Bioremediation of contaminated lake sediments and evaluation of maturity indicies as indicators of compost stability.
(1/20)
Land contamination is one of the widely addressed problems, which is gaining importance in many developed and developing countries. International efforts are actively envisaged to remediate contaminated sites as a response to adverse health effects. Popular conventional methodologies only transfer the phase of the contaminant involving cost intensive liabilities besides handling risk of the hazardous waste. Physico-chemical methods are effective for specific wastes, but are technically complex and lack public acceptance for land remediation. iBioremediatio ni, is one of the emerging low-cost technologies that offer the possibility to destroy various contaminants using natural biological activities. Resultant non-toxic end products due to the microbial activity and insitu applicability of this technology is gaining huge public acceptance. In the present study, composting is demonstrated as a bioremediation methodology for the stabilization of contaminated lake sediments of Hyderabad, A.P, India. Lake sediment contaminated with organics is collected from two stratums--upper (0.25 m) and lower (0.5m) to set up as Pile I (Upper) and Pile II (Lower) in the laboratory. Lime as a pretreatment to the lake sediments is carried out to ensure metal precipitation. The pretreated sediment is then mixed with organic and inorganic fertilizers like cow dung, poultry manure, urea and super phosphate as initial seeding amendments. Bulking agents like sawdust and other micronutrients are provided. Continuous monitoring of process control parameters like pH, moisture content, electrical conductivity, total volatile solids and various forms of nitrogen were carried out during the entire course of the study. The stability of the compost was evaluated by assessing maturity indices like C/N, Cw (water soluble carbon), CNw (Cw/Nw), nitrification index (NH4/NO-3), Cation Exchange Capacity (CEC), germination index, humification ratio, compost mineralization index (ash content/oxidizable carbon), sorption capacity index (CEC/oxidizable carbon). Enzyme activities of agricultural interest like urease, phosphatase, P-glucosidase, dehydrogenase and BAA-hydrolyzing protease, which are involved in the nitrogen, phosphorus and carbon cycles, were also assessed. Total content of macro and micronutrients in the final compost was also determined to assess the fertilizer value. The studies revealed that composting could be applied as a remediation technology after removing the top sediment. The maturity indices that are evaluated from the present study can be used to validate the success of the remediation technology. (+info)
Assessment of the impact of excessive chemical additions to municipal wastewaters and comparison of three technologies in the removal performance of pathogens and toxicity.
(2/20)
The removal efficiencies of pathogens such as Salmonella (S), helminths ova (H), protozoan cysts (P), total coliforms (TC), faecal coliforms (FC) and faecal streptococci (FS) by three treatment processes: aerated lagoon (AL), activated sludge (AS) and anaerobic membrane bioreactor (MBR) were evaluated by means of standard microbiological numeration methods. The micro-toxicity and phyto-toxicity of wastewaters were monitored by LUMIStox and germination index (GI) of Lepidium sativum tests. The results of municipal wastewaters receiving industrial effluents such as Sfax and Mahres were compared with other municipal wastewaters receiving mainly domestic effluents such as Ksour-Essaf. The anaerobic MBR allowed an effective removal of 100% for all the microorganisms tested. The average removal of TC, FC, FS, S, H and P was 1.65log(10), 1.42log(10), 1.23log(10), 0.91log(10), 52.23% and 76.15% in AL system and 0.62-0.84log(10), 0.87-0.93log(10), 0.71-0.78log(10), 0.81-2.71log(10), 59-74.1% and 59.84-72.2% in AS processes, respectively. LUMIStox and GI of L. sativum tests demonstrated that Ksour-Essaf wastewater (KW) was fairly toxic, while Sfax wastewater (SW) exhibited a high toxicity. This toxicity caused the inhibition of the anaerobic consortia when the MBR was fed with the SW. Moreover, the COD and the micro-toxicity increased during the day, parallel to the industrial and domestic activities resulting in the toxic character of SW during the day. SW treated in the AL remained toxic whereas the toxicity of KW treated in the AS or in anaerobic MBR decreased considerably. However, the anaerobic MBR showed a high efficiency in removing toxicity for both SW and KW. The quality of the anaerobic MBR permeate largely conforms with the microbiological WHO guidelines for unrestricted irrigation. (+info)
Synthetic ecosystems based on airborne inter- and intrakingdom communication.
(3/20)
Intercellular communication within an organism, between populations, or across species and kingdoms forms the basis of many ecosystems in which organisms coexist through symbiotic, parasitic, or predator-prey relationships. Using multistep airborne communication and signal transduction, we present synthetic ecosystems within a mammalian cell population, in mice, or across species and kingdoms. Inter- and intrakingdom communication was enabled by using sender cells that produce volatile aldehydes, small vitamin-derived molecules, or antibiotics that diffuse, by gas or liquid phase, to receiver cells and induce the expression of specific target genes. Intercellular and cross-kingdom communication was shown to enable quorum sensing between and among mammalian cells, bacteria, yeast, and plants, resulting in precise spatiotemporal control of IFN-beta production. Interconnection of bacterial, yeast, and mammalian cell signaling enabled the construction of multistep signal transduction and processing networks as well as the design of synthetic ecosystems that mimic fundamental coexistence patterns in nature, including symbiosis, parasitism, and oscillating predator-prey interactions. (+info)
The effects of Lepidium sativum seeds on fracture-induced healing in rabbits.
(4/20)
The Lepidium sativum plant and seeds are well known in the community of Saudi Arabia and some other Arabic countries as a good mediator for fracture healing in the human skeleton. However, there is no scientific proof for this phenomenon, except for the positive observation noted publicly by traditional medicine practitioners and people in the community as well as clinically by the author. Those healed fractures in human beings observed clinically due to the consumption of L sativum seeds propagated the attention of the author to carry out this study, with the goal of proving it in the laboratory by inducing fractures in the midshaft of the left femur of 6 adult New Zealand White rabbits divided into 2 groups (control, n = 3 and test, n = 3). The test rabbits were fed soon after surgery with L sativum seeds mixed with their normal diet, whereas no seeds were given to the control group. X-rays of the induced fractures were taken at 6 and 12 weeks postoperatively to assess the healing of the fractures and documenting the healing by direct measurements of callus formation in millimeters at the longitudinal medial (LM) and longitudinal lateral (LL) and circumferential (CM) areas. The test group had a statistically significant increase in the healing of fractures compared with the control group (P < .001 for CM/6 weeks and P < .004 for CM and P < .043 for LM/12 weeks). We concluded that L sativum seeds had a marked influence on fracture healing in rabbits, clearly supporting their effects on human beings as a well-known natural element to promote fracture healing in traditional medicine. This, of course, has a marked clinical implication that needs to be investigated further. (+info)
Peroxidases identified in a subtractive cDNA library approach show tissue-specific transcript abundance and enzyme activity during seed germination of Lepidium sativum.
(5/20)
Ethylene interacts with abscisic acid to regulate endosperm rupture during germination: a comparative approach using Lepidium sativum and Arabidopsis thaliana.
(6/20)