Linear alkylbenzenes (LAB) are semi-products in the manufacture of linear alkylbenzene sulfonate surfactants that are active ingredients of various detergents. The use of traditional soluble acids (e.g. hydrofluoric acid or aluminum chloride) as catalysts for production of LAB results in the formation of large amounts of acidic toxic wastes. In this work, an efficient heterogeneous catalyst containing immobilized phosphotungstic acid (PTA) was synthesized and tested in the alkylation of benzene by higher alkenes. Sol–gel synthesis of silica gel from tetraethyl orthosilicate and PTA, as precursors, produced a mesoporous material containing covalently embedded PTA clusters. Obtained superacidic catalyst demonstrated high catalytic activity in liquid-phase alkylation of benzene by higher alkenes. Conversion of alkenes to corresponding phenylalkanes on this catalyst was significantly higher than on pure PTA. Covalent embedding of catalytically active HPA clusters prevented their leaching from the catalyst surface, which enabled its excellent catalytic properties.

A disposição de esgoto em áreas costeiras pode causar impactos para a vida marinha, alterando a biodiversidade e o equilíbrio do ecossistema chegando a causar graves doenças nos seres humanos. Neste estudo, determinou-se a concentração de um conjunto de marcadores orgânicos moleculares de introdução de esgoto no ambiente marinho: alquilbenzeno lineares (LABs) em amostras de sedimento, ostras (Crassostrea brasiliana), mexilhões (Mytella charruana e Mytella guyanensis) e peixes (Mugil curema) (Valenciennes, 1836) nos Estuário de Cananéia - Iguape e Santos - São Vicente, SP, Brasil. As concentrações de LABs (peso seco) encontradas em amostras de sedimento de Cananéia variaram de <1,0 a 80,6 ng g-1 e em Santos variaram de 6,7 a 1234,0 ng g-1. Em moluscos bivalves as concentrações detectadas em Cananéia encontravam-se na faixa de 90 a 1849 ng g-1(peso seco) e em Santos as concentrações variaram de 110 a 50495 ng g-1(peso seco). Os estudos em peixes de Cananéia apresentaram os seguintes valores médios (ng g-1 em peso seco): músculo (64,7 ± 22,6), pele (124,0 ± 60,1), fígado (164,0 ± 79,2) e rim (9,1 ± 9,9). No estuário de Santos, os tecidos de peixes apresentaram os seguintes valores médios (ng g-1 em peso seco): músculo (95,0 ± 90,1), pele (438,0 ± 437,0), fígado (274,0 ±147,0) e rim (60,7 ± 35,6). Houve diferença significativa entre as amostras analisadas nos tecidos de peixes de Cananéia e Santos evidenciando diferenças de acúmulo de LABs de acordo com o nível de antropização. A detecção de LABs nestas matrizes evidenciou a sua capacidade de acúmulo e reflete a exposição ao esgoto e portanto pode ser utilizadas no monitoramento ambiental. / The sewage disposal in coastal areas can cause impacts to marine life, altering the balance of the ecosystem and biodiversity and causing serious diseases in humans. In this study, the concentration of a set of molecular markers for the introduction of organic sewage into the marine environment: linear alkylbenzene (LAB), in samples of sediment, oysters (Crassostrea brasiliana), mussels (Mytella charruana and Mytella guyanensis) and fish (Mugil curema) (Valenciennes, 1836) from Cananéia - Iguape and Santos - São Vicente estuaries, located in Sao Paulo State, Brazil. LABs concentrations (dry weight) found in sediment samples from Cananéia ranged from <1.0 to 80.6 ng g-1 and from Santos ranged from 6.7 to 1234.0 ng g-1. In bivalve molluscs of Cananéia, the concentrations were in the range 90 to 1849 ng g-1 (dry weight) and in Santos, the concentrations ranged from 110 to 50495 ng g-1 (dry weight). Studies in fish from Cananéia showed the following average values (ng g-1 - dry weight): muscle (64.7 ± 22.6), skin (124.0 ± 60.1), liver (164.0 ± 79.2) and kidney (9.1 ± 9.9). In the Santos estuary, the fish tissue showed the following average values (ng g-1 - dry weight): muscle (95,0 ± 90.1), skin (438 ± 437), liver (274 ± 147) and kidney (60.7 ± 35.6). There were significant differences between the samples of tissues of fish from Cananéia and Santos showing differences in accumulation of LABs according to the level of anthropogenic occupation. The LABs detection in these matrices demonstrated their ability to accumulate and reflects the exposure to sewage and therefore can be used in environmental monitoring.

