The synthesis of activated chlorine in an electrodialyzer with a tube ceramic membrane and a titanium–dioxide–manganese anode

The article has investigated the impact of the design of an electrodialyzer with a little soluble titanium–dioxide–manganese anode and a ceramic membrane separating electrode spaces, on the concentration of chlorate–ions when producing sodium hydrochlorite. It has been shown that the location of the anode inside a ceramic membrane makes it possible to obtain sodium hypochlorite without an impurity of chlorite–ions.     

By‐products formation in catalytic combustion of aromatic compounds over a pt‐based catalyst

By‐products formation in the catalytic combustion of different aromatic compounds has been experimentally investigated. A commercial Pt‐based catalyst, in the shape of a short monolith, has been employed. Toluene, styrene, o‐xylene and cumene have been tested at low concentrations for conversions in the range 5–50%. The results confirm the formation of benzene in the combustion of toluene and styrene, as previously observed by other researchers, but in a very small amount; testing cumene, significant amounts of acetone have been found in the outlet flow. Some hypothesis about the reaction mechanism are put forward.     

Evaluation of iron–epoxy metal nanocomposite in glass fibre and Kevlar

This paper deals with the enrichment of the both mechanical and electrical properties of Kevlar and glass fibres, not including mounting the weight of the structure by adding the iron (Fe) nanocomposites with the epoxy resin. The Fe is mixed well with the epoxy to increase the mechanical constancy and the electrical property of the fibre by a non-covalent approach. The synthesis of metal nanocomposite with epoxy is done by the direct mixing method. The Kevlar and the glass fibre were taken as the samples for this study. The zinc oxide and epoxy were mixed simultaneously using a mechanical stirrer to give appropriate dispersion and adhesion without disturbing the hydrophobic performance of the epoxy, and the Fe powder and epoxy are added with a hardener in the ratio of 1:1:0.1. The results show that the mechanical property of the fibre increased with the decrease in the weight of the laminate when they are treated with the metal nanocomposite.     

Flow of microorganisms in a hospital stair shaft — Full-scale measurements and mathematical model

Measurements of air flow and microorganism concentration have been made in the stair shafts of a hospital, using a diving bell-type of pressure-recording instrument, and a sampler for the microorganisms, respectively. Results of experiments were used to calculate the flow rate of microorganisms between the floors of the hospital. A mathematical model based on simplified transport equations is proposed, which would allow the prediction of the flow field and the distribution of microorganisms in the stair shaft. Comparisons between measurements and numerical calculations indicate that the mathematical model is able to predict the global flow field, qualitatively. The application of the numerical method can help to reduce the experimental work, as well as to investigate the complex exchange mechanisms of microorganisms.     

Urban and semi‐urban planning in developing countries from a water and waste water treatment point of view

Several appropriate technology alternatives are suggested for water and wastewatei treatment in less developed countries. Large‐scale water supply systems employing conventional water treatment methods should be replaced by several small‐scale water treatment units utilizing appropriate water treatment methods.

Conventional sewerage systems should be replaced by low cost on‐site sanitation systems and several other low‐cost wastewater treatment methods such as oxidation ponds, aerated lagoons and anaerobic lagoons. Wastewater renovation and re‐use should be actively encouraged in view of dwindling water resources in these countries.     

Influence of initial dry density and water content on the soil–water characteristic curve and suction stress of a reconstituted loess soil

