[Detoxification of textile industry effluents by photocatalytic treatment]. / Détoxication des effluents d'industrie de textile par photocatalyse.

In Morocco the textile industry, representing 31% of all Moroccan industries, is accompanied by high water consumption and important wastewater discharges rejected without any treatment. The focus of this study was to characterize the effluent from the textile industry, to test separately the effect of UV light and TiO2 catalyst and to determine the optimum conditions (pH, concentration and reaction time) in photocatalytic treatment to reduce chemical oxygen demand (COD) and colour. The biodegradability of the effluent was also studied using a toxicity test before and after treatment. After 90 min of reaction time at pH 4 and with 1.5 g F' of TiO2 catalyst, the photocatalytic treatment reached a global removal rate of 53% for COD and 89% for discoloration of the effluent. The relation BOD5/COD increased from around 0 to 0.3. The effluent became accessible to a biological treatment. The toxicity was studied by the Daphnia magna test over 24 hours. The results have shown the important toxicity of these effluents, which are rich in organic matter and other chemical compounds. After treatment by photocatalytic oxidation, the CI50 24 increased from 3.8% to 22.8%. This reduction of toxicity is related to the reduction of COD (53%) and colour (89%). Photocatalytic treatment has been shown to have an environmental benefit and, in combination with a secondary biological treatment, can be important for a significant reduction in the pollution of textile effluents.

[Treatment of olive mill wastewater by a process combining an intensive treatment (Jet-Loop reactor) followed by an extensive treatment (stabilization ponds)]. / Traitement des effluents d'huileries par un procédé combinant un traitement intensif (Jet-Loop reactor) suivi d'un traitement extensif (bassins de stabilisation).

Olive oil mill wastewater (OMW) is generally recognized as an environmentally troublesome by-product of the olive oil industry as its disposal without any treatment is known to cause serious environmental problems. However, this effluent has a high fertilizing power and constitutes, with urban wastewater, an important low-cost source. Biological treatment of OMW, with a process combining an aerobic reactor, 'Jet-Loop', and waste stabilization ponds, was investigated for possible agricultural reuse. The focus of the present study was to evaluate the contribution and the complementarity of the two systems in the total OMW treatment. Bio-treatment was performed using a 100-litre Jet-Loop reactor working volume achieving a chemical oxygen demand (COD) and phenolic compounds maximum removal rate of 72% and 68%, respectively, at a hydraulic retention time of 10 days. Co-treatment of OMW and domestic wastewater in waste stabilization ponds, with a hydraulic retention time of 22 days, reached a global removal rate of 66% for COD while no trace of phenolic compounds was detected on this level during the entire treatment period. Dynamics of faecal coliforms in stabilization ponds showed a total removal rate of 99.9% (3 logarithmic units (Log.U)). Preliminary results of agronomic tests on the ray-grass have evaluated the fertilizing effect of the final effluent resulting from the co-treatment.

Co-treatment of olive-mill and urban wastewaters by experimental stabilization ponds.

Olive oil mill wastewater (OMW) constitutes a source of environmental problems in Morocco due to its significantly high organic load, its phytotoxic properties and its relatively low biodegradability. An effective option for its disposal is its agricultural use after co-treatment with urban wastewater (UWW). The main objective of this investigation was to evaluate the potential of this co-treatment, using experimental waste stabilization ponds, in removing OMW phytotoxicity. We examined the influence of the organic load, at the entry of the treatment system, on the evolution of some physicochemical (chemical oxygen demand and polyphenols) and microbiological (fecal coliforms and fecal streptococci) parameters. The results showed a removal of the organic, phenolic and microbial load throughout the treatment which differed from one system to another according to the OMW load applied to each system. The results concerning the germination assays of Zea mays and Solanum lycopersicum suggested that the co-treatment of OMW with UWW would decrease the phytotoxicity of this waste.

Application of lime and calcium hypochlorite in the dephenolisation and discolouration of olive mill wastewater.

The application of hypochlorite for the removal of soluble COD, phenolic and polyphenolic like compounds, and other organic compounds responsible for the olive mill wastewater (OOWW) colour has been experimentally studied. After the OOWW filtration on a sand column, the effluent was subjected to a fast liming under optimal conditions. Lime application reduced polyphenols, COD and SS contents to half of their initial values but an important blackening of the treated OOWW was observed, especially when adding high concentrations of lime (10% (W/V) and 15% (W/V)). A second stage of treatment was applied using calcium hypochlorite. In this stage, removal of the studied compounds reached as much as 95% at higher concentrations, and particularly the colouring of OOWW which is generally difficult to eliminate was greatly reduced. The OOWW hypochloration acted through coagulation-flocculation and a rapid oxidation of the organic matter proceeded from the first 5min. The kinetic study of the degradation of the waste polluting compounds from liming showed that Ca(ClO)(2) reacts similarly in the elimination of organic compounds, polyphenols, SS and colouration. The analysis of the organochloride compounds generated by the reaction between hypochlorite and the organic compounds showed that DDD, DDT and the heptachlor contents exceeded the values recommended by the International and European drinking water standards.

