990 resultados para Ethylenediammonium sulphate


Relevância:

10.00% 10.00%

Publicador:

Resumo:

The properties of the nickel(II)/2-hydroxy-5-nonylacetophenone oxime (HNAPO), an active ingredient in LIX 84, extraction system were characterised in a micellar system. The extinction coefficient, λmax of HNAPO (316 nm) and the Ni2+ complex (387 nm) in a neutral micellar system, poly dispersed octa-ethyleneglycol mono-n-dodecyl ether (G12A8) were determined as 3100 and 3500 M−1 cm−1, respectively. HNAPO was found to have a neutral micellar phase and bulk aqueous phase pKa of 11.5 and 12.5, respectively. The extraction equilibrium constant, Kex, was determined to be 10−8.0, and the deviation from theory observed at high pH can be accounted for by consideration of the competition for nickel(II) ions by hydroxide ions and HNAPO. A micellar phase of octa-ethyleneglycol mono-n-dodecyl ether (C12E8) was determined to be an appropriate model of the free oil/water interface from the solubilised location of HNAPO. Utilising the interfacial probe, 4-heptadecyl-7-hydroxy coumarin (HHC) allowed the determination of the electrostatic surface potential of mixed micelles of G12A8 and sodium dodecyl sulphate (SDS) or dodecyl trimethyl ammonium chloride (DTAC). The electrostatic surface potential was a linear function of the number of additional surfactant monomers within the G12A8 micelle, for the concentration range studied. For G12A8/DTAC mixed micelles, the surface potential was given by +1.1 mV per DTAC molecule per micelle, and for G12A8/SDS mixed micelles the relationship was −1.4 mV per SDS molecule per micelle.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

An extracellular naringinase (an enzyme complex consisting of α-L-rhamnosidase and β-D-glucosidase activity, EC 3.2.1.40) that hydrolyses naringin (a trihydroxy flavonoid) for the production of rhamnose and glucose was purified from the culture filtrate of Aspergillus niger 1344. The enzyme was purified 38-fold by ammonium sulphate precipitation, ion exchange and gel filtration chromatography with an overall recovery of 19% with a specific activity of 867 units per mg of protein. The molecular mass of the purified enzyme was estimated to be about 168 kDa by gel filtration chromatography on a Sephadex G-200 column and the molecular mass of the subunits was estimated to be 85 kDa by sodium dodecyl sulphate-Polyacrylamide gel electrophoresis (SDS-PAGE). The enzyme had an optimum pH of 4.0 and temperature of 50 °C, respectively. The naringinase was stable at 37 °C for 72 h, whereas at 40 °C the enzyme showed 50% inactivation after 96 h of incubation. Hg2+, SDS, p-chloromercuribenzoate, Cu2+ and Mn2+ completely inhibited the enzyme activity at a concentration of 2.5–10 mM, whereas, Ca2+, Co2+ and Mg2+ showed very little inactivation even at high concentrations (10–100 mM). The enzyme activity was strongly inhibited by rhamnose, the end product of naringin hydrolysis. The enzyme activity was accelerated by Mg2+ and remained stable for one year after storage at −20 °C. The purified enzyme preparation successfully hydrolysed naringin and rutin, but not hesperidin.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A newly isolated strain of Kluyveromyces marxianus YS-1 was used for the production of extra cellular inulinase in a medium containing inulin, meat extract, CaCl2 and sodium dodecyl sulphate (SDS). Fermentation medium pH 6.5, cultivation temperature 30 °C and 5% (v/v) inoculum of 12 h-old culture were optimal for enzyme production (30.8 IU/ml) with a fermentation time of 72 h at shake flask level. Raw inulin (2%, w/v) extracted from dahlia tubers by processing at 15 kg/cm2 for 10 min was optimum for bioreactor studies. Maximum enzyme production (55.4 IU/ml) was obtained at an agitation rate of 200 rpm and aeration of 0.75 vvm in a stirred tank reactor with a fermentation time of 60 h.