In the northwest of China, many loess landslides have occurred without clear triggering factors (i.e., rainfall, earthquake, human activities, etc.). To better understand and analyze the hydro-mechanical properties of these slopes and then provide evidence for their stability analysis subjected to matric suction, it is essential to clarify the soil–water characteristic curve (SWCC). In this study, we conducted a set of experimental trials to examine the influences of initial dry density, water content upon the SWCCs of a loess soil taken from a loess landslide area, by using a conventional volumetric pressure plate extractor. Two common SWCC models have been investigated to evaluate which one is better for loess soil. The suction stress characteristic curves (SSCCs) were also estimated and analyzed. We found that behaviors of SWCCs would be different when the matric suction was greater than a certain value. The two SWCC equations have approximately the same performance in describing the SWCC. The rates of desorption decrease and residual water content increases with increasing the initial dry density, while the initial dry density has little, if any, influence on the air-entry value (AEV). The specimen compacted under higher initial water content would exhibit a higher AEV value and residual water content but lower rate of desorption as compared with the lower initial water content. The magnitude of suction stress had an approximately linear relationship with matric suction before the AEV value, the SSCC shapes will be markedly varied with the initial dry density and water content.     

Structural behavior and performance of water pipes rehabilitated with a fast-setting polyurea–urethane lining

This paper presents the structural behavior and performance of a fast-setting polyurea–urethane (PUU) lining as a structural lining material for rehabilitating water pipes. To this end, a series of experimental tests were carried out to assess the following: (1) bond strength; (2) hole and gap spanning capabilities; (3) angular displacement ability; (4) transverse shear resistance; and (5) fatigue cyclic loading resistance. First, pull-off bond tests were conducted to evaluate the bond characteristics of a fast-setting PUU lining bonded to steel specimens. Surfaces were dried to ensure adequate bond strength. Second, hole and gap spanning tests were carried out to investigate the spanning capability of the lining on the water pipes. From these tests, the hole spanning capability of water pipe with 5 mm hole was observed to be 11 MPa. Then, angular displacement and transverse shear tests on fast-setting PUU lined water pipes were also carried out to evaluate the behavior and performance in bending and shear of this material. Peel off failure of PUU occurred at an angular displacement capacity of 6.74° and no failure of PUU was observed at a transverse shear capacity of 25% of the diameter. Finally, fatigue cyclic loading test was conducted to investigate the fatigue behavior and performance of the water pipe lined with this PUU material. The fatigue resistance of PUU in the range of 10⁵ cyclic loadings was achieved.     

Three‐dimensional analytical model of atmospheric dispersion of pollutant in a stable boundary layer

A three‐dimensional atmospheric dispersion model of a heavy admixture emitted from an elevated continuous point source is presented. Appropriate boundary conditions have been employed to model the effects of various removal mechanisms like deposition, settling and leakage of pollutants. This model takes care of variation of mixing layer height with heat flux, geostrophic drag by terrain and several meteorological parameters. A realistic form of variable eddy diffusivity is used in this model for a stable atmospheric condition. It has been found that the effect of settling of large particles is to reduce pollutant concentration always far away (horizontally as well as vertically) from the source. Whereas, in the lower part of the boundary layer near the source its effect is to increase concentration for small values of settling velocity and to decrease for larger values. The present model, being three dimensional in nature, is more suitable to assess the impact of point source emission.     

Ponded infiltration and spatial–temporal prediction of the water content of silty mudstone

Bulletin of Engineering Geology and the Environment - Ponded infiltration is very common in silty mudstone and has a great influence on the stability of related slopes, road cuttings, and tunnels....     

Palygorskite–TiO2 nanocatalysts for photocatalytic degradation of tebuconazole in water

Palygorskite–TiO₂ nanoparticles are frequently used as nanocatalysts. In the present study, two different nanocatalysts were developed based on the use of different palygorskite–TiO₂ ratios: 40–60 and 10–90. The nanocomposites were investigated for the photocatalytic degradation of the common fungicide tebuconazole (TEB), under aquatic conditions. The samples were extensively characterized by X-ray powder diffraction, attenuated total reflectance–Fourier transform infrared spectroscopy, scanning electron microscopy and N₂ specific surface area (SSA) by Brunauer–Emmett–Teller (BET) analytical techniques. The TiO₂ nanoparticles were successfully dispersed on the mineral's surfaces and the photocatalytic activity reached 88.4% for the palygorskite–TiO₂ ratio of 40:60, where the dispersion was better as proved by the total pore volume and BET parameters (0.49 cm³/g and 258 m²/g compared to 0.33 cm³/g and 220 m²/g of the 10:90 ratio). The photocatalytic efficiency of the proposed materials was significantly higher than Degussa P25 (33.2%), and that makes the palygorskite–TiO₂ nanocomposites very promising for advanced application in fungicides' degradation in aquatic environments.     

