in this research, a pvc membrane electrode for manganese (ii) ions based on n-(2-picolinamidoethyl)picolinamide as neutral carrier was prepared. the electrode exhibits a nemstian responseover mn(ii) concentration range of (1.0 x10-5 t01.0 x 10-1m) with a slope of 29.3±0.5 mv perdecade of concentration with a working ph range of 4.0-9.0. it has a fast response time (

no on-site sanitation system treats both urine and faecal matter in one process. a laboratory scale biological filter was fed with high concentration of urea (4 g n/l) and 17.1 g cod/l to determine if it will be possible to treat liquid that leach from a ventilated improved pit latrine. the hlr in the proposed biological filter system was calculated to be ca 36 l/m2/d, significantly lower than ...