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Anaerobic digestion was an important way to remove phenols from saline wastewater; however the anaerobic microorganisms were adversely affected by high concentration of salts. In order to clarify the performance robustness and microbial community structure for anaerobic digestion of saline phenolic wastewater, the UASB reactors were compared to treat phenolic wastewater under saline and non-saline conditions. The saline reactors were operated stably with phenols concentration increasing from 100 to 500 mg L −1 at 10 g Na + L −1 . The robustness of the saline reactors was weakened at 1000 mg phenols L −1 and 10 g Na + L −1 . However, the substrate utilization rates (SURs) for phenol, catechol, resorcinol, hydroquinone, and the specific methanogenic activity (SMA) of sludge were decreased by 95%, 85%, 97%, 78%, and 68%, respectively with phenols concentration enhancing from 1000 to 2000 mg L −1 . Moreover, the SURs for phenol, catechol, resorcinol, hydroquinone, and the SMA of sludge were reduced by 32%, 65%, 74%, 45%, and 59%, respectively with Na + concentration increasing from 10 to 20 g L −1 , in comparison with the values obtained at 10 g Na + L −1 and 1000 mg phenols L −1 . Finally, the analysis of microbial community structure demonstrated that phenols degraders were less tolerant to high concentrations of Na + and phenols than methanogens. [ABSTRACT FROM AUTHOR]

UV-E-chlorination/hematite nanoparticles (UV/E-Cl/HNs) as a heterogeneous photocatalytic activation of electrogenerated chlorine was assessed for the degradation of bisphenol A (BPA) as a new approach based on the generation of reactive chlorine and oxygen species. The prepared sample was characterized using multiple techniques, such as XRD, FTIR, FESEM, EDS, and BET-BJH. An excellent decontamination efficiency of 99.4% was achieved within 40 min of electrolysis under optimum conditions (pH of 5, HNs dosage 100 mg/L, current density of 20 mA/cm2, and NaCl concentration of 50 mM). The HOCl content was reduced more swiftly in the presence of ultraviolet (UV) irradiation and hematite, resulting in the production of oxidative radicals (i.e., •OH, Cl•, and Cl 2 • −). The scavenging experiments also verified the vital role of these radicals in oxidative treatment. The UV/E-Cl/HNs process is readily supplied with hydroxyl radicals through several mechanisms. Bicarbonate ions showed a noticeable inhibitory impact, whereas nitrate and sulfate anions only slightly affected BPA degradation. The HNs were a recoverable and stable catalyst for six cycles. Furthermore, the ECOSAR program predicted that the UV/E-Cl/HNs can be labeled as an environmental-friendly process. Eventually, reasonable degradation pathways were proposed based on the identified by-products through experimental and theoretical approaches. [Display omitted] • Electrogenerated chlorine was activated by UV and Fe 2 O 3 (HNs) simultaneously. • BPA was completed degraded by E-Cl/UV/HNs during 40 min electrolysis time. • Hydroxyl radicals (•OH) and dichlorine radical (Cl 2 •-) were the main responsible for BPA degradation. • The pathway of BPA degradation was evaluated and the toxicity of by-products was assessed. [ABSTRACT FROM AUTHOR]

Currently, the treatment of aquaculture-origin effluents is mainly performed through land-based recirculating aquaculture systems (RAS). In this study, we evaluate and introduce a novel immobilized/packed bed bioreactor which uses a synthetic textile as the support medium. A marine microbial consortium was developed on the textile by its inoculation with the microalgae Picochlorum sp. The bioreactor was tested with variable loadings of C and N and showed outstanding performance approaching removal rates up to 95% within a few hours (4–5 h) of operation. Pyrosequencing analysis revealed a novel microbial consortium consisting mainly of chitrinomycetes, Pseudomonas sp. and the absence of β-proteobacteria, which is the Class encompassing autotrophic nitrifiers. Quantitative polymerase chain reaction further confirmed these findings suggesting heterotrophic nitrification and aerobic denitrification as the principal mechanisms of N-removal from the bioreactor. Overall our findings reveal the potential of the AdvanTex System for the treatment of marine aquaculture effluents–COD reduction and N-removal, in a single stage. [ABSTRACT FROM AUTHOR]

