Removal of sulphates acidity and iron from acid mine drainage in a bench scale biochemical treatment system.

The focus of this study was to develop a simple biochemical system to treat acid mine drainage for its safe disposal. Recovery and reuse of the metals removed were not considered. A three-step process for the treatment of acid mine drainage (AMD), proposed earlier, separates sulphate reducing activity from metal precipitation units and from a pH control system. Following our earlier work on the first step (biological reactor), this paper examines the second step (i.e. chemical reactor). The objectives of this study were: (1) to determine the increase in pH and the reduction of iron in the chemical reactor for different proportions of simulated AMD, and (2) to assess the capability of the chemical reactor. A series of experiments was conducted to study the effects of addition of alkaline sulphidogenic liquor (ASL) derived from a batch sulphidogenic biological reactor (operating with activated sludge and a COD/SO4 ratio of 1.6) on the simulated AMD characteristics. At 60-minute contact time, addition of 30% ASL (pH of 7.60-7.76) to the chemical reactor with 70% AMD (pH of 1.65-2.02), increased the pH of the AMD to 6.57 and alkalinity from 0 to 485 mg l(-1) as CaCO3, respectively and precipitated about 97% of the iron present in the simulated AMD. Others have demonstrated that metals in mine drainage can be precipitated by bacterial sulphate reduction. In this study, iron, a common and major component of mine drainage was used as a surrogate for metals in general. The results indicate the feasibility of treating AMD by an engineered sulphidogenic anaerobic reactor followed by a chemical reactor and that our three-step biochemical process has important advantages over other conventional AMD treatment systems.

Biosolids from two-stage bioleaching could produce compost for unrestricted use.

A biological process, called BIOSOL, developed in our laboratory, efficiently reduces metals and reduces pathogenic indicator bacteria in sewage sludges in a single-stage system to levels meeting Ontario Ministry of the Environment (OME) requirements for land application of biosolids. Since the requirements for unrestricted use of compost are 10 to 50 times (depending on the metal involved) more restrictive than those for land application, this study was carried out to determine whether the efficiency of the BIOSOL system could be increased to meet the more stringent limitations required for compost. A two-stage modified BIOSOL system was successfully operated for a period of 4% months, at 30 degrees C, treating anaerobically digested sludge from the Guelph Wastewater Treatment Plant. Elemental sulphur (4g l(-1)) was the energy source for the autotrophic bacteria (thiobacilli). The pH, metals (Cd, Cr, Cu, Pb and Zn), and sulphate were used to evaluate system effectiveness. At an HRT of 8 days in each solubilization tank, and a S*-concentration of 4g l(-1), sulphur oxidation efficiency was about 70%, while the metal removals were: Cd 90%, Cr 93%, Cu 96%, Pb 67% and Zn 98%. The finished product (biosolids) met the OME requirements for metal concentrations for producing compost or fertilizer for unrestricted use. The reduction of pathogenic indicator organisms was demonstrated in earlier studies.

A biological process that reduces metals in municipal sludge to yield sulphur enhanced biosolids.

Heavy metal contamination can often restrict or prohibit land application of municipal sludge. In the present investigation a continuous biological process with powdered elemental sulphur as energy source was examined for solubilization of metals from anaerobically digested municipal sludge. The results showed that the continuous process can be designed to achieve both metal solubilization and efficient sulphur utilization. With a sulphur addition of 1.5 g l(-1) and an HRT of 14 days, solubilization efficiencies of 50, 33, 48, and 74% were obtained for cadmium, copper, nickel, and zinc, and about 80% of the added sulphur was oxidized. Addition of ferrous sulphate as an additional energy source did not improve the performance of the process. The residual sulphur in the metal decontaminated biosolids was in balance with the phosphorus content, potentially making it an effective sulphur fertilizer for soils deficient in the nutrient.

Integrated, long term, sustainable, cost effective biosolids management at a large Canadian wastewater treatment facility.

The Greater Moncton Sewerage Commission's 115,000 m3/d advanced, chemically assisted primary wastewater treatment facility located in New Brunswick, Canada, has developed an integrated, long term, sustainable, cost effective programme for the management and beneficial utilization of biosolids from lime stabilized raw sludge. The paper overviews biosolids production, lime stabilization, conveyance, and odour control followed by an indepth discussion of the wastewater sludge as a resource programme, namely: composting, mine site reclamation, landfill cover, land application for agricultural use, tree farming, sod farm base as a soil enrichment, topsoil manufacturing. The paper also addresses the issues of metals, pathogens, organic compounds, the quality control program along with the regulatory requirements. Biosolids capital and operating costs are presented. Research results on removal of metals from primary sludge using a unique biological process known as BIOSOL as developed by the University of Toronto, Canada to remove metals and destroy pathogens are presented. The paper also discusses an ongoing cooperative research project with the Université de Moncton where various mixtures of plant biosolids are composted with low quality soil. Integration, approach to sustainability and "cumulative effects" as part of the overall biosolids management strategy are also discussed.

