ABSTRACT
The development of industrial activities is the source of the production of large quantities of wastewater. The last-mentioned are rejected in the environment often without any prior treatment and have serious short-term and sometimes long-term environmental consequences. The objective of this work is to assess the environmental impacts and to propose a process for treating wastewater of reject from Bayo dairy in Brazzaville-Congo. The samples were taken at four (4) stations before, during and after production of dairy products. Multivariate statistical analysis of the physicochemical data was carried out using Statistica 7.1 software. The results obtained show that the wastewater from the Bayo dairy has a basic pH which fluctuates between 8.32 and 9.17 with standard temperatures of reject. The salinity of the wastewater increases greatly during production, which shows rising mineralization. The contents of MES (49.78-181.80 mg/L), MO (40.23-72.64 mg O2/L), COD (51.08-98.91 mg O2/L), BOD5 (34.80-59.50 mg O2/L) and the turbidity (26-179) NTU are moderately high and reflect an increase pollutant load before, during and after production of dairy products in stations S2 and S3. The COD/BOD5 ratio reveals that the Bayo dairy wastewater is moderately biodegradable before, during and after production with a biodegradability coefficient which varies between 1.40 and 1.78. The ACP approves possible industrial pollution from wastewater from the Bayo dairy and reports on the impact of the rejects in the environment. Thus, this study is a contribution to raising awareness among the Congolese population and decision-makers on the quality of wastewater rejected by local industries.
ABSTRACT
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.)
ABSTRACT
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%.
ABSTRACT
L'etude; de juillet 1988 a mai 1989; de la variation des huiles essentielles des lippia cultives (Brazzaville; Congo) met en evidence un mouvement continu de ces huiles des fleurs vers les feuilles et inversement. La teneur des differents constituants varie de facon plus ou moins prononcee selon la partie de la plante consideree alors que le profil global des huiles reste le meme. Cette etude permet de situer la periode de recolte la plus favorable pour cette plante a effets bactericide et antifongide etablis