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•Waste monitoring using high-end technologies has been discussed.•Integration of technological approaches is needed for efficient waste management.•Compiled environmental and ...economical relevance of waste management technologies.•Strategic innovations in municipal solid waste management have been focused.•Tools for hazard monitoring have been included.
Rapid population growth, combined with increased industrialization, has exacerbated the issue of solid waste management. Poor management of municipal solid waste (MSW) not only has detrimental environmental consequences but also puts public health at risk and introduces several other socioeconomic problems. Many developing countries are grappling with the problem of safe disposing of large amounts of produced municipal solid waste. Unmanaged municipal solid waste pollutes the environment, so its use as a potential renewable energy source would aid in meeting both increased energy needs and waste management. This review investigates emerging strategies and monitoring tools for municipal solid waste management. Waste monitoring using high-end technologies and energy recovery from MSW has been discussed. It comprehensively covers environmental and economic relevance of waste management technologies based on innovations achieved through the integration of approaches.
This study investigated the impacts of selective sole carbon source-induced micropollutants (MPs) cometabolism of Chlorella sp. by: (i) extracellular polymeric substances (EPS), superoxide dismutase ...and peroxidase enzyme production; (ii) MPs removal efficiency and cometabolism rate; (iii) MPs’ potential degradation products identification; and (iv) degradation pathways and validation using the Eawag database to differentiate the cometabolism of Chlorella sp. with other microbes. Adding the sole carbon sources in the presence of MPs increased EPS and enzyme concentrations from 2 to 100-fold in comparison with only sole carbon sources. This confirmed that MPs cometabolism had occurred. The removal efficiencies of tetracycline, sulfamethoxazole, and bisphenol A ranged from 16-99%, 32–92%, and 58–99%, respectively. By increasing EPS and enzyme activity, the MPs concentrations accumulated in microalgae cells also fell 400-fold. The cometabolism process resulted in several degradation products of MPs. This study drew an insightful understanding of cometabolism for MPs remediation in wastewater. Based on the results, proper carbon sources for microalgae can be selected for practical applications to remediate MPs in wastewater while simultaneously recovering biomass for several industries and gaining revenue.
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•EPS and enzyme concentrations increased 2 to 100 times while exposing to MPs.•TC, SMX and BPA were removed 16–99%, 32–92% and 58–99%, respectively.•MPs concentrations in microalgae cells decreased 400 times by cometabolism.•metabolites of BPA were detected.•A straight chain product (m/z 253) was found and did not exist in Eawag database.
Co-digestion of organic waste and wastewater is receiving increased attention as a plausible waste management approach toward energy recovery. However, traditional anaerobic processes for ...co-digestion are particularly susceptible to severe organic loading rates (OLRs) under long-term treatment. To enhance technological feasibility, this work presented a two-stage Anaerobic Membrane Bioreactor (2 S-AnMBR) composed of a hydrolysis reactor (HR) followed by an anaerobic membrane bioreactor (AnMBR) for long-term co-digestion of food waste and kitchen wastewater. The OLRs were expanded from 4.5, 5.6, and 6.9 kg COD m−3 d−1 to optimize biogas yield, nitrogen recovery, and membrane fouling at ambient temperatures of 25–32 °C. Results showed that specific methane production of UASB was 249 ± 7 L CH4 kg−1 CODremoved at the OLR of 6.9 kg TCOD m−3 d−1. Total Chemical Oxygen Demand (TCOD) loss by hydrolysis was 21.6% of the input TCOD load at the hydraulic retention time (HRT) of 2 days. However, low total volatile fatty acid concentrations were found in the AnMBR, indicating that a sufficiently high hydrolysis efficiency could be accomplished with a short HRT. Furthermore, using AnMBR structure consisting of an Upflow Anaerobic Sludge Blanket Reactor (UASB) followed by a side-stream ultrafiltration membrane alleviated cake membrane fouling. The wasted digestate from the AnMBR comprised 42–47% Total Kjeldahl Nitrogen (TKN) and 57–68% total phosphorous loading, making it suitable for use in soil amendments or fertilizers. Finally, the predominance of fine particles (D10 = 0.8 μm) in the ultrafiltration membrane housing (UFMH) could lead to a faster increase in trans-membrane pressure during the filtration process.