Saline chemical wastewater containing ammonia and toxic organic pollutants has been a challenge for conventional wastewater treatment technology. Advanced treatment is thus required. In this study, the removal of ammonia and phenol in saline chemical wastewater by radiation was investigated in detail. The results showed that chloridion in saline chemical wastewater could be transferred to •Cl and •ClO by radiation, which promoted ammonia oxidation, but inhibited phenol degradation. Solution pH affected the types of reactive species, which further affected the removal of ammonia and phenol. When ammonia and phenol co-existed in saline chemical wastewater, the removal efficiency of ammonia was depressed compared to that in the absence of phenol. Similarly, the phenol removal efficiency was also depressed in the presence of ammonia when the solution pH was lower than 7.0. Interestingly, the phenol removal efficiency was improved with increase of either chloridion concentration (2–8 g/L) or dose (2–5 kGy), which was attributed to the formation of intermediate nitrogen-centered radicals that can react with phenol. In addition, the intermediate products of phenol degradation under different conditions were identified. The acute toxicity of saline chemical wastewater after radiation treatment was evaluated. The results of this study could provide an insight into the removal of ammonia and phenol from saline chemical wastewater by radiation technology. [Display omitted] • Chloridion could promote the transformation of ammonia by radiation. • Higher chloridion concentration led to the increase of nitrate concentration. • Ammonia promoted the degradation of phenol when ammonia and phenol co-existed. • Amination products were identified when ammonia and phenol co-existed. • Acute toxicity of saline wastewater decreased after radiation treatment. [ABSTRACT FROM AUTHOR]

Abstract: In this present work, electrochemical treatment of saline wastewater with organic (protein) load was studied. The influence of the critical parameters of electro-oxidation such as pH, period, salt concentration and current density on the reduction of organic load was studied using graphite electrodes. It was found that current density of 0.024A/cm2 for a period of 2h at pH 9.0 rendered best results in terms of reduction in COD and TKN. The energy requirement for the reduction of 1kg of TKN and 1kg of COD are 22.45kWh and 0.80kWh respectively at pH 9 and 0.024A/cm2. Reuse experiments were conducted at commercial scale. One of the saline waste streams in leather manufacturing process, pickling was treated and reused continuously thrice. The characteristics of the waste stream and the quality of the leathers indicate that the reuse of saline streams with intermittent electrochemical treatment is feasible. [Copyright &y& Elsevier]

Abstract: The effectiveness of the catalytic ozonation process (COP) with a GAC catalyst was assessed based on the degradation and COD removal of phenol from the saline wastewater, as compared with the single ozonation process (SOP). The COP attained a much higher level of phenol degradation compared to the SOP. The influence of several variables was investigated, including pH of solution, NaCl concentration, and dosage of GAC, for their effects on COP phenol degradation in a synthetic saline wastewater. The maximum degradation of phenol was achieved at pH 8 and 20g/L GAC. NaCl had no adverse effect on phenol removal at ranges between 0.5 and 50g/L. The activated carbon acted mostly as a catalyst for ozone decomposition, and the subsequent generation of hydroxyl radicals. Furthermore, the GAC preserved its catalytic properties after 5 times reuse. The capability of a biological process to treat COP effluent was also investigated. Results showed that a 10min reaction time in COP under optimum conditions reduces the concentrations of phenol and COD to an acceptable level for efficient post-treating in a suspended growth bioreactor at a short aeration time of 4h. Thus, the integration of COP with a biological process is proven to be a technically and economically effective method for treating saline wastewaters containing recalcitrant compounds. [Copyright &y& Elsevier]

Phenol in synthetic saline (100gL−1 NaCl) and acidic (pH 3) wastewater was treated by a hybrid solvent extraction and two-phase membrane biodegradation process at 30°C. Kerosene was adopted to be the organic solvent because it was biocompatible and had a suitable partition coefficient for phenol. Phenol in water was first extracted by kerosene in a batch stirred vessel and the loaded solvent was passed through the lumen of a polyvinylidene fluoride (PVDF) hollow-fiber membrane contactor; in the meantime, Pseudomonas putida BCRC 14365 in mineral salt medium was flowed across the shell, to which tetrasodium phyophosphate (1gL−1) was added as a dispersing agent. The effect of the initial phenol level in wastewater (110–2400mgL−1) on phenol removal and cell growth was experimentally studied. At a cell concentration of 0.023gL−1, it was shown that the removal of phenol from saline wastewater was more efficient at a level of 2000mgL−1 when 0.02-m2 membrane module was used. The effects of bigger membrane module size (0.19m2 area) and higher initial cell concentration (0.092–0.23gL−1) on the performance of such a hybrid process for the treatment of higher-level phenol in saline wastewater was also evaluated and discussed. [Copyright &y& Elsevier]