矿物材料预处理对餐厨垃圾高温厌氧消化过程的影响

选用4种矿物材料对400g餐厨垃圾在35℃下进行4h好氧预处理,比较了预处理前后餐厨垃圾水解率的变化,并且详细研究了预处理对餐厨垃圾高温厌氧消化过程及产沼气效果的影响.结果表明:在同等条件下,添加矿物材料可以有效促进餐厨垃圾的水解,其中添加1.25%(质量分数,以餐厨垃圾湿基计)膨润土和添加2.5%轻烧MgO的处理水解率分别达到了96.79%和96.51%.轻烧MgO有效地缓解了餐厨垃圾由于酸化引起的pH值下降,使产气高峰期较早来到;而在总产气量上添加白云石粉的促进作用显著.膨润土次之,其中添加2.5%白云石粉的总产气量最高,为10925mL.添加矿物材料降低了消化液中钠离子的浓度,可减轻对产甲烷细菌的抑制作用.     

城市内河蓝藻复苏和生长规律研究

主要探讨城市化对城市内河蓝藻复苏和生长的影响。这些影响包括河流中营养物的升高、高等水生植物的灭绝、河水所受光照强度的变化以及由河水滞流带来的水体复氧效率降低对内河中蓝藻爆发条件的影响。通过实验我们发现金鱼藻与水网藻的存在可以在一定程度上抑制蓝藻的生长,金鱼藻的效果比水网藻更明显。适宜的光照是蓝藻大量生长的条件。对水体进行曝气复氧可以抑制蓝藻的生长。     

A RATING-CURVE METHOD FOR HYDRODYNAMIC SIMULATIONS IN CONTAMINANT TRANSPORT MODELING1

ABSTRACT: Accurate prediction of hydrodynamics is of great importance to modeling contaminant transport and water quality in a river. Flow conditions are needed in estimating potential exposure contamination levels and the recovery time for a no-action alternative in contaminated sediments remediation. Considering highly meandering characteristics of the Buffalo River, New York, a three-dimensional hydrodynamic model was selected to route upstream flows through the 8-km river section with limited existing information based on the model's fully predictive capability and process-oriented feature. The model was employed to simulate changes in water depth and flow velocity with space and time in response to variation in flow rate and/or water surface elevation at boundaries for given bottom morphometry and initial conditions. Flow conditions of the river reach where historical flow data are not available were computed. A rating-curve approach was developed to meet continuous and event contaminant modeling needs. Rating curves (depth-discharge and velocity-discharge relationships) were constructed at selected stations from the 3-D hydrodynamic simulations of individual flow events. The curves were obtained as steady solutions to an unsteady problem. The rating-curve approach serves to link flow information provided by the hydrodynamic model to a contaminant transport model. With the approach, the linking problem resulting from incompatible model dimensions and grid sizes can be solved. The curves will be used to simulate sediment movement and to predict contaminant fate and transport in the river.     

JAZ型絮凝剂对活性染料的絮凝效果

本文介绍了新近开发的ＪＡＺ絮凝凝剂地水样中活性艳红Ｋ－２ＢＰ，活性紫Ｈ－２Ｒ和活性黑Ｋ－ＢＲ染料的絮凝效果及ＰＨ值和投药比对脱色率的影响。在中性和弱酸性中絮凝效果好。投药比增大脱色率增加。对活性艳红和活性紫，起始浓度增加则达到８８．５％脱色率的投药比降低。对三种活性染料配水和活性 染料配水和活性黑染料生产水脱色率均可达到９９％，处理液残余色度在２０倍以下。     

Promotive effect of pyridine on indole degradation by activated sludge under anoxic conditions

Batch experiments were carried out to investigate the promotive effect of pyridine on indole degradation under denitrifying conditions. The seed sludge was obtained from a local coal-coking wastewater treatment facility and was acclimated in the laboratory. Indole and pyridine were supplemented to the synthetic wastewater at different ratios. The optimum ratio of chemical oxygen demand (COD) to nitrate (C/N) was 8.4–8.9 for both denitrification and indole and pyridine degradation. At a temperature of 28°C and pH of 7.0–7.5, the nitrate reductase activity (NRA) was in the best state. The addition of pyridine could promote NRA and the degradation of indole. When the initial concentration of indole was 150 mg/L, the concentration ratio of indole to pyridine was in the range of 1–10. Under optimum C/N conditions, the degradation of indole could be described with pseudo-zero-order kinetics. There was no accumulation of nitrite during the reaction. When the concentration ratio of pyridine to indole was less than 0.25 with an increase in the pyridine proportion, there were more significant augment rates for NRA and the degradation of indole than the situation when the concentration ratio was more than 0.25.     

