days with a diet mixed with total internal fenitrothion residues in stored faba beans led to a reduction in body weight gain, and an appreciable decrease in cholinesterase activity of 32% for plasma and 15% for red blood cells (RBC(S)) after two months of experiment. Also, a significant decrease was showed in both total protein and albumin concentration at the end of feeding period (90 days). Liver and kidney function, as well as lipid profile of treated mice significantly increased at the end of feeding period. After a one-month recovery period, all the examined blood parameters returned to about the control values except blood urea and serum triglyceride.