Considering the exponential growth of today’s industry and the wastewater results of its processes, it needs to have an optimal treatment system for such effluent waters to mitigate the environmental impact generated by its discharges and comply with the environmental regulatory standards that are progressively increasing their demand. This leads to the need to innovate in the control and management information systems of the systems responsible to treat these residual waters in search of improvement. This paper proposes the development of an intelligent system that uses the data from the process and makes a prediction of its behavior to provide support in decision making related to the operation of the wastewater treatment plant (WWTP). To carry out the development of this system, a multilayer perceptron neural network with 2 hidden layers and 22 neurons each is implemented, together with process variable analysis, time-series decomposition, correlation and autocorrelation techniques; it is possible to predict the chemical oxygen demand (COD) at the input of the bioreactor with a one-day window and a mean absolute percentage error (MAPE) of 10.8%, which places this work between the adequate ranges proposed in the literature.

To reduce demand and discharge, instead of industrial wastewater being not enough treated and disposed of, it can be recycled, reused, or recovered considering well management. Thus, having a substantial decrease in the water need and environmental impacts. The challenge is to select the proper combination of processes based on the wastewater quality and budget limitations. Therefore, we aimed to provide a distinctive and comprehensive perspective on the current state of industrial wastewater treatment technologies by giving a complete overview of their major advantages, disadvantages, and upcoming challenges in the context of the circular economy. This study considered 198 peer-reviewed scientific publications from the Scopus and Google Scholar databases, mostly from the last 5 years. For this, specific search terms and Boolean Operators were applied as inclusion and exclusion criteria. Up to 57 different technologies, from conventional to advanced, were reviewed for reliable and sustainable industrial wastewater treatment and derived sludges. We evidence a vast potential to exploit and make them viable for the circular economy, even in the mature ones. Overall, we identify that regardless of the alternative, in particular those not vastly implemented, future investigations should prioritize: (1) The capacity to remove selected pollutants and decrease impurities; (2) energy recovery and efficiency; (3) environmental safety; (4) economic viability and industrial implementation; (5) hybridization; and (6) sustainability through waste processing. GRAPHICAL ABSTRACT

The main objective of this study was to evaluate the adsorption efficiency for removing nitrate and phosphate in an aqueous solution using adsorbents derived from rice husks and corn stalks. Five adsorbents were used: untreated rice husk (RH), raw corn stalk (CS), rice husk biochar (RHB), corn stalk biochar (CSB), and a rice husk biochar chemically modified with magnesium (RHB-Mg). The influence of operational variables (temperature, pH, adsorbent dose, and initial concentration) on individual and competitive adsorption of nitrate and phosphate was studied together with adsorption equilibrium and kinetics. The results showed that the best adsorbent was RHB-Mg, with maximum adsorption capacities of 111.10 mg/g for phosphate and 35.11 mg/g for nitrate, determined from Langmuir isotherm. Competitive adsorption of nitrate and phosphate was favorable using RHB-Mg, demonstrating that RHB-Mg could be used to remove these nutrients from wastewater.

NO2 ambient concentrations were measured in a coastal Caribbean city. Barranquilla is a Caribbean city located in the North of Colombia that has approximately 1.200.000 inhabitants and possesses a warm, humid climate. In order to obtain the concentration of the contaminant in an adequate resolution, 137 Passive diffusion tubes from Gradko© were installed. Tubes prepared with 20% Triethanolamine/De-ionised water were located at the roadside between 1 and 5 m from the kerb edge. The sampling period was two weeks, from 3/16/2019 to 3/30/2019. Samples were analyzed on the UV CARY1 spectrophotometer by Gradko©. Results showed an average of 19.92 ± 11.50 μg/m3, with a maximum and minimum value of 70.27 and 0.57 μg/m3, respectively. NO2 correlation with load traffic load was higher than with maximum traffic. The expected results include the analysis of the areas of the city with high concentrations of this pollutant that exceed the limit values established by the WHO in six (6) points; however, they never exceed the local legal limit for annual exposure, which is significantly less restrictive. Overall, the multiregression analysis is a very effective method to enrich the understanding of NO2 distributions. It can provide scientific evidence for the relationship between NO2 and traffic, beneficial for developing the targeted policies and measures to reduce NO2 pollution levels in hot spots. This research may subsidize knowledge to serve as a tool for environmental and health authorities.

This article had the one and only objective of consolidating the couplings of advanced oxidation processes and biological systems in the decontamination of wastewater with pesticide content reported in the Scopus and Web of Science databases, through a critical analysis of which have been the most used, what methodologies have been implemented to develop them, identifying the objectives of each work, determining the success of the research and where the main niches of knowledge are, which can lead to the generation of new scientific knowledge as well as future trends. A co-occurrence analysis was carried out through the VOSViewer software to determine the most associated key words with the treatment configurations described above. Fenton and Photo-Fenton processes, heterogeneous photocatalysis TiO2/UV, electrocatalysis, ozonization and a particular case of hydrodynamic cavitation-ozone as main advanced oxidation processes, together with advanced biological processes such as sequential batch bioreactor (SBR), membrane bioreactor (MBR), mobile bed biofilm reactor (MBBR); biodegradability and toxicity tests with bacterial strains and surface wetlands, whose treatment philosophy is activated sludge. The main future trends are the reuse of treated wastewater, the analysis and control of costs towards the efficient use of resources and the primary study of the byproducts generated in advanced oxidation to improve the efficiencies in the coupling.