Chromium speciation in municipal solid waste: effects of clay amendment and composting

1998 ◽  
Vol 38 (2) ◽  
pp. 17-23 ◽  
Author(s):  
Ho Goen ◽  
Qiao Liang
Keyword(s):  
Organic Matter ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Red Mud ◽  
Metal Speciation ◽  
Metal Mobility ◽  
Potential Hazard ◽  
Composting Process ◽  
Heavy Metal Mobility ◽  
Free Metal

The addition of clay in the form of bauxite refining residue (red mud) prior to composting has been suggested as a way to control heavy metal mobility in compost. Leachability and plant availability of metals in a mixture of grass clippings and sawdust spiked with metal solution was markedly reduced during the composting process. The fate of metals in municipal solid waste compost applied to land was examined by using a sequential step extraction to investigate metal speciation (into exchangeable and bound to carbonate forms, to Mn & Fe oxides, to organic matter and in residue phase) in red mud amended compost. The effects of red mud and the composting process on metal speciation in the compost for Cd, Cr, Cu, Ni, Pb and Zn were investigated, and a comparison of some effects with biosolids compost was made. Addition of red mud reduced the metal mobility and the potential hazard of releasing metals from compost through promoted precipitation, adsorption and complexation of free metal cations to red mud. Red mud however, was not able to desorb metals bound to organic matter. Since most of the metals in the municipal solid waste were not usually bound to organic matter, the addition of red mud prior to composting fixed the free metal ions before they bound to this fraction. Results for Cr speciation are reported in this paper.

The effect of clay amendment on speciation of heavy metals in sewage sludge

1996 ◽  
Vol 34 (7-8) ◽  
pp. 413-420 ◽  
Author(s):  
L. Qiao ◽  
Goen Ho
Keyword(s):  
Heavy Metals ◽  
Organic Matter ◽  
Sewage Sludge ◽  
Red Mud ◽  
Heavy Metal Contamination ◽  
Metal Speciation ◽  
Metal Mobility ◽  
Potential Hazard ◽  
Application Rates ◽  
Physico Chemical

When sewage sludge is used as a soil conditioner, heavy metal contamination can limit its application rates. The potential hazard of heavy metals is, however, dependent on the physico-chemical forms of the metals in the sludge and soil. Bauxite refining residue (red mud) has been used to reduce the mobility and availability of heavy metals in municipal solid waste compost. In the present research a sequential step extraction was employed to investigate metal speciation (into exchangeable, bound to carbonate, to Mn & Fe oxides, to organic matter and in residue phase) and the effect of red mud on metal speciation in sewage sludge for Cd, Cr, Cu, Ni, Pb and Zn. The effect of red mud addition on metal distribution in sewage sludge compost was significant. Red mud addition can effectively reduce the metal mobility and the potential hazard of releasing metals from sludge due to the further breakdown of organic matter. Drying of sludge makes heavy metals more available. Red mud addition will be desirable in such a case. Plant available metals (determined by DTPA extraction) are, however, not as effectively reduced except for Pb and Zn.

Co-composting as an oxygen stabilization of an organic fraction of municipal solid waste and industrial sewage sludge

2013 ◽  
Vol 68 (8) ◽  
pp. 1697-1706
Author(s):  
M. Milczarek ◽  
E. Neczaj ◽  
K. Parkitna
Keyword(s):  
Organic Matter ◽  
Sewage Sludge ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Organic Waste ◽  
Negative Impact ◽  
Good Method ◽  
Composting Process ◽  
Industrial Sewage ◽  
Industrial Sewage Sludge

The purpose of this work is to study the characteristics of the co-composting of municipal solid waste (MSW), sewage sludge, grass and sawdust. Differing proportions of biodegradable waste were investigated through changes of temperature, oxygen consumption, organic matters, moisture content, carbon, nitrogen, C/N ratio as well as heavy metals and pathogen microorganisms content. The present study has shown that addition of MSW above 10% had a negative impact on the composting process. The initial C/N of the mixtures with a higher MSW content was below 18. Lower losses of organic matter occurred during composting for the mixture with the highest addition of MSW. Although studies have shown that composting is a good method for the disposal of organic waste additional research is required in order to optimize the organic and nitrogen compounds degradation during the co-composting process. In conclusion, a 1:4:4:1 mixture of MSW:sewage sludge:grass:sawdust is recommended because it can achieve high temperature as well as the highest organic matter degradation and highest N content in the final composting product. The concentration of heavy and light metals in all composts was within the limits of regulation of the Polish Minister of Agriculture and Rural Development.

