Fish Processing Wastewater: Emission Factors and High Load Trickling Filters Evaluation

An Italian seafood factory processing frozen fish and fresh clams was investigated. Specific water consumption (SC) and pollutant emission factors (EF) are evaluated. Results evidence high SC values, in the range 18-74 1/Kg, due to defrost and extensive washing and cleaning practised; EFs appear high although not directly comparable with data reported by other authors. Two high-rate trickling filters, cross flow (CF) and vertical flow (VF), are examined over a two years period. Results suggest a pseudo half-order kinetic reaction with a superior performance of CF plastic media. From the elaboration of the experimental data a semiempirical correlation between specific surface removal (SSR) and operative parameters is obtained.

Download Full-text

Spatially Resolved Emission Factors to Reduce Uncertainties in Air Pollutant Emission Estimates from the Residential Sector

Environmental Science & Technology ◽

10.1021/acs.est.0c08568 ◽

2021 ◽

Vol 55 (8) ◽

pp. 4483-4493

Author(s):

Xinlei Liu ◽

Guofeng Shen ◽

Laiguo Chen ◽

Zhe Qian ◽

Ningning Zhang ◽

...

Keyword(s):

Emission Factors ◽

Air Pollutant ◽

Pollutant Emission ◽

Residential Sector ◽

Spatially Resolved

Download Full-text

Oxygen-Deficient β-MnO2@Graphene Oxide Cathode for High-Rate and Long-Life Aqueous Zinc Ion Batteries

Nano-Micro Letters ◽

10.1007/s40820-021-00691-7 ◽

2021 ◽

Vol 13 (1) ◽

Author(s):

Shouxiang Ding ◽

Mingzheng Zhang ◽

Runzhi Qin ◽

Jianjun Fang ◽

Hengyu Ren ◽

...

Keyword(s):

Graphene Oxide ◽

Manganese Oxides ◽

Rate Capability ◽

High Energy ◽

Zinc Ion ◽

Cycling Stability ◽

High Rate ◽

High Energy Density ◽

Superior Performance ◽

Long Life

AbstractRecent years have witnessed a booming interest in grid-scale electrochemical energy storage, where much attention has been paid to the aqueous zinc ion batteries (AZIBs). Among various cathode materials for AZIBs, manganese oxides have risen to prominence due to their high energy density and low cost. However, sluggish reaction kinetics and poor cycling stability dictate against their practical application. Herein, we demonstrate the combined use of defect engineering and interfacial optimization that can simultaneously promote rate capability and cycling stability of MnO2 cathodes. β-MnO2 with abundant oxygen vacancies (VO) and graphene oxide (GO) wrapping is synthesized, in which VO in the bulk accelerate the charge/discharge kinetics while GO on the surfaces inhibits the Mn dissolution. This electrode shows a sustained reversible capacity of ~ 129.6 mAh g−1 even after 2000 cycles at a current rate of 4C, outperforming the state-of-the-art MnO2-based cathodes. The superior performance can be rationalized by the direct interaction between surface VO and the GO coating layer, as well as the regulation of structural evolution of β-MnO2 during cycling. The combinatorial design scheme in this work offers a practical pathway for obtaining high-rate and long-life cathodes for AZIBs.

Download Full-text

Successfully Optimizing Breakers in Polyacrylamides for Slickwater and High-Viscosity Fluids

10.2118/206279-ms ◽

2021 ◽

Author(s):

Sarkis Kakadjian ◽

Jarrett Kitchen ◽

Amanda Flowers ◽

John Vu ◽

Amanuel Gebrekirstos ◽

...

Keyword(s):

Light Scattering ◽

Active Material ◽

High Viscosity ◽

High Rate ◽

Viscosity Reduction ◽

Superior Performance ◽

Size Distributions ◽

Pore Throat ◽

Eagle Ford ◽

Fracture Conductivity

Abstract Polyacrylamide-based friction reducers (FR's) - including viscosifying polyacrylamides, which are designed to decrease proppant settling by increasing molecular weight and/or active material in the FR - are used extensively in high-rate fracture stimulations. However, because polyacrylamides are difficult to break, there have been concerns about how these materials impact fracture conductivity and formation permeability. This study presents the effect of conventional and novel oxidative breakers over the viscosity and colloidal size distribution of the broken polymers. Breakers tested include conventional persulfates, perborates and patent pending peroxides, all of which generate free radicals to degrade partially hydrolyzed polyacrylamides (PHPAs). Breakers were tested at bottomhole temperatures encountered in the Permian, Bakken, Haynesville and Eagle Ford. Changes to PHPA viscosity were determined using vibrational viscometers. Size distributions and percentage of the broken colloidal PHPA were determined by dynamic light scattering. This method can measure sizes down to 0.6 nanometers, which is within the range of even the smallest pore-throat sizes in shales. Light scattering revealed surprising anomalies in breaker performance. When aged at temperatures typical of the Permian, each of the tested breakers at each of the varied concentrations caused similar levels of viscosity reduction but different size distributions. Some breakers had the unwanted effect of narrowing the colloidal size fractions to the lower end of the spectrum. At these small sizes, colloids are more likely to overlap with segments of the pore throat distribution in some shales, which could inhibit production. In addition, when the FR was aged at the higher temperatures encountered in the Bakken, Eagle Ford and Haynesville, some breakers were not able to uniformly break the PHPA. In these cases, FR's without breakers delivered superior performance. The results clearly demonstrate that breakers may not always have the desired effect of increasing the formation's permeability. In fact, depending on the type of breaker and the concentration, they can often have detrimental effects that ultimately hinder production.

