Distribution and speciation of heavy metals in two different sludge composite conditioning and deep dewatering processes

RSC Advances ◽  
2015 ◽  
Vol 5 (124) ◽  
pp. 102332-102339 ◽  
Author(s):  
Chao Li ◽  
Shinan Zhang ◽  
Jiakuan Yang ◽  
Yafei Shi ◽  
Wenbo Yu ◽  
...  

Pilot-scale sewage sludge dewatering experiments were conducted using two composite conditioners: FeCl3 + lime (Fe-lime) and Fenton's reagents + red mud (Fenton-RM).

1996 ◽  
Vol 34 (7-8) ◽  
pp. 413-420 ◽  
Author(s):  
L. Qiao ◽  
Goen Ho

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.


2018 ◽  
Vol 135 ◽  
pp. 133-140 ◽  
Author(s):  
He Li ◽  
Min Zhou ◽  
Yi Han ◽  
Bingchen Shi ◽  
Qiao Xiong ◽  
...  

2003 ◽  
Vol 48 (5) ◽  
pp. 111-117 ◽  
Author(s):  
H. Obarska-Pempkowiak ◽  
A. Tuszyńska ◽  
Z. Sobociński

Macrophyte plants e.g. reed, cattails, bulrush, can be applied to sewage sludge utilisation. One of the first facilities of this type in the Gdansk region (Northern Poland) was established in Darzlubie in 1995 and primary sludge has been utilised in reed beds there. The objective of the undertaken research was evaluating the influence of sewage sludge storage on its chemical and biological properties. A total of 5.5 m thick layer of primary, anaerobically stabilised sludge (moisture 90-96%) was loaded to the reed bed during 6 years of operation. As a consequence of dewatering and biochemical transformation, the sludge layer decreased to 30 cm. Moisture, organic matter, total nitrogen and total phosphorus contents, as well as coli index, Clostridium perfringens index and the number of Ascaris lumbricoides ova were measured. Also the contents of heavy metals (Cu, Pb, Zn, Ni, Cr and Cd) were determined in sludge samples. The study showed that sludge storage in reed beds results in dewatering and partial stabilisation. In the reed lagoons in Swarzewo and Zambrow, dewatering of secondary sludges was investigated. The results of measurements of the quality of sludge and effluent from the reed lagoon in Zambrow are also presented.


2021 ◽  
Vol 5 (4) ◽  
pp. 77
Author(s):  
Lam-Van Tan ◽  
Thanh Tran

Widespread use of chemical fertilizers in agricultural activities poses a high risk of multi-micro metal contamination in soils and potentially causes health issues through consumption of contaminated foods. Bio-organic fertilizers from sewage sludge have been regarded as a suitable substitute for chemical fertilizer for rice farming. In this study, we investigated accumulation of heavy metals (Cu and Zn) in soil, water and rice plant in three pilot-scale rice paddy fields treated with different fertilization schemes. The control field was treated with conventional chemical fertilizers while the soil of two treatment fields was mixed with biological sewage sludge obtained from a local wastewater treatment system in Vietnam at different ratios (1% and 3%). Initial results showed that heavy metals accumulated in the soil, water, and rice plant at varying levels and most of the Cu and Zn contents found in soils, water and rice products exceeded permissible Vietnamese standards (QCVN 03: 2008) and US EPA 503. Notably, the rice field whose soil was treated with sludge at 3% ratio showed a significantly lower accumulation of heavy metals in soil, water and in rice plant. However, treatment of sludge at this level seemed to cause higher heavy metal retention in soil after one harvest. Semi-quantitative risk analysis revealed that the risk of metal contamination in soil and water of the control field ranged from medium (RQ index between 0.1 and 1) to high risk (RQ index higher than 1) and that fertilization methods would also affect the level of risk to the environment.


RSC Advances ◽  
2014 ◽  
Vol 4 (47) ◽  
pp. 24762-24768 ◽  
Author(s):  
An Ding ◽  
Fangshu Qu ◽  
Heng Liang ◽  
Shaodong Guo ◽  
Yuhui Ren ◽  
...  

Schematic mechanism of the effect of adding wood chips on sludge dewatering: (a) sludge without conditioning; (b) sludge with chemical conditioning; (c) sludge with chemical and physical conditioning; and (d) a physical image of a dewatered sludge cake with wood chip conditioning.


1982 ◽  
Vol 11 (2) ◽  
pp. 182-186 ◽  
Author(s):  
W. E. Emmerich ◽  
L. J. Lund ◽  
A. L. Page ◽  
A. C. Chang

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