Protozooplankton in the Deep Oligotrophic Traunsee (Austria) Influenced by Discharges of Soda and Salt Industries

Traunsee is a deep oligotrophic lake in Austria characterised by an artificial enrichment of chloride in the hypolimnion (up to 170 mg L^-1) caused by waste disposal of soda and salt industries. Protists were collected monthly over one year, observed alive and after Quantitative Protargol Staining (ciliates) or via epifluorescence microscopy (heterotrophic flagellates). Three sites within the lake (0–40 m depths) were compared to deeper water layers from 60–160 m depths where chloride concentrations and conductivity were increased. In addition, we observed the protozooplankton of two neighbouring lakes, i.e. reference systems, during one sampling occasion. In Traunsee the abundance of ciliates was low (200–36 600 cells L^-1) in contrast to high species diversity (at least 60 different species; H_S = 2.6) throughout the year. The main pelagic species in terms of abundance were small oligotrichs and prostomatids like Rimostrombidium brachykinetum/hyalinum, Balanion planctonicum and Urotricha spp. throughout the investigation period. Among free-living heterotrophic flagellates, which occurred at densities of 40–2800 cells mL^-1, small morphotypes dominated in the pelagial. No differences at the community level between the three lakes could be observed and pelagic ciliates and flagellates seemed not to be affected by increased chloride concentrations or by enhanced conductivity.     

高温堆肥法处理污泥的探讨

对于污水处理后所产生的污泥,较好的方法是采用无害化、资源化农用技术,利用污泥为原料,制成有机复合肥,不仅解决了污水污泥的处理问题,还可推动环保产业的发展,促进农业生产,具有明显的经济、社会和环境效益。     

城市污水厂污泥浓缩新技术的应用

分析了新型污泥浓缩设备的技术经济优点,现行污泥浓缩池的缺点、城市污水处理新工艺对浓缩的要求,介绍了2类污泥浓缩机在城市污水厂的选用和运行实例.     

EFFECTS OF SLUDGE AND CHEMICAL FERTILIZER APPLICATION ON RUNOFF WATER QUALITY1

ABSTRACT: Simulated rainfall was used on experimental field plots to compare the effect of chemical fertilizer and sludge application on sediment, nitrogen, and phosphorus in runoff from no-till and conventional tillage systems. Chemical fertilizer application under the no-till system resulted in the least amount of total N and P in surface runoff. However, sludge application under the no-till system resulted in the least amount of NO₃-N and sediment in surface runoff. The worst water quality scenarios were observed when either sludge or chemical fertilizer were surface-applied under a conventional tillage system. Nitrogen losses from the conventional tillage system were minimized when sludge was incorporated into the soil. However, phosphorus and sediment yield from such a system were significantly higher when compared to phosphorus and sediment yield from the no-till system. The results from this study indicate that the use of sludge on agricultural land under a no-till system can be a viable alternative to chemical fertilizer for nitrogen and phosphorus control in runoff. A more cautious approach is recommended when the sludge is incorporated into the soil in a conventional tillage system because of potential for high sediment and phosphorus yield in surface runoff.     

FACTORS THAT AFFECT ACTIVATED SLUDGE PHOSPHATE RELEASE1

The activated sludge process can remove significant amounts of phosphorus from sewage, but the removal efficiency is usually significantly reduced by the release of phosphate back to solution during subsequent treatment steps. This research presents a study of soluble phosphate release from activated sludge with emphasis on defining the factors that affect such release and the actual release mechanisms. Laboratory units were used for experimental purposes. The experiments were designed to study the relationship between soluble phosphate release and various environmental factors such as redox potential (ORP), dissolved oxygen (DO), pH, solids concentration, solids destruction, and sulfate salt addition. The effect of substrate utilization on phosphate uptake and the relationship between uptake characteristics and subsequent phosphate release were also studied. The results show that some phosphate storage occurs during aerobic substrate utilization. Following substrate utilization, activated sludge phosphate release is directly related to the amount of biological stress the organisms are subjected to, and the mechanism of release is primarily cell lysis. The phosphate released per unit sludge under anoxic conditions is relatively constant. Under normal environmental conditions, neither ORP or pH change have a significant affect on phosphate release.     

微好氧颗粒污泥工艺降解五氯酚的实验研究

微好氧颗粒污泥工艺能够同时进行好氧氧化和厌氧还原过程，是处理五氯酚（PCP）的理想方法。对影响好氧颗粒污泥降解PCP的因素水力学上升流速、碱加入量以及水力停留时间进行考察。结果表明，水力学上升流速为4.58m／h，进水NaHCO3浓度为900mg／L，水力停留时间为24h时，处理效果比较好。     

Reusability of sewage sludge in clay bricks

Bricks produced from sewage sludge in different compositions were investigated. Results of the tests indicated that the sludge proportion is a key factor in determining the brick quality. Increasing the sludge content results in a decrease in brick shrinkage, bulk density, and compressive strength. Brick weight loss on ignition was mainly due to the contribution of the contained organic matter from the sludge being burnt off during the firing process, as well as inorganic substances found in both clay and sludge. The physical, mechanical, and chemical properties of the bricks that were supplemented with various proportions of dried sludge from 10 to 40wt% and generally complied with the General Specification for Brick as per the Malaysian Standard MS 7.6:1972, which dictates the requirements for clay bricks used in walling in general. A standard leaching test method also showed that the leaching of metals from the bricks is very low.     

The composting potential of different organic solid wastes: experience from the island of Crete

For the past 20 years, the National Foundation for Agricultural Research in Crete and the School of Agricultural Technology of the Technological and Educational Institute of Crete have been involved in a number of research and development activities, related to the production and evaluation of compost derived from a variety of local solid, mainly agricultural organic wastes. Materials such as olive press cake, olive tree leaves (OTL) and branches, vine branches (VB), pressed grape skins (PGS), pig manure (PM), sewage sludge and the organic fraction of municipal solid waste (OFMSW) have been evaluated for their behaviour during composting, their compatibility in mixtures and the quality of the end product. The quality evaluation included both a detailed physiochemical (pH, electrical conductivity (EC), nutrients concentration, heavy metal concentration, etc.) and biological analyses (pathogenic microorganisms). It also included an agronomic evaluation, in which composts were used either as a soil amendment or as a component for substrates in open air or covered (greenhouse) cultivation mainly of local vegetables (tomatoes, cucumbers, etc.). All materials were composted successfully, especially when mixed. The end products contained large amounts of organic matter, usually combined with an increased EC value. Pressed grape skins should be considered as the ideal raw material, producing a high quality compost, with the lowest EC value (1.57 mS cm(-1)) and the largest organic matter concentration (84.50%), compared to all other materials. When any of the produced compost was used in a ratio of 30% by volume (v/v), it increased plant growth, whereas in larger volumes, it presented phytotoxic behaviour, inhibiting both root and shoot development.     

东涌工业污水处理站污泥处置方法的研究和探讨

本文通过番禺区东涌工业污水处理站污泥特性和污泥堆肥技术的研究,提出了污泥堆肥的可行性,并用之于实践,变废为宝,解决了污泥的处置问题.     

国内外油田含油污泥处理技术

通过对国内外各种含油污泥处理工艺技术的调查分析和对比,提出了适合国内实际的含油污泥处理技术方案。以离心分离技术为核心,辅之以调质、倾析等多种预处理技术和高温裂解、生物处理等后续处理技术的污泥综合处理工艺,适于我国现阶段的含油污泥处理。