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Nonmammalian vertebrates possess some unusual features in their hormonal systems/ when compared to mammals. As a consequence, they can make an important contribution in investigations concerning the fundamental mechanisms operating in endocrinology. Such studies concerning androgens include inter alia their effects on developmental aspects in the brain of birds and related singing behaviour; the role of neural enzymes in reproductive processes in fish; and the relation between androgens and the stages of spermatogenesis in amphibia, The present thesis examines the biochemistry of androgens in the Australian lizard Tiliqua rugosa. The major compounds studied were testosterone and epitestosterone, which are known to be present in high concentrations in the plasma of the male animal. Previous investigations are expanded, particularly in the areas of steroid identification and testicular biosynthesis. In addition, preliminary studies on the metabolism in the brain (and other tissues) and plasma protein binding are reported. The presence of epitestosterone as a major free androgen in the plasma of the male lizard was confirmed. Other steroids were found in the sulphate fraction. Testosterone sulphate was the most rigorously identified compound, while some evidence was also found for the presence of conjugated 5-androstene-3β,17-diols, etiocholanolone and dehydroepiandrosterone (DHA). Epitestosterone does not appear to be extensively conjugated in this animal. Steroids were not found to be conjugated as glucuronides. The identification studies employed a novel method of electrochemical detection of steroids. This technique was investigated and extended in the current thesis. Biosynthetic studies were carried out on androgen interconversions in the testis, in vitro. The major enzyme activities detected were 17α-arid 17β-oxidoreductases (17α-OR and l7β-OR) and 3β-hydroxysteroid dehydrogenase (3β-HSD)/isonerase. No evidence was found for the presence of a steroid-17-epimerase that would directly interconvert testosterone and epitestosterone. The 17-oxidoreductases were found to be dependent on the cofactor NBDFH. Testosterone appears to be formed mainly via the 4-ene pathway, whereas epitestosterone is formed from both the 4- and 5-ene routes. The compound 5-androstene-3β, 17α-diol was found to be an intermediate in the synthesis of epitestosterone from DHA. Temperature was found to significantly affect 17α-OR activity (maximum at 32°C). In contrast,17β-OR activity was independent of this factor in the testis. Androgen metabolism in the testis was found to be regulated by cofactors, temperature and season. The major enzyme activities found in the male brain were 17α- and 17β-OR. 3βHSD/isomerase was not found; however a low activity of 5α-reductase was identified. Aromatase activity was not positively identified, but preliminary results suggest that it may be present at low levels. The 17-oxidoreductases were widespread throughout the brain. The 17α-OR was significantly lower in the forebrain than other brain sections. The 170-OR activity did not vary significantly throughout the organ, although there was a trend for its activity to be higher in the midbrain region (containing the hypothalamus in these sections). The concentration of endogenous steroids in brain tissue was estimated by radioimmunoassay. Epitestosterone was found throughout the organ structure, whereas testosterone was found mainly in the midbrain (containing hypothalamic regions in these sections). Correlations between enzyme activities and steroid concentrations in brain regions suggested that the main function of 17α-OR is to produce epitestosterone, whereas the 17β-OR may catalyse a more reversible reaction in vivo. Temperature was found to significantly affect both 17α- and 17β-OR activities in the brain. In contrast to the testis, the maximum activity of the brain enzymes occurred at 37°C. The level of 17α-OR activity in the male lizard (100 nmol/g tissue/h) is the highest reported for this enzyme in vertebrates. Both activities were found to be quantitatively similar in the whole brain homogenates of male and female animals, and did not vary seasonally when examined in the male. The 17-oxidoreductases were also found in most other tissues in T.rugosa, including epididymis, adrenal, kidney and liver (but not blood). This suggests that the high activities of both 17α-OR and 17β-OR are dominant features of the steroid system in this animal. The formation of 11-oxygenated compounds was found in the adrenal, in addition to the formation of polar metabolites in the kidney and liver (possibly polyhydroxylated and conjugated steroids). A preliminary investigation into the plasma binding of androgens was carried out. The insults suggest that there are several binding sites for testosterone; one with high affinity and low capacity; the other with low affinity and high capacity. Binding experiments were carried out at 32°C. At this temperature, specific binding was greater than at 25 or 37°C. From the results of competition studies it was suggested that epitestosterone (with a K(i)= 3 X 10 (-6)M for testosterone binding) regulates the binding of testosterone (K(i)=10(-7)M) and hence the concentrations of the latter steroid as a free compound in plasma. In general, the study has shown that the biochemistry of androgens in the reptile T.rugosa is largely similar to that found in other vertebrates. The major difference is a greatly increased activity of 17α-OR, which causes a higher concentration of 17α-compounds to be present in the tissues of this lizard. The physiological roles for epitestosterone are not yet clear. However it appears from this study that this steroid regulates testosterone concentrations in several tissues by either steroidogenic or binding mechanisms. Several major influences on this regulation include temperature, availability of cofactors and seasonal effects.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The Co2+ sorption of two wool powders was investigated using its radioisotope 57Co (T1/2=271.8 days and γ=122.1 and 136.5 keV) as a tracer. The effects of the type of buffer, the pH value, the contact time and the initial concentration of Co2+ on the sorption behaviour of wool powders were studied. The Co2+ releasing ability of wool powders and the re-use of wool powders to sorb Co2+ were also examined. The optimum sorption of Co2+ by the powders occurred at pH 8 in phosphate buffer and pH 10 in ammonium sulphate buffer. Fourier-transform infrared spectroscopy (FTIR) was used to study the changes in chemical structure of the wool after exposure to both buffer solutions. Compared to the untreated wool fibre, the fine wool powders showed rapid sorption rates and high sorption capacities for Co2+. Co2+ ions were recovered after exposing the Co2+ loaded wool to HCl (0.1 M) and buffer at pH 3 (glycine/sodium chloride). After releasing Co2+ ions from wool powders, the efficiency of wool powders re-used to sorb Co2+ was 80% of that of the fresh wool powders. It is concluded from this study that wool powder can be used as an efficient sorbent to remove and release Co2+ from solution.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This study was carried out to investigate the treatment of various salt solutions and synthetic dye bath liquors by nanofiltration using Nanomax-50 membrane in a stirred cell with 150 mL working volume. Donnan exclusion was compared by filtering salts with monovalent and divalent cations and anions. This was done by comparing three salts including sodium chloride (NaCl), calcium chloride (CaCl2) and sodium sulphate (Na2SO4). The rejection order determined was Na2SO4>NaCl>CaCl2 which is typical of a negatively charged membrane where Donnan and steric exclusion play an important role in separation. Studies on the flux and rejection characteristics of sodium sulphate were undertaken for concentrations ranging from 10 to 40 gl−1 thereby replicating actual dye bath salt concentrations. Synthetic dye bath liquors were prepared using acidic dye (Acid Green 25) at a fixed concentration of 100 mgl−1 with 10 and 15 gl−1 of sodium sulphate solutions. While, the results showed evidence of flux decline due to increased resistance and decreased transmembrane pressure, pore enlargement occurred after the filtration experiments with sodium sulphate solutions greater than 20 gl−1. Pore enlargement was even more prominent in the two synthetic dye bath liquors filtered. Pore enlargement was determined by observing the pure water flux before and after filtering sodium sulphate solutions or dye bath liquors. An increase in pore diameter of 58 and 94 %was estimated when dye bath liquors containing 10 and 15 gl−1 of sodium sulphate, respectively were filtered through the membrane. The following equation was derived in estimating the pore enlargement, where de1 and de2 are the apparent diameter of membrane pore sizes before and after filtration of salt solutions or dye bath liquors and Rm1 and Rm2 are the membrane resistance of pure water flux before and after filtration of salt solutions or dye bath liquors. These results have important implications for the application of nanofiltration technology to textile wastewater treatment and reuse.