J. Santos Oliveira

Ecotoxicological assessment of leachates from MSWI bottom ashes.

In this paper, chemical and ecotoxicological data of leachates from bottom ashes collected in different Municipal Solid Waste Incinerators (MSWI) are shown. The bottom ashes were collected in Belgium (three incinerators--samples B1 to B3), France, Germany, Italy and United Kingdom (one incinerator in each country--samples F1, D1, I1 and UK1, respectively). Both chemical and ecotoxicological characterizations of leachates were done on the framework of the European Directive 91/689/EEC and the European Council Decision 94/904/EC. This work was carried out under the European project called Valomat, which was supported by the European Commission through Brite-Euram III program. Twenty-one inorganic parameters were analyzed. The ecotoxicological assays were done under standard laboratory conditions, using the bacterium Photobacterium phosphoreum, the freshwater alga Pseudokirchneriella subcapitata, the crustacean Daphnia magna and the vegetable Lactuca sativa. Chemical data varied from sample to sample. Similar results were obtained in biological assays. The samples can be classified as ecotoxic/hazardous according to the French proposal for a Criterion and Evaluation Methods of Waste Ecotoxicity (CEMWE) and the German regulation on Hazardous Waste Classification (HWC). However, samples B1, B2, B3 and D1 comply the maximum limits for direct valorization category defined in the French Classification of Bottom Ashes based on their Polluting Potential (CBAPP). Sample B1 presented the lowest level of ecotoxicity, being considered as the most interesting to be used in the development of new materials for civil engineering works.

The nutritional value of four species of insects consumed in Angola

Samples of four insects cooked according to traditional methods in central Angola, were analysed by approved chemical and microbiological techniques. The quality of the proteins was evaluated by several chemical indices. The larvae of Usta terpsichore had the greatest potential nutritional value but the other insects were also useful sources of nutrients.

An ecotoxic risk assessment of residue materials produced by the plasma pyrolysis/vitrification (PP/V) process.

Plasma is the fourth state of matter, following the three states of solid, liquid and gas. Experience has amply demonstrated that solids exposed to the oxygen-deficient plasma flame are converted to liquid, and liquid exposed to the same flame is converted to gas. A low amount of vitrified solid residue material usually remains at the end of this process. Plasma pyrolysis/vitrification (PP/V) has been demonstrated as a safe, efficient, cost-effective technology for the treatment of wastes, including hazardous wastes. Besides the low amounts of gaseous byproducts that PP/V produces, the solid vitrified residue presents a low leachability of pollutants. Studies have been performed in many countries in order to assess the leachability of chemical substances. But from the results of identified studies, none has reported results on the ecotoxicological properties of the leachates. The aim of this study was to contribute to the assessment of ecotoxic risk of four different vitrified materials. Vitrified samples of contaminated soils, municipal solid wastes, and incinerator bottom ashes were submitted to the European leaching pre-standard test number prEN 12457-2. The leachates were analyzed for 22 chemical parameters. The biological characterization comprised the assessment of bioluminescence inhibition of Photobacterium phosphoreum bacterium, growth inhibition of Pseudokirchneriella subcapitata algae and the germination inhibition of Lactuca sativa vegetable. The chemical and ecotoxicological results were analyzed according to the French proposal of Criteria on the Evaluation Methods of Waste Toxicity (CEMWT) and a Toxicity Classification System (TCS). The chemical and ecotoxicological results indicated a low leachability of pollutants and a low toxicity level of leachates. All samples studied were as below the TCS class 1 level (no significant toxicity observed) and as non-ecotoxic for CEMWT. Therefore, the environmental ecotoxic risk of the analyzed vitrified samples was determined to be very low.

Re-use of industrial orange wastes as organic fertilizers

The aim of this study was to evaluate the possibility of the re-use of industrial orange wastes as organic soil fertilizer. The assay was performed with a lettuce variety widely produced and consumed in Portugal and, consequently, with great commercial interest. Lactuca sativa L. (osteolata variety) was cultivated in Mitcherlich pots containing samples of a poor soil of the Algarve region. This soil was prepared with different amounts of either pulp or peel orange-wastes from an orange-juice industry. The wastes were applied according to an increasing amount of nitrogen. The results obtained were submitted to statistical tests, in order to find the relations between the production of fresh and dry matter, and the percentages of nutrients (nitrogen, phosphorous, potassium, calcium, magnesium and iron) that were obtained in the dry matter, with the types and amounts of wastes applied. An increase in the average production of both fresh- and dry-matter with increasing amounts of either pulp or peel wastes applied, and high positive correlation coefficients between the average percentages of nitrogen, phosphorus and potassium obtained in the dry matter with the average production of both fresh- and dry-matter were found. No phytotoxicity was observed.

