Assessment of intensive agriculture on water quality in the Culiacan River basin, Sinaloa, Mexico

Evaluation of rapeseed cake as a protein substitute in the feed of edible crickets: A case study using Gryllus assimilis

This paper aimed to investigate the optimization of Gryllus assimilis farming production by examining the effects of replacing soybean meal with rapeseed cake (25-100%) and supplementing it with rapeseed oil. The results reveal no adverse effects of soybean meal replacement on the feed conversion ratio and weight of the harvested crickets. However, incorporating larger quantities of rapeseed cake into the diet increased crude protein and decreased fat content. Moreover, the composition of fatty acids varied significantly, with increased levels of oleic acid and decreased levels of palmitic acid, while a high rapeseed cake content led to a decrease in the atherogenic and thrombogenic index values. The amino acid composition remained unaffected. In conclusion, the study demonstrates that rapeseed cake can serve as a viable substitute for soybean meal in the diet of Gryllus assimilis.

Implementation of remote sensing algorithms to estimate TOC, Chl-a, and TDS in a tropical water body; Sanalona reservoir, Sinaloa, Mexico

The present study implements a methodology to estimate water quality values using statistical tools and remote sensing techniques in a tropical water body Sanalona. Linear regression models developed by Box-Cox transformations and processed data from LANDSAT-8 imagery (bands) were used to estimate TOC, TDS, and Chl-a of the Sanalona reservoir from 2013 to 2020 at five sampling sites measured every 6 months. A band discriminant analysis was carried out to statistically fit and optimize the proposed algorithms. Coefficients of determination beyond 0.9 were obtained for these water quality parameters (r2TOC = 0.90, r2TDS = 0.95, and r2Chl-a = 0.96). A comparison between the estimated and observed water quality was carried out using different data for validation. The validation of the models showed favorable results with R2TOC = 0.8525, R2TDS = 0.8172, and R2Chl-a = 0.9256. The present study implemented, validated, and compared the results obtained by using an ordered and standardized methodology proposed for the estimation of TOC, TDS, and Chl-a values based on water quality parameters measured in the field and using satellite images.

Efficient Malathion Removal in Constructed Wetlands Coupled to UV/H2O2 Pretreatment

Intensive agriculture has led to the increasing application of pesticides, such as malathion, thus generating large volumes of untreated cropland wastewater (CropWW). In this work, a hybrid system constructed wetlands (CW) coupled in continuous with an optimized UV/H2O2 pretreatment was evaluated for the efficient removal of malathion contained in CropWW. In the first stage, 90 min UV irradiation time (UV IR) and 65 mM hydrogen peroxide (H2O2) were identified as optimal operation parameters through a central composite design. The second stage consisted of CW planted with Phragmites australis collected from the agricultural discharge area and operated as a piston flow reactor. Furthermore, CW hydraulic residence times (HRT) of 1, 2 and 3 days, including hydraulic coupling, were evaluated. The removal efficiencies obtained in the first stage (UV/H2O2) were 94 ± 2.5% of malathion and 45 ± 2.5% of total organic carbon (TOC). In stage two (CW) 65 ± 9.6% TOC removal was achieved during the first 17 days, from which around 24% was associated to the biosorption of malathion byproducts. Subsequently, and until the operation ends, CW removed about 80% of TOC for 2 and 3 days HRT, with no significant differences (p > 0.2), which is higher than those reported in several studies involving only advanced oxidation processes (AOP) with UV IR times above 240 min and even for systems using catalysts. The results obtained indicate that the system UV/H2O2-CW is a technically suitable option for the treatment of CropWW with a high content of malathion mainly found in developing countries. Moreover, the hybrid system proposed also represent significant reduction in the size of the treatment plant.

A Fractional High-Gain Nonlinear Observer Design—Application for Rivers Environmental Monitoring Model

The deterioration of current environmental water sources has led to the need to find ways to monitor water quality conditions. In this paper, we propose the use of Streeter–Phelps contaminant distribution models and state estimation techniques (observer) to be able to estimate variables that are very difficult to measure in rivers with online sensors, such as Biochemical Oxygen Demand (BOD). We propose the design of a novel Fractional Order High Gain Observer (FOHO) and consider the use of Lyapunov convergence functions to demonstrate stability, as it is compared to classical extended Luenberger Observer published in the literature, to study the convergence in BOD estimation in rivers. The proposed methodology was used to estimated Dissolved oxygen (DO) and BOD monitoring of River Culiacan, Sinaloa, Mexico. The use of fractional order in high-gain observers has a very effective effect on BOD estimation performance, as shown by our numerical studies. The theoretical results have shown that robust observer design can help solve problems in estimating complex variables.