Ethnopharmacological studies of medicinal plants in central Zagros, Lorestan Province, Iran.

ETHNOPHARMACOLOGICAL RELEVANCE: Lorestan Province (Iran) has a great diversity of habitats and plant diversity and the people living in this province have a good knowledge of herbal therapies. AIM OF THE STUDY: In this study, the authors aimed to identify and report the medicinal plants used in the folk medicine of Lorestan. MATERIAL AND METHODS: The indigenous medicinal information was collected with a semi-structured open-ended questionnaire, interviews, and personal observations. The relative importance of the species were estimated through frequency of citations (FC). RESULTS: and discussion: A total of 555 plants belonging to 91 families were identified. The plants belong to Asteraceae with 62 species followed by Lamiaceae (56), Apiaceae (44), Fabaceae (41), and Brassicaceae (31). The plants were mostly used as a decoction or eaten raw (32%). Leaves (22%) were the most utilized plant parts followed by shoots (16%), and seeds (13%). Thymus daenensis, Thymus eriocalyx, Mentha longifolia, Mentha spicata, Mentha piperitha, Alium sativum, Quercus infectoria, Quercus persica, Ziziphora clinopodioides, and Malus domestica had the highest FC values. Most of the plants were used for gastrointestinal, respiratory, and skin problems. CONCLUSION: Lorestan is a region rich in medicinal plants. The local knowledge of herbal therapies can be used as complementary medicine, particularly by people in remote areas and as a guide for the future pharmacological and phytochemical studies. While the known medicinal plants can be harvested or cultivated for medical and pharmaceutical purposes, the less known plants with high FC scores can be investigated phytochemically and pharmacologically in the future studies.

Formation and performance of self-forming dynamic membrane (SFDM) in membrane bioreactor (MBR) for treating low-strength wastewater.

This study introduces a self-forming dynamic membrane (SFDM) with large-pore mesh filter materials instead of conventional MF/UF membranes for wastewater treatment. Development of SFDM on the mesh filter surface plays a major role in reducing the wastewater turbidity and its performance in a self-formation dynamic membrane bioreactor (SFDMBR). To evaluate formation of the dynamic membrane, biological and hydrodynamic parameters, including mixed liquor suspended solids (MLSS) and aeration rate, were examined. The experimental results showed that with elevation of MLSS in the bioreactor (up to MLSS = 9,000 mg/L), the effluent turbidity diminishes with rapid formation of SFDM, with the shortest formation time (5 min) obtained in SFDM operations, though it results in increased membrane fouling. SFDM was well formed at low aeration rates of 2.5 L/min and 5 L/min, due to very low shear stress on the mesh filter surface, given the results of turbidity in comparison with aeration rates of 10 L/min and 15 L/min. The filtration performance of SFDM in treatment of synthetic wastewater was tested under a constant operational flux (58 L/m2 h). Total chemical oxygen demand (COD) and NH4-N removals were 88-93% and 96-98.8%, respectively. These results indicated that the treatment process can be performed effectively by SFDMBR.

Enhancing purification efficiency of affinity functionalized composite agarose micro beads using Fe3O4 nanoparticles.

In this work, a series of magnetic and nonmagnetic agarose matrices were fabricated for protein purification. Certain amounts of Fe3O4 nanoparticles were encapsulated in agarose beads to form composite magnetic matrices with enhanced purification efficiency. Structure and morphology of prepared matrices were studied by optical and scanning electron microscopes, FT-IR, and BET-BJH analysis. The prepared matrices had regular spherical shape, followed by a uniform size distribution. By nanoparticles addition, the number of mesopores decreased while population of pores with radius ≤10nm increased; thus, higher specific area achieved. According to VSM results, magnetization degree was one of the characteristics affected by agarose content of the beads. A dye ligand, Cibacron Blue F3GA (CB), was covalently bound to beads to adsorb Bovine serum albumin. CB concentration was determined by elemental analysis. It was shown that magnetic beads hold higher CB concentrations than nonmagnetic ones due to higher specific area. As a result, magnetic 8%-agarose beads had the highest affinity adsorption capacity in static experiments. Moreover, breakthrough curves were monitored to calculate dynamic binding capacity. And, it was shown that magnetic 4%-agarose had the highest adsorbing amount (6.00mg/mL). It was implied that pore diffusion in magnetic 4%-agarose may be the reason for higher dynamic capacity. Plus, column efficiency was evaluated. It was revealed that all magnetic beads had lower HETP (0.11, 0.12 and 0.11cm for magnetic 4, 6, and 8%-agarose beads) than nonmagnetic ones (P-value<0.05).