Study on UV–Visible Spectra Characteristic of Dissolved Organic Matter during Municipal Solid Waste Composting

2014 ◽  
Vol 878 ◽  
pp. 840-849 ◽  
Author(s):  
Dan Li ◽  
Xiao Song He ◽  
Bei Dou Xi ◽  
Zi Min Wei ◽  
Hong Wei Pan ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Pure Water ◽  
Treatment Plant ◽  
Composting Process ◽  
Humus Substances ◽  
Absorbance Ratio ◽  
Uv Visible

This paper aims to characterize the evolution of organic matter during the composting of municipal solid waste (MSW). During the 46-day composting process, six samples with different composting time were collected from Songjiang Solid Waste Biological Treatment Plant in Shanghai, China. Dissolved organic matter (DOM) was extracted by ultra-pure water, and the UV-Visible (UV-Vis) spectra of DOM were scanned and investigated. The results showed that, during the composting process, non-humus substances in DOM were gradually transformed into humus substances, the aromatization, molecular weight and humification of humus substances increased. Correlation analysis showed that the absorbance value at 280 nm (SUVA280), and the area of 226~400 nm (A226~400) correlated positively with each other. The dissolved organic carbon (DOC) concentration exhibited a negative correlation with the parameters S275~295, SUVA280 and A200~226, and the correlation coefficients between the DOC content and the A220~226 value was the best (r= -0.976, P=0.001). The absorbance ratio bewteen 465 and 665 nm (E465/E665) showed a significant correlation with SUVA280 (r=-0.892, P=0.017), A226~400 (r=-0.909, P=0.012) and DOC (r=0.840, P=0.036). The absorbance ratio of 250 to 365 nm (E250/E365) correlated significantly with DOC (r=-0.880, P=0.021), and showed no correlation with the other parameters. Absorption curve slope in the range of 275~295nm (S275~295) showed a significantly positive correlation with the DOC content (r=0.961, P=0.002). Among all parameters, the A200~226, A226~400 and S275~295 values reflected compost maturity best.

scholarly journals Process modeling of municipal solid waste compost ash for reactive red 198 dye adsorption from wastewater using data driven approaches

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mohammad Hadi Dehghani ◽  
Mehdi Salari ◽  
Rama Rao Karri ◽  
Farshad Hamidi ◽  
Roghayeh Bahadori
Keyword(s):  
Organic Matter ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Adsorption Process ◽  
Operating Time ◽  
Organic Matter Content ◽  
Order Kinetic ◽  
Box Behnken Design ◽  
Reactive Red 198 ◽  
Msw Compost

AbstractIn the present study, reactive red 198 (RR198) dye removal from aqueous solutions by adsorption using municipal solid waste (MSW) compost ash was investigated in batch mode. SEM, XRF, XRD, and BET/BJH analyses were used to characterize MSW compost ash. CNHS and organic matter content analyses showed a low percentage of carbon and organic matter to be incorporated in MSW compost ash. The design of adsorption experiments was performed by Box–Behnken design (BBD), and process variables were modeled and optimized using Box–Behnken design-response surface methodology (BBD-RSM) and genetic algorithm-artificial neural network (GA-ANN). BBD-RSM approach disclosed that a quadratic polynomial model fitted well to the experimental data (F-value = 94.596 and R2 = 0.9436), and ANN suggested a three-layer model with test-R2 = 0.9832, the structure of 4-8-1, and learning algorithm type of Levenberg–Marquardt backpropagation. The same optimization results were suggested by BBD-RSM and GA-ANN approaches so that the optimum conditions for RR198 absorption was observed at pH = 3, operating time = 80 min, RR198 = 20 mg L−1 and MSW compost ash dosage = 2 g L−1. The adsorption behavior was appropriately described by Freundlich isotherm, pseudo-second-order kinetic model. Further, the data were found to be better described with the nonlinear when compared to the linear form of these equations. Also, the thermodynamic study revealed the spontaneous and exothermic nature of the adsorption process. In relation to the reuse, a 12.1% reduction in the adsorption efficiency was seen after five successive cycles. The present study showed that MSW compost ash as an economical, reusable, and efficient adsorbent would be desirable for application in the adsorption process to dye wastewater treatment, and both BBD-RSM and GA-ANN approaches are highly potential methods in adsorption modeling and optimization study of the adsorption process. The present work also provides preliminary information, which is helpful for developing the adsorption process on an industrial scale.

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