Performance Evaluation of Industrial Brewery Wastewater Biologic Treatment in an UASB Reactor Using Activated Sludge in Republic of Congo

The brewing industry generates large amounts of wastewater which are released into surface water after treatment. The aim of this study is to evaluate the performance of the anaerobic treatment of brewery wastewaters in a UASB bioreactor containing activated sludge. After six-weeks operation, 30 samples were taken. Physicochemical analyzes were carried out on activated sludge (T, pH, VFA) and raw and treated waters (T, pH, AT, CAT, TSS, and COD). These analyzes showed that the conditions of the environment were favorable to an optimal growth of the bacteria:  temperatures and pH were mostly mesophilic. the ionization of VFA was continuous and their concentration increased at the exit of the bioreactor thus revealing a significant conversion of organic materials by bacteria. The average values ​​of the physicochemical parameters of the raw and treated wastewaters respectively increased from 31.5°C to 35°C for the temperature, from 8.9 to 7.5 for the pH, to 5.54 mg/l at 0 for AT, from 12.35 mg/l to 3.45 mg/l for TAC, from 234.08 mg/l to 129.61 mg/l for TSS and from 1637 mg/l to 282, 46 mg/l for COD. The effectiveness of the treatment allowed a COD reduction ranging from 70 to 94%

Comparative Chemical and Analgesic Properties of Essential Oils of Cymbopogon Nardus (L) Rendle of Benin and Congo

The chemical and analgesic comparison of essential oils of Cymbopogon nardus (L) Rendle of Benin and Congo was investigated. The Chemical analysis wa carried out by using GS/MS for identification of components of the two essential oils while acetic acid-induced writhings, hot plate and tail flick test models were used for analgesic activity. The results showed that the two essential oils exhibited comparable activity on acetic acid- induced writhings, however, the essential oil of Benin induced more significant effect on hot plate model while the Congolese specie showed more effect in the tail flick test. These observations could be explained by some qualitative and /or quantitative differences observed between the constituents of the two essential oils studied

Phytoremediation of Industrial Waste Leachates by Planted Filters Composed of Phragmites australis (Cav) Trin ex Steud, Typha latifolia L. and Cyperus papyrus L.

The aim of this study is to evaluate the purifying ability of 3 parallel planted filters (PF1, PF2 and PF3) composed of three plants (Phragmites australis (Cav) Trin ex Steud, Typha latifolia L., Cyperus papyrus L.) on leachates from a landfill of industrial waste in Pointe-Noire (Republic of Congo). This landfill site includes a technical landfill for ordinary industrial waste (OIW) and a technical landfill for hazardous and soiled industrial waste (SIW). In order to assess purifying ability, we sampled 14 samples over 8 weeks, with 7 samples of the raw leachates from the technical landfill center, and 7 samples of leachates cleaned after passing through the tryptic vegetable filter. The physico-chemical analyzes made it possible to determine the following parameters: TOC, COD, NO3 -,PO42-, Ni, Cd, CrVI, Zn, Cu and Pb. The results showed a significant decrease in organic pollution with abatement rates in TOC and COD greater than 90%. The average removal efficiency is respectively 45.97% for nitrates and 40.2% for phosphates. The abatement rates for heavy metals range from 41.2% to 60.9% for nickel, from 52.2% to 68.5 % for cadmium, from 49% to 71.7% for chromium VI, from 59% to 74.6% for zinc, from 50.9 % to 65 % for copper and from 61.4% to 75.1% for lead. However, additional analyzes are needed to confirm the hypperaccumulator nature of these plant filters in particular absorption isotherms and kinetics of extraction of heavy metals of Phragmites australis (Cav) Trin ex Steud, Typha latifolia L., Cyperus papyrus L.

Proposal of a Fermi–Dirac-Derived Reactivity Descriptor: Beyond the Frontier MO Model

International audienceIn this paper, we derive a reactivity descriptor stemming from the Fermi-Dirac population scheme, applied to density functional calculations on molecular systems. Assuming molecular orbitals only marginally change when temperature is slightly increased from 0 K, we study the response of electron density to a change in temperature. Connection with usual conceptual DFT descriptors is made, and the T-variation of electron density for some representative examples is given and discussed