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A biosorption process has been developed for the bioremediation of heavy metal-contaminated acid drainages from Merladet and Faith open-cast mines, located in western Spain. The process is based on the physico-chemical properties for the adsorption, ion exchange, and complexation of metal ions by biopolymers (chitin and α (1,3) β-D-glucan) from industrial biowaste exhausted brewer's yeast (Saccharomyces cerevisiae L.). Firstly, the chemical composition (U, Mn, Al, Fe, Cu, Zn, and Ni) and the physico-chemical and ecological states of these acid mine drainages were characterised. Furthermore, the selectivity for Zn, Cu, Mn, Ni, and Al the first order kinetics and the performance of the metals biosorption process by exhausted brewer's yeast were evaluated with polluted acid synthetic waters and mine drainages. The biosorption equilibria were reached in 10 ~ 15 min following Langmuir type isotherms with higher affinity constants for metal-biosorbent binding for synthetic waters than for acid mine drainages. The efficiency of the process with real water samples was markedly lower for the case of Mn, and zero for Zn and Al. An antagonistic interference on the biosorption of a metal due to the presence of other metals is proposed. Finally, the ecotoxicity of the acid mine drainage was removed when it was incubated with brewer's yeast trapped in polyurethane foam.

The aim of the work was to study the mycorrhizal status of the plants spantaneously estabilishing during the successional stages of the revegetation of Katowice-Welnowiec zinc wastes. In total 69 vascular plant species (25 families) appearing on the investigated area have been noted. More than 60 percent were mycorrhizal. Non mycorrhizal species, such as Cardaminopsis arenosa and Silene vulgaris dominated the early successional part of the zinc heap

Three types of proteinases, namely cysteine, metallo and serine proteinases, were found in squid hepatopancreas by studying the inhibition spectra using carp myofibril as substrate. The cysteine, metallo and serine types showed the highest activities at 50, 35 and 40degC, respectively. The optimal pHs were 5, 7 and 9 for the cysteine, metallo and serine types, respectively. When assayed at 20degC and pH 7.5, the metallo type showed the highest activity. The metallo type was characterized by a high selectivity in the digestion of myosin. Among the three enzymes, the cysteine type was found to be the most stable against thermal and acid treatments. Heat-treated myofibrils were more susceptible to the cysteine and serine types, but less susceptible to the metallo type. Acid treatment of myofibrils also enhanced the digestibility by the cysteine type. The results indicated that the cysteine type seemed to be the most suitable enzyme to produce peptides from denatured myofibrils by their random digestion.

In the northeast USA, most soil samples analyzed for soil test P (STP) in 1990 exceeded P levels needed for plant production. Converting soil P to less soluble forms with applications of materials containing lime or Ca may reduce the release of soil P to runoff. We investigated the effect of several coal combustion by-products on STP (Bray-1 and Mehlich-III), water extractable P, and equilibrium P concentration (EPC0) of high P soils. Three widely available by-products were used: fluidized bed combustion flyash (FBC), flue gas desulfurization by-product (FGD), and pulverized coal flyash (PC). In a by-product type and rate experiment, a Berks soil with high STP was incubated for 21 d with each by-product (0, 10, 20, 40, and 80 g kg soil-1). The highest rates of FBC and FGD reduced Mehlich-III P (45%), Bray-1 P (50%), water extractable P (72%) and EPC0 (37%). The PC had no effect on soil P solubility due to the addition of P with this by-product. For eight soils ranging in physical and chemical properties, FBC at 10 g kg soil-1 reduced Mehlich-III P 13%, and water-extractable P 71%, while FGD reduced Mehlich-III P 8% and water-extractable P 48%. These reductions resulted from the conversion of readily desorbable soil P to less soluble Ca-bound or Al- and Fe-bound pools. Amending high P soils with FBC or FGD by-products has the potential to reduce P enrichment of runoff by decreasing the solubility of soil P without reducing STP below optimum levels for plant growth

Lactic acid is a relatively cheap chemical with a wide range of applications: as a preservative and acidifying agent in food and dairy industry, a monomer for biodegradable poly-lactide polymers (PLA) in pharmaceutical industry, precursor and chemical feedstock for chemical, textile and leather industries. Traditional raw materials for fermentative production of lactic acid, refined sugars, are now being replaced with starch from corn, rice and other crops for industrial production, with a tendency for utilization of agro-industrial wastes. Processes based on renewable waste sources have ecological (zero CO2 emission, eco-friendly byproducts) and economical (cheap raw materials, reduction of storage costs) advantages. An intensive research interest has been recently devoted to develop and improve the lactic acid production on more complex industrial by-products, like thin stillage from bioethanol production, corncobs, paper waste, straw etc. Complex and variable chemical composition and purity of these raw materials and high nutritional requirements of lacid acid bacteria (LAB) are the main obstacles in these production processes. Media supplementation to improve the fermentation is an important factor, especially from an economic point of view. Today, a particular challenge is to increase the productivity of lactic acid production on complex renewable biomass. Several strategies are currently being explored for this purpose such as process integration, use of LAB with amylolytic activity, employment of mixed cultures of LAB and/or utilization of genetically engineered microorganisms. Modern techniques of genetic engineering enable construction of microorganisms with desired characteristics and implementation of single step processes without or with minimal pre-treatment. In addition, new bioreactor constructions (such as membrane bioreactors), utilization of immobilized systems are also being explored. Electrodialysis, bipolar membrane separation process, enhanced filtration techniques etc., can provide some progress in purification technologies, although it is still remaining the most expensive phase in the lactic acid production. A new approach of parallel production of lactic bacteria biomass with probiotic activity and lactic acid could provide additional benefit and profit rise in the production process.

