Effects of alumina refinery wastewater and signature metal constituents at the upper thermal tolerance of: 1. The tropical diatom Nitzschia closterium

Ecotoxicological studies, using the tropical marine diatom, Nitzschia closterium (72-h growth rate), were undertaken to assess potential issues relating to the discharge from an alumina refinery in northern Australia. The studies assessed: (i) the species’ upper thermal tolerance; (ii) the effects of three signature metals, aluminium (Al), vanadium (V) and gallium (Ga) (at 32 °C); and (iii) the effects of wastewater (at 27 and 32 °C). The critical thermal maximum and median inhibition temperature for N. closterium were 32.7 °C and 33.1 °C, respectively. Single metal toxicity tests found that N. closterium was more sensitive to Al compared to Ga and V, with IC₅₀s (95% confidence limits) of 190 (140-280), 19,640 (11,600-25,200) and 42,000 (32,770-56,000) μg L⁻¹, respectively. The undiluted wastewater samples were of low toxicity to N. closterium (IC₅₀s > 100% wastewater). Environmental chemistry data suggested that the key metals and discharge are a very low risk to this species.     

Toxicity Assessment by Microtox® in Sediments,Pore Waters and Sediment Saline Elutriates in the Gulf of Gdansk (Baltic Sea)

The toxicity of sediments in the Gulf of Gdansk is analyzed in relation to the chemical composition of interstitial and near‐bottom waters, and sediment properties. The toxicity of sediments, pore waters and saline elutriates is determined by using the Microtox® test based on changes in light production of the luminescent bacteria Vibrio fischeri. The results indicate considerable toxicity in the majority of examined sediments. Since the sediment elutriates and pore waters are toxic in some cases, the total toxicity of the sediments is likely to be due to both sediment‐bound and water soluble substances. The sediment toxicity is related to the percentage contribution of the fine fraction of sediments. A significant correlation between the toxicity of the sediments and the black carbon content implies anthropogenic contamination. The toxicity of the sediments is seen to increase with the increase of hydrogen sulfide concentration in pore waters. The ammonia in pore waters was found not to be responsible for the toxicity of the sediments.     

Synthesis of Calix(aza)crown and its Oligomeric Analogue for the Extraction of Selected Metal Cations and Dichromate Anions

The present study reports the synthesis of a novel ionophore, calix[4]azacrown ( 5 ) bearing two amino groups at the lower rim along with its oligomeric analogue ( 6 ). The liquid‐liquid extraction properties of these compounds towards selected metal cations and dichromate anions have been evaluated. It is observed that ( 5 ) and ( 6 ) are good extractants for the selected metal cations. However, in the case of dichromate anion, only species ( 5 ) shows remarkable extraction properties at low pH, whereas species ( 6 ) shows poor extraction behavior. The results have importance especially in wastewater treatment to obtain environmentally safe industrial effluent and they should also assist supramolecular chemists in designing and synthesizing more sophisticated host molecules for the removal of toxic pollutants.     

Dry separation of respirable lunar dust: Providing samples for the lunar airborne dust toxicity advisory group

In order to study the toxicity of lunar dust, the respirable size fraction of lunar soil needed to be separated with an apparatus that possesses the following capabilities: no use of liquid; fully recoverable sample; and use of only small sample quantities (<1 gm). We report the design of a simple apparatus that meets these requirements and implements an inertial-impaction mechanism established in aerosol science. Lunar soil was agitated at a frequency of 100 Hz using a vibration table with a containment chamber under a constant air flow. The air flow carried the lofted lunar dust particles past four impactors (four T-junction connectors), upon which a fraction of large particles were captured during the impaction. The fine particles in the air flow were then collected by an end-of-the line membrane filter. Detailed examination of particles on the filter showed that the majority (∼80-90 wt%) are <3 μm (geometric diameter), suggesting a high level of effectiveness for the apparatus.     

Observations on impaired vitality of Unio crassus (Bivalvia: Najadae) populations in conjunction with elevated nitrate concentration in running waters

A number of publications show relationships between impairment of vitality and reproduction as well as excessive shares of aged individuals within populations of Unio crassus with nitrate concentrations in the field. Our own examination of available data on nitrate concentrations in selected rivers of Brandenburg with known remainder populations of Unio crassus and of rivers without that species confirmed that above 2 mg L^–1 NO₃^–‐N Unio crassus populations are impaired. Current toxicity data on nitrate do not indicate any mechanism by which the observations can be explained. Probably high NO₃^–‐N concentrations and the impaired production and vitality of Unio crassus populations share the same causes. These need to be identified.     

Rapid detection of bioavailable heavy metals in sediment porewaters using acid-volatile sulfide gel probes

The acid-volatile sulfide (AVS) pool in anoxic sediments is believed to play an important role in the sequestration of heavy metals, forming less soluble mineral sulfides via replacement and coprecipitation reactions. In this study, novel sediment gel probes containing immobilized FeS or MnS particles were evaluated for their ability to concentrate and detect reactive heavy metals in solution. MnS-containing gels were more effective than FeS gels at concentrating most metals in solution external to the gels, but they were more difficult to prepare and use. Copper reacted with FeS in gel probes to form one or more secondary sulfide minerals insoluble in 1 N HCl. The pixel density of digital images of these gels was highly correlated with the concentration of copper in gels and total copper in solution, suggesting a method for rapid screening of bioavailable heavy metals. Copper added to Youghiogheny River (PA, USA) sediments could be detected using this approach.     

