Tertiary treatment of slaughterhouse effluent: degradation kinetics applying UV radiation or H2O2/UV.

In some Brazilian regions, surface water has become scarce, e.g. semi arid climate areas and densely populated and industrial areas, where water over-exploitation and/or fluvial pollution has been more common. Advanced oxidative processes (AOP) provide treated water as a source of reuse water even with the characteristics of drinking water enabling water reuse practices also in food industries. The secondary wastewater of a slaughterhouse was the water source for a tertiary treatment study evaluating the kinetics of the photo-induced degradation of color and UV254 under UV radiation with and without the addition of H2O2. The proximity of the k' values of color and UV254 degradation by UV indicates that the compounds responsible for color may be the same content measured by UV254. The H2O2/UV treatment was 5.2 times faster than simple UV in removing aromatic compounds. The degradation kinetics of aromatic compounds in both treatments followed a pseudo-first order law. The pseudo-first order constant for H2O2/UV and UV treatments were kUV254'=0.0306 min(-1) and kUV254'=0.0056 min(-1), respectively.

Amebiasis in Nicaragua: class specific serum antibody responses.

With the aid of the indirect hemagglutination (IHA) test and IgG ELISA the antibody profile against E. histolytica in León, Nicaragua was investigated in 562 sera from individuals belonging to various age groups. The highest reactivity was invariably recorded in the age group 6-15 years where 48% were seropositive. Several sera reactive by either one of IHA and IgG ELISA were negative by the other test. The main reason for this seems to be reactivity in different Ig classes. Treatment with 2-mercaptoethanol reduced the titre level in 63 of the 66 sera tested. Immunofluorescence using an anti-IgM conjugate showed that 26 of 43 sera contained specific IgM-antibodies, indicating that also unspecific reactions are involved in the IHA test. A comparison was made between class-specific reactivity in three population groups: healthy residents, healthy cyst carriers and patients with recent or acute liver abscess. No significant difference in the prevalence of reactions above the diagnostic significance level was recorded between cyst carriers and healthy residents. However, among the cyst carriers 33% had IgA and/or IgM antibodies but no demonstrable specific IgG. Most patients with recent and all with acute liver abscess reacted significantly above the diagnostic limit in all three tests.

Detection of IgG, IgA, IgM and IgE in antibodies in invasive amoebiasis in endemic areas.

Entamoeba histolytica--specific serum IgG, IgA, IgM and IgE were assayed in cases of amoebiasis in an endemic area. Patient groups consisted of amoebic liver abscess (n = 18), pre abscess hepatic amoebiasis (n = 22) and amoebic colitis (n = 30). Control subjects comprised 26 asymptomatic cyst passers, 13 giardiasis cases, 20 typhoid patients and 24 non amoebic individuals. Serum IgG was assayed by ELISA: using a monoclonal anti IgG beta-galactosidase (IgG beta-gal) conjugate, a polyclonal avidin biotin horse radish peroxidase (AB-HRP) and a polyclonal anti IgG horse radish peroxidase (IgG HRP) conjugate. IgA and IgM were assayed by the beta-gal ELISA and IgE by AB-HRP. Diagnostically significant IgG and IgA while lower IgM and IgE levels were seen in extra intestinal cases. About 40% of suspected pre abscess hepatic amoebiasis cases were confirmed by antibody estimation. All isotype levels in most dysentery cases were in the range of the controls. Inter assay coefficient of variation and assay specificity/sensitivity are also discussed.