Performances of three R-AN-D-N wastewater treatment plants in the Czech Republic

The evolution of Czech standards requires higher efficiency of nutrient removal from municipal wastewaters. At the beginning of the last decade of 20th century, a new activated sludge configuration called R-AN-D-N process has been described, successfully tested and now largely used at several wastewater treatment plants (WWTP) in the Czech republic. The main feature of the R-AN-D-N process is the introduction of a regeneration zone in sludge recycle, which enables to increase sludge age in the system without any substantial increase in WWTP volume. Performances of three Czech large WWTP with R-AN-D-N configuration have been monitored and compared within a period of one and a half years. The results confirmed excellent nutrient removal efficiency for wastewaters with different proportion between sewage and industrial effluents. Two of three monitored WWTP received wastewaters from breweries (Budweiser and Pilsner Urquell). The settleability of activated sludge from all three WWTP was correct, with SVI values usually ranging from 50 to 150 ml/g. Monitoring of sludge composition indicated proliferation of several filamentous bacteria, particularly types 0581, 0092 and M. parvicella. No severe bulking events were observed. Finally, the operational costs expressed in CZK (Czech crown: 1 CZK = [see symbol in text]0.0322) per cubic metre of treated sewage or per capita amounts respectively from 2.24 to 6.52, and from 285 to 342.

[An open and controlled study of effectiveness and tolerance of Livostin eyedrops]

The authors present the result of an open controlled trial of the effectiveness of a new antiallergic ophthalmological preparation, Livostin, for local use, a product of Janssen-CILAG. They evaluate the results obtained in 86 patients with symptoms of allergic conjunctivitis. The preparation was followed up for four weeks, in particular the rate of onset of effect and its duration. Evidence was provided that this preparation is a highly effective local antiallergic drug with a long-term effect.

[Cataract surgery in patients with endogenous uveitis]

The authors present an account of surgery of complicated cataract in 20 patients with anterior and intermediate uveitis. During a one-year follow-up period they evaluate the difference of postoperative development and visual acuity in extracapsular extraction without or with implantation of an intraocular lens. In 10 patients (5x m. Fuchs, 3x anterior uveitis, 2x intermediate uveitis) they performed only ECCE. In 10 patients with the same diagnosis an intraocular lens was implemented. The authors did not find marked differences between the ECCE operation and ECCE operation with an intraocular lens in patients with uveitis. The visual acuity improved in all 20 patients, a marked inflammatory reaction in the anterior chamber was observed in both groups only during the first days after surgery. The two groups did not differ markedly as regards late complications. From the investigation ensues that implantation of an intraocular lens is well tolerated in patients with anterior and intermediate uveitis assuming a minimum 12-week remission of the disease.

[Endogenous uveitis]

In a brief historical review of views on inflammatory affections of the uveal tissue the authors focused attention also on distinguished personalities in Czech ophthalmology who worked at the Czech Ophthalmological Clinic and participated in the development of uveology. Based on their own observations, they give an account on of their experience with the diagnosis of endogenous uveitis. Consistent with the world literature, they were able to reveal in a group of 174 patients with endogenous uveitis that the condition was associated with a systemic disease in 30%, in 9% they found an infectious aetiology and the remaining 61% were described as idiopathic endogenous uveitis. From the group of idiopathic uveitis they separated clinical entities diagnosed in 29%.

[Evaluation of the long-term therapeutic effect of bacterial vaccines administered 1960-1968 to patients with recurrent anterior uveitis]

The authors evaluate after an interval of many years the effectiveness of treatment of relapsing anterior uveitis by streptococcal vaccines administered in the sixties by L. Klenka, I. Hána, M. Koleckárová. The evaluation is based on a survey conducted by means of questionnaires. After 21 years 91% of the respondents do not report relapses. The authors discuss possible reasons why this desensitization treatment is successful.

Preliminary studies on the toxicity and metabolism of palladium and platinum

Preliminary data are given on the LD50 of PdCl2 following different routes of exposure and on the LD50 of PtCl4 following intravenous exposure. The retention, tissue distribution, and excretion of 103Pd and 191Pt in rats was determined following oral, intravenous, intratracheal, and inhalation exposure. The highest retention for both 103Pd and 191Pt was obtained following intravenous dosing, and the lowest retention occurred after oral dosing. Following a single oral dose, almost all of the 103Pd and 191Pt was excreted in the feces due to nonabsorption, whereas after intravenous dosing, similar quantities were excreted in both the urine and feces. Tissues containing the highest concentrations of these metals were the kidney, spleen and liver. Following intravenous dosing of pregnant rats, a small amount of 103Pd and 191Pt was found in the fetuses.