Electricity production from municipal solid waste using microbial fuel cells.

The organic content of municipal solid waste has long been an attractive source of renewable energy, mainly as a solid fuel in waste-to-energy plants. This study focuses on the potential to use microbial fuel cells to convert municipal solid waste organics into energy using various operational conditions. The results showed that two-chamber microbial fuel cells with carbon felt and carbon felt allocation had a higher maximal power density (20.12 and 30.47 mW m(-2) for 1.5 and 4 L, respectively) than those of other electrode plate allocations. Most two-chamber microbial fuel cells (1.5 and 4 L) had a higher maximal power density than single-chamber ones with corresponding electrode plate allocations. Municipal solid waste with alkali hydrolysis pre-treatment and K3Fe(CN)6 as an electron acceptor improved the maximal power density to 1817.88 mW m(-2) (~0.49% coulomb efficiency, from 0.05-0.49%). The maximal power density from experiments using individual 1.5 and 4 L two-chamber microbial fuel cells, and serial and parallel connections of 1.5 and 4 L two-chamber microbial fuel cells, was found to be in the order of individual 4 L (30.47 mW m(-2)) > serial connection of 1.5 and 4 L (27.75) > individual 1.5 L (20.12) > parallel connection of 1.5 and 4 L (17.04) two-chamber microbial fuel cells . The power density using municipal solid waste microbial fuel cells was compared with information in the literature and discussed.

Effects of different SRT on anaerobic digestion of MSW dosed with various MSWI ashes.

This study investigated different solid retention time (SRT) on municipal solid waste (MSW) anaerobic digestion with various MSW incinerator fly ash (FA) and bottom ash (BA) addition. Results showed that biogas production rates (BPRs, ≈ 200 to ≈ 400 mL/gVS) with organic loading rate of ≈ 0.053 gVS/gVS(reactor) (Day 1-435, SRT 20 days, SRT20) at FA 1g/d (FA1), BA 12 g/d (BA12) and BA 24 g/d (BA24) dosed bioreactors increased after adaptation. BPRs with SRT10 and SRT5 decreased while BPRs with SRT40 showed to increase compared to initial BPRs (≈ 200 mL/gVS) with SRT20. SRT5 operation reduced the BPRs (≈ 10 - ≈ 90 mL/gVS) significantly and only BA12 and BA24 dosed bioreactors could recover the BPRs (≈ 100 - ≈ 200 mL/gVS) after SRT20 operation (Day 613-617) compared to FA1 and FA3 and control. Released levels of Co, Mo and W at BA12 and BA24 dosed bioreactors showed most potential to improve MSW anaerobic digestion.

Effects of micro-nano and non micro-nano MSWI ashes addition on MSW anaerobic digestion.

This study aims at investigating the effects of micro-nano municipal solid waste (MSW) incinerator (MSWI) fly ash (FA) and bottom ash (BA) on the MSW anaerobic digestion. Results showed that suitable micro-nano and non micro-nano MSWI ashes addition (FA/MSW 3, 6, 18 and 30 g g(-1) VS and BA/MSW 12, 36, 60 and 120 g g(-1) VS) could enhance the biogas production compared to the control. It was particularly found to have the highest biogas production at the micro-nano MSWI BA/MSW ratio of 36 g g(-1) VS (∼193 mL g(-1) VS MSW, ∼3.5 times to the control). Micro-nano MSWI FA and BA added bioreactors had the higher biogas production than the corresponding non micro-nano MSWI FA and BA added ones. Suitable MSWI ashes addition could improve the biogas production due to the released metals levels suitable for the MSW anaerobic digestion particularly found in the micro-nano added bioreactors.

Effects of spiked metals on the MSW anaerobic digestion.

This study aimed to investigate the effects of eight metals on the anaerobic digestion of the organic fraction of municipal solid waste (OFMSW) in bioreactors. Anaerobic bioreactors containing 200 mL MSW mixed completely with 200 m L sludge seeding. Ca and K (0, 1000, 2000 and 6,000 mg L(-1)) and Cr, Ni, Zn, Co, Mo and W (0, 5, 50 and 100 mg L(-1)) of various dose were added to anaerobic bioreactors to examine their anaerobic digestion performance. Results showed that except K and Zn, Ca (~728 to ~1,461 mg L(-1)), Cr (~0.0022 to ~0.0212 mg L(-1)), Ni (~0.801 to ~5.362 mg L(-1)), Co (~0.148 to ~0.580 mg L(-1)), Mo (~0.044 to ~52.94 mg L(-1)) and W (~0.658 to ~40.39 mg L(-1)) had the potential to enhance the biogas production. On the other hand, except Mo and W, inhibitory concentrations IC(50) of Ca, K, Cr, Ni, Zn and Co were found to be ~3252, ~2097, ~0.124, ~7.239, ~0.482, ~8.625 mg L(-1), respectively. Eight spiked metals showed that they were adsorbed by MSW to a different extent resulting in different liquid metals levels and potential stimulation and inhibition on MSW anaerobic digestion. These results were discussed and compared to results from literature.

Novel mutation and prenatal sonographic findings of glutaric aciduria (type I) in two Taiwanese families.