Changes of Acute Toxicity of Organic Chemicals to Daphnia magna in the Presence of Dissolved Humic Material (DHM)

With a series of substituted anilines, a series of substituted phenols as well as diazinon and tetrabromobisphenol-A alterations of short-term acute toxicity to the waterflea Daphnia magna have been studied in the presence of dissolved humic material (DHM). The results may be categorised as follows: No alteration in acute toxicity occurred with: tetrabromobisphenol-A, o-toluidine, 3,4-dichloroaniline, and pentachlorophenol. Toxicity decreases significantly with: diazinon, 4-chloroaniline, and 4-nitrophenol. Significant toxicity increases were observed with 2,4-dichlorophenol and 2,4,5-trichlorophenol. As demonstrated for diazinon, our study reveals that in the presence of DHM and light the chemical speciation of this chemical is altered and daughter products are produced most likely via photoactive species of DHM. Most probably the toxicity of both the parent and daughter compounds is changed as well. Alterations in acute toxicity of organic chemicals may thus be attributed to the adsorption to DHM as well as to the photoactive species mediated production of daughter products with toxicity different from that of the parent compounds.     

Anwendung von biologischen Testverfahren an Abwässern der Textilindustrie

Testing Effluents of the Textile Refining Industry with Biological Methods The environmental problems caused by the manufacture of finished textiles involve a long chain of individual processes. This “textile chain” includes very diverse enterprises of varied size and structure. The textile refiners occupy a key position in the “textile chain”. On the one hand, this is due to their use of an obscurely large number of chemicals which can end up in the wastewater as well as in the textile products. On the other hand, this key role of the textile refining industry is based on their central position between the preproduction stage and the consumers. This study dealt with the textile refining industry's wastewater. As measured by volume and contents of its wastewater, this industry can be counted among the major industrial plants which discharge into municipal wastewater treatment plants. German wastewater legislation includes the provision that substances which are toxic, persistent, capable of accumulating, carcinogenic, fetotoxic or mutagenic be kept out of natural waters as well as technically possible (Wasserhaushaltsgesetz WHG). Several biotest methods for examining the effect of the substances contained in the wastewater were incorporated into the appendix of the German wastewater regulation (Rahmenabwasser-Verwaltungsvorschrift based on § 7a WHG). The aim of this study was to show, with the aid of biotest methods, how strongly the wastewater of textile refining companies is polluted as compared to other known industrial branches and to what degree the pollution of these wastewaters is eliminated by the treatment in wastewater treatment plants. Finally, we experimented to find out which biotest methods were suited for the examination of these wastewaters. The study's results show that the ecotoxicity of the textile refining industry's wastewater was only extraordinary high in isolated cases as compared to other examined branches of industry. The textile wastewaters exhibit values of G_L = 3 to G_L = 96 in the luminescent bacteria test, G_D = 1 to G_D = 192 (with one exception of G_D > 30000) in the daphnia test and G_F < = 2 to G_F = 32 in the fish test. It turned out though, that a large number of the samples from the textile refining companies (27%) reacted mutagenically in the Ames test in their native state. Consecutive tests for chromosomal aberrations (V79 hamster cell test) also showed mutagenic potential in five out of nine native samples. The employed testing methods with fish, daphnia and luminescent bacteria demonstrate a higher sensitivity of the luminescent bacteria and/or the daphnia as opposed to the fish in most cases. As the fish test is controversial anyway on the grounds of animal protection, a replacement of the fish test by these other tests should be aimed at: on account of the different end points of the luminescent bacteria and the daphnia test, a combination of these tests appears most sensible.     

Belastung von Krankenhausabwasser mit gefährlichen Stoffen im Sinne § 7a WHG

Contamination of Hospital Wastewater with Hazardous Compounds as Defined by § 7a WHG In total, 45 samples of hospital wastewater obtained from different origins (total wastewater, nursing, and laboratories) were investigated using chemical analyses as well as biological testing methods. In parallel, the consumption of several product groups relevant to the wastewater has been calculated. The water consumption strongly influenced the quality of the corresponding wastewater. Most of the values of the chemical parameters determined were found within a range as would have been expected for municipal wastewater. The AOX concentrations were distinctly elevated (0.41 mg/L in total wastewater and 0.95 mg/L in nursing wastewater). As could be shown by the calculated consumption of different compounds, the iodoferous X-ray contrast media represented a predominant proportion of the total AOX load of the clinical wastewaters tested. The values of some of the total wastewater samples and the laboratory wastewater samples showed a high toxicity as determined using the daphnia and luminescent bacteria tests. Using Ames and hamster cell tests, 5 out of 23 samples in the clinical area and 7 out of 9 samples from the laboratories turned out to be mutagenic. The origin of this mutagenic potential could not be determined though.     

Toxicity of Substances to Activated Sludge – Course of Inhibition Curves

A method is described for determining the course of inhibition curves substantiating the influence of some inorganic (Cr (VI)) and organic substances (phenol, synthetic tanning agents) on respiratory activity of heterogeneous biomass (activated sludge). Presented results prove that calculated inhibition curves have the course of a normal distribution function.