Aquifer characteristics and water quality of Miocene–Pleistocene sediments, Kuwait

Al-Atraf is one of the water well fields of Kuwait supplying Kuwait City with the brackish groundwater obtained from the Kuwait Group aquifer of Miocene–Pleistocene age. The study determined the hydrogeological and hydrochemical characteristics of the groundwater in order to identify the major chemical processes that influence the groundwater quality of the study area. The results of the aquifer test analyses indicate that the Kuwait Group is a confined to semi-confined aquifer, with a transmissivity ranging between 62 and 321 m²/day. The flow net analysis implied that the groundwater moves from southwest to northeast. The estimated transmissivity values agree well with those calculated from the aquifer test. The results of the chemical analyses data of the Al-Atraf field show that the groundwater is mainly brackish, of NaCl and Na₂SO₄ water types. The groundwater is undersaturated with respect to halite, gypsum and anhydrite and supersaturated with respect to quartz, dolomite and calcite in the direction of groundwater flow. The average Pco₂ of the groundwater is higher than the Pco₂ of the earths atmosphere indicating that the groundwater is supplied with CO₂ during the infiltration processes and dissolves the carbonate minerals under closed-system conditions.     

“Between a Rock and a Hard Place”: Planning Reform,Localism and the Role of the Planning Inspectorate in England

Like many European countries, England saw the establishment in the late 1990s and early twenty-first century of regional-scale spatial planning. Radical reform of English planning following the Localism Act 2011 however saw the whole intermediate tier of regional planning stripped out of the national planning system along with detailed guidance and top-down targets for house-building at a local level. This had a major impact on the Planning Inspectorate, the agency responsible on behalf of government for approving local development plans. Reform left the Inspectorate fully exposed to the tensions and contradictions between top-down policy and local autonomy inherent under the new planning framework. Focussing on future levels of housing development, a key responsibility of local councils under the new framework, we examine the implications of reform for the Planning Inspectorate in practice. We draw on approaches to localism and planning theory, in particular the idea of ‘conditional localism’, in order to situate and understand these changes. The study was based on interviews with elite respondents in or close to the Planning Inspectorate together with documentary sources. Lack of previous work on the Inspectorate, coupled with their key role in the national planning system, reinforced by recent reforms, emphasises the significance of the study. The importance of such ‘land-use tribunals’ internationally, points to the study’s wider relevance. It provides, as well, a study of planning reform with relevance in a wider European context and suggests how recent contributions to the localism debate can help make sense of these changes.     

Effect of water–silt composite blasting on the stability of rocks surrounding a tunnel

This paper describes a new method using water–silt composite blasting for tunneling and the field tests conducted in the Tieshanping tunnel, Chongqing City, China. In this method, water–silt composite is substituted for the traditional pure silt stemming of the blast holes. Because of the incompressibility of water, the attenuation of the blasting wave is postponed and the effect of the blast air extended. The water–silt blasting method resulted in a larger crack zone, improved the breakage of rock, reduced the rock heap, lowered the dust and saved explosive. The stability of the surrounding rock was studied using theoretical analysis, in situ measurements and numerical modeling. The measured displacement at the tunnel crown was in good agreement with the theoretical and numerical results.     

