Zero Liquid Discharge approach in plating industry: treatment of degreasing effluents by electrocoagulation and anodic oxidation.

Degreasing waste effluents issued from a surface treatment plant were treated by electrochemical techniques in an attempt to reduce COD so that clean water can be returned to the rinse bath. Electrocoagulation, both with iron and aluminium anodes, and anodic oxidation with boron doped diamond (BDD) anodes were tested. In the electrocoagulation tests, the nature of the anodes did not impact significantly the reduction of COD. Electrocoagulation showed good COD removal rates, superior to 80%, but it was not able to reduce COD down to low levels. Anodic oxidation was able to reduce COD down to discharge limits; the oxidation efficiency was superior to 50%. Economical calculations show that anodic oxidation is best used as a polishing step after electrocoagulation. The bulk of the COD would be reduced by electrocoagulation and, then, anodic oxidation would reduce COD below discharge limits. The maximum treatable flow is somewhat hindered by the small sizes of current BDD installation but it would reach 600 m(3)/year if anodic oxidation is coupled with electrocoagulation, the operational cost being 2.90 Euros /m(3).

The yield of laboratory investigations in children with infantile autism.

PURPOSE: To evaluate the yield of laboratory investigations in infantile autism. METHODS: We retrieved and evaluated the results of investigative procedures recorded in the medical files of autistic infants in four child developmental centers and two pediatric psychiatric outpatient clinics. RESULTS: One-hundred and thirty-two infants were included in the study of whom 47 (36%) underwent autistic regression at an average age of 20 months. The investigative procedures included electroencephalogram (n = 132), neuroimaging (n = 70), genetic studies to detect Fragile-X (n = 59) and a metabolic workup (n = 53). Except for the molecular diagnosis that revealed Fragile-X syndrome in two children (3%), all other tests were negative. The two infants with the Fragile-X syndrome belonged to the non-regressive group. CONCLUSIONS: The only investigative study that contributed to the diagnosis of autistic infants was the molecular diagnosis detecting Fragile-X. In spite of the high frequency of epilepsy and epileptiform abnormalities in the electroencephalograms of autistic children in general, the contribution of epilepsy, both clinical and subclinical, to the etiology of autism is apparently minimal.