scholarly journals Effective removal of aromatic pollutants via adsorption and photocatalysis of porous organic frameworks

RSC Advances ◽  
2020 ◽  
Vol 10 (53) ◽  
pp. 32016-32019
Author(s):  
Congcong Wang ◽  
Wei Wang ◽  
Jian Wang ◽  
Peiping Zhang ◽  
Shiding Miao ◽  
...  
Keyword(s):  
Pollutant Removal ◽  
Conjugation System ◽  
Excellent Performance ◽  
Aromatic Pollutants ◽  
Effective Removal ◽  
Intrinsic Microporosity

PAF-45 with a wholly aromatic framework, intrinsic microporosity and π–π conjugation system shows excellent performance in aromatic pollutant removal.

scholarly journals Treatment of Poultry Slaughterhouse Wastewater with Membrane Technologies: A Review

Water ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 1905
Author(s):  
Faryal Fatima ◽  
Hongbo Du ◽  
Raghava R. Kommalapati
Keyword(s):  
High Efficiency ◽  
Membrane Technology ◽  
Pollutant Removal ◽  
Excellent Performance ◽  
Slaughterhouse Wastewater ◽  
Alternative Approach ◽  
Poultry Processing ◽  
Quality Water ◽  
Membrane Technologies ◽  
Conventional Methods

Poultry slaughterhouses produce a large amount of wastewater, which is usually treated by conventional methods. The traditional techniques face some challenges, especially the incapability of recovering valuable nutrients and reusing the treated water. Therefore, membrane technology has been widely adopted by researchers due to its enormous advantages over conventional methods. Pressure-driven membranes, such as microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), and reverse osmosis (RO), have been studied to purify poultry slaughterhouse wastewater (PSWW) as a standalone process or an integrated process with other procedures. Membrane technology showed excellent performance by providing high efficiency for pollutant removal and the recovery of water and valuable products. It may remove approximately all the pollutants from PSWW and purify the water to the required level for discharge to the environment and even reuse for industrial poultry processing purposes while being economically efficient. This article comprehensively reviews the treatment and reuse of PSWW with MF, UF, NF, and RO. Most valuable nutrients can be recovered by UF, and high-quality water for reuse in poultry processing can be produced by RO from PSWW. The incredible performance of membrane technology indicates that membrane technology is an alternative approach for treating PSWW.

Computer programs for the calculation of x-ray intensities emitted by elements in multi-layer structures

1990 ◽  
Vol 48 (2) ◽  
pp. 216-217
Author(s):  
G.F. Bastin ◽  
H.J.M. Heijligers ◽  
J.M. Dijkstra
Keyword(s):  
Software Package ◽  
Light Element ◽  
Matrix Correction ◽  
Excellent Performance ◽  
Element Analysis ◽  
X Ray ◽  
Know How ◽  
Accurate Knowledge ◽  
Layer Structures ◽  
Bulk Matrix

For the calculation of X-ray intensities emitted by elements present in multi-layer systems it is vital to have an accurate knowledge of the x-ray ionization vs. mass-depth (ϕ(ρz)) curves as a function of accelerating voltage and atomic number of films and substrate. Once this knowledge is available the way is open to the analysis of thin films in which both the thicknesses as well as the compositions can usually be determined simultaneously.Our bulk matrix correction “PROZA” with its proven excellent performance for a wide variety of applications (e.g., ultra-light element analysis, extremes in accelerating voltage) has been used as the basis for the development of the software package discussed here. The PROZA program is based on our own modifications of the surface-centred Gaussian ϕ(ρz) model, originally introduced by Packwood and Brown. For its extension towards thin film applications it is required to know how the 4 Gaussian parameters α, β, γ and ϕ(o) for each element in each of the films are affected by the film thickness and the presence of other layers and the substrate.

Macrocellular Titanosilicate Monoliths as Highly Efficient Structured Olefin Epoxidation Catalysts

2019 ◽  
Author(s):  
Valentin Smeets ◽  
Ludivine van den Biggelaar ◽  
Tarek Barakat ◽  
Eric M. Gaigneaux ◽  
Damien Debecker
Keyword(s):  
Sol Gel ◽  
Silica Matrix ◽  
Flow Mode ◽  
Tetrahedral Coordination ◽  
Excellent Performance ◽  
One Pot ◽  
Templating Method ◽  
Porous Texture ◽  
Internal Phase ◽  
Epoxidation Of Cyclohexene

