Investigation of Quality and Reclamation of Urban Storm Runoff in City of Shiraz

Urban storm runoff is considered as a potentially reclaimable and valuable resource in many arid and semiarid areas, in Iran. Urban storm runoff in Shiraz is collected mainly by Khoshk River and transported to the Maharloo Lake without any treatment or reclamation. In this study, storm runoff quality and the possibility for its reclamation from different parts of the city in certain canals and pipes are investigated. The quality of the first flush in three relatively large and small suburban areas with different land uses is studied. For the purposes of this study, three stations were considered: one near the downstream end of the city on Khoshk River with a relatively large watershed, one in the middle of the city where street runoff is the main constituent of the flush, and a third one near the western outskirts of the city with relatively small mainly residential watershed

Effects of Hydraulic Retention Time on the Performance of a Membrane Bioreactor Treating Municipal Wastewater

There is an increasing demand for effluents of higher quality from wastewater treatment plants due to the more stringent quality standards as well as the increasing pressure on water resources worldwide, which calls for effluent recycle and reuse. Membrane bioreactors (MBRs) have been recently gaining rapid popularity as a promising technology for wastewater treatment. In order to improve the quality of the effluent from Shiraz wastewater treatment plant, an on-site pilot-scale membrane bioreactor was operated for 9 months. The pilot plant built at Shiraz wastewater treatment plant consisted of an aerobic reactor and a membrane compartment containing one submerged hollow fiber membrane module. In this study, eleven different aerobic hydraulic retention times (HRT) ranging from 2 to 12 hours were tested to determine the membrane capacity and to investigate the performance of the system in removing total ammonia nitrogen, organic matter, total suspended solids, and turbidity.The system recorded a perfectly stable removal efficiency over the whole experimental period, except for the 2-hour aerobic HRT, so that its COD and BOD reductions exceeded 95% and 99%, respectively. Moreover, the system achieved complete nitrification in a stable manner during the whole study period, except for the 2-hour aerobic operation period. TSS concentration was almost zero and turbidity was less than 1 NTU. Membrane capacity measurements showed an average flux of 5.5 Lm-2h-1 with a mean trans-membrane pressure difference of 30 kPa. Results showed that the MBR outperformed the conventional sewage treatment processes. Additionally, it was not affected by aerobic HRT changes (12, 10, 8, 6, 4, and 3h). Based on the effluent qulity, teh system may be recommended for application toward water reuse in industrial and agricultural setting

Experimental Study and Numerical Verification of Silted-Up Dam Break

In this study, multiphase flood waves caused by failure of silted-up dams have been scrutinized experimentally, and efficacy of the public-domain CFD software OpenFOAM numerical models to represent such phenomenon is evaluated. Experimental observations are sparse on dam break for reservoirs with high sediment depths, called silted-up reservoirs. Sediment layer, in this case, may behave as a viscous fluid and produce a complex multi-layer flow of air and water overtopping a sediment layer. Massive sediment quantities can have a substantial impact on the wave propagation pattern caused by dam break. This study contributes to an experiment-based understanding of dam break phenomenon with silted-up reservoir, and elaborates the propagation of multi-layer waves. Herein, different hydraulic conditions were experimentally observed including 8 different upstream sediment depths in the range of 0–0.24 m and 4 downstream initial water levels of 0, 0.02, 0.04 and 0.05 m, which collectively created 32 scenarios. The resulted waves were filmed by high-speed cameras and data were extracted through image processing. An open-source CFD software, namely OpenFOAM, was employed to simulate the experiments using two distinct numerical approaches: volume of fluid (VOF) and Eulerian. Results of both numerical approaches were in good agreement with the experimental measurements; with MAE and RMSE error values varying from 0.006 m to 0.031 m and 0.008 m to 0.043 m, respectively (2% to 10% and 2.6% to 14% with respect to the reservoir height of 0.3 m). The Eulerian approach showed marginally superior performance to VOF, especially in cases with high sediment depths, which is likely due to accommodating phase mixing. A wide collection of high-quality data is made available online in the Appendix Data and could be utilized in future studies

A Game Theoretical Low Impact Development Optimization Model for Urban Storm Water Management

This study presents a novel framework to optimize Low Impact Development (LID) practices for urban storm water management. First, the Storm Water Management Model (SWMM) model was executed for different possible scenarios of input parameters and various LIDs to simulate runoff volume, Biochemical Oxygen Demand (BOD) and Total Suspended Solids (TSS) loads. Next, a neural network (MLP-ANN) was trained and validated, as a surrogate model, against the set of inputs and output variables from the SWMM model simulations. The inherent uncertainties in the rainfall-runoff modeling were accounted for using a Nonlinear Interval Number Programming (NINP) model, and stakeholders\u27 interactions are considered using a leader-follower game model. Velenjak urban watershed in Tehran, Iran, with four key stakeholders was considered as the study area. Tehran Municipality is the financial service provider that makes the first decision the leader-follower structure, and is considered as the leader with the priority of minimizing LIDs’ construction and maintenance costs. Tehran Department of Environmental Protection, Tehran Regional Water company, and Tehran Province Water and Wastewater company are the main followers in the decision making structure in the study area. This game theoretical framework yields several Pareto optimal solutions given the conflicting utilities of various players, and a Multi Criteria Decision Making procedure – i.e. PROMETHEE model – selects the most preferred compromised option. Fourteen weighting scenarios were considered in the PROMETHEE model to determine the compromise solution among the 52 solutions on the trade-off curve. The novelty of this study lies in using a nonlinear interval conflict resolution multi-objective optimization model for urban storm water management based on a leader-follower game. The proposed methodology warrants BOD and TSS loads, as well as storm water volume, are all reduced, with the highest reductions of 93, 86 and 90 percent, respectively. Results testify to the efficacy of the proposed model for urban storm water management