Glutaric aciduria type I (GA I) is an autosomal recessively inherited inborn error with a defect of the enzyme glutaryl-CoA dehydrogenase (GCDH), which has never been diagnosed prenatally in Taiwanese patients. We present the prenatal sonographic findings and mutational analysis data of three children in two Taiwanese families. One patient from each family was diagnosed postnatally due to macrocephaly and neurological deterioration at 4 months and 10 months, respectively. The third child, sister of the first patient, was diagnosed prenatally at 11 weeks' gestation through chorionic villus sampling (CVS). Molecular analysis revealed that the fetus and child in Family 1 were homozygous for a common mutation, IVS10 -2A>C, which has not been reported in the Caucasian population. The patient in Family 2 was a compound heterozygote for IVS10 -2A>C and a novel mutation 749T>C (L238P). After genetic counseling, the couple decided to continue the second pregnancy. However, dilatation of quadrigeminal cistern (QC) and suspicious macrocephaly were noted at 30 weeks. Progressive dilatation of the QC associated with macrocephaly, fronto-temporal atrophy and wide space of perisylvian fissure were found in the follow-up scans. The affected girl was delivered at 37 weeks' gestation by cesarean section. Postnatal magnetic resonance imaging (MRI) studies confirmed the prenatal sonographic findings. With prenatal sonographic findings and mutational analysis presented in the present cases, the feasibility of prenatal diagnosis of GA I in high-risk pregnancy can not be overlooked.

Assessment of trophoblastic flow in abnormal first trimester intrauterine pregnancy.

BACKGROUND: The use of color Doppler sonography in assessing feto-maternal circulation during pregnancy has recently been advocated. However, studies of evaluation of trophoblastic flow in the first trimester of pregnancy, with color Doppler sonography, are rare. The objects of this study were to assess the trophoblastic flow in first trimester pregnancy failure by using transvaginal color Doppler sonography, and attempted to elucidate the pathophysiology of early feto-maternal circulation. METHODS: One hundred and five cases of first trimester intrauterine pregnancy were enrolled in this study, including 34 cases of blighted ova, 50 missed abortions and 21 normal pregnancies. All patients received transvaginal sonography (Acuson 128, 5MHz). First, color Doppler was mapped and then trophoblastic flow (TBF) was detected and the resistance index (RI) was calculated. Main uterine artery (UA) flow was measured in the later part of this study. Serial sonographic examinations with serum beta-human chorionic gonadotropin (beta-hCG) levels were obtained to confirm a diagnosis of pregnancy failure. Discrepancy in gestational age calculated by the last menstrual period and by sonar measurement was recorded for analysis. The aborted tissues were submitted for karyotyping from six cases of normal pregnancy, 11 cases of blighted ovum and 22 cases of missed abortion. RESULTS: Preliminary result showed TBF can be detected at as early as the fifth week of gestation. The RIs of TBF and UA seemed to decrease; however, serum beta-hCG levels increased as gestational age advanced in normal pregnancies. This change was not shown in the abnormal groups. No significant difference in the RI of TBF or UA flow was noted between normal and abnormal pregnancies. Also the result of karyotyping did not correlate well with the RIs of TBF and UA, and serum beta-hCG levels. CONCLUSIONS: The assessment of feto-maternal circulation in early pregnancy does provide information on the physiology of early normal placentation, but not of the early pregnancy failure. Limited case numbers and different time intervals between fetal demise and sonographic diagnosis may play roles in the above findings.

Alagille syndrome with interstitial 20p deletion derived from maternal ins(7;20).

We present a 6-year-old Chinese boy with Alagille syndrome and an interstitial 20p deletion, with a karyotype of 46,XY,der(20)dir ins(7;20)(q11.23;p11.23p12.2 or p12.2p13)mat. He had a peculiar face and suffered from congenital heart disease, growth retardation, severe cholestasis, hepatosplenomegaly, and impaired renal function. The karyotype of his mother showed a balanced translocation, 46,XX,dir ins(7;20)(q11.23; p11.23p12.2 or p12.2p13), and her phenotype was normal. His dead elder brother was highly suspected as another victim of Alagille syndrome. The findings in the present family suggested that if Alagille syndrome is a single gene defect, the putative gene responsible for the syndrome would not be located at the insertion breakpoints but located within the deletion extent.

Toxicity and persistence of low-level PCB in adult wistar rats, fetuses, and young.

Aroclor 1254 was fed to female and male rats daily for 9 weeks at a dose of 6.4 mg/kg in their drinking water. Control animals received plain tap water plus the emulsified (0.15% Tween 80). Elevated mixed function oxidase (MFO) activity appeared to be due to 2,4,5,2',4',5'- and 2,4,5,2'3'4'-hexachlorobiphenyls, since only these compounds were present to any degree in the tissues of the animals when MFO activity persisted after termination of exposure. The placenta apparently is an effective barrier to PCB transfer.

Analytical response of polychlorinated biphenyl homologues and isomers in thin-layer and gas chromatography.

Except for pure synthetic polychlorinated biphenyl (PCB), estimation methods of PCB by thin-layer and gas chromatography with electron capture detection give comparable results. Both give a good estimate of the true mass of a biologically modified residue, but where mostly hexachlorobiphenyls and above make up the residue, the estimate will be up to 50% too high. The Coulson detector does not, in our hands, yield comparable results with modified residues: the reason for this difference is not clear at present.