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•Co-digestion of wastewater and kitchen waste using 2 S-AnMBR were surveyed•Hydrolysis and acetogenesis stages enhanced the performance of methanogenesis stage•Short SRT of the 2nd stage reduced digestate solid accumulation in AnMBR•Predominance of colloids (<1 μm) was a challenge for membrane fouling control
Surface water and sediment samples from the most contaminated river in Taiwan, Houjing River, were collected for five years (2015 to 2019) and from five locations to study the contamination trends of ...eight heavy metals (As, Cd, Cr, Cu, Hg, Pb, Ni, and Zn). Five locations along the river were picked based on their potential of being contaminated by nearby industrial activities. The monitoring data, geo-accumulation index (Igeo), contamination factor (CF), modified degree of contamination (mCd), pollution load index (PLI), and metal index (MI) were used to provide a detailed assessment of the heavy metal contamination. Demin (L3) and Chuwai (L4), two sampling sites close to the Nanzih Export Processing Zone (NEPZ) discharge points, were the most contaminated. The most contaminated periods were 2015–2016 and 2018–2019 for surface water and sediment samples, respectively. The surface water showed signs of heavy metal contamination in 2016 with mCd> 1.5. For the sediment samples, the heavy metal concentration fingerprints for the five years were similar. This implied that the natural attenuation process was not adequate, and treatment technologies are required to improve sediment quality. This study provides a basis for comprehensive risk assessments and integrated environmental management measures for the river’s surface water and sediment quality. Also, it would contribute to a more inclusive evaluation of heavy metal contamination in global rivers.
•Five-year data from five sites were used to assess heavy metal contamination trends.•The surface water showed signs of heavy metal contamination.•Heavy metal contamination in sediment samples was alarming.•The sediment quality in the five years did not change significantly.•Sediment quality needs to be improved and discharge quality needs to be controlled.
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•GQDs@MnOOH could enhance the CIP degradation and inhibit the formation of bromate.•GQDs@MnOOH exhibited excellent electron transport capability for catalytic ...ozonation.•GQDs@MnOOH + O3 system exhibits good efficiency of CIP removal over different water conditions.•Radicals and non-radicals were involved in CIP degradation by catalytic ozonation process.
A catalyst GQDs@MnOOH was successfully synthesized by attaching graphene quantum dots (GQDs) on the surface of MnOOH nanorods to boost catalytic ozonation of antibiotic, exemplified by ciprofloxacin (CIP). The result demonstrated that the GQDs@MnOOH/O3 system had the greatest CIP removal effectiveness, followed by that of MnOOH/O3 and O3 only. The 0.02 mM CIP was degraded with 99.9% efficiency in 30 min in the presence 9.6 mg L-1 of O3 catalyzed by 12.5 mg L-1 of GQDs@MnOOH. The kinetic rate constants were in the order: GQDs@MnOOH/O3 (0.161 min−1) > MnOOH/O3 (0.079 min−1) > O3 (0.055 min−1). The GQDs@MnOOH could enhance CIP degradation and inhibit BrO3- formation in different water sources. Results of scavenger and electron paramagnetic resonance (EPR) experiments demonstrated that oxygen radical (O2•-), singlet oxygen (1O2), and hydroxyl radicals (•OH) were involved in CIP degradation by the GQDs@MnOOH/O3 system. Accordingly, the degradation pathways of CIP and mechanism of catalytic ozonation over GQDs@MnOOH were investigated and proposed. This research is expected to shed light on the connection between carbonaceous material and metal hydroxide in catalytic ozonation.
Green technologies for sustainable water Hao Ngo, Huu; Bui, Xuan-Thanh; Nghiem, Long D. ...
Bioresource technology,
December 2020, 2020-12-00, 20201201, Letnik:
317
Journal Article
A pilot-scale two-stage anaerobic digestion system, which includes a feed tank (0.4 m3), a hydrolysis reactor (1.2 m3) followed by a methane fermenter (4.0 m3) was set up and run at the municipal ...solid waste landfill located in Ho Chi Minh City (HCMC), Vietnam. The feed that was separated from urban organic solid waste was collected at households and restaurants in District 1, HCMC. This study aimed to investigate the resource recovery performance of the pilot two-stage anaerobic digestion system, in terms of carbon recovery via biogas production and nutrient recovery from digestate. The average organic loading rate (OLR) of the system was step increased from 1.6 kg volatile solids (VS)·m−3·d−1, 2.5 kg VS·m−3·d−1 and 3.8 kg VS·m−3·d−1 during 400 days of operation. During the long-term operation at three OLRs, pH values and alkalinity were stable at both hydrolysis and methanogenesis stages without any addition of alkalinity for the methanogenesis phase. High buildup of propanoic acid and total volatile fatty acid concentrations in the fermenter did not drop pH values and inhibit the methanogenic process at high OLRs (2.5–3.8 kg VS m−3·d−1). The obtained total chemical oxygen demand (tCOD) removal performance was 83–87% at the OLRs ranging from 2.5 kg VS·m−3·d−1 and 3.8 kg VS·m−3·d−1, respectively. The highest biogas yield of 263 ± 64 L·kg−1 tCOD removed obtained at OLR of 2.5 kg VS·m−3·d−1. It is expected that a full scale 2S-AD plant with capacity of 5200 tons day−1 of biowaste collected currently from municipal solid waste in HCMC may create daily electricity of 552 MWh, thermal energy of 630 MWh, and recovery of 16.1 tons of NH4+-N, 11.4 tons of organic-N, and 2.1 tons of TP as both organic liquid and solid fertilizers.