[Impact of olive oil wastewater on the physicochemical and biological quality of groundwater in the Haouz plain, south of Marrakesh (Morocco)]. / Impact des effluents des huileries d'olive sur la qualité physico-chimique et biologique des eaux souterraines dans la plaine du Haouz au sud de Marrakech (Maroc).

Olive Oil Waste Water (OOWW) is acidic water known for its antibacterial and phytotoxic effects. In Morocco, these effluents are generally drained into the surrounding environment without any treatment or are collected and retained in large evaporation basins, which can constitute a source of potential pollution of groundwater. The analysis of water from 14 wells, in an agricultural zone, where there are four storage basins of OOWW coming from various types of oil mills, showed that their physicochemical and biological quality is largely influenced by the presence of these basins. Indeed, high values of COD (400 mg O2 L(-1)), polyphenols (180 mg l(-1)) and electrical conductivity (1.89 mS cm-') were recorded in P5 water. This well is located only 5 m from a storage basin of OOWW coming from the H4 oil mill which rejects OOWW charged with organic matter (more than 290 g of O2 L(-1) of COD, on average). However, the settlement of a basin, dug close to a modern oil mill (H3), which produces large OOWW volumes but is loaded with low organic pollutant concentration (100 g of O2L(-1) of COD), reduced notably the effect of the OOWW infiltration on groundwater. This resulted in the improvement of the groundwater physicochemical quality near this basin (P7 and P8); the organic matter contents expressed by COD vary from 26.7 mg l(-1) to 30 mg l(-1) and the polyphenol contents are on average between 41 mg l(-1) and 47.6 mg l(-1). The analysis of the total well water fauna showed a great taxonomic richness with variations in time and space. The biodiversity decreases in groundwater polluted by the oil mill waste and the underground fauna disappears completely if the degree of contamination of groundwater is high.

[Impact of polymetallic mine (Zn, Pb, Cu) residues on surface water, sediments and soils at the vicinity (Marrakech, Morocco)]. / Impact des residus d'une mine polymetallique (Zn, Pb, Cu) sur les eaux de surface, les sediments et les sols avoisinants (Marrakech, Maroc).

Metal sulphide tailings present a potential risk for the environment because of their natural oxidability which leads to the production of acid mine drainage. The prospected site close to Marrakech includes zinc, lead and copper sulphide deposits. This site is located in an agricultural area near the Tensift River which is used for irrigation. In addition to the tailing leachates, underground mine waters are also discharged into the river. This represents a potential risk for the environment and human health. The aim of this study was to assess the tailings impact on surface water, sediments and soil qualities. Chemical analysis of surface water and sediments collected downstream of the mine revealed that, water and sediments present high concentrations of major ions and heavy metals. The analysis also revealed spatial as well as temporal changes in the chemical properties of the studied water and sediments. These changes are attributed to the rising phenomena. The soil near the mine presents high content of sulphate. Its Zn, Pb, Cu and Fe contents are respectively 38, 15, 11 and 1.6 times higher than non contaminated soils located far away from the site. The soil irrigated with underground mine waters shows concentrations of SO4(2-), Cu, Zn, Fe, Cd and Pb which are respectively 4, 10, 28, 2, 9 and 12 times higher than soils which are not irrigated with this mine water. This study also showed that there has been a change in the physicochemical characteristics of water and sediments in the sampling points downstream of the mine before its closure and after its activity renewal.

[Effect and bioaccumulation of heavy metals (Zn, Cd) on Micractinium pusillum ALGA]. / Effet et bioaccumulation des metaux lourds (Zn, Cd) chez l'algue Micractinium pusillum.

Heavy metals (Zn and Cd) effect and their bioaccumulation by a microalga Micractinium pusillum were investigated. Results showed that Cd was more toxic than Zn on Micractinium pusillum. Indeed, inhibitory concentrations of 50% of alga population in 72h (IC(50,72h)) were 0.28 and 0.34 mg l(-1) respectively for Cd and Zn. On the other hand, metal extracted rates from medium solution were more important for Zn than for Cd, essentially for the two first concentrations tested (0.06 and 0.12 mg l(-1)). Furthermore, Zn and Cd extracted proportions were more important for the low concentrations tested and decreased progressively with increasing concentrations applied. This mechanism of extraction corresponds principally to their biosorption by Micractinium pusillum.

