Evaluating peats for their capacities to remove odorous compounds from liquid swine manure using headspace “solid‐phase microextraction”

Abstract

This paper reports on research designed to investigate the capacities of different highly characterized peats to remove odorous compounds from liquid swine manure (LSM). Peat types representing a wide range of properties were tested in order to establish which chemical and physical properties might be most indicative of their capacities to remediate odors produced by LSM. Eight percent slurries (of peat/LSM) were measured for odor changes after 24 hours using odor panel and GC/MS‐Solid‐phase microextraction (GC/MS‐SPME) analysis.

The GC/MS‐SPME and odor panel results indicated that, although all peats tested in this study were found to be effective at removing odor‐causing compounds found in LSM, some peats tended to work better than others. Overall, the peats that were the most effective at removing odor‐causing compounds tended to have lower bulk densities, ash contents, fulvic acids contents, and guaiacyl lignins contents,and higher water holding capacities, hydraulic conductivities, “total other lignins”; contents, hydrogen contents, carbon contents, and total cellulose contents.

GC/MS‐SPME analysis was found to be a reasonably inexpensive and efficient way of conducting this type of research. It allows one to identify a large number of the odor‐causing compounds found in LSM, and more importantly, to detect with some precision specific differences in the amounts of these compounds between peat types.     

Fabric-filter-supported catalyst for removal of harmful solid and gaseous compounds in municipal waste incinerator exhaust gas: characteristics of NO x reduction

We have investigated a fabric-filter-supported catalyst for removing harmful solid and gaseous compounds simultaneously from municipal incinerator exhaust gas. We studied the ways in which the efficiency of NO _x removal is influenced by filter temperature, gas flow rate, and catalyst content. The reduction of the catalyst content by mechanical reverse washing was investigated, and the state of the catalyst supported in the fabric filter was also observed using a scanning electron microscope. The catalyst supported by the fabric filter showed a removal efficiency above 75% when the filter temperature was 200°C, the gas flow rate was 1 m/min, and the catalyst content of the fabric filter was above 300 g/m². The catalyst was supported uniformly on the fibers of the fabric filter, and fine catalyst particles remained on the fibers after mechanical reverse washing. Received: October 15, 1997 / Accepted: March 19, 1999     

利用声凝聚机理提高喷雾降尘效果的研究

本文论述了利用声凝聚机理提高喷雾降尘效果,特别是对呼吸尘的降尘效果的研究过程。由该机理建立了声波频率和声强与降尘效果之间的数学模型。在此数学模型的基础上,开展了对声波发生器和声学喷嘴的研究。实验及使用结果表明,声学喷嘴可以显著提高对呼吸尘的降尘效果。     

吸附法处理含铬废水的研究

天然沸石、膨润土基材经镁铝等修饰并活化而制的ＦＭＡ，ＢＭＡ吸附剂处理含铬废水，铬的去除率可达９９％。     

人工湿地-氧化塘工艺组合对氮和磷去除效果研究

本文在小试规模上，研究了下行流湿地、推流床湿地、氧化塘和兼性塘四种处理单元的四种工艺组合对氮、磷的去除效果，研究结果表明：下行流湿地 氧化塘工艺组合具有较好的充氧效果，推流床湿地后置也可以提高出水的溶解氧。四种工艺组合对离子和TP、IP的去除无显著差异。人工湿地中硝化作用的发生有利于NH^ 4f-N的去除，增加氧化塘可以提高系统的硝化能力，但同时也会增加出水中的N0^-3-N浓度。     

高铁酸盐在水和废水处理中的应用进展

本文综述了高铁酸盐用于饮用水的消毒、杀菌、除藻，有机废水的氧化混凝，恶臭物质的氧化去除，重金属离子及放射性废水的混凝沉淀，以及色度浊度的去除等领域的最新进展。并对今后的研究进行了展望。     

LONG-TERM EQUILIBRIUM PHOSPHORUS CONCENTRATIONS IN THE EVERGLADES AS PREDICTED BY A VOLLENWEIDER-TYPE MODEL1

ABSTRACT: Anthropogenic phosphorus loading, mainly from the Everglades Agricultural Area (EAA), is believed to be the primary cause of eutrophication in the Everglades. The state of Florida has adopted a plan for addressing Everglades eutrophication problems by reducing anthropogenic phosphorus loads through the implementation of Best Management Practices (BMPs) in agricultural watersheds and the construction of stormwater treatment areas (STAs). Optimizing the effectiveness of these STAs for reducing phosphorus concentrations from agricultural runoff is a critical component of the District's comprehensive Everglades protection effort. Therefore, the objective of this study was to develop a simple tool that can be used to estimate STAs’performance and evaluate management alternatives considered in the Everglades restoration efforts. The model was tested at two south Florida wetland sites and then was used to simulate several management alternatives and predict ecosystem responses to reduced external phosphorus (P) loadings. Good agreement between model predictions at the two wetland sites and actual observations indicated that the model can be used as a management tool to predict wetlands’response to reductions in external phosphorus load and long-term P levels in aquatic ecosystems. Model results showed that lowering P content of the Everglades Protection Area (EPA) depends on reducing P loads originating from EAA discharges, not from rainfall. Assuming no action is taken (e.g., no BMPs or STAs implemented), the steady state model predicted that the average concentration within the modeled area of the marsh would reach 20 μg L^?1 within five years. With an 85 percent reduction in P loading, the steady-state model predicted that Water Conservation Area 2A (WCA-2A) P concentration will equilibrate at approximately 10 μ L^?1, while elimination of all loadings is projected to further reduce marsh P to values less than 10 μg L^?1.     

改性氢氧化钙粉体的研制及其特性

介绍了作为氯气清除剂的粉体应具有的特性,并对粉体的研制方法进行了简单叙述。同时,对改性氢氧化钙粉体特性作了详细介绍。不难看出,研制的改性氢氧化钙粉体具有高度活性,与氯气捕消器配合使用,将成为氯气泄漏时的抢险措施     

OPTICAL CHARACTERISTICS OF NEW ZEALAND RIVERS IN RELATION TO FLOW1

ABSTRACT: Six years (1989–1994) of data from New Zealand's National Rivers Water Quality Network were used to characterize the optical water quality regime of river waters as regards: visual clarity (black disc visibility), turbidity, and light-absorbing aquatic humic material (referred to as ‘yellow substance,’ measured as light absorption at 440 nm). Quantitative relationships between optical water quality variables and flow in rivers are well-described by power law expressions. Visual clarity usually decreases strongly with increasing flow in individual rivers. There is a strong, inverse relationship between turbidity and visibility, but, because of differences between sites, turbidity is not a good general predictor of visual clarity (the attribute of real interest) in rivers. Yellow substance tends to increase with increasing flow, probably because during rainstorms, soil water high in yellow-colored humic material, rather than rain water or ground water, dominates discharge. Therefore, rivers are typically clear and low in humic matter at low flow, and turbid and yellow-colored at high flow.     

磨料水射流除鳞技术在钢厂的应用

为了暴露各种钢材在热轧过程中产生的表面缺陷，需清除附于其上的氧化铁皮，称之为“除鳞”。传统的除鳞方法有酸洗、表面剥皮、喷丸处理等，这些方法存在很多缺点。本文介绍已在湖南涟钢用于生产的磨料水射流除鳞生产线，用磨料水射流除鳞具有速度快、质量高、成本低、操作简便等独特的优点。