Molecular characterization and transient expression in plants of a Mirabilis jalapa antiviral protein (MAP), and its use in functional studies

33 p.-8 fig.Crude protein fractions from Mirabilis jalapa of northern Iran containing Mirabilis Antiviral Protein (MAP) reduced the systemic accumulation of a plant RNA virus in Nicotiana benthamiana. A MAP gene was amplified by RT-PCR from total RNAs isolated from these Iranian M. jalapa plants (MAP-Tehran) without the 5´-end signal peptide sequence, to set up an experimental system that would transiently express the protein in the cell cytosol by agroinfiltration and simultaneously trigger a response to study its antiviral effects. The amplified fragment was first cloned into a high-copy plasmid without promoters flanking the cloning site and its nucleotide and amino acid sequences were determined and compared to available MAP sequences. Two putative ribosome inhibitor domains were found in the protein N-terminal and C-terminal regions, respectively. The cloned MAP-Tehran was transferred to binary vectors for agroinfiltration. Only constructs that expressed MAP-Tehran fused to the N- or C- halves of the monomeric red fluorescent protein used for bimolecular fluorescence complementation assays were obtained. In N. benthamiana leaves agroinfiltrated with these constructs, signs of cell plasmolysis became detectable under confocal microscopy at day 3 after infiltration (dai), and from day 4 necrotic lesions were visible. In agroinfiltrated patches at 2–3 dai, before the onset of cell death, reduced accumulation of a co-expressed reporter gene and also of a mechanically inoculated virus were observed. A double-alanine substitution (Glu → Ala, Arg → Ala) in the C-terminal region inhibitor domain of the MAP constructs sufficed to abolish all of these effects. Agroinfiltration of either the necrosis-inducing or non-inducing MAP variants caused no significant effect on the accumulation of an RNA virus inoculated on upper, non-infiltrated leaves.Peer reviewe

Reservoir Release Allocation and Weir Design MATLAB® Toolbox

Designing reservoir outlets is a challenging subject in flood management among water resource managers. However, although several kinds of research are dedicated to flood mitigation strategies, rare studies exist in the literature considering flood uncertainties in reservoir outlet designs. This study fills this knowledge gap by developing a MATLAB® Toolbox application, entitled Release Allocation and Weir Design (RAWD), based on MATLAB® App Designer to obtain optimum reservoirs outlet design for effective flood management considering four outlets types, including an orifice as well as a proportional, a triangular, and a rectangular weir. The RAWD application handles uncertainties using non-linear interval number programming (NINP) and conditional value-at-risk (CVaR) approaches within an optimization model. Results show that the RAWD Toolbox application’s user can effectively and accurately meet downstream water demands and minimize water allocation shortages during the flood for a reservoir subjected to different shapes of inflow hydrographs.</p

Hydraulic characterization and removal of metals and nutrients in an aerated horizontal subsurface flow “racetrack” wetland treating primary-treated oil industry effluent

Summarization: Constructed wetlands (CW) are an attractive technology due to their operational simplicity and low life-cycle cost. It has been applied for refinery effluent treatment but mostly single-stage designs (e.g., vertical or horizontal flow) have been tested. However, to achieve a good treatment efficiency for industrial effluents, different treatment conditions (both aerobic and anaerobic) are needed. This means that hybrid CW systems are typically required with a respectively increased area demand. In addition, a strong aerobic environment that facilitates the formation of iron, manganese, zinc and aluminum precipitates cannot be established with passive wetland systems, while the role of these oxyhydroxide compounds in the further co-precipitation and removal of heavy metals such as copper, nickel, lead, and chromium that can simplify the overall treatment of industrial wastewaters is poorly understood in CW. Therefore, this study tests for the first time an innovative CW design that combines an artificially aerated section with a non-aerated section in a single unit applied for oil refinery wastewater treatment. Four pilot units were tested with different design (i.e., planted/unplanted, aerated/non-aerated) and operational (two different hydraulic loading rates) characteristics to estimate the role of plants and artificial aeration and to identify the optimum design configuration. The pilot units received a primary refinery effluent, i.e., after passing through a dissolved air flotation unit. The first-order removal of heavy metals under aerobic conditions is evaluated, along with the removal of phenols and nutrients. High removal rates for Fe (96–98%), Mn (38–81%), Al (49–73%), and Zn (99–100%) generally as oxyhydroxide precipitates were found, while removal of Cu (61–80%), Ni (70–85%), Pb (96–99%) and Cr (60–92%) under aerobic conditions was also observed, likely through co-precipitation. Complete phenols and ammonia nitrogen removal was also found. The first-order rate coefficient (k) calculated from the collected data demonstrates that the tested CW represents an advanced wetland design reaching higher removal rates at a smaller area demand than the common CW systems.Presented on: Water Researc