Summary of 25 Years of Xylem Tracheids and Sewage/Sludge in the Sea

The Rapid Sewage/Sludge Indicator Technique (RSIT), developed during the early 1970′s, responded to critical needs within the Bureau of Water Pollution Control. It enabled quick detection of contamination in ocean water and bottom sediments during sewage-related emergencies and routine monitoring. RSIT became an invaluable tool for resource management, in determining where and to what extent marine environments are impacted, and when immediate information is necessary for public health decisions.

The RSIT utilizes microscopic examination for terrestrial plant vascular tissue, especially the xylem tracheid elements, as identifiers of sewage/sludge. Not normally found in ocean waters, this material, in toilet paper and the roughage of the human diet which passes through the digestive system intact, is an indicator of human faecal contamination. Minimal training and common laboratory materials allow gross screening in five minutes. New studies by the United States Environmental Protection Agency (USEPA), United States Geologic Survey (USGS) and National Oceanic and Atmospheric Administration (NOAA), most recently at the 106-mile dump site off the New York Bight, revalidated the technique as a rapid, inexpensive, easy to use, semiquantitative indicator both for water column and sediment samples.     

Capacity to Influence Sources of Heavy Metals to Wastewater Treatment Sludge

Wastewater treatment sludge contains valuable nutrients, yet represents a residue problem due to the amount of heavy metals, which is one of the factors preventing the use of sludge as fertilizer. In Sweden, the government has a declared aim of closing the ecocycles of nutrients to arable land, while at the same time the existing limit values are among the lowest in the world. This paper focuses on the opportunities for Swedish wastewater utilities (WWUs) to manage and reduce sources of heavy metals in order to get sludge approved and recycled. A case study focusing on sources of the heavy metals Cd, Cu, Hg, Ni, Pb, and Zn and the WWUs ability to influence the source by means of existing regulations was traced and categorized. A substantial fraction of the heavy metals were shown to be caused by diffuse emissions, such as the use of goods and products in society. For most sources discussed in the paper, a WWU can only manage the sources to a limited extent, if at all. This study shows that the WWUs cannot manage both recycling of nutrients and a decrease in heavy metals ending up in sludge. Diffuse emissions of heavy metals must be examined in context, not as a separate phenomenon or an issue for a single actor. The existing environmental legislation does not handle diffuse sources, yet long-term strategies for reducing the emissions to wastewater treatment must involve the reduction of diffuse emissions.     

Bioremediation of Soil Degraded by Sewage Sludge: Effects on Soil Properties and Erosion Losses

Soils in the Mediterranean area are very prone to erosion due to the loss of organic matter and the consequent lack of protective vegetation. In this experiment a Mediterranean degraded soil with a 15% slope was amended at a rate of 250 t ha^–1 wet weight with sewage sludge and with a mixture of sewage sludge and barley straw (70% carbon from sewage sludge and 30% from the straw) in order to study their influence on soil structure recovery and hence the soilss resistance to erosion processes. Both types of organic amendment led to an improvement in several soil properties (physical, biological, and microbiological) as a result of the spontaneous growth plant covering that became evident three months after amendment. This vegetation remained throughout the two years of the experiment and prevented the water erosion processes that normally precede soil degradation. Amendment by sewage sludge alone reduced soil loss by 80% compared with the control soil, while the mixture that included both sewage sludge and barley straw reduced losses by 84%, both reducing runoff by 57%. The amended soils showed increases in the percentage of stable aggregates, the levels of the total and water-soluble C fractions, microbial biomass C, basal respiration, and the activity of the different enzymes involved in the biogeochemical cycles of C, N, and P. The results confirm the usefulness of sewage sludge as an organic amendment for recovering damaged soils.     

Toxicity of copper in sewage sludge

Sewage sludge is a source of organic matter and nutrients, but a major obstacle for its recycling is that the municipal wastewater sludge has low but significant levels of contaminants. This investigation, on the acute toxicity of copper in sewage sludge, was conducted with three organisms, Daphnia magna, Lemna minor and Raphanus sativus (seeds). The toxicity of the leakage water from sewage sludge spiked with CuSO(4) was studied for 64 days. The toxicity increased during the first 8-16 days and then started to decrease. The first increase in toxicity was due to ammonia, but after 32 days, a dose-related effect of copper was found. After 64 days, L. minor had an EC50 of 3800 mg Cu/kg dw for 7 days growth inhibition, a LOEC of 3200 mg Cu/kg dw and a NOEC of 1600 mg Cu/kg dw. D. magna had an EC50 of 18100 mg Cu/kg dw (24-h immobility) and a NOEC of 12800 mg Cu/kg dw. Root elongation of R. sativus was reduced at 25600 mg Cu/kg dw. Both for Daphnia and Lemna, the pH of the leakage water had an effect of the toxicity. This means that chemical speciation and bioavailability is very important for the hazard assessment of copper in sludge and soil.     

洁净技术在广播发射台的应用

提出了我国目前广播、电视发射机房存在的一‘些问题,介绍了用亚高效过滤器处理广播、电视发射机房的空气净化问题,以及对发射机散热的处理方法。     

陆源排海污水生物毒性控制限值研究——以秦皇岛市为例

在枯水期和丰水期,对秦皇岛市15个典型入海排污口污水进行生物效应监测,选用发光细菌(费歇尔弧菌)、藻类(中肋骨条藻)、甲壳类(卤虫)、鱼类(海水青鳉幼鱼) 4种不同的生物毒性测试生物对污水进行短期急性毒性测试。结果表明:排海污水的毒性大小易受雨水稀释影响;海水青鳉幼鱼对污水最为敏感,其次为卤虫和中肋骨条藻,费歇尔弧菌敏感性最低。对排海污水毒性评估结果与理化指标的相关性分析进一步表明,仅仅依靠理化指标来评估污水的环境影响具有局限性。     

炼化污水处理过程中存在问题及应对措施

对炼油、化工废水治理生产实践进行研究与探讨，提出应对高浓度混合污水的处理方法，对各种影响治理的因素有针对性地采取应对措施，提高了污水处理抗冲击能力和治理效果，对实现长周期平稳运行具有积极意义。     

连续流序批式活性污泥法

连续流序批式活性污泥法是一种新型污水生物处理工艺，介绍了该工艺的结构组成、流程控制、生物脱氮除磷基本原理、自动化管理以及与其它处理工艺的比较。     

污泥上清液的有机物浓度及其生物降解性

在进行城市生活污水的生物处理过程中，会产生一定量的生化污泥。在浓缩和处理剩余污泥时，所产生的含高浓度有机物的污泥上清液被回流到污水处理系统，不适当的回流会增加水处理系统的负荷并严重影响，出水的水质。实验证明，在污泥浓缩中，污泥上清液中有机物含有与浓缩温度成ｅ指数关系，与浓缩时间成小于１的指数关系。     

城镇生活污水深度处理实验研究

采用SBR—化学混凝处理城镇生活污水,结果表明:经SBR处理后,废水中的COD、氮、磷得到很好的去除,最佳的混凝工艺条件为:废水pH7.30左右,聚合氯化铝钙用量20mg/L废水,搅拌强度120r/min,搅拌时间15min,加入PAM用量0.15mg/L废水。