Low temperature conversion (LTC)--an alternative method to treat sludge generated in an industrial wastewater treatment station--batch and continuous process comparison.

In this work low temperature conversion (LTC) process was applied in a dried sludge from a petrochemical industry wastewater treatment station located in Rio de Janeiro, Brazil. The process was performed in two modes: continuous and batch-scale. This process produced a pyrolysis oil (continuous 14%; batch-scale 40% yield); pyrolytic char (continuous 46%; batch-scale 56% yield); gas and water. Pyrolysis oil fraction was analyzed by gas chromatographic mass spectrometry (GCMS) and the main components identified were toluene, ethylbenzene, styrene, isopropyl benzene, alpha-methylstyrene, butanenitrile and 1,3- biphenyl propane. Metals content, sulfur content and calorific value have been determined for the pyrolysis oil fraction. The results showed that the pyrolysis oil obtained could be used for industrial purposes and/or as energetic matrix.

Distribution and possible source of trace elements in the sediment cores of a tropical macrotidal estuary and their ecotoxicological significance.

The paper presents the first document regarding concentration, distribution and possible sources of selected trace elements (Cu, Fe, Mn, Zn, Cr, Co, Ni, Pb, Al, B and Ba) in core sediments (<63 micro particle size) from the lower stretch of Hugli (Ganges) estuary, northeast coast of Bay of Bengal by ICP-AES and EDXRF to evaluate geochemical processes influencing their distribution and possible environmental consequences. The levels of elements showed a wide range of variations in different core depths, in upper and lower intertidal zones as well as among three sampling stations. The most interesting feature of the study is the downward increase of concentrations of majority of the elements reaching overall maximum values at a depth of 20-28 cm in upper littoral zone of the site located in the extreme downstream stretch of the estuary. Values of organic carbon showed very strong positive correlations with most of the elements as revealed by correlation matrix (r) values. The interelemental relationship revealed the identical behavior of element during its transport in the estuarine environment. The overall variation in concentration can be attributed to differential discharge of untreated effluents originating from industrial, agricultural, and aquacultural sources as well as from domestic sewage along with the fishing and boating activities. The resulting compositional dataset was tested by principal component analyses and cluster analyses. Pollution load index (PLI) and index of Geoaccumulation (Igeo) revealed overall low values but the enrichment factors (EFs) for Pb were typically high for all the stations. The mean concentrations of Zn and to some extent Cu exceeded the Effects Range-Low (ER-L) values in the majority of the cases indicating that there may be some ecotoxicological risk to organisms living in sediments. The concentration of the trace elements reported in this work is useful as baselines for comparison in future sediment quality studies.