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This paper investigates the bending deformation of a cantilever biosensor based on a single-walled carbon nanotube (CNT) and single-walled boron nitride nanotube (BNNT) due to bioparticle detection. Through 3-D modeling and simulations, the performance of the CNT and BNNT cantilever biosensors is analyzed. It is found that the BNNT cantilever has better response and sensitivity compared to the CNT counterpart. Additionally, an algorithm for an electrostatic-mechanical coupled system is developed. The cantilever (both BNNT and CNT) is modelled by accounting that a conductive polymer is deposited onto the nanotube surfaces. Two main approaches are considered for the mechanical deformation of the nanotube beam. The first one is differential surface stress produced by the binding of biomolecules onto the surface. The second one is the charge released from the biomolecular interaction. Also, different ambient conditions are considered in the study of sensitivity. Sodium Dodisyl Sulphate (SDS) provides better bending deformation than the air medium. Other parameters including length of beam, variation of beam's location, and chiralities are considered in the design. The results are in excellent agreement with the electrostatic equations that govern the deformation of cantilever.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Plasma treatment is an emerging surface modification technique that alters dye uptake of wool without using chemicals or water for pre-treatment. Padding is an established continuous dyeing technique known for its efficient use of water, time and energy. This study combined these two techniques for colouration of wool fabric using two natural dyes derived from the Acacia plant family. The investigation focused on the effects of plasma treatment and obtaining unique patterning effects. Helium (100%) and a mixture of helium and nitrogen (95%/5%) were used as the plasma gases under atmospheric conditions. Plasma treated wool fabric was padded with the above natural dyes. Copper sulphate and ferrous sulphate were applied on the dyed fabric as mordant yielding neutral shades of beige and grey respectively. Up to a 30% enhancement of dye adsorption on plasma treated wool substrate was observed as compared to untreated sample for both gases used. This higher adsorption indicates the hydrophilic character of the natural dyes used. Key performance parameters such as fastness to washing, rubbing and light were tested and found to be satisfactory. A single process tone-on-tone pattern was achieved by controlling the plasma exposure of treated area. This study concluded that a merger of natural dyes with modern plasma treatment and padding techniques for wool colouration was feasible.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

 Early timing of adrenarche, associated with relatively high levels of dehydroepiandrosterone (DHEA) and its sulphate (DHEA-S) in children, has been linked with mental health problems, particularly anxiety. However, little is known about possible neurobiological mechanisms underlying this association. The pituitary gland is a key component of the hypothalamic–pituitary–adrenal (HPA) axis, the activation of which triggers the onset of adrenarche. The purpose of this study was to examine the extent to which pituitary gland volume mediated the relationship between levels of DHEA/DHEA-S relative to age (i.e., adrenarcheal timing) and symptoms of anxiety in 95 children (50 female, M age 9.50 years, SD 0.34 years). Relatively high DHEA and DHEA-S (DHEA/S) levels were found to be associated with larger pituitary gland volumes. There was no significant direct effect of relative DHEA/S levels on overall symptoms of anxiety. However, results supported an indirect link between relatively high DHEA/S levels and symptoms of social anxiety, mediated by pituitary gland volume. No sex differences were observed for any relationship. Our findings suggest that neurobiological mechanisms may be partly responsible for the link between relatively early adrenarche and anxiety symptoms in children. One possible mechanism for this finding is that an enlarged pituitary gland in children experiencing relatively advanced adrenarche might be associated with hyper-activity/reactivity of the HPA axis. Further research is needed to understand the role of stress in the link between adrenarcheal timing and HPA-axis function, especially in relation to the development of anxiety symptoms in children and adolescents.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In this paper, some recent work on the flow induced by an external magnetic fields acting on electrochemical cell is reviewed. Although the influence of the magnetic field on the hydrodynamics has been studied for over 5 decades, the magnetohydrodynamics (MHD) remains relatively unfamiliar to all but a few research groups. There are nearly a countless number of dimensionless parameters in electrolytic flow (bubble induced flow) and MHD, but they have been introduced for convenience by different authors. The similitude parameter proposed by Solheim, Johansen, Rolseth, and Thonstad (1989) and Perron, Kiss, and Poncsák (2006) have been modified to provide a full set of parameters for electrolytic cell operating under external magnetic field. The bubble sliding characteristics underneath an inclined plane are studied using copper sulphate solution (as an electrolyte) in lab-based-scale and discussed.