Self-standing macrocellular titanosilicate monolith foams are obtained using a one-pot sol-gel route and show excellent performance in the epoxidation of cyclohexene. Thanks to the High Internal Phase Emulsion (HIPE) templating method, the materials feature a high void fraction, a hierarchically porous texture and good mechanical strength. Highly dispersed Ti species can be incorporated in tetrahedral coordination the silica matrix. These characteristics allow the obtained ‘SiTi(HIPE)’ materials to reach high catalytic turnover in the epoxidation of cyclohexene. The monoliths can advantageously be used to run the reaction in continuous flow mode.<br>

LDX 2101

Alloy Digest ◽  
2015 ◽  
Vol 64 (8) ◽  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Physical Properties ◽  
Duplex Stainless Steel ◽  
Tensile Properties ◽  
Lower Cost ◽  
Heat Treating ◽  
General Purpose ◽  
Research Centre ◽  
Excellent Performance

Abstract LDX 2101 is a low-alloyed duplex stainless designed as a general-purpose duplex stainless steel. Designed for excellent performance at lower cost. This datasheet provides information on composition, physical properties, microstructure, hardness, and tensile properties as well as fatigue. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-1220. Producer or source: Outokumpu Stainless AB, Avesta Research Centre.

FORMALOY

Alloy Digest ◽  
1975 ◽  
Vol 24 (1) ◽  
Keyword(s):  
Fracture Toughness ◽  
Compressive Strength ◽  
Corrosion Resistance ◽  
Sheet Metal ◽  
High Purity ◽  
Base Alloy ◽  
High Strength ◽  
Heat Treating ◽  
Grain Structure ◽  
Excellent Performance

Abstract FORMALOY is a high-strength, high-purity zinc-base alloy with excellent performance in dies for forming sheet metal. It has a fine, dense grain structure which contributes markedly to its good toughness, excellent machinability and ability to develop a high polish. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive strength as well as fracture toughness. It also includes information on corrosion resistance as well as casting, forming, heat treating, machining, and joining. Filing Code: Zn-17. Producer or source: Federated Metals Corporation, ASARCO Inc..

Synthesizing Conjunctive & Disjunctive Linear Invariants by K-means++ and SVM

2020 ◽  
Vol 17 (6) ◽  
pp. 847-856
Author(s):  
Shengbing Ren ◽  
Xiang Zhang
Keyword(s):  
Software Verification ◽  
State Of The Art ◽  
Positive Sample ◽  
Machine Learning Algorithms ◽  
Support Vector ◽  
Hoare Logic ◽  
Excellent Performance ◽  
Automated Software ◽  
Inductive Invariants ◽  
Linear Invariants

The problem of synthesizing adequate inductive invariants lies at the heart of automated software verification. The state-of-the-art machine learning algorithms for synthesizing invariants have gradually shown its excellent performance. However, synthesizing disjunctive invariants is a difficult task. In this paper, we propose a method k++ Support Vector Machine (SVM) integrating k-means++ and SVM to synthesize conjunctive and disjunctive invariants. At first, given a program, we start with executing the program to collect program states. Next, k++SVM adopts k-means++ to cluster the positive samples and then applies SVM to distinguish each positive sample cluster from all negative samples to synthesize the candidate invariants. Finally, a set of theories founded on Hoare logic are adopted to check whether the candidate invariants are true invariants. If the candidate invariants fail the check, we should sample more states and repeat our algorithm. The experimental results show that k++SVM is compatible with the algorithms for Intersection Of Half-space (IOH) and more efficient than the tool of Interproc. Furthermore, it is shown that our method can synthesize conjunctive and disjunctive invariants automatically

Field-Scale Studies of Subsurface Flow Constructed Wetlands for Stormwater Quality Enhancement

1997 ◽  
Vol 32 (1) ◽  
pp. 101-118 ◽  
Author(s):  
Q.J. ROCHFORT ◽  
W.E. Watt ◽  
J. Marsalek ◽  
B.C. Anderson ◽  
A.A. Crowder
Keyword(s):  
Organic Carbon ◽  
Constructed Wetlands ◽  
Suspended Solids ◽  
Nutrient Loading ◽  
Subsurface Flow ◽  
Reaction Rates ◽  
Pollutant Removal ◽  
Order Kinetic ◽  
Dissolved Metals ◽  
Subsurface Flow Constructed Wetlands

