Biodegradation of natural and synthetic estrogens in moving bed bioreactor

Estrogen hormones as a group of endocrine disruptive compounds(EDC) can interfere with endocrine system in humans and animals. The goal of this study was to investigate the elimination rate of Estrone(El), 17β-estradiol(E2) and 17α-ethinyl estradiol(EE2) in Moving Bed Bioreactor(MBBR). These analytes extracted by Dispersive Liquid-Liquid Microextraction(DLLME) technique, followed by derivatization, and detected by GC/MS. Estrogen removal efficiency in MBBR improved at high solid retention times(SRTs), which notion is owing to development of nitrification. Estrogen specific removal rate was between 0.22-1.45 μg·(g VSS)^(-1)·d^(-1) for natural and synthetic hormones. The adsorption rate was 0.9%-3.2%, 0-1.3%, and 0.7%-5.7% for El, E2, and EE2, respectively. In addition, the biodegradation rates were more than 95% for these compounds. These results illustrated that in MBBR,the biodegradation and the adsorption to biomass are considered as two significant routes for elimination of estrogenic compounds. As a whole, the deterioration rate of estrogens enhanced by MBBR compared to other biological wastewater treatment processes such as conventional activated sludge.

Determination of 4-nonylphenol and 4-tert-octylphenol compounds in various types of wastewater and their removal rates in different treatment processes in nine wastewater treatment plants of Iran

Alkylphenols(APs), considered as xenoestrogenic compounds, mainly exist as 4-nonylphenol(4-NP) and 4-tertoctylphenol(4-t-OP) in environments. The high stability and accumulation of APs in aquatic systems have caused endocrine disruption. In this study we measured APs in the wastewater influent and effluent samples, from the urban, rural, livestock, commercial and hospital wastewater treatment plants(WWTPs) in Iran. Dispersive liquid–liquid microextraction(DLLME) combined with gas chromatography–mass spectrometry(GC–MS) was used for the extraction and determination of 4-NP and 4-t-OP. In these treatment plants, various processes such as activated sludge, aerated lagoon, moving bed biofilm reactor and activated sludge along with wetland were applied. The highest concentration of 4-NP and 4-t-OP was observed in commercial and livestock sewages. The activated sludge along with wetland and then the MBBR process showed the highest removal rates of pollutants. The rates of biodegradability and accumulation in sludge were determined and also the specific adsorption coefficient Kdand the organic carbon–water partition coefficient kOCof the sludge for APs were calculated.

Evaluation of the effects of Alkyl Phenolic compounds on kinetic coefficients and biomass activity in MBBR by means of respirometric techniques

The presence of Alkyl Phenols(APs) in aquatic systems is considered as one of the environmental concerns in recent decades which are generally used as surfactants. APs are endocrine disruptors and estrogen-mimicking,causing harmful effects such as feminization and carcinogenesis on aquatic environment and human health.The most commercially important APs are 4-Nonyl Phenol(4-NP) and 4-tert-OctylP henol(4-t-OP). Moving bed biofilm reactor(MBBR), which combined attached and suspended growth advantages, is an advanced biological treatment process for municipal and industrial wastewaters that has drawn considerable attention from many researchers to remove toxic pollutants from wastewater. The aim of this research was to evaluate Bacterial activities and kinetic coefficients in the presence of APs. This study was carried out using laboratory-scale MBBR fed with synthetic wastewater containing 4-NP and 4-t-OP. The reactor was operated at different loads of chemical oxygen demand(COD) and APs and different hydraulic retention time(HRT). The respirometric technique was applied to investigate the effect of APs on heterotrophic and autotrophic activity and kinetic coefficients in biomass obtained from MBBR. Respirometric technique demonstrates a reliable tool in order to assess the biofilm kinetic coefficients and biomass viability to insert in the mathematical models. The calculated kinetic parameters were in the range of conventional and extended aeration activated sludge processes. The results demonstrate that APs have significant inhibitory effects on activity and growth rate of heterotrophic and autotrophic bacteria, heterotrophs have been less affected by the presence of 4-NP and 4-t-OP, and these compounds had greater inhibitory effects on autotrophic bacteria.

Paraben Content in Adjacent Normal-malignant Breast Tissues from Women with Breast Cancer

Objective Accumulation of estrogenic compounds and other carcinogens in normal breast tissues contributes to unpredictable breast cancer incidence during adolescence and throughout life.To assess the role of parabens in this phenomenon,the paraben content of adjacent normal-malignant breast tissues is measured in women with breast cancer living in Isfahan Province,Iran.Methods Adjacent normal-malignant breast tissue samples were obtained from 53 subjects.The parabens including methyl-paraben(Me PB),ethyl-paraben(Et PB),propyl-paraben(Pr PB),and butylparaben(Bu PB)were extracted from the sample supernatant and then subjected to gas chromatography analysis.Results Some risk factors for breast cancer were stimulated by parabens in adjacent malignant-normal breast tissues among young and middle-aged women with breast cancer.We observed a significant association for dose-response pattern of Me PB[OR=98.34(11.43–185.2),P=0.027]for both ER+and PR+women and Me PB[OR=164.3(CI:112.3–216.3),P<0.001]for HER2+women than women with negative receptors.The risk of 95-fold increase in Me PB dose and 164-fold increase in∑PBs dose were significant for women with hereditary breast cancer in first-degree relatives.Conclusions These results may promote future epidemiology studies and strategies to improve women's lifestyle and consume paraben-free products.

The occurrence,fate,and distribution of natural and synthetic hormones in different types of wastewater treatment plants in Iran

Over the past few years, the presence of steroid estrogens in the environment has become a major concern. In this study, the concentrations of estrone(E1), 17β-estradiol(E2), and 17α-ethinyl estradiol(EE2) were measured in some wastewater treatment plants(WWTPs) in Iran. These samples were collected from the municipal, rural,livestock, commercial, and hospital WWTPs, extracted by dispersive liquid–liquid micro extraction(DLLME)technique, derivatized, and detected by GC/MS. In these treatment plants, various processes including conventional activated sludge(CAS), aerated lagoon(AL), moving bed biofilm reactor(MBBR), and activated sludge with wetland(AS + WL) are used. The highest concentration of hormones was observed in the influents and effluents of livestock, municipal, commercial, and hospital WWTPs, respectively. The maximum elimination rate was obtained in MBBR followed by AS + WL, CAS and AL. The biodegradation and adsorption rates along with adsorption coefficients of lg kdand lg kocwere measured for all target compounds.

Benzene removal by nano magnetic particles under continuous condition from aqueous solutions

Benzene removal evaluated using Fe304 nano continuous condition. A 44 initial benzene concentration, from aqueous solutions was magnetic particles （NM） in factorial design including NM dose, contact time and pH was investigated in 16 experiments （Taguchi OA design）. The results indicated that all factors were significant and the optimum condition was： pH 8, NM dose of 2000 mg.L-1, benzene concentrations of 100 mg.L-1 and contact time of 14min. The maximum benzene uptake and distribution ratio in the optimum situation were 49.4mg.g-1 and 38.4L.g-1, respectively. The nano particles were shown to capture 98.7% of the benzene in optimum batch condition and 94.5% in continuous condition. The isotherm data proved that the Bmnauer-Emmett-Teller model fit more closely and produced an isotherm constant （b） less than one, indicating favorable adsorption. Regeneration studies verified that the benzene adsorbed by the NM could be easily desorbed by temperature, and thereby, NM can be employed repeatedly in water and wastewater management.