Recent progress of photocatalytic membrane reactors in water treatment and in synthesis of organic compounds. A review

2017 ◽  
Vol 281 ◽  
pp. 144-164 ◽  
Author(s):  
Raffaele Molinari ◽  
Cristina Lavorato ◽  
Pietro Argurio
2020 ◽  
Vol 0 (2) ◽  
pp. 21-25
Author(s):  
Nikolay Dubenok ◽  
Andrey Novikov ◽  
Sergei Borodychev ◽  
Maria Lamskova

At the stage of water treatment for irrigation systems, the efficiency capture coarse and fine mechanical impurities, as well as oil products and organic compounds affects the reliability of the equipment of the irrigation network and the safety of energy exchange processes in irrigated agricultural landscapes. The violation of work irrigation system can cause disruptions in irrigation schedules of agricultural crops, crop shortages, degradation phenomena on the soil and ecological tension. For the combined irrigation system, a water treatment unit has been developed, representing a hydrocyclone apparatus with a pipe filter in the case. For the capacity of 250 m3/h the main geometrical dimensions of hydrocyclone have been calculated. To organize the capture petroleum products and organic compounds, it has been proposed a modernization of a hydrocyclone unit, consisting in dividing the cylindrical part of the apparatus into two section. The first is section is for input irrigation water, the second one is for additional drainage of clarified irrigation water after sorption purification by the filter, placed on the disk and installed coaxially with the drain pipe and the pipe filter.


1995 ◽  
Vol 31 (10) ◽  
pp. 103-121
Author(s):  
J.-O. Frier ◽  
J. From ◽  
T. Larsen ◽  
G. Rasmussen

The aim of waste modelling in aquaculture is to provide tools for simulating input, transformation, output and subsidiary degradation in recipients of organic compounds, nitrogen, and phosphorus. The direct purpose of this modelling is to make it possible for caretakers and water authorities to calculate waste discharge from existing and planned aquaculture activities. A special purpose is simulating outcome of waste water treatment and altered feeding programmes. Different submodels must be applied for P, N, and organics, as well as for the different phases of food and waste treatment. Altogether this calls for an array of co-operating submodels for a sufficient coverage of the options. In all the required fields there is some scientific background for numerical model approaches, and some submodels have been proposed. Because of its multidisciplinary character a synthesized approach is still lacking. Within trout farming this work attempts to establish the different submodels and outlines future possibilities for synthesizing the knowledge to a numerical model.


Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 720
Author(s):  
Satomi Niwayama

Symmetric organic compounds are generally obtained inexpensively, and therefore they can be attractive building blocks for the total synthesis of various pharmaceuticals and natural products. The drawback is that discriminating the identical functional groups in the symmetric compounds is difficult. Water is the most environmentally benign and inexpensive solvent. However, successful organic reactions in water are rather limited due to the hydrophobicity of organic compounds in general. Therefore, desymmetrization reactions in aqueous media are expected to offer versatile strategies for the synthesis of a variety of significant organic compounds. This review focuses on the recent progress of desymmetrization reactions of symmetric organic compounds in aqueous media without utilizing enzymes.


Author(s):  
Guanghui Jing ◽  
Li Wang ◽  
Haojie Yu ◽  
Wael A. Amer ◽  
Lei Zhang

2020 ◽  
Vol 16 (5) ◽  
pp. 55-62
Author(s):  
V. V. Borodychev ◽  
A. E. Novikov ◽  
M. I. Lamskova ◽  
M. I. Filimonov

An increase in the volume of industrial effluents, ship accidents, oil breakthroughs at drilling rigs lead to a deterioration in the quality indicators of water in open water sources, including in terms of the content of organic compounds and oil products. The water used for irrigation of agricultural crops, according to most indicators, must meet the water quality requirements for household and drinking purposes. Thus, the total content of oil products in the irrigation water should not exceed 0.1 mg / l. The use of water with the MPC excess leads to significant changes in the morphological properties of the soil, reduces the biological productivity and phytomass of the plant cover. Therefore, the issue of improving machines and devices used in water treatment technologies to increase their reliability and efficiency is one of the topical areas of the research. The aim of the study is to develop a hydrocyclone complex cleaning apparatus, which implements combined processes of capturing both coarse and finely dispersed impurities. Unlike the standard design, the hydrocyclone is supplemented with a filter element installed on the drain pipe, which provides additional water purification from fine mechanical impurities, and a sorption filter designed to remove oil products and other floating organic compounds from water. The proposed hydrocyclone unit provides a comprehensive purification of irrigation water from various types of impurities, due to the combined processes of centrifugal separation and sorption filtration. It eliminates the multistage process of water purification, and regeneration of the sorption filter by the action of centrifugal forces or pressure does not require the use of special regenerating solutions, which increases the manufacturability and environmental friendliness of the water treatment process.


2010 ◽  
Vol 2 (5) ◽  
pp. 5-8
Author(s):  
Ramunė Albrektienė ◽  
Mindaugas Rimeika

The article examines different methods for determining organic matter and colour in water. Most of organic compounds in water have a humic substance. These substances frequently form complexes with iron. Humic matter gives water a yellow-brownish colour. Water filtration through conventional sand filters does not remove colour and organic compounds, and therefore complicated water treatment methods shall be applied. The methods utilized for organic matter determination in water included research on total organic carbon, permanganate index and the bichromate number of UV absorption of 254 nm wave length. The obtained results showed the greatest dependence between water colour and permanganate index. However, UV adsorption could be used for organic matter determination during the operation of a water treatment plant and the start-up of plants as easy and fast methods.


1982 ◽  
Vol 65 (6) ◽  
pp. 1370-1374
Author(s):  
Rein Otson ◽  
David T Williams ◽  
Peter D Bothwell

Abstract A static headspace technique and previously developed and evaluated dynamic headspace and liquid-liquid extraction techniques were applied in a survey of volatile organic compounds in water at 30 Canadian potable water treatment facilities. Of the 43 compounds investigated, 27 compounds were detected in the water samples. Chloroform and bromodichloromethane occurred most frequently in treated water, and trichloroethylene, tetrachloroethylene, 1,2-dichloroethane, dichloromethane, benzene, toluene, ethylbenzene, and the xylenes occurred frequently in both treated and raw water. Only chloroform occurred frequently at levels above 10 μg/L in treated water. Generally, higher levels of organic compounds were found during August-September than during November-December.


2019 ◽  
Vol 100 ◽  
pp. 00019 ◽  
Author(s):  
Renata Gmurkowska

During water treatment a large amount of sludge is created – in the form of sewage and sediments. The largest amounts of sludge are produced during coagulation, ozonation and backwashing rapid filters. The quality and quantity of treated water, the type and dose of used coagulants are factors affecting the quantity, composition and properties of the sludge. Sludge produced during processing of drinking water is important problem and their quantity has been increasing. The study focuses on characteristics of water treatment sludge from four water treatment plants in Cracow. It includes theoretical and experimental part. The first part is based on analysis of literature and information obtained from MPWiK [3]. The second experimental part, concerns the analysis of dry matter, organic dry matter, capillary suction time and visual parameters: the color and consistency of the sludge. Result shows that every sludge contains organic matter. The highest concentrations of organic compounds and the largest diversity has been observed in the sludge collected in the Water Treatment Plant Raba, reaching even up to 70% of organic compounds in the dry mass of sludge.


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