A greenhouse study was conducted to investigate the growth of the grass cover crops Agrostis capillaris, Festuca ovina, F. rubra, Lolium perenne, and Phleum pratense and their accumulation of Cu, Pb, Zn, Ni, and Cr in three metal-contaminated wastes arising from a steelworks, a lead mine, and a chemical works. Soil metals were extracted by five reagents (Mehlich 1, 0.1 M HCl, 0.005 M DTPA, 0.005 M EDTA, 0.005 M NTA) and values were correlated with plant tissue accumulation of metals. Agrostis capillaris accumulated the greatest concentration of metals from each waste material. Dry matter production for all grasses decreased on contaminated substrates compared to the control; however, overall ground cover was satisfactory except for A. capillaris on the chemical works waste. Lolium perenne and P. pratense consistently produced the highest dry matter yields. All grasses accumulated excessive amounts of Cr on the chemical waste and Pb on the mine waste, presumably from reservoirs in the readily extractable and soluble forms. The extractability of most metals was generally 0.1 M HCl Mehlich 1 DTPA = EDTA = NTA. Mehlich 1 did not appreciably extract Pb from two wastes. No extractant was able to represent metal uptake by a particular grass in a linear fashion

The usage of plastics in packaging and disposable products, and the generation of plastic waste, have been increasing drastically. Broader usage of biodegradable plastics in packaging and disposable products as a solution to environmental problems would heavily depend on further reduction of costs and the discovery of novel biodegradable plastics with improved properties. In the authors' laboratories, various carbohydrates in the growth media, including sucrose, lactic acid, butyric acid, valeric acid, and various combinations of butyric and valeric acids, were utilized as the carbon (c) sources for the production of bioplastics by Alcaligenes eutrophus. As the first step in pursuit of eventual usage of industrial food wastewater as nutrients for microorganisms to synthesize bioplastics, the authors investigated the usage of malt wastes from a beer brewery plant as the C sources for the production of bioplastics by microorganisms. Specific polymer production yield by A. Latus DSM 1124 increased to 70% polymer/cell (g/g) and 32g/L cell dry wt, using malt wastes as the C source. The results of these experiments indicated that, with the use of different types of food wastes as the C source, different polyhydroxyal-kanoate copolymers could be produced with distinct polymer properties

Our previous study indicated the existence of some low molecular weight contaminants in separated fractions (F1 to F4) of alkaline-oxygen stage waste liquor by spectroscopic analysis. In the present study, the quantities of these compounds were determined by capillary electropheresis (CE). Substantial amounts of oxalate and acetate were found in F3. The complexes between Al and oxalate as well as F3 were characterized by 27Al-nuclear magnetic resonance (NMR) spectroscopy, and the spectra of Al-oxalate complexes demonstrated the ability of oxalate to chelate Al and to produce different forms of complexes at varied molar ratios. Plant growth experiments in the presence of Al-oxalate complexes suggested that at a proper range, oxalate has a favorable effect on the detoxification of Al toxicity. It can be assumed that oxalate in F3 also plays an important role in the efficiency of removing Al toxicity. 27Al-NMR was proved to be a useful method for the study of complexes between Al and organic compounds without disturbing their equilibrium conditions.

Wastewaters from fish-canning industries have a high concentration of organic polluting substances (10-50 g chemical oxygen demand${\\rm L}^{-1}$[COD]) and, in some cases, a high content of sea salts (${\\rm Cl}^{-}$: 8-19 g${\\rm L}^{-1}$,${\\rm Na}^{+}$: 5-12 g${\\rm L}^{-1}$,${\\rm SO}_{4}^{2-}$: 0.6-2.7 g${\\rm L}^{-1}$). The presence of high sodium ion concentrations in wastewaters with high organic content traditionally is considered as a very negative factor for their anaerobic treatment. In fact, both the presence of${\\rm Na}^{+}$and${\\rm SO}_{4}^{2-}$, transformed into${\\rm H}_{2}{\\rm S}$during the anaerobic degradation process, may cause toxicity and inhibition on the methanogenic process. This work deals with the operation and treatment efficiency of two lab-scale mesophilic and thermophilic anaerobic filters (MAF and TAF, respectively). So that the adaptation of anaerobic sludge to high saline concentrations is attained, a prolonged start-up period of about nine months was necessary. After this, a stable operation and similar treatment efficiencies were reached, even when organic loading rate (OLR) as high as 9 kg COD${\\rm m}^{-3}$ ${\\rm d}^{-1}$(TAF) or 24 kg COD${\\rm m}^{-3}$ ${\\rm d}^{-1}$(MAF) were applied at chloride concentration of 13 g${\\rm L}^{-1}$. At these conditions, the COD removal reached 73% (TAF) and 64% (MAF), and the COD methanized reached 69% (TAF) and 66% (MAF). The sulphate in the influent was removed practically completely, leading to a${\\rm H}_{2}{\\rm S}$concentration in the biogas between 3-4%. In spite of the lower specific activity of sludge from MAF (0.21 g COD${\\rm g}^{-1}$volatile suspended solids [VSS]${\\rm d}^{-1}$) than from TAF (0.66), the MAF reached a higher OLR than TAF. This fact can be explained because of the higher retention of sludge into MAF (72 g VSS${\\rm L}^{-1}$) than TAF (10 g VSS${\\rm L}^{-1}$). Two practical conclusions may be derived from this work: the thermophilic operation needs the use of a packing material with a higher capacity to retain biomass and the mesophilic operation requires a more frequent detachment of biomass from the support in order to avoid clogging problems.