Acute toxic effects of organic effluents on Chironomus travalensis Kieffer (Chironomidae: Diptera)

The acute toxicity of abattoir and sewage effluents on Chironomus travalensis was determined in a 96?h static bioassay. The toxicity was undertaken in replicates using effluent concentrations between 5% and 100%. Determination of the physical and chemical parameters of both effluents was carried out. The abattoir effluent was toxic to the test organisms at different concentrations while the sewage effluent did not produce lethality. The 96?h LC₅₀ value of the abattoir effluent was 23%. The acute toxicity unit at 96?h was 4.3. To avoid the adverse effect of effluent waste to aquatic life, it is recommended that effluent waste needs to be channelled through normal treatment procedures in industrial and residential areas.     

Differential toxic response of Chironomus travalensis kieffer ( Chironomidae : Diptera ) to some industrial effluents

Acute toxicity testing of some industrial effluents (rubber (Rr), brewery (Br), and bottling (Bt)) on Chironomus travalensis (Diptera larvae) was determined at 96-h using a static bioassay technique. Effluent quality characterization revealed acidic pH values of 4.5 for Rr, 5.64 for Br, and 4.32 for Bt effluents. Tests were carried out in replicates between 10 and 100% effluent concentrations. Mortality rate rose progressively with increasing concentrations. Bt effluent was the most toxic with 96-h LC₅₀ of 61.5%, closely followed by Rr effluent with 96-h LC₅₀ of 87% and the least toxic was Br effluent with 96-h LC₅₀ of 90%.     

Attraction to prey and stimulus to attack in the predatory gastropod Urosalpinx cinerea

Urosalpinx cinerea (Say), accustomed to feeding on Balanus balanoides, were strongly attracted in a choice chamber by the effluents of B. balanoides and B. eburneus, were indifferent to the effluents of Crassostrea virginica, Crepidula fornicata and Mytilus edulis, and responded negatively to the effluent of their own species. Oyster drills from a population feeding on Crassostrea virginica were attracted to oyster effluent; when these snails were offered a choice between Crassostrea virginica and B. balanoides effluents, they responded in equal numbers to the two effluents. Concentrations of NH₄Cl-ammonia in the range 18.2 to 73.3 mol did not attract the snails, and their responses to animal effluents were not correlated with the ammonia and amino-acid concentrations of the effluents, which ranged from 11.8 to 21.0 mol. It is argued that these results deny ammonia the role of a nonspecific distance attractant. Confined separately with various potential prey species, Urosalpinx drilled Balanus balanoides, B. eburneus, Crassostrea virginica, Crepidula fornicata, C. plana, Mercenaria mercenaria, Modiolus demissus, Mya arenaria, Mytilus edulis, Spisula solidissima, and Yoldia limatula, but not Anomia simplex. The prey species that were the least attractive in running water were generally rendered attractive and subject to attack in standing water. Freshly shucked Crepidula fornicata shells were scarcely drilled unless continuously perfused by C. fornicata effluent, and then only in small numbers. Altering the texture of living C. fornicata shells by wrapping them in nylon netting, by polishing, or by roughening, did not make them immune to drilling. Oyster drills in contact with C. fornicata attacked only if they received the effluent of the living prey, proving that tactile stimuli alone are not adequate to induce drilling.     

Bioremediation of shrimp biofloc wastewater using clam,seaweed and fish

The aim of this study was to evaluate the bioremediation of effluents in the biofloc culture of shrimp juveniles using clams, seaweed and fish. Four treatments were considered: CLT – without bioremediating organisms; AB – using Anomalocardia brasiliana; GB – using Gracilaria birdiae and ON – using Oreochomis niloticus with 2.5?kg wet weight per m³ of shrimp effluent. In the AB treatment, significant differences were observed in the effluent at the end of the experiment (96?h) for values of nitrite-nitrogen, nitrate, alkalinity, TSS and orthophosphate. The ISS and VSS levels recorded for the AB treatment varied respectively from 336 to 127?mg?L^?1, and from 505 to 130?mg?L^?1, with a corresponding gradual reduction of approximately 62% and 74% at the end of the experiment. The use of a clam species to treat effluents in a biofloc system with salinity near 25?g?L^?1 reduced waste solids and increased the nitrification process from 72 to 96?h, indicating that this clam can be used as a bioremediator and contributes to effluent treatment in shrimp.     