What rights and whose responsibilities in water? Revisiting the purpose and reassessing the value of water services tariffs

Access to water and sanitation are recognized as human rights by the United Nations, reflecting their vital importance to every person's life. At a fundamental level - delivering minimum standards of water services to meet basic human needs - it is a simple equation. People are rights-holders and States are responsible under international law to provide those services. Rights-holders can claim their rights and duty-bearers must guarantee the rights to water and sanitation equally and without discrimination. This paper explores the relationship between the human rights to water and sanitation, the Sustainable Development Goals, water services and the role of water service tariffs in helping or hindering delivery of a broad range of societal objectives, including human rights and sustainability. Two key questions emerge: (i) What are the rights that apply in these circumstances and who is responsible for addressing those rights? (ii) How can the viability of the water service system be maintained without imposing dramatic price increase, and without compromising the social and human right to water in good quality and affordable conditions? In this paper we argue that human rights to water and sanitation, and the tariffs that are applied to them, should not be addressed as technical problems but rather as social and political issues of justice. We conclude that the re-politicisation of water, and of the setting of water tariffs, would help ensure that the responsibilities upon Governments for delivering human rights to water and sanitation are clear.     

Development and verification of a soil–water coupled finite deformation analysis based on u–w–p formulation with fluid convective nonlinearity

Most soil–water coupled analyses of saturated soil are based on the u–p formulation, where a set of equations is reduced by assuming that the acceleration of the fluid phase relative to that of the solid phase is less than that of the solid phase. Therefore, this analysis cannot be used for a coupled analysis with dynamic water flow in highly permeable soil. This study aims to present a soil–water coupled finite deformation analysis method based on full formulation, or u–w–p formulation. This method differs from conventional methods in the following ways: (1) the governing equations explicitly include the equation of motion for the fluid phase, (2) a relative convective term is used to describe a change in the relative configuration between the two phases, and (3) the moving/inclined discharge boundary is directly implemented to the discretized governing equations. Herein, one/two dimensional seepage and plane-strain deformation analysis results are reported. In the seepage analysis, accelerating permeation of pore water is obtained and the undrained constraint condition is verified. In the deformation analysis, dynamic migration in a high permeable soil specimen, i.e., wave propagation and rotational flow of pore water, is observed.     

Design and simulation of a solar–wind–biogas hybrid system architecture using HOMER in India

The renewable energy sources are accompanied by certain constraints as reliability, availability and continuous generation. In India, biomass is considered as the second best suitable combination with other renewable energy sources. Both solar and wind are undependable renewable energies as they are unpredictable. Now the key to successful renewable energy harvesting lies in the selection of hybrid system architecture for power generation. In rural areas, light is usually unavailable and if it does, it is mostly an incandescent light used for household lighting instead of fluorescent. System reliability, economy and environmental issues are the three major issues for decentralised electrification. So, finding the best suited hybrid system configuration to overcome these constraints is the need of the hour. It is at this stage that HOMER comes into the picture. HOMER, abbreviated name of hybrid optimization model for electric renewable, successfully realises system configuration before its installation and works for on-grid, off-grid and stand-alone systems, which make it useful for rural to urban applications. It simulates and optimises the best suitable solution for a hybrid system and generates reports incorporating all the aspects in designing a system. Here, a typical hybrid system is considered and the implementation of HOMER software has been incorporated.     

Optimum configuration and design of a photovoltaic–diesel–battery hybrid energy system for a facility in University of Port Harcourt,Nigeria

Optimum configuration, using a hybrid optimisation model for electric renewable software, and design of a photovoltaic (PV)–diesel–battery hybrid energy system has been proposed to power a facility in the University of Port Harcourt, which is located in the suburb of Port Harcourt city, Nigeria. The configuration of the optimum hybrid system is selected based on top-ranked system configuration, according to the net present cost. An optimal system design delivers the best components alongside appropriate operating strategies to provide the most efficient, reliable cost-effective system possible. The system investigated reduces CO₂ emissions by 36.3%/year. This will reduce costs imposed on CO₂ emissions by future environmental legislation. The system has a better potential for providing the energy needs of the facility considered in this paper compared with a stand-alone PV–battery system as capital costs are reduced by 55%. Reliability was improved as the diesel generator can provide power as and when it is needed.