Abstract Two subsurface flow constructed wetlands were tested for pollutant removal performance in conjunction with an on-line stormwater detention pond, in Kingston Township, Ontario. The 4.9 m2 wetland cells were filled with 9 mm limestone gravel, and planted with cattail, common reed and spike rush. Changes in nutrient (total organic carbon, PO43- and NH4+), suspended solids and metal (Cu, Pb, Zn) concentrations were used to assess performance. Contaminant removal occurred through a combination of physical, chemical and biological means. As with any biological system, variation in performance of stormwater wetlands can be expected to occur as a result of fluctuations in contaminant loading, contact time and ambient environmental conditions. Storm pond effluent was delivered in continuous flow through the wetlands (during baseflow and event conditions), with a detention time of 1 to 3 days. The wetlands were able to maintain removal rates of up to 39% for orthophosphate even during the more severe conditions of fall dieback. Average removal of suspended solids (46%) and dissolved metals (Cu 50%) remained similar throughout all tests. Organic carbon was reduced by less than 10% during these tests. Low nutrient levels in the pond effluent were supplemented by spiking with sources of carbon, nitrogen and phosphorus during pulsed loading conditions. Daily sampling produced a time series, which illustrated the rates of decline in concentration of nutrients. First order kinetic assimilation rates ranged from 1.7 d-1 for NH4002B to 0.12 d-1 for organic carbon, which were noticeably lower when compared with municipal and industrial wastewater treatment rates. Three methods of sizing stormwater wetlands (impervious surface area, volumetric load and kinetic reaction rates) were compared using the same design storm and data from this study. From this comparison it was seen that the kinetic sizing approach proved to be the most versatile, and allowed for adaptation to northern climatic conditions and anticipated nutrient loading.

Performance and Modelling of a Highway Wet Detention Pond Designed for Cold Climate

2009 ◽  
Vol 44 (3) ◽  
pp. 253-262 ◽  
Author(s):  
Jes Vollertsen ◽  
Svein Ole Åstebøl ◽  
Jan Emil Coward ◽  
Tor Fageraas ◽  
Asbjørn Haaning Nielsen ◽  
...  
Keyword(s):  
Rate Constants ◽  
Pond Water ◽  
Pollutant Removal ◽  
Cold Climate ◽  
Traffic Load ◽  
Substantial Part ◽  
First Order ◽  
Detention Pond ◽  
Time Of Year ◽  
Wet Detention Pond

Abstract A wet detention pond in Norway has been monitored for 12 months. The pond receives runoff from a highway with a traffic load of 42,000 average daily traffic. Hydraulic conditions in terms of inflow, outflow, and pond water level were recorded every minute. Water quality was monitored by volume proportional inlet and outlet samples. During most of the year, excellent pollutant removal was achieved; however, during two snowmelt events the pollutant removal was poor or even negative. The two snowmelt events accounted for one third of the annual water load and for a substantial part of the annual pollutant discharge. The performance of the pond was analyzed using a dynamic model and pollutant removal was simulated by first-order kinetics. Good agreement between measurement and simulation could be achieved only when choosing different first-order rate constants for different parts of the year. However, no relation between the rate constants obtained and the time of year could be identified, and neither did the rate constants for different pollutants correlate. The study indicates that even detailed measurements of pollutant input and output allow only average performance to be simulated and are insufficient for simulating event-based variability in pond performance.

Clay liner materials for land disposal of hazardous non-metal wastes

1996 ◽  
Vol 33 (8) ◽  
pp. 71-77
Author(s):  
I. M.-C. Lo ◽  
H. M. Liljestrand ◽  
J. Khim ◽  
Y. Shimizu
Keyword(s):  
Sorption Capacity ◽  
Organic Anion ◽  
Surface Exchange ◽  
Clay Liner ◽  
Effective Removal ◽  
Exchange Constants ◽  
Anionic Species ◽  
Surface Ligand ◽  
Land Disposal

Simple land disposal systems for hazardous and mixed wastes contain heavy metal cationic species through precipitation and ion exchange mechanisms but typically fail by releasing soluble organic and inorganic anionic species. To enhance the removal of anions from leachate, clays are modified with coatings of iron or aluminium cations to bridge between the anionic surface and the anionic pollutants. A competitive surface ligand exchange model indicates that surface coatings of 10 meq cation/gm montmorillonite under typical leachate conditions increase the inorganic anion sorption capacity by at least a factor of 6 and increase the intrinsic surface exchange constants by more than a factor of 100. Similarly, metal hydroxide coatings on montmorillonite increase the organic anion sorption capacity by a factor of 9 and increase the intrinsic surface exchange constants by a factor of 20. For historical concentrations of non-metal anions in US hazardous and mixed waste leachate, sorption onto natural clay liner materials is dominated by arsenate sorption. With cation coatings, anion exchange provides an effective removal for arsenate, selenate, phenols, cresols, and phthalates. Engineering applications are presented for the use of modified clays as in situ barriers to leachate transport of anionic pollutants as well as for above ground treatment of recovered leachate.

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