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The main purpose of this study resides essentially in the development of a new tool to quantify the biomass in the bioreactor operating under steady state conditions.

Modeling is the most relevant tool for understanding the functioning of some complex processes such as biological wastewater treatment. A steady state model equation of activated sludge model 1 (ASM1) was developed, especially for autotrophic biomass (XBA) and for oxygen uptake rate (OUR). Furthermore, a respirometric measurement, under steady state and endogenous conditions, was used as a new tool for quantifying the viable biomass concentration in the bioreactor.

The developed steady state equations simplified the sensitivity analysis and allowed the autotrophic biomass (XBA) quantification. Indeed, the XBA concentration was approximately 212 mg COD/L and 454 mgCOD/L for SRT, equal to 20 and 40 d, respectively. Under the steady state condition, monitoring of endogenous OUR permitted biomass quantification in the bioreactor. Comparing XBA obtained by the steady state equation and respirometric tool indicated a percentage deviation of about 3 to 13%. Modeling bioreactor using GPS-X showed an excellent agreement between simulation and experimental measurements concerning the XBA evolution.

These results confirmed the importance of respirometric measurements as a simple and available tool for quantifying biomass.

The purpose of this study is analysis on fluid flow characteristics inside a modified designed spiral bubble column photo-bioreactor. Available fluid dynamic simulation of bubble column reactor (BCR) (which is well-known conventional photobioreactor) had shown significance contribution over the past two decades, where the fluid dynamics of the culture medium and mixing will influence the average irradiance and the light regimen to which the cells are exposed. This enhances the growth. To develop this, and also to cut down the cost parameter involving the production of biodiesel from algae, the growth rate of algae has to be enhanced.

Some design modification through a staggered spiral-path inside the bubble column design had been proposed and comparative simulation of the modified design has been reported. Three-dimensional simulations of gas–liquid flow both in the BCR and spiral path column reactor have been carried out using the Euler–Euler approach. Various graphs are plotted, and from comparing, it has been seen that the proposed reactor will enhance better mixing rate, which could help the growth rate in microalgae in the present proposed model. In this paper, an earnest attempt had made to carry out computational simulation of conventional BCR and designed reactor used for cultivation of microalgae which had analyzed using commercial code ANSYS 14.

From this work, it was observed that the average turbulence kinetic energy fluctuates more in designed reactor over the conventional photo bioreactor, which will in turn increase diffusivity and enhance transfer of mass, momentum and energy. The results provide comprehensive information concerning effect of fluid flow characteristics inside a modified designed spiral bubble-column photo-bioreactor.

Some of our earlier published results (www.scientific.net/AMM.592-594.2427) are also referred in this paper. This work had been performed under the financial aid from RPS project (no. 8,023/RID/RPS/27/11/12), sponsored by All India Council for Technical Education.

This paper aims to develop a computational approach to analyze the mechanical behavior, perfusion bioreactor test and degradation of the designed scaffolds. Five types of pore architecture scaffolds have been made using a computer-aided designed tool and fabricated through fused deposition modeling.

Compressive structural analysis has been performed using the finite element method to forecast the mechanical performance of the scaffolds. Also, the experimental study was done to validate the simulation outcomes. A computational fluid dynamic analysis was performed to ascertain the fluid pressure distribution, velocity profile, wall shear stress, strain rate and permeability of scaffolds. The interconnected pore architecture of the scaffolds plays a crucial role in enhancing the mechanical properties and fluid flow characteristics.

The scaffolds with continuous vertical support columns resulted in better strength because they provide better ways to transfer the load. The pore architecture of the scaffold plays a significant role in the path of fluid flow. Scaffolds with regular interconnected pore architecture showed better accessibility of the fluid. The degradation analysis showed that the degradation rate is dependent on the architecture of the scaffolds because of different surface area to volume ratios.

The simulation results provide a straightforward prediction of the scaffold suitability in terms of mechanical strength, perfusion and degradation behavior.

Membrane biological reactor (MBR) is recognized as an efficient and steady wastewater treatment process. The purpose of this study is to reveal the research trends of scientific outputs on MBR for the past 32 years.

A method of bibliometric analysis was performed, based on the online version of the Science Citation Index Expanded, Web of Science, from 1982 to 2013. In total, 5,305 articles related to MBR were evaluated. A new method named “word cluster analysis” was also used for further analysis.

Results showed a rising trend of publications in this research field. English was the main language used in these articles. Journal of membrane science published the most articles, proving to be one of the most authoritative journals. China and Dalian University of Technology were the most productive country and institute, respectively. Except for “membrane bioreactor” and “MBR”, “membrane fouling” was the most cited keyword, indicating the research hotspot nowadays and future.

This study serves as an alternative and innovative way of revealing the research trends in MBR research.

Pharmaceutical and personal care products (PPCPs) and phosphorus are pollutants that can cause a wide array of negative environmental impacts. Phosphorus is a regulated pollutant in many industrial countries, while PPCPs are widely unregulated. Many technologies designed to remove phosphorus from wastewater can remove PPCPs, therefore the purpose of this paper is to explore the ability of these technologies to also reduce the emission of unregulated PPCPs.

