The worldwide pressure on water resources is aggravated by rapid industrialization, with the food industry, particularly sugar factories, being the foremost contributor. Sugarcane, a primary source of sugar production, requires vast amounts of water, over half of which is discharged as wastewater, often mixed with several byproducts. The discharge of untreated wastewater can have detrimental effects on the environment, making the treatment and reuse of effluents crucial. However, conventional treatment systems may not be adequate for sugarcane industry effluent treatment due to the high organic load and variable chemical and mineral pollution. It is essential to explore pollution-remediating technologies that can achieve a nexus (water, energy, and food) approach and contribute to sustainable development. Based on the extensive literature, membrane technologies such as the membrane bioreactor have shown promising results in treating sugarcane industry wastewater, producing treated water of higher quality, and the possibility of biogas recovery. The byproducts generated from this treatment can also be recovered and used in agriculture for food security. To date, membrane technologies have demonstrated successful results in treating industrial wastewater. This critical review aims to evaluate the performance of traditional and conventional processes in order to propose sustainable perspectives. It also serves to emphasize the need for further research on operating conditions related to membrane bioreactors for valuing sugarcane effluent, to establish it as a sustainable treatment system.

Breweries release significant amounts of wastewater loaded with various organic and mineral materials. Prior studies of membrane bioreactor (MBR) wastewater treatment have been conducted with very little interest granted to the conditions of biomass acclimation. This study displays biomass behavior during brewery wastewater treatment by an aerobic MBR. In addition, nanofiltration and electrodialysis have been studied as potential post-treatment to decrease mineral concentrations and permit further water reuse for agriculture. An anoxic/aerobic laboratory MBR, associated with a flat sulfonated polyether membrane was used for synthetic brewery wastewater treatment. Biomass acclimation was performed using a feeding substrate. Organic concentrations in the MBR influent varied from 700 mg COD/L to 10,600 mg COD/L (COD: chemical oxygen demand) for 110 days. The results indicate a good acclimation to effluent with high salts and organic matter loads. Steady evolution of biomass concentration and activities was achieved after 90 days of operation. A reduction of COD of around 95% was obtained with MBR and up to 99% with nanofiltration post-treatment for the reconstructed brewery effluent with an organic loading rate of 7 g COD/L·d and a solid and hydraulic retention time of 30 days and 36 hours. A good reduction of the salt content was also recorded primarily with the nanofiltration and electrodialysis processes.

Wastewater management remains a major challenge in developing countries due to the lack of adequate infrastructure, making the need for economically viable and efficient technologies that can be sustained by emerging economies imperative. The upflow anaerobic sludge blanket (UASB) reactor represents an efficient and low-cost technology that produces by-products from which valuable resources can be recovered. This study assessed the energy recovery potential in the form of electricity from biogas and sludge by-products produced by a full-scale UASB reactor. Biogas production rate and composition were monitored to determine the biogas energy recovery potential. Dehydrated sludge from sludge drying beds was likewise quantified and characterised for its elemental composition, immediate composition, gross calorific value and net calorific value to estimate sludge energy recovery potential. The average daily biogas production was found to be 611 ± 275 Nm³/d, with 65% methane in the biogas output. Average sludge dry matter production was determined to be 358.24 TS kg/d. The net energy recovery potential was estimated to be 534.1 MWh/yr, 36% more than the yearly energy demand (392.7 MWh/yr) of the entire plant. Conservative energy recovery at a UASB-based municipal wastewater treatment facility could serve as a self-supply energy option to support its operations.

