Water environment

About: Water environment is a research topic. Over the lifetime, 13384 publications have been published within this topic receiving 125138 citations.

An Optimization Model for Water Management Based on Water Resources and Environmental Carrying Capacities: A Case Study of the Yinma River Basin, Northeast China

Abstract: In this study, an inexact two-stage stochastic programming (ITSP) model was developed for supporting water resources allocation for the four main water use sectors (industry, municipal, environmental, and agriculture) and total amount control of the pollutant emissions. The Yinma River Basin in northeast China was selected for a case study. A number of scenarios corresponding to different flow levels were examined. The flow levels reflect different probabilities of water resource availability and environmental carrying capacity. The results revealed that the optimal allocation strategies for each sector depend on water resource carrying capacity, wastewater treatment capacity, the total amount of regional control, and the water environment carrying capacity. Water ecology projects were identified that are needed to treat contaminated water and to address the insufficient carrying capacity for pollutant emissions generated in water-using processes. The results will be helpful for establishing sensible water management systems that integrate the development and utilization of water resources and protect the environment, and for providing a basis for water pollution prevention plans, the model can be used to guide management interventions to improve the water environment by regional pollutant emission control and the improvement of carrying capacity in the Yinma River Basin.

Structure of the inclusion complex of β‐cyclodextrin with 1,12‐dodecanedioic acid using synchrotron radiation data; a detailed dimeric β‐­cyclodextrin structure

Abstract: A detailed crystal structure study of the dimeric inclusion complex of β-cyclodextrin (βCD) with 1,12-dodecanedioic acid is presented [IUPAC name: β-cyclodextrin–1,12-dodecanedioic acid (2/1)]. The structure was solved with synchrotron high-resolution data (0.65 A) at 100 K [crystal data: P1, Z = 1, a = 18.153 (7), b = 15.456 (8), c = 15.251 (4) A, α = 102.81 (2), β = 113.13 (2), γ = 99.90 (3)°, V = 3673 (3) A3, R = 0.0474 for 25 134 unique reflections with I > 2σ(I)]. Moreover, the room-temperature structure is used for comparison [crystal data: P1, Z = 1, a = 18.220 (3), b = 15.488 (3), c = 15.409 (3) A, α = 102.903 (6), β = 113.122 (5), γ = 99.708 (5)°, V = 3735.2 (12) A3, R = 0.0828 for 8235 unique reflections with I > 2σ(I)]. Combining the high-resolution data and the low-temperature made possible the location of the disordered guest molecule, 1,12-dodecanedioic acid, inside the wide cavity of the macrocycle formed by two βCD monomers. Moreover, almost all the H atoms of the βCD macrocycle and many of the water molecules have been located in the low-temperature structure. Thus, for the first time, it has been possible to show in detail, up to now only given by neutron diffraction data, that two βCD monomers self-assemble through O3⋯O3 intermolecular hydrogen bonds to form the βCD dimer, as well as describe the hydrogen-bonding scheme between the dimer's hydroxyl groups among themselves and with water molecules in the lattice. The long guest threads through two host molecules forming a [3]pseudo­rotaxane. Its polar carboxyl groups, fully hydrated at the primary faces of the βCD dimers, influence their packing so that those faces are exposed to the solvent. This is in contrast to the packing of the β-cyclodextrin complexes of the corresponding aliphatic monoacids, where the dimeric complexes form channels in order to isolate the terminal methyl group from the water environment of the lattice.

Removal of Heavy Metals from Waste Water Using Water Hyacinth

Abstract: Water pollution has become one of the most serious problems of today's civilization. In the last few years considerable amount of research has been done on the potential of aquatic macrophytes for pollutant removal or even as bio-indicators for heavy metals in aquatic ecosystems. Water hyacinth is one of the aquatic plant species successfully used for wastewater treatment. It is very efficient in removing pollutants like suspended solids, BOD, organic matter, heavy metals and pathogens. This paper mainly focuses on the treatment of waste water using the plant 'water hyacinth' and has given emphasis to the removal of heavy metals by the plant. Water hyacinth' could grow in sewage; they absorb and digest the pollutants in wastewater, thus converting sewage effluents to relatively clean water. Thus, the plants hold promise as a natural water purification system, which could be established at a fraction of the cost of a conventional sewage treatment facility. The study conducted in this regard revealed how efficiently wastewater could be treated using the plant 'Water hyacinth'. Water scarcity has been increasing all over the world and in many countries may become absolute by the year 2025 "Ref. (17)". This problem becomes more apprehensive when recognizing that the severity of surface water pollution is a worldwide problem "Ref. (18)". To tackle the problem, several measures for sustainable water resource utilization have been developed, of which wastewater reclamation and reuse is currently one of the top priorities "Ref. (14)". It was reported that domestic and Industrial discharges are probably the two most important anthropogenic sources for metals in the water environment "Ref. (4)". The presence of heavy metals in water are toxic even at very low concentrations "Ref. (7)". Pollution of the biosphere with toxic metals has accelerated dramatically since the beginning of the industrial revolution. Water hyacinth (Eichhornia crassipes) an aquatic plant which could successfully used for removing various pollutants from water thus has great importance in wastewater treatment. It has a huge potential for removal of the vast range of pollutants from wastewater "Ref. (3)". II. RESEARCH SIGNIFICANCE In this paper the main focus was on studying the efficiency of water hyacinth in removing dissolved solids, B.O.D, heavy metals mainly chromium and copper from the waste water, and the effect of the growth of water hyacinth on the pH of the waste water. To achieve this objective, water hyacinth was grown in synthetic wastewater prepared by adding varying concentrate ions of Cr and Cu. The concentrations of heavy metals, pH, B.O.D and total dissolved solids were noted in the waste water before and after cultivating water hyacinth and compared the results with the standard values.