Download Full-text

Cross-Flow Ultrafiltration Used in Algal High Rate Oxidation Pond Treatment of Saline Organic Effluents with the Recovery of Products of Value

Water Science & Technology ◽

10.2166/wst.1992.0258 ◽

1992 ◽

Vol 25 (10) ◽

pp. 319-327 ◽

Cited By ~ 7

Author(s):

P. D. Rose ◽

B. A. Maart ◽

T. D. Phillips ◽

S. L. Tucker ◽

A. K. Cowan ◽

...

Keyword(s):

Waste Treatment ◽

Production Systems ◽

Algal Cell ◽

Cross Flow ◽

Viable Cell ◽

High Rate ◽

Limiting Factor ◽

Algal Biotechnology ◽

Cross Flow Filtration ◽

Flow Filtration

An algal high rate oxidation ponding process for treating organic s present in saline effluents has been described. The extreme halophile Dunaliella salina can be made to predominate in the system by manipulating salinity, producing products of value together with a waste treatment function. Application in treating tannery saline organic wastes was examined. Techniques appropriate for the harvesting of micro-algae from this and other algal production systems presents a limiting factor in the development of algal biotechnology. Cross-flow filtration was evaluated as a technique for micro-algal cell separation. Both microfiltration and ultrafiltration were found to produce effective algal removal from the medium, Cross-flow ultrafiltration with a polyethersulfone coated tubular filter produced effective separation with the production of cell concentrates in a viable condition. Flux rates of 30 - 40 LMH fall within acceptable levels for application in industrial processes. Cell shattering observed with microfiltration precludes its use for recovering whole or viable cell concentrates.

Download Full-text

Production of free radicals by the Co2+/Oxone system to carry out diclofenac degradation in aqueous medium

Water Science & Technology ◽

10.2166/wst.2018.489 ◽

2018 ◽

Vol 78 (10) ◽

pp. 2131-2140 ◽

Cited By ~ 6

Author(s):

Oscar M. Rodríguez-Narváez ◽

Oracio Serrano-Torres ◽

Kazimierz Wrobel ◽

Enric Brillas ◽

Juan M. Peralta-Hernandez

Keyword(s):

Free Radicals ◽

High Performance ◽

Hplc Analysis ◽

Apparent Rate Constant ◽

Oxygen Demand ◽

Co2 Concentration ◽

Oh Radicals ◽

Order Kinetic ◽

Kinetic Reaction ◽

Ion Exclusion

Abstract This paper reports the degradation of a solution of 0.314 mM diclofenac (DCF), while using 5–15 mM Oxone as oxidizing agent with the catalytic action of 0.05–0.2 mM Co2+. The best performance was obtained for 10 mM Oxone and 0.2 mM Co2+, achieving the total DCF abatement and 77% removal of chemical oxygen demand after 30 min. Oxidizing of sulfate () and hydroxyl (•OH) radicals was formed by the Co2+/Oxone system. Oxone was firstly oxidized to persulfate ion that was then quickly converted into the above free radicals. For Oxone contents ≥10 mM, the decay of DCF concentration followed a second-order kinetic reaction, but the apparent rate constant changed with the Co2+ concentration used. High-performance liquid chromatography (HPLC) analysis of treated solutions showed the formation of some intermediates, whereas oxalic acid was identified as the prevalent final short-linear carboxylic acid by ion-exclusion HPLC.

Download Full-text

Photocatalytic degradation of indigo carmine by ZnO photocatalyst under visible light irradiation

Baghdad Science Journal ◽

10.21123/bsj.14.3.582-587 ◽

2017 ◽

Vol 14 (3) ◽

pp. 582-587

Author(s):

Baghdad Science Journal

Keyword(s):

Zinc Oxide ◽

Photocatalytic Degradation ◽

Indigo Carmine ◽

Catalyst Loading ◽

Order Kinetic ◽

Kinetic Reaction ◽

First Order ◽

Pseudo First Order ◽

The Relationship ◽

Influential Parameters

In this work, the photocatalytic degradation of indigo carmine (IC) using zinc oxide suspension was studied. The effect of influential parameters such as initial indigo carmine concentration and catalyst loading were studied with the effect of Vis irradiation in the presence of reused ZnO was also investigated. The increased in initial dye concentration decreased the photodegradation and the increased catalyst loading increased the degradation percentage and the reused-ZnO exhibits lower photocatalytic activity than the ZnO catalyst. It has been found that the photocatalytic degradation of indigo carmine obeyed the pseudo-first-order kinetic reaction in presence of zinc oxide. This was found from plotting the relationship between ln (C0/Ct) and irradiation the rate constant of the process.UV- spectrophotometer was used to study the indigo carmine photodegradation.

Download Full-text