Feasibility of Rainwater Harvesting and Consumption in a Middle Eastern Semiarid Urban Area

Recent developments of Middle Eastern metropolitans, and the related soaring trend of population increase, is contemporary with the impacts of climate changes. This applies extra pressures to the centralized large-scale water treatment and distribution systems. Rainwater harvesting (RWH) for domestic urban activities can be a sustainable option of adapting with the rising demand of soft water in such an arid/semiarid area. A pilot system of rainwater draining and storage was constructed for alleviating parts of soft water scarcity in Mashhad, the second most populous city of Iran. Measurements were collected for two years at the drainage basin outlet and inside of a storage tank, which has been equipped for water harvesting purposes. We performed some preliminary stochastic analysis and evaluated probabilistic properties of the collected dataset, aiming to explain them with respect to the physical characteristics of the RWH system. Data clustering analysis confirmed that the quality of the water may change during rainwater draining and storage in the RWH tank. Particularly, sodium content of the sampled water in the drainage catchment illustrated higher variations, compared with the ones evaluated for the stored water in the reservoir tank. This can confirm that the quality of the stored water in the RWH reservoir is more stable than that obtained for each separate rainfall–runoff event. We assessed the potential of the harvested water in different consumption contexts, in light of some national and international water quality (physicochemical, biological, and toxic pollutants) guidelines. We relied on water quality indices (WQI) to interpret multiparametric properties of the collected rainwater from urban surfaces; consequently, the quality of the harvested water was categorized with moderate to almost good attributes. This makes it well suited for irrigation uses, which can play a relevant role against water shortages in the analyzed semiarid urban region. Otherwise, infiltration and treatments need to be performed if using harvested water for drinking consumptions (of human or livestock), some of which may be costly for local owners/uses. We provide some suggestions for improving efficiency of the system and enhancing the quality of the harvesting water.

Effect of Reflecting Material on CPC to Improve the Performance of Hybrid Groundwater Solar Desalination System

Water-energy nexus is a crucial and challenging concern that addressing it is noteworthy for the future of human beings. In addition, freshwater production is a highly energy-intensive procedure. Therefore, developing a suitable solution for this problem is of importance. In the present scenario, solar energy is one of the suitable options for desalination because solar energy is available at a low cost, is clean for the environment, and is widely available. Generally, solar collectors such as flat plate collectors (FPC) and evacuated tube collectors were experimented for desalination applications. This work presents an experimental investigation of a single-stage hybrid (ETC-CPC) groundwater solar desalination system. A compound parabolic concentrator (CPC) is placed below the evacuated tube collector (ETC) for collecting solar radiations to transfer heat to evacuated tubes which improves performance in the case of different weather conditions of Pune city in India. Experimental results show that the hybrid solar groundwater desalination system, by maintaining the optimum distance of 20 mm between ETC and CPC with Mylar as the reflecting material, could offer a drinking water production rate of up to 3.4 l/(m2h)/day. However, the proposed single-stage hybrid (ETC+CPC) groundwater solar desalination system with aluminum foil as a reflecting material could generate 1.9 liters of soft water per day. Further, the use of Mylar as a reflecting material could generate 3.5 liters of soft water per day.

Analisa Persebaran Wetland Berdasarkan Metode Geolistrik di Kecamatan Pandak, Kab. Bantul, DIY

ABSTRAKWetland merupakan tanah lunak tersaturasi air yang berada di dekat permukaan yang menjadi permasalahan dalam pembangunan di sekitar daerah penelitian di Desa Gilangharjo, Kab. Bantul, DIY. Oleh karena itu dilakukan pengukuran metode geolistrik untuk mengetahui persebaran kedalaman wetland di sekitar daerah penelitian sebagai bahan kajian pendukung dalam program pembangunan desa. Dalam penelitian ini dilakukan pengukuran metode geolistrik sounding sebanyak lima titik sounding, kemudian data lapangan diproses menggunakan pemodelan inversi 1 Dimensi (1D) untuk mendapatkan kurva model 1D resistivitas batuan. Berdasarkan kurva model 1D resistivitas batuan didapatkan nilai resistivitas wetland berkisar antara 5.66 - 29.6 ohm.m dan kedalaman wetland berkisar antara 0.592 - 2.25 meter yang meningkat ke arah tenggara. kata kunci : Wet soils, resistivitas, geolistrik sounding ABSTRACTWetlands is a soft water saturated rocks in near surface which becomes a problems of developement in surrounding area of Gilangharjo Village, Bantul District, DIY. Therefore, the research with using geoelectrical methods has been conducted to delineating spreading of wetlands depth in surrounding research areas as a supporting data for village developing programs. In this research is conducted sounding geoelectrical methods measurements as much five sounding points, then the field data is processes with using 1D inversion modelling to get 1D resistivity models curve of rocks. Based on 1D resistivity models curve of rocks is obtained wetlands resistivity value is between 5.66 - 29.6 ohm.m and the depth of wetlands is between 0.592 - 2.25 meters which increase to southwest. keywords : Wet soils, resistivity, sounding geoelectric.