Organics in wheat and rye straw pulp bleaching and combined mill effluents (II) ecotoxicological screening

Potential environmental effects of the discharge of industrial wastewater from manufacturing of bleached straw pulp have been studied. Bleached neutral sulphite straw pulping results in discharges of both black cooking and spent bleaching liquors. Time proportional samples were taken from the combined bleaching effluent and the combined mill effluent, (i) Mutagenic activity of the two samples in an Ames’ test, and (ii) acute toxicity of the combined mill effluent sample towards the photosynthetic activity of natural marine phytoplankton from the receiving waters were determined. Also, acute toxicity was determined of the slowly biodegradable or persistent organics remaining after aerobic stabilization of the sample towards (ii) photosynthetic activity of natural phytoplankton, (iii) mussels (Mytilus edulis), (iv) eels (Anguilla anguilla) and, (v) crustacean (Nitocra spinipes); and furthermore, (vi) reproduction test of the crustacean and (vii) growth inhibition test of the marine diatom (Phaeodactylum tricornutum) were performed. Mutagenicity emission factors (MEF's) and toxicity emission factors (TEF's) were calculated to classify the effluents. Combined mill effluent sample showed a mutagenic activity per t₉₀ of one fourth the activity of a kraft pulp bleaching effluent, and the inhibition of the photosynthesis of natural phytoplankton was significant up to 2600 times dilution. After aerobic stabilization, inhibition was observed up to 400 times dilution. Other effects of the combined mill effluent sample were only significant below 40 times dilution. The bleaching effluent showed a mutagenic activity per t₉₀ comparable to kraft bleaching effluents. Other effects were only significant below 20 times dilution.     

The response of Gymnodinium breve to municipal waste materials

The response of the unarmored dinoflagellate Gymnodinium breve, which is the causative organism in catastrophic fish kills along the Florida Gulf coast, to enrichment with selected inorganic nutrients, municipal waste materials, and various detergent components has been determined. The biostimulatory effects of the various enrichments were determined by a modification of the Provisional Algal Assay Procedure of the Joint Industry/Government Task Force on Eutrophication. Inorganic nutrients (orthophosphate, nitrate, and ammonia) were added individually and in combination, and the results were compared to equivalent enrichments with the effluent from a secondary sewage-treatment plant. The maximum cell population, Nmax, attained could be increased 3-fold by the sew-age-treatment plant effluent or by the equivalent combination of inorganic nutrients; individually, however, the inorganic nutrients had no pronounced effect on maximum cell population, Nmax (except for a 30% increase produced by slight orthophosphate enrichment). The results of these studies indiccate that, at concentrations of orthophosphate typical of Florida coastal waters (ca. 0.10 ppm), the growth-promoting potential (as reflected by Nmax) of the medium was a linear function of the ammonia-nitrogen concentration (0.01 to 0.11 ppm). The sewage-treatment plant effluent was presumably low in detergent phosphate, having been obtained from a treatment plant some 6 months after the enactment of a ban on phosphate-containing detergents. Additions of orthophosphate or detergent-phosphate to the treatment-plant effluent did not significantly increase the observed biostimulatory effect of the waste material.     

