Installation of a water disinfection system in a Mexico City hospital.

With a view to evaluating a small-scale water disinfection system based on production and application of oxidizing gases, the level of equivalent residual chlorine and the degree of contamination by fecal and total coliform bacteria was assessed at various points in the drinking water system of a Mexico City hospital before and after installation of the disinfection equipment. Tests done in May and June 1989, prior to installation of the equipment, showed that residual chlorine concentrations were lower than the national standard in most of the samples and that a sizable portion of these samples were also contaminated with fecal and total coliform concentrations exceeding national standards. After installation of the disinfection system at the main inflow to the hospital's drinking water supply in August 1989, the equivalent residual chlorine concentrations were found adequate and no coliform bacteria were detected. These results indicate that the oxidant mixture generated by the newly installed system was effectively disinfecting the water.

[The evaluation of the integral water treatment system of a general hospital in Mexico City]. / Evaluación del sistema integral para tratamiento del agua en un hospital general de la Ciudad de México.

The Mexican Health Office (SSA) promotes the use and progeny of the appropriate technology for the bacteriological quality evaluation and disinfect the water by means of the in situ progeny of the clorus and ozonus gases when needed, for the human consumption in suburban and rural communities. The clorus water disinfecting conventional methods by many reasons are useless, even in urbanized cities. CEDAT has built and design a group of apparatus, called: "Water treatment whole equipment for small communities", and it's build up by: Membrane Filter, Double Chamber Incubator, ultraviolet Light Sterilizer and a clorus and ozonus progenic gas electrolytic cell with CA and CD power box and a Venturi Tube. The electrolytic cell raw material is the sodium chlorine (salt) water mixed. The evaluation of these equipment was made at the Manuel Gea González Medical Doctor General Hospital. During 38 days there was a daily measure of chlorine sewage in six different parts of the hospital. It was used the cellulose membrane filter technic with a 0.45 mm porus and a sowing in M-Endo and M-FC Broth cultivation was in a 37 and 44 centigrade incubation. The first 10 days chlorine sewage was found, the last 28 weren't measurable. Total coliforms in 23 of 42, 7 days samples and excrement coliforms in 5 of 18, 3 days samples, were developed during the 38 days period. The electrolytic cell was settled for the water gas measure up in its way to the reservoir. Afterwards chlorine sewage was measured from 0.2 mg/l to 1 mg/l in all the sample parts. No germ kind was discovered during the 10 days sampling.(ABSTRACT TRUNCATED AT 250 WORDS)

[Removal of arsenic from water for human consumption in homes in rural communities in the Comarca Lagunera, Mexico]. / Remoción del arsénico del agua para consumo humano en domicilios de comunidades rurales de la Comarca Lagunera, México.

This paper presents the results of an intradomiciliary procedure for arsenic removal from water, by means of flocculation with ferric sulphate. The reaction was carried out in a specifically designed tank with a manual agitator (reactor) installed in a vertical support. The salts to flocculate were handed in two small envelopes, whose contents were added independently, agitating the water and letting it settle for two to three hours. Water is decanted by opening a faucet connected to the inferior part of the recipient. Ten families of the states of Durango and Coahuila (the Comarca Lagunera) were selected. Samples of water were taken before and after the treatment. In 70 percent of these samples the arsenic removal was total, and in the remaining 30 percent the removal was superior to 93 percent. The arsenic removal of water in the domicile was very effective, for which it is suggested as a palliative method for those groups with higher levels of exposition.