Coupling Fluid Flow to Hydrogel Fluidic Devices with Reversible “Pop-it” Connections

Hydrogels are soft, water-based polymer gels that are increasingly used to fabricate free-standing fluidic devices for tissue and biological engineering applications. In many of these applications, pressurized liquid must be...

Effects of soft water attack on Portland and natural zeolite blended cements

The durability of concrete infrastructure is related to the properties of the applied concrete and the effects of the aggressive external environment on it. When concrete is directly exposed to soft water, the leaching of calcium ions from hardened cement or cement-based pastes occurs, causing reduction in strength and further deterioration of the concrete structure. This paper presents the experimental results of soft water attack effects on phase composition and compressive strength of blended cement pastes, when cement is replaced with 0%, 10%, 20% and 30% of natural zeolite. In order to simulate soft water attack in laboratory conditions, paste specimens were exposed to leaching in deionised water up to 180 days. The evaluation of the changes in phase composition (ettringite, portlandite, calcium silicate hydrate gel) due to calcium ion leaching was made based on X-ray diffraction analysis, Fourier transform infrared spectroscopy and paste compressive strength tests. The presence of portlandite and ettringite after 180 days of exposure to deionised water indicates that leaching did not influence the stability of the hydration products in blended cement pastes. Moreover, blended cement paste with 10% of natural zeolite had a higher compressive strength than the reference one.

Protection of emergency hydraulic structures made of soft water-filled dams from mechanical damage by moving in water objects

Проанализированы различные способы и технологии защиты аварийных гидротехнических сооружений из мягких водоналивных дамб, используемых подразделениями МЧС России для борьбы с опасными гидрологическими явлениями. Сделан вывод о том, что все они либо не в полной мере обеспечивают защиту дамб, либо их применение подразумевает большие временные и экономические затраты при недостаточной эффективности. Описывается способ и технология защиты дамб с применением рукавов пожарных напорных, входящих в комплект дамбы для наполнения ее водой. Рукава при заполнении их воздухом обладают положительной (при необходимости переменной) плавучестью. Их нормативная длина, применяемые материалы, физико-механические свойства и конструктивные особенности позволяют использовать рукава в качестве защитного барьера, для предохранения дамб от механических повреждений. The use of soft water-filled dams as emergency water protection structures is quite effective for combating and eliminating the consequences of hazardous hydrological phenomena. They are widely used for these purposes by units of EMERCOM of Russia. The dams are made of various materials with a polymer film coating applied on a fabric base. The practical use of dams has shown that one of the problems arising in this case is to ensure their protection from mechanical damage caused by the dynamic pressure of solid objects moving throughout the water - boards, logs, fragments of wooden or plastic building structures. The methods and technologies of dam protection analyzed in the article are either insufficiently effective or require a lot of time, labor and financial expenses. In the process of developing a water-filled protective dam of a new design for the needs of EMERCOM of Russia there was proposed a method of its protection from physical and mechanical effects by using fire pressure hoses included in the dam kit as a protective barrier. When filling with air the hoses, hermetically connected by means of hose heads in a line, have positive (and, if necessary, variable) buoyancy, which is confirmed by the calculations performed. It is possible to fasten the hoses to the dam in various ways, by means of the structural elements of the dam or with use of the devices and accessories included in its kit. The standard length of one fire-fighting hose is 20 m, which is either equal or multiple of the length of one dam module. The design of the fire pressure hoses as well as materials used at their manufacture ensure a sufficiently tight fit of the hose to the body of the dam in spite of bends and deformations caused by water pressure. The power frame of the pressure fire hose of a dense weaving, made of high-strength threads, and an external polymer coating, have sufficient strength under external physical and mechanical influences. The use of fire hoses as protection of soft water-filled dams does not require additional financial costs. Fire pressure hoses can be used to protect other objects in the water during hazardous hydrological events in the area of possible movement of various solid objects.

Copper and zinc generated by the Aquascape IonGen pond clarifier system can be detrimental to koi (Cyprinus carpio) health

BackgroundCopper is frequently used as an algicide, and copper ion generators such as the Aquascape IonGen claim to be safe for use in systems containing fish. In 2012, a die-off of koi (Cyprinus carpio) in a pond in Raleigh, North Carolina, occurred after the IonGen was added to the system.MethodsPhysical and postmortem examinations suggested that heavy metal toxicity was the likely cause of morbidity and mortality. This was supported by a heavy metal screening of the owners’ pond. Additional experiments were performed to determine if the IonGen produced toxic levels of copper and zinc.ResultsThe tank containing the IonGen had higher concentrations of copper and zinc, and copper levels exceeded those associated with toxicity in both hard and soft water.ConclusionThe results of this study indicate that ion generators might not be safe for fish, and copper should only be used as an algicide if concentrations are closely monitored.