Effets à court terme et à long terme d'un narcotique sur quelques activités enzymatiques chez le copépode harpacticoïde Tisbe holothuriae

The anaesthetic properties of clomethiazole ethane disulfonate (hydrochloric ester of thiazole fraction of Vitamin B 1) were tested on the harpacticoid copepod Tisbe holothuriae Humes. Concentrations of 0.250, 0.50, 0.625, 0.714 and 0.833 in sea water were tested. The copepod was exposed to the anaesthetic solutions for periods of 30 min and 1 h. A concentration of 0.250 was sufficient to induce immobility within a few minutes; the lethal concentration is 1. Immediate and delayed effects of narcosis on the activities of the enzymes esterases (EST), leucine aminopeptidase (LAP), alkaline phosphatase (ALP), malate dehydrogenase (MDH), malic enzyme (ME) and phosphoglucomutase (PGM) were studied using electrophoresis in polyacrylamide gel. No change in EST, LAP and ALP zymograms was observed during 48 h postnarcosis, whatever the clomethiazole concentration used, but changes in MDH, ME and PGM activity were observed after anaesthesia in 0.714 and 0.833 clomethiazole. The stronger the concentration used, the earlier and longer-lasting was the decrease in activity. For MDH, which is coded by two loci, electrophoresis revealed that one locus (the fast fraction) is more sensitive to the narcotic than the other, slow one.     

人工湿地中沸石对铵吸附能力的生物再生研究

利用铵吸附饱和的天然斜发沸石和沙质土壤作为基质,构建了沸石柱和芦苇、菖蒲沸石人工湿地试验系统,采用曝气供氧、自然复氧、植物根系输氧以及培养系统中基质上的硝化菌群的方法,研究了铵吸附饱和的沸石在沸石柱和湿地中的生物再生过程。结果显示,沸石在湿地中再生过程符合指数模拟,在试验周期内沸石在沸石柱中再生可以用指数和线性模拟。沸石在湿地系统和沸石柱中经过1个月的再生,交换容量分别恢复到了原来的60.3%~62.6%和11.8%,3个月后分别恢复到了原来的94.6%~94.8%和38.4%。试验证明,沸石在湿地中再生比在沸石柱中再生效果好,交换容量恢复率高出约50%~63%。根据试验结果,探讨了铵吸附饱和的沸石在人工湿地中的生物再生机理,证明了饱和沸石在湿地中生物再生的可行性。     

两相厌氧消化工艺处理有机废水的进展和应用

两相厌氧消化工艺是近年来发展很快的一种处理有机废水的新技术.本文介绍了该技术的微生物学原理和基本特点,总结了国内外的研究和应用现状,简要分析了该技术的研究动态.     

Reduction of hexavalent chromium by ascorbic acid in aqueous solutions

Hexavalent chromium is a priority pollutant in the USA and many other countries. Reduction of Cr(VI) to Cr(III) is environmentally favorable as the latter species is not toxic to most living organisms and also has a low mobility and bioavailability. Reduction of Cr(VI) by ascorbic acid (vitamin C) as a reductant was studied using potassium dichromate solution as the model pollutant. Effects of concentration of vitamin C, pH, temperature, irradiation and reaction time on the reduction of Cr(VI) were examined. Cr(VI) might be reduced by vitamin C not only in acidic conditions but also in weakly alkaline solutions. The reduction of Cr(VI) by vitamin C might occur not only under irradiation but also in the dark. Vitamin C is an important biological reductant in humans and animals, and not toxic. It is water-soluble and can easily permeate through various types of soils. The results indicate that vitamin C could be used in effective remediation of Cr(VI)-contaminated soils and groundwater in a wide range of pH, with or without sunlight.     

核桃壳过滤器与超滤对宁化排水的除油研究

采用核桃壳过滤器与超滤组合工艺的中试装置处理宁夏石化总排放水,考察了该工艺对石化废水中油分的处理效果,并且使用模拟废水考察了该工艺对油污染负荷的抗冲击能力.实验结果表明,核桃壳过滤器与超滤组合工艺对石化总排水中油以及油类造成的COD都有较好的处理效果,并且具备一定的抗污染冲击能力.