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•High build-up of total volatile fatty acids in the fermenter of the 2S-AD process did not cause failure of the methanogenesis.•The biogas yield obtained from the 2S-AD plant was higher than that from the 1S-AD process.•The 2S-AD plant potentially produces high value of renewable energy and organic fertilizer from recovery of nutrients in the digestate.
Di-(2-ethylhexyl) phthalate (DEHP), a plasticizer derived from phthalate ester, is used as an additive in industrial products such as plastics, paints, and medical devices. However, DEHP is known as ...an endocrine-disrupting chemical, causing cancers and adverse effects on human health. This study evaluated DEHP biodegradation efficiency via food waste composting during 35 days of incubation. At high DEHP concentrations (2167 mg kg−1) in food waste compost mixture, the DEHP biodegradation efficiency was 99% after 35 days. The highest degradation efficiency was recorded at the thermophilic phase (day 3 - day 11) with the biodegradation rate reached 187 mg kg−1 day−1. DEHP was metabolized to dibutyl phthalate (DBP) and dimethyl phthalate (DMP) and would be oxidized to benzyl alcohol (BA) and mineralized into CO2 and water via various metabolisms. Finally, the compost's quality with residual DEHP was evaluated using Brassica chinensis L. seeds via 96 h of germination tests. The compost (at day 35) with a trace amount of DEHP as the end product showed no significant effect on the germination rate of Brassica chinensis L. seeds (88%) compared to that without DEHP (94%), indicating that the compost can be reused as fertilizer in agricultural applications. These results provide an improved understanding of the DEHP biodegradation via food waste composting without bioaugmentation and hence facilitating its green remediation and conversion into value-added products. Nevertheless, further studies are needed on DEHP biodegradation in large-scale food waste composting or industrial applications.
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•Yields of starch and PHB can be increased through culture with nutrient starvation.•Cyanobacteria are a suitable source of PHB during cultivation and harvesting.•Inconsistency in the ...polysaccharide composition of seaweed affects yield extraction.•Carrageenan is a good additive for the production of edible food packaging.•Membrane photobioreactor could be a sustainable production of algal derivatives.
Improper use of conventional plastics poses challenges for sustainable energy and environmental protection. Algal derivatives have been considered as a potential renewable biomass source for bioplastic production. Algae derivatives include a multitude of valuable substances, especially starch from microalgae, short-chain length polyhydroxyalkanoates (PHAs) from cyanobacteria, polysaccharides from marine and freshwater macroalgae. The algae derivatives have the potential to be used as key ingredients for bioplastic production, such as starch and PHAs or only as an additive such as sulfated polysaccharides. The presence of distinctive functional groups in algae, such as carboxyl, hydroxyl, and sulfate, can be manipulated or tailored to provide desirable bioplastic quality, especially for food, pharmaceutical, and medical packaging. Standardizing strains, growing conditions, harvesting and extracting algae in an environmentally friendly manner would be a promising strategy for pollution control and bioplastic production.
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•NiCo2O4 and biochar composite was used for PMS activation to degrade TC.•The combination could synergistically enhanced the PMS activation for TC degradation.•The composite possessed ...excellent durability.•Radical and non-radical activation occurred for TC degradation.
In this study, biochar produced from sunflower seeds husk was activated through ZnCl2 to support the NiCo2O4 nanoparticles (NiCo2O4@ZSF) in catalytic activation of peroxymonosulfate (PMS) toward tetracycline (TC) removal from aqueous solution. The good dispersion of NiCo2O4 NPs on the ZSF surface provided sufficient active sites and abundant functional groups for the adsorption and catalytic reaction. The NiCo2O4@ZSF activating PMS showed high removal efficiency up to 99% after 30 min under optimal condition (NiCo2O4@ZSF = 25 mg L-1, PMS = 0.04 mM, TC = 0.02 mM and pH = 7). The catalyst also exhibited good adsorption performance with a maximum adsorption capacity of 322.58 mg g−1. Sulfate radicals (SO4•−), superoxide radical (O2•−), and singlet oxygen (1O2) played a decisive role in the NiCo2O4@ZSF/PMS system. In conclusion, our research elucidated the production of highly efficient carbon-based catalysts for environmental remediation, and also emphasized the potential application of NiCo2O4 doped biochar.