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Neste trabalho estuda-se o processo de flotação por ar dissolvido (FAD) como método de remoção de óleos emulsificados. Realizou-se uma revisão bibliográfica tanto do processo de flotação como dos fundamentos físico-químicos envolvidos na estabilidade e flotação de emulsões. Foram realizados testes de estabilidade de emulsões, de FAD descontínuos e contínuos, utilizando-se emulsões de 1000 mg/l de Óleo diesel e heptano. Verificou-se a eficiência do sulfato de alumínio e de compostos poliméricos como agentes desestabilizantes. Estudou-se a influência do tipo e concentração dos agentes desestabilizantes, pH da emulsão, do tipo de água e agitação nos testes de estabilidade como também na flotação por ar dissolvido. Os resultados obtidos indicaram a viabilidade técnica da aplicação do processo para a clarificação de efluentes oleosos atingindo valores de turbidez residual satisfatórios (menores que 5 UNT). O sulfato de alumínio mostrou-se mais eficiente como agente desestabilizante de ambas emulsões nos estudos de estabilidade e testes de PAD descontínuos, mas o polímero catiônico C-505 apresentou melhores resultados nos testes de flotação contínuos. O presente trabalho ainda apresenta um estudo de dimensionamento e do custo da unidade de FAD para remoção de óleos emulsificados que leva em consideração os custos de investimentos e de operação da unidade. Verifica-se que o custo total da unidade depende da vazão de alimentação, taxa de recirculação, taxa ar/sólido em massa e concentração inicial de óleos. Conclui-se que para as taxas de ar/sólido usados na indústria (geralmente menores que 0,1) o custo operacional do reagente é o parâmetro determinante do custo total atualizado da unidade. Isto faz com que o custo total atualizado seja essencialmente independente da relação taxa de aplicação - taxa ar/sólido.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

O presente trabalho estuda a viabilidade da utilização do processo de flotação a ar dissolvido (FAD) no tratamento de efluentes contendo cromo. Tal processo é analisado comparativamente à sedimentação. Urna revisão dos diferentes tipos de processos de separação ou de recuperação do cromo é, também, aqui apresentada. Soluções contendo 200 mg.l" de cromo tri ou hexavalente foram estudadas quanto às condições ideais de precipitação, às características de sedimentação e de flotação a ar dissalvido em regime descontínuo e contlnuo. Agentes poliméricos foram testados no intuito de melhorar as condições de clarificação. O processo de FAD foi o que apresentou melhores resultados no que se refere a cinética de separação sólido/líquido, e em termos de clarificação das soluções. Estudos de separação sólido/líquido de soluções contendo cromo VI foram feitos por estes dois processos empregando sulfato ferroso e sulfito de sódio como agentes redutores. A FAD mostrou ser eficiente para tratar as soluções quando reduzidas com sulfito de sódio. Porém, no caso da utilização do sulfato ferroso como redutor, o rendimento da FAD diminuiu no tratamento de soluções que continham sólidos suspensos acima de uma concentração crítica. Polímeros também foram empregados neste caso, e confirmaram sua atuação melhorando a cinética de separação sólido/líquido e como agentes que beneficiam a clarificação das soluções. Os resultados dos estudos de flotação por ar dissolvido em uma unidade contínua mostraram que é viavel a FAD sem agentes floculantes ou tensoativos. No entanto, estes aumentam os níveis de clarificação das soluções. Apenas os floculantes a base de amido mostraram-se ineficientes nesta aplicação. Conclui-se que o processo de FAD pode ser utilizado no tratamento de efluentes contendo cromo permitindo obter efluentes finais dentro dos padrões de emissão da legislação brasileira.