Reduction of indicator organisms during biological solubilization of metals: a pilot study.

Laboratory and pilot scale studies on the biological solubilization of metals from undigested raw sludge were carried out using elemental sulphur as the energy source. Metals (Cu, Zn, Ni and Cd), pH, sulfate and indicator bacteria [total coliforms (TC) faecal coliforms (FC) and faecal streptococci (FS)] were used to evaluate the system effectiveness. This paper does not report the detailed design and operational data of the pilot plant (available elsewhere [1]) but focuses on the biological tests carried out at the Main Wastewater Treatment Plant in Toronto from July to December, 1997. Since the indicator bacteria are injured from exposure to low pH and potentially toxic metal concentrations, improved alternative methods for their enumeration and their ability to repair acid-metal induced injury in a resuscitation medium (CASO tryptone soya broth) were also investigated. Resuscitation was not effective in repairing cells injured during bacterial leaching. The MPN technique (using lauryl tryptose broth) for enumerating indicator bacteria (total coliforms) gave higher counts and was therefore superior to the spread plate technique (using m-Endo agar) in recovering bacteria from acidic leached sludge (biosolids). However, the coliform bacterial counts from raw sludge were similar by the two methods. This study indicated that the biological solubilization process could significantly reduce the pathogenic indicators. Concentrations of TC, FC and FS in the leached biosolids from the solubilization tank were lower than concentrations in the raw sludge by 4 to 6 orders of magnitude and the finished product (biosolids) met US. EPA requirements for pathogen and metal concentrations for Class A biosolids to be used on agricultural land.

Serum calcitonin in renal transplant patients.

We obtained blood samples from 60 renal transplant patients from our transplant clinic and from control subjects for biochemical analyses. Cyclosporin levels were measured in whole blood. Serum levels of calcitonin, calcium, phosphate, albumin, urea, creatinine, and activity of alkaline phosphatase were determined. Serum calcitonin levels were significantly higher in renal transplant patients. There was no correlation between serum calcitonin levels and activity of serum alkaline phosphatase, or levels of serum calcium, phosphate, albumin, urea, creatinine or cyclosporin. Serum calcitonin also showed no correlation with patient age or transplant age.

Anaerobic treatment of landfill leachate by sulfate reduction.

The present study was conducted to investigate the effectiveness of the sulphate-reduction pathway in the anaerobic treatment of landfill leachate. The effects of several COD/SO4 ratios (keeping COD constant) and loadings on anaerobic filter performance were studied and compared with the results from anaerobic filters which followed the methanogenic pathway. Results indicated that the treatability of leachate by sulphate reducing bacteria (SRB) was dependent upon the leachate strength. With high strength leachate (COD = 15,000 mg/L) from the Keele Valley Landfill, it was found that at lower COD/SO4 ratios (< or = 1.6) toxic conditions developed in the system that were more inhibitory to the SRB than to the methane producing bacteria (MPB). As the COD/SO4 ratio increased, methanogenesis predominated. No predominance of SRB occurred at any COD/SO4 ratio with high strength leachate. The highest COD removal achieved was about 70% of which 20% was accomplished by the SRB at a COD/SO4 ratio of 1.6 and an organic loading rate (OLR) of 4 kg COD/m3.d. With low strength leachate (COD = 1500-3300 mg/L) from the Brock West Landfill, and a COD/SO4 ratio < or = 1, SRB became predominant. In these anaerobic filters in which SRB were predominant, the SRB reduced the COD as well as the MPB could. Sulphide inhibition did not take place at any loading in units treating low strength leachate. Consequently, both SRB and MPB should function at COD/SO4 ratios between 1 and 3. About 60% COD removal was achieved at a loading of 2.8 kg COD/m3.d and a COD/SO4 ratio of 1.0. However at a loading of 6 kg COD/m3.d only 27% COD removal was achieved, all of it through the sulphate-reduction pathway. These OLR values are comparable to those applied in systems where methanogenesis was dominant. It was also observed that once the methanogens were established in the units, it was not possible to displace them completely. However, where methanogenesis had not been previously established, it was found that sulphate-reduction could be the sole pathway for COD removal. From this study, it can be concluded that there is no advantage to the sulphate-reduction pathway in the anaerobic treatment of landfill leachate. The other options for increasing the loadings, i.e. the use of high surface/volume filter media (to achieve higher biomass concentrations) or high rate systems are likely to be more successful.

Parathyroid hormone-related protein-(1-36) is biologically active when administered subcutaneously to humans.