Effect of exogenous lysine on the expression of early cephamycin C biosynthetic genes and antibiotic production in Nocardia lactamdurans MA4213

Abstract. In β-lactam producing microorganisms, the first step in the biosynthesis of the β-lactam ring is the condensation of three amino acid precursors: α-aminoadipate, L-cysteine and D-valine. In Nocardia lactamdurans and other cephamycin-producing actinomycetes, α-aminoadipate is generated from L-lysine by two sequential enzymatic steps. The first step involves a lysine-6-aminotransferase activity (LAT), considered to be one of the rate-limiting steps for antibiotic biosynthesis. Here, we report the effect of exogenous lysine on antibiotic production by N. lactamdurans MA4213. Lysine-supplemented cultures showed higher titers of cephamycin C, an effect that was more significant at early fermentation times. The increase in cephamycin C production was not quantitatively correlated with specific LAT activity in lysine-supplemented cultures. Observation of a positive effect of lysine on cephamycin C production by N. lactamdurans was dependent on carbon source availability in the culture media. Supplementation of the culture media with exogenous lysine did not affect the mRNA levels of the early biosynthetic genes controlled by the bidirectional promoter. These results indicate that L-lysine is required not only for antibiotic biosynthesis, but particularly as carbon or nitrogen source.

Efficiency of removal in stabilization ponds I. Influence of climate

Abstract Owing to the existing or predictable water deficiencies in the South of Portugal, it is necessary to carry out the appropriate management of water resources, by reducing and/or minimizing the negative impacts of untreated/treated domestic effluents in the aquatic environment. As Portugal has a great diversity of ecoclimatic areas, five different stabilization pond systems were chosen to carry out a control study during one year (from March 1991 to March 1992). According to Pina Manique & Albuquerque the ecological classification of these stations is different, varying from Ibero-mediterranean (continental) up to mediterranean (maritime). The physical and chemical parameters studied were: temperature, pH, dissolved oxygen, conductivity, BOD, COD, nitrates, nitrites, ammonia and total nitrogen, total suspended and volatile solids, total phosphorus and orthophosphates. The microbiological parameters studied were: total and faecal coliforms, faecal Streptococci, Clostridium perfringens and Pseudomonas aeruginosa . The correlations between climatic parameters and the efficiency of the removal of organic matter were analysed.

Co-composting of sweet sorghum biomass with different nitrogen sources

Abstract Composting of waste biomass from sweet sorghum seems to be a good alternative for its valorization in Portugal. The purpose of this work was to establish the best experimental conditions for the aerobic bioconversion of this material, starting with different C:N ratios and using different nitrogen sources. The material came from two fields with a fertilization level of 100 kg N/ha, and it was composted using bovine blood, domestic sludge and yeast extract as nitrogen sources, starting with initial C:N ratios of approximately 20 and 30. The experiment was carried out in a constant temperature chamber at 37°C and lasted for two and a half months. Samples were periodically collected and analyzed. The hygienic state of the product was also evaluated. The best quality compost from a fertilizer perspective was obtained with domestic sludge as a nitrogen source and starting from an initial C:N ratio equal to about 20:1. Starting from this C:N ratio could bring problems with the content of cadmium, so the recommended starting conditions must be about 30:1.

Metals in sediment and water of three reed (Phragmites australis (Cav.) Trin. ex Stend.) stands

In the frame of the research program EUREED (Effects of interaction between eutrophication and major environmental factors on the ecosystem stability of reed (Phragmites australis) vegetation in European land-water ecotones), three reed stands, established near Alcácer do Sal, Lagoa de Albufeira and Montargil, were studied. The stands were monitored monthly between December 1993 and December 1994 for productivity, soil and water chemistry. The relationship between the concentration of some metals in soil and water and its influence on the stability of the reed vegetation was studied. Environmental factors, such as salinity, negative redox potential on the root system and high Cu, Na and Zn concentrations in soil did not affect the normal development of reed vegetation and its capability to recover after mechanical damage.

Comparative evaluation of European methods for sampling and sample preparation of soils — the Portuguese contribution

The main purpose of this work was to prepare a Portuguese sampling strategy, according to the existing Portuguese recommendations, for the soil sampling exercise at Dornach in the framework of the CEEM soil project of the SMT Programme of the EU. Within this project, the results obtained from the Dornach study were compared with the results obtained by other European participants and also with the reference sampling. The objective of this comparison was to validate the method used and to evaluate possible factors of uncertainty that may arise from the application of our national guideline as well as possible advantages. Another objective, also important, was to provide information regarding the need for a harmonised procedure within the European Union related to soil sampling and sample preparation of soils. The results obtained were consistent with the results obtained by other participants, however, in the Portuguese recommendations there is a general lack of specific information that may complicate its application to polluted scenarios. In fact, those guidelines are valuable to detect the average contamination of the soil, but they are not useful to identify hot spots or the edge influence in a contaminated land. As a conclusion, the results obtained by the CEEM soil project helped to evaluate the Portuguese sampling plan. This may provide a basis for further standardisation of soil sampling for specific purposes, e.g. contaminated land, and to establish a technical support for criteria used in the accreditation of laboratories for soil sampling.

Evaluation and utilisation of effluents from the tomato concentrate industry

Abstract The tomato concentrate industry is of considerable economic significance in Portugal and is also an important source of pollution in both rivers and lakes. Data collected over three years at industrial plants are presented in an attempt to assess the most suitable treatment strategy. Results of experiments using the effluent from the major polluting process, juicing, to produce a yeasty animal food supplement are also presented.