Application of eggshell waste for the immobilization of cadmium and lead in a contaminated soil

Liming materials have been used to immobilize heavy metals in contaminated soils. However, no studies have evaluated the use of eggshell waste as a source of calcium carbonate (CaCO₃) to immobilize both cadmium (Cd) and lead (Pb) in soils. This study was conducted to evaluate the effectiveness of eggshell waste on the immobilization of Cd and Pb and to determine the metal availability following various single extraction techniques. Incubation experiments were conducted by mixing 0–5% powdered eggshell waste and curing the soil (1,246 mg Pb kg^?1 soil and 17 mg Cd kg^?1 soil) for 30 days. Five extractants, 0.01 M calcium chloride (CaCl₂), 1 M CaCl₂, 0.1 M hydrochloric acid (HCl), 0.43 M acetic acid (CH₃COOH), and 0.05 M ethylendiaminetetraacetic acid (EDTA), were used to determine the extractability of Cd and Pb following treatments with CaCO₃ and eggshell waste. Generally, the extractability of Cd and Pb in the soils decreased in response to treatments with CaCO₃ and eggshell waste, regardless of extractant. Using CaCl₂ extraction, the lowest Cd concentration was achieved upon both CaCO₃ and eggshell waste treatments, while the lowest Pb concentration was observed using HCl extraction. The highest amount of immobilized Cd and Pb was extracted by CH₃COOH or EDTA in soils treated with CaCO₃ and eggshell waste, indicating that remobilization of Cd and Pb may occur under acidic conditions. Based on the findings obtained, eggshell waste can be used as an alternative to CaCO₃ for the immobilization of heavy metals in soils.     

A homogeneous and low-cost biosorbent for Cd,Pb and Cu removal from aqueous effluents

Heavy metal pollution of aqueous effluents is a matter of widespread concern. The use of low-cost materials for the adsorption of heavy metals seems to be a suitable choice for waste water treatment. Polyporus tenuiculus, easily cultivated on lignocellulosic waste, was assayed for Cu, Pb and Cd removal from aqueous solutions. Pb was removed more efficiently. Kinetics studies suggested a pseudo-second-order reaction and equilibrium was reached in ～ 30 min in all cases. The metal-sorption data were analysed according to several two-parameter isotherms. Data better fitted the Langmuir model for the three metals. A great dependence of metal adsorption with pH was observed. Characterisation of both the biomass and the complex metal-biomass was performed by FT-IR and SEM-EDX. Results suggest an ion exchange mechanism.     

Etude des modifications du métabolisme respiratoire de populations d'Acartia clausi (Crustacea: Copepoda) après passage dans le circuit de refroidissement d'une centrale thermo-électrique

The respiratory metabolism of the copepod Acartia clausi, the most abundant species of zooplankton in the area investigated (Gulf of Fos, Mediterranean Sea, France) was studied at different temperatures during an annual cycle. Copepods were collected from three different stations: first the intake area, where sea water was pumped into the cooling circuit of a power plant; second, the outlet area of this circuit, where the heated effluents were discharged with an average t of 6°C; third, a small protected bay directly influenced by the flow of the heated waters. Seasonal variations in respiration intensity were observed, with a spring maximum. Specimens collected from the heated effluents exhibited comparatively reduced metabolism. Q₁₀ varied with temperature and time of year, suggesting seasonal regulation of metabolism. Except in March, where metabolic curves differed markedly according to the origin of the sample (species from the heated effluents displaying a metabolic curve of the summer type), the principal difference in shape of the respiration-temperature curves appeared in the range of 10° to 14°C, where reduced respiration was observed in specimens from the heated effluents. When A. clausi from external areas were exposed to artificial thermal stress, they displayed a respiratory metabolism pattern similar to that of specimens sampled from the heated effluents. Experiments performed with warm-acclimated copepods revealed respiratory modifications similar to those observed in copepods from the heated effluent. These results are discussed in relation to the thermal conditions prevailing at the investigated site.

---

---

Ces recherches ont été effectuées dans le cadre d'un contrat de recherche financé par l'E.D.F. (Electricité de France) pour l'année 1975.     

