Separation of solids and disinfection for agronomical use of the effluent from a UASB reactor.

The present work addresses the preparation of the effluent from a full-scale upflow anaerobic sludge blanket (UASB) reactor for drip irrigation of orange crops. The pilot plant included a lamella plate clarifier followed by a geo-textile blanket filter and a UV disinfection reactor. The clarifier operated with a surface load of 115 m(3)m(-2)d(-1), whereas the filter operated with 10 m(3)m(-2)d(-1). The UV reactor was an open-channel type and the effective dose was approximately 2.8 W h m(-3). The effluent of the UASB reactor received 0.5 mg L(-1) cationic polyelectrolyte before entering the high-rate clarifier. Suspended solids' concentrations and Escherichia coli and helminth egg's densities were monitored throughout the treatment system for 12 months. Results showed that the total suspended solids concentration in the filter effluent was lower than 7 mg L(-1) and helminth density was below 1.0 egg L(-1). The UV disinfection demonstrated the ability to produce a final effluent with E. coli density lower than 10(3)MPN/100 mL (MPN: most probable number) during the entire process. Thus, the World Health Organization standards for unrestricted crop use were met. Agronomic interest parameters were controlled and it was possible to identify the important contribution of treated sewage in terms of the main nutrients.

Sanitation assessment of wastewater treated by stabilization ponds for potential reuse in agricultural irrigation sanitation assessment.

Wastewater reuse has become an important alternative to agricultural irrigation; on the other hand, it poses concern with regard to public health. Total coliform and Escherichia coli concentration, presence of helminth eggs and Salmonella, and physical-chemical parameters were evaluated in raw and treated wastewater. Chemical and biochemical oxygen demand removal efficiency was 74.6 and 77.9%, respectively. As for organic nitrogen, total phosphorus, and total suspended solids, total efficiency removal was 17.4, 12.5, and 32.9%, respectively. The average density of total coliforms and E. coli was 3.5 x 10(9) and 1.8 x 10(8) MPN/100 mL and 1.1 x 10(7) MPN/100 mL and 3.9 x 10(5) MPN/100 mL for raw and treated wastewater, respectively. Ascaris eggs were observed in 80.8% of the samples collected, and viable eggs in 42.3% of the samples. Salmonella was detected in 36.4% of the samples. The values observed in treated wastewater did not show the adequate bacteriological quality, as recommended by World Health Organization (Geneva, Switzerland). Therefore, additional measures should be taken to achieve an improved microbiological and parasitological quality.

Palliative treatment of carcinoma of the rectum by endoscopic injection of polidocanol.

Between January 1987 and December 1988, at the Surgical Department of Chiarenzi Hospital, five patients underwent endoscopic intratumoral injection of polidocanol for palliative treatment of inoperable carcinoma of the rectum. Histological evaluation was performed in all cases. The patients comprised two males and three females aged 78 to 88 years (mean 83.4). One of them refused surgery for recurrent rectal cancer, four consulted us with impending intestinal obstruction; three were inoperable due to local spread of the tumor and poor general condition, the other was in a poor general condition due to massive metastatic hepatic disease. In all the patients, we observed remission of the obstructive symptoms with no major complications; none of them has required a colostomy. The follow-up period has covered a period of two months to two years. The technique of injection is simple, inexpensive and, properly performed, safe. All these advantages make this type of palliative treatment for rectal cancer interesting, even when compared with laser treatment, urological resectoscope or electric snare resection, and electrocoagulation.