[Impact of mining wastes on the physicochemical and biological characteristics of groundwater in a mining area in Marrakech (Morocco)]. / Impact des rejets miniers sur la qualite physico-chimique et biologique des eaux souterraines d'une zone miniere dans la region de Marrakech (Maroc).

Metal sulphide tailings represent a potential risk basically for the environment and particularly for water resources, because of their natural oxidisability which leads to the production of acid/neutral mine drainage. The prospected site close to Marrakech includes zinc, lead and copper sulphide deposits. This site is located in an agricultural area where ground water is used both for irrigation and drinking. Eco-toxicological investigations have been undertaken in order to asses the tailings impact on water quality in nearby wells. These investigations include physico-chemical characterization of the groundwaters as well as faunistic population determination. As compared to standard wells, waters from the wells located downstream of the mining site, have high electrical conductivities and high major ions contents, which can reach: 755 mg l(-1) in SO4(2-), 1670 mg l(-1) in Ca2+, 528 mg l(-1) in Mg2+, 2289 mg I(-1) in Na+ and 14981 mg l(-1) in Cl-. The fauna distribution analysis carried out around the studied wells shows qualitative and quantitative differences according to the flow gradient of the groundwaters. Areas located upstream of the mine tailings site are richer in stygobite species (Type and quantity) than those located downstream or close to it. It is likely that these biological differences are due to water quality alteration induced by the mining activity.

Eliminating toxic compounds by composting olive mill wastewater-straw mixtures.

The present work studies the changes occurring in organic matter, phenols and biotoxicity on composting olive mill wastewater with barley straw. The total organic matter decreased, a drop of 25% was reached after the stabilization phase and 52% at the end of the maturation phase. Degradation of the phenols reached 54% and 95%, respectively, after these periods. The toxicity of the water extract, evaluated by the Photobacterium phosphoreum fluorescence, decreased to disappear after only 2 months of composting. This trend was confirmed by the tight correlation between the physico-chemical and toxicity parameters, indicating that the degradation of organic matter leads to a strong reduction of the C/N ratio and of toxicity. The results obtained indicate a normal process of humification occurring during the composting of the formerly highly toxic olive mill wastewater-straw mixture and resulting in a product, which has good agricultural properties as organic fertilizer.

[Impact of acid mining drainage on the quality of superficial waters and sediments in the Marrakesh region, Morocco]. / Impact du drainage acide minier sur la qualite des eaux de surface et des sediments dans la region de Marrakech, Maroc.

The aim of the present study is the evaluation of the effects of the acid drainage of three abandoned mining sites: SB-Othmane, Kettara and Draâ-sfar, on water and sediment quality of the Tensift River and its two temporary tributaries, the Kettara and El-Coudia Oueds. These mining sites located near Marrakesh contain mining residues abandoned for ten to twenty years. They are presently in an agricultural region of the Haouz district. In each site, these uncontrolled mining residues present a high level of metallic sulphide and generate, during rainy periods, leaching products which have physical and chemical characteristics of acid mine drainage (AMD). These percolates display an acidic pH ranging from 2.5 to 5.2, a high electric conductivity, large amounts of sulphate and heavy metals, especially under dissolved form (e.g. Cd: 17.34 mg l(-1); Fe: 1734 mg l(-1); Zn: 3935 mg l(-1)). Except for Pb, the free ionic form is the most abundant metallic form, as showed by calculations using the speciation GEOCHEM program. The analysis of water and sediments of the surrounding superficial aquatic ecosystems shows a modification of water chemical facies and an enrichment in heavy metals, mainly under the solid phase for Fe, Pb, Cu, Co, Cr and Ni, and under dissolved fraction for Cd and Zn. The dissolved fraction of these metals is dominated by the free ionic form, considered as available for organisms. Furthermore, sediments contain important quantities of heavy metals (Pb: 1450 microg g(-1), Zn: 1562 microg g(-1)) with an available fraction which is higher than 40% for the Cd and Zn. The abundance of trace elements (free ionic and available forms) in water and sediment presents a durable risk of their transfer to food chains.

The fate of heavy metals (Zn, Cu, Pb, Cd and Cr) in an integrated wastewater treatment plant: two phase anaerobic reactor (RAP) - high rate algal pond (HRAP).