Environmental fate of pesticides used in Australian viticulture IV. Aqueous stability of dithianon

Dithianon formulations are unstable in slightly basic aqueous solutions (pH 9, 20°C, t _½ = 5.6 h) but relatively stable in neutral or acidic solution (pH 4,20°C, t _½ = 6443 h). To ensure the efficacy of this fungicide it is important to prepare the spray mix fresh with neutral or slightly acidic water. Dithianon is unstable towards natural sunlight in the solid and aqueous phase, with half‐lives of approximately 68 and 42 days, respectively. Thermal hydrolysis does not seem to be the preferred degradation pathway when aqueous solutions are heated by the South Australian summer sun. The major aqueous phase photodegradation product has been identified as 2,3‐dihydro‐1,4‐dithiaanthraquinone. These results strongly suggest that should dithianon be accidentally released into basic Australian waters then it is likely to be rapidly chemically hydrolysed and pose little long term environmental threat. However, dithianon is only slowly chemically and photo‐lytically hydrolysed in neutral and acidic waters, and in this case accidentally release may pose a significant short term environmental threat.     

Changes in the level of transaminases in Indian major carp, Labeo rohita exposed to sublethal concentration of tannery and distillery effluents

The activity of alanine aminotransferase (ALAT) and aspartate aminotransferase (AAT) of different tissues of fingerlings of Labeo rohita under the influence of two effluents has been studied. The alanine aminotransferase activity was increased over the control in different exposed periods of tannery and distillery effluent treatments. The alanine aminotransferase in the liver showed increased activity at different periods than that of the muscle, kidney, gill and brain (p < 0.001) (60.09%) over the control during the 40 days exposure in both the effluents treatments. The increased activity of alanine aminotransferase was highly significant (p > 0.001) in all the tissue in tannery and distillery effluents treatments. Similarly aspartate aminotransferase activity was increased over the control in all the treated tissues from 10 to 40 days exposure. But this increase, was not significant in the muscle tissue in distillery and tannery treatements after 10 days exposure. From 10 to 40 days, the activity was increased but a maxmum elevation was observed during 40 days, where the elevation was more in the liver, which was followed by muscle, kidney, gill, brain (brain < gill < kidney < muscle < liver).     

Up to 95 % reduction of chemical oxygen demand of slaughterhouse effluents using Fenton and photo-Fenton oxidation

Meat industries produce effluents containing high concentrations of organic and inorganic compounds, which must be removed before being discharged or reused. Advanced oxidation processes using Fenton reaction coupled with UV, solar radiation, and electrochemical oxidation are promising methods. Here, we treated the effluent from an anaerobic digester using: (a) the photoelectro-Fenton process, using a system with a Ti-RuO₂ anode and a carbon felt cathode, (b) the solar photo-Fenton process, using a batch reactor and a compound parabolic collector, and (c) a combination of Fenton and solar photo-Fenton processes. The effluent had an initial chemical oxygen demand (COD) of 1159 mgL^?1, and we obtained high removal efficiencies of COD, up to 95 %, using the combination of Fenton and solar photo-Fenton processes.     

Plutonium and Americium: Uptake from contaminated sediments by the polychaete Nereis diversicolor

The polychaete Nereis diversicolor O.F. Müller was exposed to marine sediments which had been contaminated with plutonium and americium either through the testing of nuclear devices or by the release of liquid waste effluent from a nuclear fuel reprocessing plant. The uptake of both plutonium and americium was small, about 0.5% of the concentration of these transuranics in the sediments. The degree of relative uptake of plutonium from both sediments was comparable; relative uptake of americium from sediments contaminated by waste effluent was greater than that from nuclear sediment and those previously determined from water-uptake experiments to environmentally determined plutonium concentrations in sediments and overlying waters leads to the tentative conclusion that water may be the predominant pathway for plutonium accumulation by deposit-feeding worms like N. diversicolor.     