The influence of zeolite (clinoptilolite) on the performance of a hybrid membrane bioreactor.

This work aims to investigate the effect of clinoptilolite on the performance of membrane bioreactor (MBR). The control membrane bioreactor without clinoptilolite (CMBR) and the hybrid membrane bioreactor with clinoptilolite (HMBR), in two parallel simultaneous MBRs within long and short term filtration experiments, were studied. Sludge properties, transmembrane pressure (TMP) rise as an index for membrane fouling and nutrient removal from synthetic wastewater in the CMBR and HMBR were compared. In HMBR, sludge properties improvement such as 22.5% rise in MLSS, 7% more accumulation of large particles, reduction of soluble microbial products (SMP) to half of this value in CMBR, no increase in sludge volume index (SVI) and 66% TMP reduced. The results of short term filtration showed that the trend of TMP increase in terms of flux will be slower in HMBR. Improvement of biological wastewater treatment quality and ease of membrane operation are concluded from this study.

Effects of biofilm formation on membrane performance in submerged membrane bioreactors.

The effects of biofilm formation on membrane performance were evaluated for a submerged membrane bioreactor (sMBR) system with six different types of micro- and ultrafiltration membranes (working volume=19 l). After operation for 24 h the permeability of the membranes with a larger pore size (microfiltration) decreased to that of the membranes with a much smaller pore size (ultrafiltration). Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) confirmed that biofilms could reduce the influence of the membrane surface properties. The chemical oxygen demand (COD) removal efficiency was 95% for the oily wastewater treatment in the sMBR where the filtration process made an important contribution (47% based on feed COD). Significant enhancement in COD removal occurred at the initial filtration stage because of biofilm formation and the dynamic member role of the biofilm layer. Membranes with various pore sizes had approximately the same permeate quality that was attributed to the biofilm on the membrane surfaces. Nevertheless, the ultrafiltration membranes had 43% more COD removal efficiency than the other applied membranes at the beginning of filtration (before biofilm formation) because of the smaller pore sizes and better sieving.

Effect of membrane characteristics on the performance of membrane bioreactors for oily wastewater treatment.

Influence of membrane material and pore size on the performance of a submerged membrane bioreactor (sMBR) for oily wastewater treatment was investigated. The sMBR had a working volume of about 19 L with flat sheet modules at the same hydrodynamic conditions. Five types of micro- and ultra-polymeric membranes containing cellulose acetate (CA), cellulose nitrate (CN), polyamide (PA), polyvinylidene difluoride (PVDF) and polyethersulfone (PES) were used and their filtration performance in terms of permeability, permeate quality and fouling intensity were evaluated. Characterization of the membranes was done by performing some analysis such as pore size distribution; contact angle and scanning electronic microscopy (SEM) microphotograph on all membranes. The quality of permeates from each membrane was identified by measuring chemical oxygen demand (COD). The results showed more irreversible fouling intensity for membranes with larger pore size which can be due to more permeation of bioparticles and colloids inside the pores. Membrane characteristics have a major role in the preliminary time of the filtration before cake layer formation so that the PA with the highest hydrophilicity had the lowest permeability decline by fouling in this period. Also, the PVDF and PES membranes had better performance according to better permeate quality in the preliminary time of the filtration related to smaller pore size and also their better fouling resistance and chemical stability properties. However, all membranes resulted in the same permeability and permeate quality after cake layer formation. An overall efficiency of about 95% in COD removal was obtained for oily wastewater treatment by the membranes used in this study.

Biological treatment of toluene contaminated wastewater by Alcaligenese faecalis in an extractive membrane bioreactor; experiments and modeling.

Conventional wastewater treatment methods are not efficient in treating wastewaters contaminated with volatile hydrocarbons such as benzene, toluene and xylenes (BTX). The aim of this study is to enhance the efficiency of an extractive membrane bioreactor (EMBR) in treating toluene contaminated wastewater by usage of pure culture of Alcaligenese faecalis. Toluene was used as a model of toxic contaminant because of its wide presence in wastewaters contaminated with petrol derivatives. The Haldane kinetic model adequately described the dynamic behavior of the toluene biodegradation by the strain of A. faecalis over a wide range of initial toluene concentrations (50-1,000 mg L(-1)) with kinetic constants micro(max) = 0.066 h(-1), k(s) = 91.7 mg/L and k(I) = 278.2. Overall mass transfer coefficient has been measured and described as resistance in the series model. No biofilm formed on the exterior surface of the membrane; however in previous works the layer of the biofilm on the exterior surface of the membrane acts as a mass transfer resistance. A mathematical model was developed to predict the pollutant concentration profile along the tube side of the membrane modules.