Colloid-mediated vertical phosphorus transport in a waste-amended soil

Geoderma ◽  
2006 ◽  
Vol 136 (1-2) ◽  
pp. 174-183 ◽  
Author(s):  
K.C. Makris ◽  
J.H. Grove ◽  
C.J. Matocha
2019 ◽  
Vol 35 (2) ◽  
pp. 215-224
Author(s):  
Poonam Rani ◽  
◽  
Adarsh Kumar ◽  
Ramesh Chandra Arya ◽  
◽  
...  

1995 ◽  
Vol 31 (5-6) ◽  
pp. 311-315 ◽  
Author(s):  
Timothy M. Straub ◽  
Ian L. Pepper ◽  
Charles P. Gerba

Current methods for the detection of enteric viruses in soil involve elution of viruses from soil colloids using beef extract or other proteins. These eluates are then assayed in cell culture and observed daily for cytopathic effects (CPE). While this method is suitable for detection of enteric viruses by cell culture, these eluates contain humic acids and heavy metals that interfere with polymerase chain reaction (PCR) detection. Using beef extract eluates prepared from sludge amended soil, 10 different methods of eluate purification were evaluated for their ability to remove PCR inhibition and maximize sensitivity. The treatment method providing the greatest sensitivity of poliovirus detection by PCR was the combination of Sephadex G-50 and Chelex-100. Using this method 2 plaque forming units (PFU) could be detected after reverse transcription and 30 cycles of PCR. Thirty (30) cycles of seminested PCR were performed on these samples to verify nucleic acid sequences and increase sensitivity after the first 30 cycles of PCR. Using seminested PCR, sensitivity of detection using the Sephadex G-50 and Chelex-100 treatment method to 0.2 PFU. In addition to providing excellent sensitivity for viruses in sludge amended soils, this treatment method is relatively simple compared to other methods.


1996 ◽  
Vol 34 (1-2) ◽  
pp. 153-160 ◽  
Author(s):  
S. H. Lee ◽  
S. Vigneswaran ◽  
K. Bajracharya

Excessive phosphorus (P as orthophosphate) is one of the major pollutants in natural water that are responsible for algal blooms and eutrophication. P removal by slag is an attractive solution if the P sorption capacity of slag is significant. To design an efficient land treatment facility, basic information on the behaviour of P in the media-water environment is required. In this study, detailed column experiments were conducted to study the P transport under dynamic condition, and mathematical models were developed to describe this process. The column experiments conducted with dust and cake waste products (slag) from a steel industry as adsorbing indicated that they had higher sorption capacity of P than that of a sandy loam soil from North Sydney, Australia. P transport in the dust and cake columns exhibited characteristic S-shaped or curvilinear breakthrough curves. The simulated results from a dynamic physical nonequilibrium sorption model (DPNSM) and Freundlich isotherm constants satisfactorily matched the corresponding experimental breakthrough data. The mobility of P is restricted by the adsorbents and it is proportional to the sorption capacity of them.


Biochar ◽  
2021 ◽  
Author(s):  
Ngitheni Winnie-Kate Nyoka ◽  
Ozekeke Ogbeide ◽  
Patricks Voua Otomo

AbstractTerrestrial and aquatic ecosystems are increasingly threatened by pesticide pollution resulting from extensive use of pesticides, and due to the lack of regulatory measures in the developing world, there is a need for affordable means to lessen environmental effects. This study aimed to investigate the impact of biochar amendment on the toxicity of imidacloprid to life-cycle parameters and biomarker responses of the earthworm Eisenia fetida. E. fetida was exposed to 10% biochar-amended and non-amended OECD artificial soils spiked with 0, 0.75, 1.5, 2.25 and 3 mg imidacloprid/kg for 28 days. An LC50 of 2.7 mg/kg was only computed in the non-amended soil but not in the biochar-amended soil due to insignificant mortality. The EC50 calculated in the non-amended soil (0.92 mg/kg) for reproduction (fertility) was lower than the one computed in the biochar amended (0.98 mg/kg), indicating a decrease in toxicity in the biochar-amended substrate. Significant weight loss was observed at the two highest imidacloprid treatments in the non-amended soil and only at the highest treatment in the biochar-amended substrate, further highlighting the beneficial effects of biochar. Catalase activity decreased significantly at the two highest concentrations of non-amended soil. Yet, in the amended soil, the activity remained high, especially in the highest concentration, where it was significantly higher than the controls. This indicated more severe oxidative stress in the absence of biochar. In all non-amended treatments, there was a significant acetylcholinesterase inhibition, while lower inhibition percentages were observed in the biochar-amended soil. In most endpoints, the addition of biochar alleviated the toxic effects of imidacloprid, which shows that biochar has the potential to be useful in soil remediation. However, there is still a need for field studies to identify the most effective application rate of biochar for land application.


2021 ◽  
Vol 9 (5) ◽  
pp. 885
Author(s):  
Dorcas Oladayo Fatoba ◽  
Akebe Luther King Abia ◽  
Daniel G. Amoako ◽  
Sabiha Y. Essack

The current study investigated the impact of chicken litter application on the abundance of multidrug-resistant Enterococcus spp. in agricultural soil. Soil samples were collected from five different strategic places on a sugarcane farm before and after manure application for four months. Chicken litter samples were also collected. Enterococci were enumerated using the Enterolert®/Quanti-Tray 2000® system and confirm and differentiated into species using real-time PCR. The antibiotic susceptibility profile of the isolates was determined using the disk diffusion method following the European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines. The overall mean bacterial count was significantly higher (p < 0.05) in manure-amended soil (3.87 × 107 MPN/g) than unamended soil (2.89 × 107 MPN/g). Eight hundred and thirty-five enterococci (680 from soil and 155 from litter) were isolated, with E. casseliflavus being the most prevalent species (469; 56.2%) and E. gallinarum being the least (16; 1.2%). Approximately 56% of all the isolates were resistant to at least one antibiotic tested, with the highest resistance observed against tetracycline (33%) and the lowest against chloramphenicol (0.1%); 17% of E. faecium were resistant to quinupristin-dalfopristin. Additionally, 27.9% (130/466) of the isolates were multidrug-resistant, with litter-amended soil harbouring more multidrug-resistant (MDR) isolates (67.7%; 88/130) than unamended soil (10.0%; 13/130). All isolates were susceptible to tigecycline, linezolid and gentamicin. About 7% of the isolates had a multiple antimicrobial resistance index > 0.2, indicative of high antibiotic exposure. Although organic fertilizers are regarded as eco-friendly compared to chemical fertilizers for improving soil fertility, the application of untreated animal manure could promote the accumulation of antibiotics and their residues and antibiotic-resistant bacteria in the soil, creating an environmental reservoir of antimicrobial resistance, with potential human and environmental health risks.


Chemosphere ◽  
1997 ◽  
Vol 35 (3) ◽  
pp. 413-425 ◽  
Author(s):  
S.D. Haigh-Baird ◽  
J. Bus ◽  
C. Engelen ◽  
R.N. Hill

Heliyon ◽  
2020 ◽  
Vol 6 (12) ◽  
pp. e05718
Author(s):  
Md. Akhter Hossain Chowdhury ◽  
Taslima Sultana ◽  
Md. Arifur Rahman ◽  
Tanzin Chowdhury ◽  
Christian Ebere Enyoh ◽  
...  

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