Treatment of wastewaters from ore flotation containing aliphatic amines and hydrofluoric acid

Wastewaters from feldspar flotation containing hydrofluoric acid and amines were effectively purified by neutralization‐clarification with a 10% solution of lime and polyelectrolytes, followed by a coke filtration and/or a Zeolite or Activated Alumina adsorption. A Polish synthetic Ca‐type Zeolite proved to be efficient in the elimination of fluoride ions at the pH of 7.8. At this pH the Zeolite was more efficient than the Activated Alumina N. Wastewaters from feldspar washing were effectively treated by coagulation with A1₂(SO₄)₃, yielding final effluents with the characteristics very close to the clarified postilotation wastewaters. After clarification amines and fluoride ions could be removed from feldspar postflotation and feldspar washing effluents mixed together. A final concentration of fluorides and amines in the purified wastewaters was below 2 mg/1.     

Effects of secondarily-treated sewage effluent on the early life-history stages of two species of brown macroalgae: Hormosira banksii and Durvillaea potatorum

Sewage effluent has a deleterious effect on the early life-history stages of Hormosira banksii (Turner) Decaisne and Durvillaea potatorum (Labillardière) Areschoug. High concentrations of sewage effluent (28 and 40% in seawater) inhibit zygote germination by 55 to 95%, retard embryo growth (80 to 100%) and cause severe embryo mortality, with less than 60 and 5% surviving after 14 d, respectively. It is probable that such adverse effects would significantly reduce levels of recruitment of these species in sewage-affected localities, and that sewage effluent has played an important role in the decline of these species from several rock platforms in south-east Victoria, Australia. Zygote germination, embryo growth and embryo mortality were inhibited 40% more strongly in sewage effluent than diluted seawater, showing that the effect of sewage effluent is not simply one of seawater dilution. However, this effect was only observed at high concentrations (28 and 40%). The absence of any difference between the low concentrations of sewage effluent (4 and 12% in seawater) and diluted seawater suggests that the dilution of waste water is important in mitigating its more harmful effects. The sensitivity of H. banksii and D. potatorum embryos to the composition of the medium in which they grow and the ease with which they can be manipulated in culture suggest that they may be utilised as biological indicators of water quality.     

Photocatalytic oxidation of the textile dye basic red 18 with irradiated titanium dioxide

One of the major problems of textile wastewater is the presence of dye materials, because colour is visible to the public even if the dye concentration is lower than other pollutants, and needs therefore to be removed from the wastewater before it is discharged. Techniques based on “advanced oxidative processes” such as photocatalysed oxidation seem to be very promising for industrial wastewater treatment, especially for decolourization of textile effluents. In this work, we describe the photocatalytic degradation of the textile dye Basic Red 18 (BR 18) in aqueous solution using two different types of TiO₂ as photocatalyst: Degussa P25 (80% anatase) and Framitalia (100% anatase). Photooxidation of BR 18 was followed by HPLC analysis, and kinetic parameters were evaluated in order to optimise the treatment procedure. The results obtained in this work showed that the colour became virtually zero and the chemical oxygen demand (COD) is strongly reduced at the end of the treatment. The obtained results are compared with the efficiency of decolourization using the H₂O₂/UV System. Finally, marine mussel test was used to evaluate the efficiency of photocatalytic oxidation with TiO₂ in terms of ecotoxicity. A significant reduction of cumulative mortality was observed for the treated effluent.     

Physico-chemical characteristics of fine fraction materials from an old crystal glass dumpsite in Sweden

Physico-chemical characteristics of waste, particularly fine fraction (FF), from an old crystal glass waste dump in Sweden were studied to assess recycling or disposal alternatives. Hand-sorting of the waste indicated glass content of 44.1% while sieving established the FF as a more soil-like mix of glass and other materials constituting 33.3% of all excavated waste. The FF was around neutral pH with 24.4% moisture content, low values of Total Dissolved Solids, Dissolved Organic Carbon and fluorides, but hazardous concentrations of As, Cd, Pb and Zn according to the Swedish Environmental Protection Agency guidelines. While the FF leached metals in low concentrations at neutral pH, it leached considerably during digestion with nitric acid, implying leaching risks at low pH. Thus, the waste requires safe storage in hazardous waste class ‘bank account’ storage cells to avoid environmental contamination as metal recovery and other recycling strategies for the glass waste are being developed. The study could fill the information gap regarding preservation of potential resources in the on-going, fast-paced excavation and re-landfilling of heavy metal contaminated materials in the region.     

