HCI Sorption by Dry NaHCO3 for Incinerator Emissions Control

The sorption of hydrochloric acid (HCI) by thermally decomposed sodium bicarbonate (NaHCO₃) was investigated using a fixed-bed reactor containing sorbent particles dispersed in a bed of spherical glass beads. The gas flow rate (68° F and 760 mm Hg) was 0.039 cfm (1.1 liter/min) and the bed had a cross-sectional area of 0.0055 sq. ft. (5.1 sq. cm). The influence of particle diameter (10, 45 and 163 μm), temperature (225, 275, 375, 455, and 550° F), superficial gas velocity (11 and 21 fpm at reactor conditions, 375° F), and Inlet HCI gas concentration (415 ppm and 760 ppm in N₂, 275 and 455° F) were studied. Results showed that HCI sorption increased strongly with increasing temperature but was only weakly dependent on particle diameter, superficial gas velocity, and HCI gas concentration.     

Habitat and Biodiversity of On-Farm Water Storages: A Case Study in Southeast Queensland, Australia

On-farm water storages (locally known as farm dams or farm ponds) are an important part of many agricultural landscapes, as they provide a reliable source of water for irrigation and stock. Although these waterbodies are artificially constructed and morphologically simple, there is increasing interest in their potential role as habitat for native flora and fauna. In this article, we present results from a case study which examined the habitat characteristics (such as water physical and chemical parameters, benthic metabolism, and macrophyte cover) and the macrophyte and macroinvertebrate biodiversity of eight farm ponds on four properties in the Stanley Catchment, Southeast Queensland, Australia. Each landowner was interviewed to allow a comparison of the management of the ponds with measured habitat and biodiversity characteristics, and to understand landowners’ motivations in making farm pond management decisions. The physical and chemical water characteristics of the study ponds were comparable to the limited number of Australian farm ponds described in published literature. Littoral zones supported forty-five macroinvertebrate families, with most belonging to the orders Hemiptera, Coleoptera, Odonata, and Diptera. Invertebrate community composition was strongly influenced by littoral zone macrophyte structure, with significant differences between ponds with high macrophyte cover compared to those with bare littoral zones. The importance of littoral zone macrophytes was also suggested by a significant positive relationship between invertebrate taxonomic richness and macrophyte cover. The landowners in this study demonstrated sound ecological knowledge of their farm ponds, but many had not previously acknowledged them as having high habitat value for native flora and fauna. If managed for aquatic organisms as well as reliable water sources, these artificial habitats may help to maintain regional biodiversity, particularly given the large number of farm ponds across the landscape.     

SEEPAGE FLOW INTO FLORIDA LAKES1

ABSTRACT: Direct measurements indicate that subsurface seepage in the littoral zone contributed 17.5 and 2.0 percent of the total hydraulic inputs, respectively, to Lakes Conway and Apopka, Florida. Two variations of seepage measuring devices were evaluated and gave relative standard deviations of 7 and 24 percent. Measurement inaccuracies were minimized by using large diameter (0.9 cm ID) plastic tubing. For a given transect perpendicular to shore, flow patterns were reproducible over time. Seepage flows ranged from 0 to 112 1/m²-day and most were between 4 and 30 1/m²-day. The detection limit was about 0.2 1/m²-day for a one-hour collection period. Seepage occured primarily within 30 m of shore and generally decreased exponentially with distance from shore. The shape of the bottom profile influenced flow patterns; lake bottoms with steeper slopes had higher flows that were compressed within a narrower zone. After a short-term rain event at Lake Conway, seepage flows increased rapidly to 2.4 times the prerain flow for 1 h and decreased to near background within about 6 h.     

In vivo effects of deltamethrin on some biochemical parameters of carp (Cyprinus carpio L.)

Thein vivo effects of deltamethrin (DM) on the blood sugar level, the acetylcholinesterase (AChE, EC 3.1.1.7) activities of the blood serum and various organs (heart, liver and intestine), the lactate dehydrogenase (LDH, EC 1.1.2.3), glutamic-oxaloacetic transaminase (GOT, EC 2.6.1.1), and glutamic-pyruvic transaminase (GPT, EC 2.6.1.2) activities of the blood serum, the adenosine triphosphatases (EC 3.6.1.3; Na⁺/K⁺-ATPase and Mg²⁺-ATPase) activities of the erythrocyte plasma membrane and the catalase (EC 1.11.1.6) activity of the liver were examined throughout 96 h in adult carp (Cyprinus carpio L.) Two sublethal concentrations, 1.0 and 1.5 µg/l of deltamethrin, were used. All fish survived the experiment except one, in an aquarium containing 1.5 ppb of DM, which died after 72 h.The AChE specific activity was significantly inhibited in the heart and intestine after 96 h at both concentrations compared to that in the control animals (P<0.05, Student'st-test), while there was no detectable difference between the two treatment. At the same time there was no detectable change in the liver. In the serum, the AChE activity almost remained unchanged; the only significant decrease could be measured after 96 h at 1.5 µg/l deltamethrin concentration. The blood glucose content exhibited interesting changes: after 24 h fish exposed at 1 µg/l DM seemed to be stressed, although this increase was not significant. When these fish became used to the new conditions (in practice this meant the presence of DM), the glucose level decreased, especially after 72 h. At the same time the control animals kept in similar circumstances showed a small insignificant decrease. Meanwhile fish in aquaria containing 1.5 µg/l DM reacted to the treatment with an increased blood glucose level after 48 h, and this did not change until the end of the treatment. The Na⁺/K⁺-ATPase activity decreased in a dose-dependant manner, while Mg²⁺-ATPase was less affected. A small increase in LDH level was observed, indicating damage of different muscle tissues. However, this phenomenon appeared only with the small dosage after 24 h (P<0.05). It has to be mentioned that the individual values varied to a large extent among of the eight fish.The GOT activities of the serum increased during the treatment. However, significant changes were only expressed after 72 and 96 h at 1 µg/l DM concentrations (P<0.01 andP<0.05), and after a similar long treatment at the high dosage (P<0.05, 72 and 96 h). The GPT did not change significantly in aquaria containing 1 µg/l DM. The only larger increase was measured after 96 h at 1.5 µg/l DM concentration (P<0.05). The catalase activity in the liver of treated carp remained practically at the same level compared to that in control fish.All these changes (concerning the primary effects of this compound) demonstrate the effect of DM on different fish enzymes, at low concentrations under laboratory conditions, which might be useful in practice for biomonitoring using fish.