The use of faecal sludge (FS) in anaerobic digestion (AD) requires a perfect knowledge of their composition. Considered as a very heterogeneous material, the high variability of FS can disturb biodigesters’ functionality and impact biogas production. Unique in West Africa, Kossodo’s biogas plant in Ouagadougou receives sludge from septic tanks and pit latrines. To evaluate the quality of sludge discharged in this treatment plant and its ability for AD, a characterization of 130 FS trucks from several onsite sanitation facilities was carried out. Physico-chemicals, including heavy metals and microbiological parameters, were analyzed using standard protocols. A biochemical methane potential test was employed to evaluate biogas yield. Results showed that raw sludge averaged 1.12% total solids (TS), 54.74% volatile solids (VS), 9253 mg/L chemical oxygen demand (COD), and 1645 mg/L biochemical oxygen demand (BOD). Settled faecal sludge exhibited higher levels of total coliforms, E. coli, helminth eggs, and heavy metals. Heavy metal levels met AD standards defined by VDI 4630, with decreasing toxicity order: Zn > Mn > Cu > Cr > Ni > Pb > As ≥ Hg. The carbon-to-nitrogen (C/N) ratio was 6.7 ± 4.3, indicating unsuitability for AD. Sludge settling increased C/N ratio by 46%, which was still below optimal AD conditions (20–30). Methane yield of raw and settled FS averaged 61 ± 0.2 and 156 ± 3.2 NL CH₄/kg VS removed, respectively. Co-substrate addition could enhance the methanogenic yield of these sludges. This study provides a valuable database on the characteristics of FS, supporting sustainable recovery options.

In the Sahel, ensuring food security remains a critical challenge due to the region’s prolonged nine-month dry season and the severe scarcity of water resources for irrigation. This study explores an innovative approach integrating two traditional Sahelian soil conservation methods (Zaï and Half-moon) with controlled irrigation to enhance dry-season crop yields, methods not previously explored in combination. A field experiment was performed using a randomized Fisher block design with seven replications assessing the impact of different soil practices on onion and jute production. It also examined the key soil elements and dynamic properties, including N, P, K, pH, temperature, and electrical conductivity. Results showed that the Half-moon technique yields the highest onion production (20.1 t ha⁻¹ ± 0.82), followed by Zaï (18.6 t ha⁻¹ ± 0.48) and flat tillage (14.2 t ha⁻¹ ± 0.84). For jute, the highest third-harvest yield was recorded with Half-moon (9.68 t ha⁻¹ ± 0.63), followed by Zaï (9.56 t ha⁻¹ ± 0.48) and flat tillage (7.53 t ha⁻¹ ± 0.37). These findings offer a viable solution for adapting to climate change by improving water use efficiency and promoting sustainable farming practices in water-limited environments. This research underscores the potential for integrating indigenous knowledge with modern agricultural techniques to mitigate food insecurity in the Sahel.

Sugarcane industries, like other agro-food industries, generate significant volumes of wastewater containing high concentrations of organic and inorganic pollutants. Among the proposed treatment solutions, the anaerobic membrane bioreactor (AnMBR) has proven highly effective in degrading organic pollutants but has limitations in removing color and inorganic pollutants. To address this gap, integrating other technologies with AnMBR is necessary. In this study, we propose coupling AnMBR with either Coagulation-flocculation followed by nanofiltration or reverse osmosis for treating wastewater from sugar industries after initial AnMBR treatment. The wastewater treated by an anaerobic AnMBR pilot plant, fed with wastewater from a sugar cane production unit, was used for the tests. Various formulations of Moringa oleifera were tested, including its defatting and dehulling products with hexane and ethanol. For nanofiltration and reverse osmosis, pressures of 4 and 8 bars respectively were applied. For the coagulation-flocculation phase, granular alum and powdered moringa oleifera seeds were compared as coagulants. Thus, the coupling of the coagulation-flocculation system with nanofiltration and reverse osmosis membranes effectively reduced both organic and inorganic matter. The use of aluminum sulphate proved more effective at high pollution concentrations, while Moringa oleifera extracted with hexane achieved removal rates exceeding 70 % for heavy metals (Cd, Cr, Cu, Zn). Purification efficiencies of over 90 % were obtained after filtration with the reverse osmosis membrane, while the nanofiltration membrane showed retention rates of 90 % for color, but less than 50 % for monovalent ions. The treated effluent at the outlet of the nanofiltration and reverse osmosis systems complies with Burkina Faso's discharge standards, with superior quality allowing for direct reuse in the industry.