Degradation of dibutyl phthalate in refuse from different phases of landfill by its dominant bacterial strain,Enterobacter sp. T1

A facultative bacterial strain isolated from municipal solid waste (MSW) obtained from a simulated landfill bioreactor was found to have the ability to use dibutyl phthalate (DBP) as its sole source of carbon and energy. Based on its morphology, physiochemical characteristics, and 16S rDNA sequence, the strain was identified as Enterobacter sp. T1. Evaluation of the degradation of DBP in refuse collected during the initial, acidic, and methanogenic phases of landfill before and after inoculation with Enterobacter sp. T1 revealed that the degradation fits first-order kinetic models for refuse from all phases. The removal rate of DBP in the refuse of the methanogenic phase increased from 59.3% to 74.5% when Enterobacter T1 was added. The half-life of DBP in refuse from the methanogenic phase that was inoculated with Enterobacter T1 decreased by 36.7% relative to uninoculated samples, and the intermediate products monobutyl phthalate (MBP) and phthalic acid were detected in all samples. These results provide new evidence for the potential of applying Enterobacter sp. for phthalic acid ester-polluted area remediation.     

Seasonal differences in treatment efficiency of a set of stabilization ponds in a semi-arid region

This article aims to determine the significant differences of the seasonal changes of pH, chemical oxygen demand (COD), biological oxygen demand (BOD), and total suspended solids (TSS) parameters in a wastewater stabilization pond. The variation of these parameters followed the seasonal pattern of temperature. The mean seasonal pH of the influent wastewater ranged between 7.8 (in spring) and 7.9 (in summer), while in the final effluents it was between 7.9 (in winter) and 8.3 (in summer). The mean seasonal COD of the influent wastewater ranged between 650?mg?L^?1 in spring and 600?mg?L^?1 in autumn, whereas in the effluents it was between 150?mg?L^?1 in autumn and 270?mg?L^?1 in spring. The mean seasonal BOD₅ of the influent wastewater ranged between 360?mg?L^?1 in autumn and 390?mg?L^?1 in winter, whereas in the effluents it was between 66?mg?L^?1 in summer and 130?mg?L^?1 in winter. The results showed that the percent removals of COD, BOD₅ and TSS from final effluents were maximum in summer for COD and BOD₅ (76%), summer (83%) and for TSS in winter (78%), respectively. Data analysis showed that there were significant differences between parameters of pH, COD, BOD₅ and TSS at four different seasons (p?相似文献   

印染废水处理过程及排放水对草履虫遗传毒性评价

草履虫作为指示生物评估印染废水处理过程及排放水的毒性效应。急性毒性结果显示,原水、厌氧工段印染废水、好氧工段印染废水对草履虫的半数致死浓度(24h-LC₅₀)分别为54%、41%、98%;遗传毒性结果显示,印染废水原水、经处理的排放水在6.25%、12.25%稀释梯度下对草履虫造成的DNA损伤较对照组呈显著升高(p<0.01),而排放水对草履虫的DNA损伤较原水无显著性差异;草履虫增殖速率结果显示,印染废水排放水50%稀释梯度下对草履虫增殖速率有抑制作用。暴露于印染废水排放水中10%的草履虫其游动行为发生改变。以上结果表明,印染废水在经过处理后,理化指标均达到国家印染废水行业排放标准,但排放水仍对草履虫产生急性毒性,且遗传毒性较原水没有显著降低。水生生物毒性测试能有效补充理化指标评价,为印染废水行业全面达标排放提供依据。