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Introdução: Pirose e regurgitação são manifestações da Doença do Refluxo Gastresofágico (DRGE) que ocorrem freqüentemente no terceiro trimestre da gravidez, porém seu impacto na qualidade de vida de gestantes é pouco conhecido. Objetivos: 1. Mensurar a qualidade de vida em gestantes no terceiro trimestre da gravidez com Pirose e Regurgitação; 2. Avaliar a relação entre Pirose e Regurgitação e a dieta. Pacientes e Métodos: Gestantes no terceiro trimestre acompanhadas ambulatorialmente foram entrevistadas para colher dados referentes à história obstétrica, freqüência, intensidade e passado de P e R, qualidade de vida (mensurada a partir do questionário genérico SF-36), ingestão alimentar (avaliada por recordatório de 24h) e medidas antropométricas; Resultados: Foram estudadas consecutivamente 82 gestantes: 62 com pirose e/ou regurgitação e 20 assintomáticas. Pirose foi relatada por 62 (76%) gestantes e regurgitação por 58 (71%). A idade gestacional média foi 33,8±3,7 semanas, 35 (43%) apresentavam história familiar positiva de pirose e/ou regurgitação e 57 (70%) não apresentavam tais sintomas fora da gravidez. Houve redução estatisticamente significativa na qualidade de vida das gestantes sintomáticas nos seguintes domínios: Para pirose, em Limitação Física e Aspectos Sociais; para regurgitação, em Limitação Física, Aspectos Sociais, Aspectos Emocionais e Dor. Houve concordância entre presença de pirose em gestações passadas e a atual. Gestantes com pirose apresentaram-se significativamente com maior peso corporal. Ácidos graxos poli e monoinsaturados, cafeína, ácido ascórbico e sulfato ferroso foram significativamente associados com pirose e/ou regurgitação. Conclusões: 1.Pirose e / ou regurgitação diminuíram a qualidade de vida em gestantes no terceiro trimestre; 2. ácidos graxos, cafeína, ácido ascórbico e sulfato ferroso estiveram associados com pirose e/ou regurgitação.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A proteinaceous trypsin inhibitor was purified from Crotalaria pallida seeds by ammonium sulphate fractionation, affinity chromatography on immobilized Trypsin-Sepharose and TCA precipitation. The trypsin inhibitor, named ITC, had Mr of 32.5 kDa by SDS-PAGE and was composed by two subunits with 27.7 and 5.6 kDa linked by disulphide bridges, a typical characteristic of Kunitz-Inhibitor family. ITC was stable until 50°C, and at 100°C its residual activity was of about 60%. Also, ITC was stable at pHs 2 to 12. The inhibition of trypsin by ITC was non-competitive, with a Ki of 8,8 x 10-7M. ITC inhibits weakly other serine proteinases such as chymotrypsin and elastase. The inhibition of papain (44% of inhibition), a cysteine proteinase was an indicative of the bi-functionality of ITC. In vitro assays against digestive proteinases from several Lepdoptera, Diptera and Coleoptera pests were made. ITC inhibited in 100% digestive enzymes of Ceratitis capitata (fruit fly), Spodoptera frugiperda and Alabama argillacea, the last one being a cotton pest. It also inhibited in 74.4% Callosobruchus maculatus (bean weevil) digestive enzymes, a Coleoptera pest. ITC, when added in artificial diet models, affected weakly the development of C. capitata larvae and it had a WD50 of 2.65% to C. maculatus larvae

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This work studies the involved enzymatic way in the metabolism of glycosaminoglycans sulfateds in the mollusc Pomacea sp. Had been identified endoglycosidases and exoglycosidases in the enzymatic extract of the mollusc Pomacea sp by means of hydrolysis activity in condroitim sulphate of whale cartilage and of the p-Nitrofenil-β-glucuronide, respectively. The enzymatic extracts qere obtained of Pomacea sp. being used of 0.1 sodium acetate buffer, pH 5.0 and later centrifugated the 8,000 x g and the presents proteins in the sobrenadante were submitted to the fractionament with two crescents ammonium sulphate concentrations, the visualized activity biggest in the F2 fraction (50-80%). The β-glucuronidase (F3) was isolated in gel chromatography filtration Biogel 1.5m, the purification degree was ratified in Chromatography Liquid of high efficiency (HPLC). The enzyme was purificated 6.362,5 times with 35,6% yield. The β -glucuronidase isolated in this work showed a molecular mass of 100 kDa, determined for eletroforese in poliacrilamida gel . The determination of the ideal kinetic parameters for the catalysis of the p-nitrofenil- β -glucuronide for β-glucuronidase, showed excellent activity in pH 5,0 and temperature 65ºC for 6 hours and apparent Km of 72 x 10-2 mM. It is necessary for the total degradation of 3mM of p-N-β-glucoronide, the amount of 1,2μg of ss-glucuronidase. The BaCl2 increased the activity of ss-glucuronidase, and the activity was inhibited completely by the composites SDS and NaH2PO4