A disposição de esgoto em áreas costeiras pode causar impactos para a vida marinha, alterando a biodiversidade e o equilíbrio do ecossistema chegando a causar graves doenças nos seres humanos. Neste estudo, determinou-se a concentração de um conjunto de marcadores orgânicos moleculares de introdução de esgoto no ambiente marinho: alquilbenzeno lineares (LABs) em amostras de sedimento, ostras (Crassostrea brasiliana), mexilhões (Mytella charruana e Mytella guyanensis) e peixes (Mugil curema) (Valenciennes, 1836) nos Estuário de Cananéia - Iguape e Santos - São Vicente, SP, Brasil. As concentrações de LABs (peso seco) encontradas em amostras de sedimento de Cananéia variaram de <1,0 a 80,6 ng g-1 e em Santos variaram de 6,7 a 1234,0 ng g-1. Em moluscos bivalves as concentrações detectadas em Cananéia encontravam-se na faixa de 90 a 1849 ng g-1(peso seco) e em Santos as concentrações variaram de 110 a 50495 ng g-1(peso seco). Os estudos em peixes de Cananéia apresentaram os seguintes valores médios (ng g-1 em peso seco): músculo (64,7 ± 22,6), pele (124,0 ± 60,1), fígado (164,0 ± 79,2) e rim (9,1 ± 9,9). No estuário de Santos, os tecidos de peixes apresentaram os seguintes valores médios (ng g-1 em peso seco): músculo (95,0 ± 90,1), pele (438,0 ± 437,0), fígado (274,0 ±147,0) e rim (60,7 ± 35,6). Houve diferença significativa entre as amostras analisadas nos tecidos de peixes de Cananéia e Santos evidenciando diferenças de acúmulo de LABs de acordo com o nível de antropização. A detecção de LABs nestas matrizes evidenciou a sua capacidade de acúmulo e reflete a exposição ao esgoto e portanto pode ser utilizadas no monitoramento ambiental. / The sewage disposal in coastal areas can cause impacts to marine life, altering the balance of the ecosystem and biodiversity and causing serious diseases in humans. In this study, the concentration of a set of molecular markers for the introduction of organic sewage into the marine environment: linear alkylbenzene (LAB), in samples of sediment, oysters (Crassostrea brasiliana), mussels (Mytella charruana and Mytella guyanensis) and fish (Mugil curema) (Valenciennes, 1836) from Cananéia - Iguape and Santos - São Vicente estuaries, located in Sao Paulo State, Brazil. LABs concentrations (dry weight) found in sediment samples from Cananéia ranged from <1.0 to 80.6 ng g-1 and from Santos ranged from 6.7 to 1234.0 ng g-1. In bivalve molluscs of Cananéia, the concentrations were in the range 90 to 1849 ng g-1 (dry weight) and in Santos, the concentrations ranged from 110 to 50495 ng g-1 (dry weight). Studies in fish from Cananéia showed the following average values (ng g-1 - dry weight): muscle (64.7 ± 22.6), skin (124.0 ± 60.1), liver (164.0 ± 79.2) and kidney (9.1 ± 9.9). In the Santos estuary, the fish tissue showed the following average values (ng g-1 - dry weight): muscle (95,0 ± 90.1), skin (438 ± 437), liver (274 ± 147) and kidney (60.7 ± 35.6). There were significant differences between the samples of tissues of fish from Cananéia and Santos showing differences in accumulation of LABs according to the level of anthropogenic occupation. The LABs detection in these matrices demonstrated their ability to accumulate and reflects the exposure to sewage and therefore can be used in environmental monitoring.