Slaughterhouse Wastewater: Treatment, Management and Resource Recovery

The meat processing industry is one of the largest consumers of total freshwater used in the agricultural and livestock industry worldwide. Meat processing plants (MPPs) produce large amounts of slaughterhouse wastewater (SWW) because of the slaughtering process and cleaning of facilities. SWWs need significant treatment for a sustainable and safe discharge to the environment due to the high content of organics and nutrients. Therefore, the treatment and final disposal of SWW are a public health necessity. In this chapter, the regulatory frameworks relevant to the SWW management, environmental impacts, health effects, and treatment methods are discussed. Although physical, chemical, and biological treatment can be used for SWW degradation, each treatment process has different advantages and drawbacks depending on the SWW characteristics, best available technology, jurisdictions, and regulations. SWWs are typically assessed using bulk parameters because of the various pollutant loads derived from the type and the number of animals slaughtered that fluctuate amid the meat industry. Thus, an on-site treatment using combined processes would be the best option to treat and disinfect the slaughterhouse effluents to be safely discharged into receiving waters

Sources, characteristics, toxicity, and control of ultrafine particles: an overview

Air pollution by particulate matter (PM) is one of the main threats to human health, particularly in large cities where pollution levels are continually exceeded. According to their source of emission, geography, and local meteorology, the pollutant particles vary in size and composition. These particles are conditioned to the aerodynamic diameter and thus classified as coarse (2.5–10 μm), fine (0.1–2.5 μm), and ultrafine (<0.1 μm), where the degree of toxicity becomes greater for smaller particles. These particles can get into the lungs and translocate into vital organs due to their size, causing significant human health consequences. Besides, PM pollutants have been linked to respiratory conditions, genotoxic, mutagenic, and carcinogenic activity in human beings. This paper presents an overview of emission sources, physicochemical characteristics, collection and measurement methodologies, toxicity, and existing control mechanisms for ultrafine particles (UFPs) in the last fifteen years

New Concepts in Oxidation Processes

This Special Issue of Catalysts aims to cover the recent progress and novel trends in the field of catalytic oxidation reaction. Topics addressed in this special issue concern the influence of different parameters on catalytic activity at various scales (atomic, laboratory, pilot, or industrial scales), the development of new catalytic materials of environmental or industrial importance, as well as the development of new methods, both microscopic and spectroscopic, to analyze oxidation processes

Scale-Up and Optimization for Slurry Photoreactors

Several aspects of scale-up and optimization of heterogeneous photocatalytic reactors are detailed in the following chapter. The relevance of the dimensionless numbers, the critical factors of the photoreactor design, and the optimization methods are explored from an engineering point of view. The apparent optical thickness is the most crucial dimensionless parameter for photoreactor design and optimization; therefore, the study will be more focused on this topic. Moreover, a real case for a commercial application of the solar photocatalysis will be presented in this chapter. This full-scale plant is currently operating as an industrial wastewater treatment plant in a flexographic company located in Cali, Colombia

Special Issue: Application of Advanced Oxidation Processes

Advanced oxidation processes (AOPs) are nowadays not only considered as a complementary treatment option but as an attractive alternative to conventional methods [...

Editorial: Special issue “new concepts in oxidation processes”

SCOPUS: ed.jinfo:eu-repo/semantics/publishe

Photocatalytic Degradation of Commercial Acetaminophen: Evaluation, Modeling, and Scaling-Up of Photoreactors

In this work, the performance of a pilot-scale solar CPC reactor was evaluated for the degradation of commercial acetaminophen, using TiO2 P25 as a catalyst. The statistical Taguchi&rsquo;s method was used to estimate the combination of initial pH and catalyst load while tackling the variability of the solar radiation intensity under tropical weather conditions through the estimation of the signal-to-noise ratios (S/N) of the controllable variables. Moreover, a kinetic law that included the explicit dependence on the local volumetric rate of photon absorption (LVRPA) was used. The radiant field was estimated by joining the Six Flux Model (SFM) with a solar emission model based on clarity index (KC), whereas the mass balance was coupled to the hydrodynamic equations, corresponding to the turbulent regime. For scaling-up purposes, the ratio of the total area-to-total-pollutant volume (AT/VT) was varied for observing the effect of this parameter on the overall plant performance. The Taguchi&rsquo;s experimental design results showed that the best combination of initial pH and catalyst load was 9 and 0.6 g L&minus;1, respectively. Also, full-scale plants would require far fewer ratios of AT/VT than for pilot or intermediate-scale ones. This information may be beneficial for reducing assembling costs of photocatalytic reactors scaling-up

Degradation and Loss of Antibacterial Activity of Commercial Amoxicillin with TiO2/WO3-Assisted Solar Photocatalysis

In this study, a TiO2 catalyst, modified with tungsten oxide (WO3), was synthesized to reduce its bandgap energy (Eg) and to improve its photocatalytic performance. For the catalyst evaluation, the effect of the calcination temperature on the solar photocatalytic degradation was analyzed. The experimental runs were carried out in a CPC (compound parabolic collector) pilot-scale solar reactor, following a multilevel factorial experimental design, which allowed analysis of the effect of the calcination temperature, the initial concentration of amoxicillin, and the catalyst load on the amoxicillin removal. The most favorable calcination temperature for the catalyst performance, concerning the removal of amoxicillin, was 700 &deg;C; because it was the only sample that showed the rutile phase in its crystalline structure. Regarding the loss of the antibiotic activity, the inhibition tests showed that the treated solution of amoxicillin exhibited lower antibacterial activity. The highest amoxicillin removal achieved in these experiments was 64.4% with 100 ppm of amoxicillin concentration, 700 &deg;C of calcination temperature, and 0.1 g L&minus;1 of catalyst load. Nonetheless, the modified TiO2/WO3 underperformed compared to the commercial TiO2 P25, due to its low specific surface and the particles sintering during the sol-gel synthesis

Recent Developments in the Photocatalytic Treatment of Cyanide Wastewater: An Approach to Remediation and Recovery of Metals

For gold extraction, the most used extraction technique is the Merrill-Crow process, which uses lixiviants as sodium or potassium cyanide for gold leaching at alkaline conditions. The cyanide ion has an affinity not only for gold and silver, but for other metals in the ores, such as Al, Fe, Cu, Ni, Zn, and other toxic metals like Hg, As, Cr, Co, Pb, Sn, and Mn. After the extraction stage, the resulting wastewater is concentrated at alkaline conditions with concentrations up to 1000 ppm of metals. Photocatalysis is an advanced oxidation process (AOP) able to generate a photoreaction in the solid surface of a semiconductor activated by light. Although it is well known that photocatalytic processes can remove metals in solution, there are no compilations about the researches on photocatalytic removal of metals in wastewater with cyanide. Hence, this review comprises the existing applications of photocatalytic processes to remove metal and in some cases recover cyanide from recalcitrant wastewater from gold extraction. The use of this process, in general, requires the addition of several scavengers in order to force the mechanism to a pathway where the electrons can be transferred to the metal-cyanide matrices, or elsewhere the entire metallic cyanocomplex can be degraded by an oxidative pathway