PTH-related protein (PTHrP) is responsible for most cases of humoral hypercalcemia of malignancy (HHM). It mimics the actions of PTH as a result of its structural homology with PTH and its ability to bind to and signal via the PTH/PTHrP receptor in bone and kidney. PTHrP-(1-36) appears to be one of several secretory forms of PTHrP. This peptide has been administered iv to normal volunteers previously and has been shown to produce effects that are qualitatively and quantitatively the same as those produced by PTH-(1-34). To determine whether PTHrP-(1-36) could be used sc in humans as a diagnostic reagent for elucidating the differences between HHM and hyperparathyroidism, we performed a 12-h dose-finding study examining whether sc PTHrP-(1-36) could elicit effects on mineral homeostasis. PTHrP-(1-36) administered sc in three doses (0.82, 1.64, and 3.28 micrograms/kg) to 21 normal women produced increases in circulating PTHrP-(1-36), reductions in serum phosphorus and the renal phosphorus threshold, increments in fractional calcium excretion and nephrogenous cAMP excretion, and increases in plasma 1,25-dihydroxyvitamin D. These changes were highly significant in statistical terms and were observed at doses that had no effect on serum calcium or endogenous PTH. These studies demonstrate the feasibility of using PTHrP-(1-36) as a diagnostic probe for future studies aimed at elucidating the differing pathophysiologies of HHM and hyperparathyroidism.

Co-purification and characterization of ATP-sulfurylase and adenosine-5'-phosphosulfate kinase from rat chondrosarcoma.

The two sulfate-activating enzymes, ATP-sulfurylase (EC 2.7.7.4) and adenosine-5'-phosphosulfate kinase (adenylylsulfate kinase, EC 2.7.1.25), were each purified about 2000-fold from crude rat chondrosarcoma homogenate. Throughout a purification protocol which included Sephacryl S-300 gel filtration, DEAE-Sephadex ion exchange, hydroxylapatite, and ATP-agarose affinity chromatography, these two activities consistently co-purified. ATP-sulfurylase and adenosine-5'-phosphosulfate kinase each showed a pH optima of 7.0-7.4 and a bimodal temperature optima of 46 and 52-54 degrees C. Both activities preferred Mg2+ as their divalent cation source over Mn2+, Co2+, or Zn2+. The apparent Km values determined for adenosine 5'-phosphosulfate in both assays was 1-5 microM; the Km for pyrophosphate in the sulfurylase reaction was 40 microM and for ATP in the kinase reaction was 5 mM. Gel electrophoresis indicated major bands at Mr = 160,000 in nondenaturing systems and 35,000-37,000 and 60,000 under dissociative conditions, whereas gel filtration of the most highly purified fractions yielded a coincident peak in the molecular weight range 260,000.

[Antibiotic therapy in ophthalmology]. / L'antibiothérapie en ophtalmologie.

Eye drops containing antibiotics are more and more numerous, we prescribe them more and more frequently. We found it interesting first to gather in six lists all antibiotics used locally in ophthalmology and to study for everyone its bacterial spectrum. After that we see which bacteria are most frequently met by ophthalmologists and when (presurgery examination, conjunctivitis, blepharitis, chalazion, meibomianitis, sty, corneal ulcer, lens infection). All this helps the ophthalmologist to choose the antibiotic he prescribes before the bacteriological specimen, with high confidence. At last, we sum up the little that is presently known about penetration of antibiotics into the eye.

The treatment of quinine poisoning with charcoal haemoperfusion.

Quinine poisoning is rare but serious. Attempts at treatment by active removal have proved unsuccessful because of its high degree of protein binding. We describe two cases of non-accidental overdose of quinine (19.5 g and 15 g) with potentially fatal serum quinine levels. Both patients were treated by 2 periods of charcoal haemoperfusion during which quinine clearances of up to 125 ml/min were obtained. Both patients recovered, though one had some residual visual disturbance. We suggest that in cases of quinine poisoning, charcoal haemoperfusion may be a safe and effective method of drug removal, to be used with stellate ganglion block.

Neuronal ceroid lipofuscinosis in the amaurotic retardate: electron microscopic confirmation.

The clinical features of two cases of blindness with pigmentary retinopathy in young retardates are presented. The diagnosis of neuronal ceroid lipofuscinosis (Batten's Disease) was suspected. This was confirmed in both cases by electron microscopic examination of blood and skin with demonstration of fingerprint and curvilinear inclusions. These inclusions are present in cells other than neurons; circulating lymphocytes, smooth muscle cells and eccrine sweat glands suggesting a more widespread pathological process. Less invasive procedures namely venepuncture and skin biopsy may be preferred to brain and rectal biopsy in the absence of a practical biochemical analysis at the present time.

Visual deterioration as presentation of subacute sclerosing panencephalitis.

A 7-year-old boy presented with deteriorating vision and macular degenerative changes. A month later he had developed unusual behaviour and increasing forgetfulness. An electroencephalogram showing periodic complexes, and high measles complement-fixation titres in the cerebrospinal fluid and blood, confirmed the diagnosis of subacute sclerosing panencephalitis. Four months after the onset of visual symptoms he started having myoclonic jerks.

Stenosis of the coronary sinus ostium. An unusual site of obstruction in total anomalous pulmonary venous drainage.

A patient with total anomalous pulmonary venous connection to the coronary sinus and stenosis of the right atrial opening of the coronary sinus is described. While the initial studies were compatible with increased pulmonary blood flow, subsequent evaluation demonstrated severe pulmonary venous obstruction. Successful operative correction was performed.