Suchergebnisse

Photo-assisted peroxi-coagulation (PPC) was investigated for treatment of high TDS (total dissolved solids) wastewater. The most important characteristics of the studied wastewater were high TDS of around 16428 mg L–1 and BOD5/COD ratio of 0.07. Effective operating parameters, including initial pH values of 3–8, reaction time of 60–240 min, electrode distance values of 2–6 cm, and voltage values of 0.5–3 V were investigated in batch mode experiments. Optimum conditions were obtained at pH = 3, voltage = 1.5 V, electrode distance = 2 cm, and reaction time = 420 min, corresponding to 89.44 % COD removal, which meets the Iran environmental discharge legislation (COD = 100 mg L–1). Kinetic analysis showed that pseudo first-order kinetic model was best fitted (R2 = 0.97). GC mass chromatograms before and after treatment showed degradation of complex compounds to more simple constituents. This work is licensed under a Creative Commons Attribution 4.0 International License.

Polyhydroxyalkanoates (PHA) are biodegradable polymers that can be intracellularly produced by microorganisms valorizing organic-rich wastes. In the present study, a PHA production system was fed with mussel cooker wastewater after acidogenic fermentation. Besides low pH (4.0 ± 0.3) and high salt (21.7 ± 2.9 g NaCl/L) concentrations, this wastewater also contained nitrogen concentrations (0.8 ± 0.1 g N/L), which were previously reported to be a challenge to the PHA accumulating bacteria enrichment. Bacteria with a PHA storage capacity were selected in an enrichment sequencing batch reactor (SBR) after 60 days of operation. The enriched mixed microbial culture (MMC) was mainly formed by microorganisms from phylum Bacteroidetes, and genera Azoarcus, Comamonas and Thauera from phylum Proteobacteria. The MMC was able to accumulate up to 25 wt% of PHA that was mainly limited by the wastewater nitrogen content, which promoted biomass growth instead of PHA accumulation. Indeed, when the presence of nutrient was limited, PHA stored in the accumulation reactor increased to up to 40.9 wt%. This work demonstrated the feasibility of the enrichment of a MMC with a PHA storage ability valorizing the fish-canning industrial wastewater at low pH, which is generally difficult to treat in wastewater treatment plants ; This research was funded by the Spanish Government (AEI) through the FISHPOL (CTQ2014-55021-R) and TREASURE (CTQ2017-83225-C2-1-R) projects. The authors belong to the Galician Competitive Research Group GRC ED431C 2017/29 and to the CRETUS Strategic Partnership (ED431E 2018/01). All these programs are co-funded by the FEDER (EU) ; SI

Polyhydroxyalkanoates (PHA) are biodegradable polymers that can be intracellularly produced by microorganisms valorizing organic-rich wastes. In the present study, a PHA production system was fed with mussel cooker wastewater after acidogenic fermentation. Besides low pH (4.0 ± 0.3) and high salt (21.7 ± 2.9 g NaCl/L) concentrations, this wastewater also contained nitrogen concentrations (0.8 ± 0.1 g N/L), which were previously reported to be a challenge to the PHA accumulating bacteria enrichment. Bacteria with a PHA storage capacity were selected in an enrichment sequencing batch reactor (SBR) after 60 days of operation. The enriched mixed microbial culture (MMC) was mainly formed by microorganisms from phylum Bacteroidetes, and genera Azoarcus, Comamonas and Thauera from phylum Proteobacteria. The MMC was able to accumulate up to 25 wt% of PHA that was mainly limited by the wastewater nitrogen content, which promoted biomass growth instead of PHA accumulation. Indeed, when the presence of nutrient was limited, PHA stored in the accumulation reactor increased to up to 40.9 wt%. This work demonstrated the feasibility of the enrichment of a MMC with a PHA storage ability valorizing the fish-canning industrial wastewater at low pH, which is generally difficult to treat in wastewater treatment plants ; This research was funded by the Spanish Government (AEI) through the FISHPOL (CTQ2014-55021-R) and TREASURE (CTQ2017-83225-C2-1-R) projects. The authors belong to the Galician Competitive Research Group GRC ED431C 2017/29 and to the CRETUS Strategic Partnership (ED431E 2018/01). All these programs are co-funded by the FEDER (EU) ; SI

Wastewater management is one of the main hurdles encountered by the shale gas industry for boosting overall process cost-effectiveness while reducing environmental impacts. In this light, this paper introduces a new multi-objective model for the thermo-economic and environmental optimization of solar-based zero-liquid discharge (ZLD) desalination systems. The solar-driven ZLD system is especially developed for desalinating high-salinity wastewaters from shale gas process. A decentralized system is proposed, encompassing a solar thermal system, a Rankine power cycle, and a multiple-effect evaporator combined with mechanical vapor recompression. The environment-friendly ZLD operation is ensured by specifying the salt concentration of brine discharges close to saturation conditions. The mathematical modelling approach is centered on a multi-objective non-linear programming (MoNLP) formulation, which is aimed at simultaneously minimizing thermo-economic and environmental objective functions. The latter objective function is quantified by the ReCiPe methodology based on life cycle assessment. The MoNLP model is implemented in GAMS software, and solved through the epsilon-constraint method. A set of trade-off Pareto-optimal solutions is presented to support decision-makers towards implementing more sustainable and cost-efficient solar-driven ZLD desalination systems. The comprehensive energy, economic and environmental analysis reveals that the innovative system significantly decreases costs and environmental impacts in shale gas wastewater operations. ; This project has received funding from the European Union's Horizon 2020 Research and Innovation Programme under grant agreement No. 640979.

Long term operation of an anaerobic membrane bioreactor (AnMBR) treating municipal wastewater was investigated in a real seawater intrusion spot in Falconara Marittima (Central Italy) on the Adriatic coastline. Changes in biological conversion and system stability were determined with respect to varying organic loading rate (OLR) and high salinity conditions. At an OLR of 1 kgCOD.m3-1d-1, biogas production was around 0.39 ± 0.2 L.d-1. The increase of the OLR to 2 kgCOD.m3-1d-1 resulted in the increase of biogas production to 2.8 ± 1.5 L.d-1 (with 33.6% ± 10.5% of CH4) with methanol addition and to 4.11 ± 3.1 L.d-1 (with 29.7% ± 11.8% of CH4) with fermented cellulosic sludge addition. COD removal by the AnMBR was 83% ± 1% when the effluent COD concentration was below 100 mg O2.L-1. The addition of the fermented sludge affected the membrane operation; significant fouling occurred after long-term filtration, where the trans-membrane pressure (TMP) reached up to 500 mbar. Citric acid solution was applied to remove scalants and the TMP reached the initial value. High saline conditions of 1500 mgCl-.L-1 adversely affected the biogas production without deteriorating the membrane operation. The treated effluent met the EU quality standards of the D.M. 185/2003 and the new European Commission Resolution for reuse in agriculture. ; This study was carried out within the framework of the "SMART-Plant" Innovation Action which has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 690323. This study was carried out within "Safe and Sustainable Solutions for the Integrated Use of Non-Conventional Water Resources in the Mediterranean Agricultural Sector (FIT4REUSE)" which has received funding from the Partnership on Research and Innovation in the Mediterranean Area (PRIMA) under grant agreement number 1823 (Call 2018 Section 1 Water). The authors kindly acknowledge Diego Cingolani, Gianluigi Buttiglieri and VivaServizi.