Through meta-analysis, the authors use the PPCPs’ risk quotient (RQ) to measure and compare the effectiveness of different wastewater treatment technologies. The RQ data are then applied via a case study that uses phosphorus effluent regulations to determine the ability of the recommended technologies to also mitigate PPCPs.

The tertiary membrane bioreactor and nanofiltration processes recommended to remove phosphorus can reduce the median RQ from PPCPs by 71 and 81 percent, respectively. The ultrafiltration technology was estimated to reduce the median RQ from PPCPs by 28 percent with no cost in addition to the costs expected under the current phosphorus effluent regulations. RQ reduction is expected with a membrane bioreactor and the cost of upgrading to this technology was found to be $11.76 per capita/year.

The authors discuss the management implications, including watershed management, alternative PPCPs reduction strategies, and water quality trading.

The evaluation of the co-management of priority and emerging pollutants illuminates how the removal of regulated pollutants from wastewater could significantly reduce the emission of unregulated PPCPs.

Stephen McClelland takes a detailed look at a key market area for the European sensor industry — the monitoring of fermentation and bioreactors.

The purpose of this paper is to investigate the intentional formation of business networks in the wastewater industry. It enriches the theory‐building of the formation of business networks by drawing on theoretical contributions to business networks and capabilities. The paper describes, assesses and predicts scenarios relevant to the formation of business networks in the wastewater industry.

The research methodology employed is based on multiple sources of data in a multi‐method design, interpreting potential scenarios of business networks.

The findings reveal that water scarcity, population growth and economic constrains jeopardize existing business networks in the wastewater industry. Two potential scenarios: re‐inventing the centralized system through on‐site systems for mass‐markets; and expanding on‐site systems into mass‐markets seem realizable. A comparison of the two scenarios suggests that the first scenario is in a superior position to utilize the business opportunities offered.

Research limitations arise from the qualitative nature of the research undertaken.

Capability alignments and barriers suggest that the re‐inventing the centralized system through on‐site systems for mass‐markets scenario, is the most suitable for implementation. The knowledge gained allows managers to outline a specific approach for developing the capabilities required, in order to take advantage of the alignments and overcome the barriers that may exist.

The paper highlights that building theories of business networks may benefit from combining the formation of business networks with dynamic and operational capabilities.

The purpose of this paper is to examine a greenhouse gas (GHG) emission reduction potential from different waste management practices in Croatia. Energetic, environmental and economic benefits can be accomplished by utilizing municipal solid waste (MSW) and landfill gas as fuel in industry and energy sector, which is emphasized in this paper. The paper gives an overview of measures for energy recovery from MSW and landfill gas that could be implemented in Croatia. These measures also represent measures for an additional GHG emission reduction by decreased use of fossil fuels.

A methodology used for emission calculation (kinetic model) is explained. Three different scenarios of GHG reduction in waste management were defined. Implementation of best available techniques in waste management is envisaged by cross‐sectoral impact and effect of respective measures. Findings –This paper gives maximum achievable potential of GHG emission reduction with defined measure implementation dynamics. It was calculated that around one million ton of CO₂ can be avoided in 2020, which is 2.7 percent of projected GHG emissions in Croatia. The energy that could be recovered from waste (8.34 PJ in 2020) is relatively small in relation to the total final energy consumption in Croatia (about 3 percent).

The novelty of this work is achieved through integrated approach to GHG emission reduction and energy potential from MSW management in Croatia. The GHG reduction potentials are calculated by taking into account dependencies and interactions between the measures.

During the past 50 years the phenomenon of nuclear magnetic resonance (NMR) has evolved from a scientific curiosity to a powerful analytical tool for physical scientists and the medical community. Its primary use is for analytical chemistry and medical imaging. NMR imaging and spectroscopy can non‐invasively and non‐destructively examine the physical and chemical composition of materials. The technology is now at a level of sophistication and maturity where industrial applications are possible. This article describes the basis of NMR imaging and spectroscopy and examines the application of NMR to a broad range of industrial applications.

As the United States is making a significant move toward rejoining the Paris Agreement on climate change, there is a high demand for sustainable solutions across various industries, including construction and hospitality sectors. The aim of this project was to design and model an on-site greywater treatment system for a hotel building for the effective reuse of sewage water. The study considered Los Angeles, California, as a case study location and referred to respective climate conditions and construction standards.

This study considered various options of greywater treatment plants such as membrane bioreactor (MBR), sequencing batch reactor and reverse osmosis with upflow anaerobic sludge blanket which were carefully reviewed and modeled using the GPS-X software. The design and modeling results were verified by hand calculations and were followed by the estimation of capital and operational expenses required for the implementation of the plants.

Having relatively low capital and operational expenditure requirements as well as superior technical performance, the MBR plant proved to be the most effective solution for the considered location and standards and was recommended for use in hotel buildings.

Designing and modeling several greywater treatment plants allowed selecting the most optimal option which in the long run will help to preserve the eco-system, stay compliant with the government laws and regulations and be financially sustainable.

The outcomes of the present study provide a detailed procedure for designing and modeling a greywater treatment plant for a hotel building that can be used for the localities with a similar climate. The most effective option selected as a result of cost-benefit analysis provides an efficient and viable solution for the relevant industry and the type of buildings.