Removal of heavy metals (Zn, Cu, Pb, Cd and Cr) by an integrated wastewater treatment system, Two Phase Anaerobic Reactor (RAP) - High Rate Algal Pond (HRAP), was investigated. Results indicate a good reduction of these micro-pollutants by this system. Global elimination rates of treatment system are 80%, 87%, 38%, 60% and 63%, respectively for Zn, Cu, Pb, Cd and Cr. Primary treatment (RAP) was not involved in this reduction. Metal concentrations detected in RAP effluent are higher than those detected in raw wastewater. However, the essential metal removal was ensured by the HRAP and thetwo maturation ponds. Sedimentation of metals adsorbed on suspended matters is the principal factor that intervened in metal elimination by these ponds. Indeed, metal analysis of wastewater dissolved and particulate fractions showed that the majority of these cations was in particulate fraction, notably for Zn, Cu, Cd and Cr. Their distribution between these fractions evolved towards their solubilization, during the treatment. Otherwise, metal sediment analysis of different ponds showed that sludges accumulate important quantities of metals, especially in RAP sludges. Thereafter, Zn, Cu and Cd concentrations increased in HRAP sludges, but Pb and Cr contents decreased. However, in maturation pond sludges metal quantities are lower. On the other hand, metal contents in sludges are variable from upstream to downstream of each pond.

[Study of the effect of earthworm Lumbricus terrestris on the speciation of heavy metals in soils]. / Etude de l'effet du ver de terre Lumbricus terrestris sur la speciation des metaux lourds du sol.

Evaluation of the effect of earthworm Lumbricus terrestris on the speciation of copper and cadmium was carried out on two types of soils with a high metallic contamination due to municipal wastes spreading. The concentrations of total dissolved metals were higher in the soil containing earthworms. This increase was larger for the soil submitted to disturbance by earthworms for a long time (3 months). The main chemical species in the lixiviates of all type of soils including controls, were labile forms of cadmium with 52 to 87% and stable forms of copper which represents 67 to 95% of total concentration of dissolved metal. In the solid phase, there was a slight transfer of cadmium and copper from the oxidizable fraction into the exchangeable and acid soluble fractions. This suggests that soil disturbance by earthworms increases the mobility of these metals particularly cadmium. On the contrary copper appears in lixiviates as non labile organic complexes. Analysis of the whole results showed differences between soils as regards the mobility of the metals studied, which reflected the role of the mains physico-chemical characteristics (pH, C.E.C. and total calcareous content).

[Influence of the earthworm Lumbricus terrestris on soil solution complexation capacity]. / Etude de l'influence du ver de terre Lumbricus terrestris sur la capacite complexante de la solution du sol.

Four soil samples highly contaminated with metals of urban and mine origin (SE1, SE2, SM1, SM2) and having different physico-chemical proprieties were selected to study copper complexation capacity (LT) of soil solution. The effect of Lumbricus terrestris on copper complexation capacity of soil solution was investigated on SE1 and SE2. The complexation capacity was estimated by amperometric titration of soil solution by copper. Free hydrated cation and labile complexes of copper were determined by DPASV. The results show that the copper complexation capacity variation depends on the physico-chemical characteristics of soils, particularly pH. Thus, the values of copper complexation capacity are 0; 0.6 x 10(-7); 1.8 x 10(-7) and 5.5 x 10(-7) mol l-1 respectively for SM2; SM1; SE1 and SE2 which are pH 5; 5.4; 6.5 and 7.4. Based on these results, the bioavailability levels of heavy metals show the following pool ranking: SM2 > SM1 > SE1 > SE2. The copper complexation capacity of soil solution increases with the soil disturbance by Lumbricus terrestris. This is more obvious when the time of disturbance by lumbrics is longer. Indeed, average values determined for 1 month and 3 months are 3.8 x 10(-7) and 7.8 x 10(-7) mol l-1 for SE1; 7.7 x 10(-7) and 15.2 x 10(-7) mol l-1 for SE2 respectively. It seems that the action of earthworm on soil can contribute to the decrease of bioavailability of heavy metals, particularly copper.

Lead and traditional Moroccan pharmacopoeia.

The use of traditional cosmetics and remedies such as kohl and henna is very common in Morocco, especially among women, children and babies. Kohl is a dangerous eye cosmetic. It is usually mixed with other harmful substances, then applied on women's eyebrows and used in skin treatments for infants. Henna is another traditional product, with religious associations, which has been widely used over the centuries for cosmetic and medical purposes. Many people add various herbs or other substances to the henna in order to strengthen it or to give it a stronger colour. Our results were reassuring in that the concentrations of lead found in non-elaborate (henna only) samples of henna were low. However, when henna was mixed with other products (elaborate henna), these concentrations increased. Lead concentrations in kohl were very high however, unlike henna, were lower in mixed kohl as mixing with other products diluted the concentration of lead. Nevertheless, in both types of kohl, lead concentrations were very high and consequently constitute a risk for public health, particularly for children.

Trace elements in children's hair, as related exposure in wastewater spreading field of Marrakesh (Morocco).

Lead and cadmium concentration was determined in the hair of 327 school children living in a wastewater spreading field of Marrakesh (Morocco). The influence of age, sex, food habits and family occupation on the children's hair Pb and Cd concentration was also evaluated. Girls had more metal in their hair than boys (16.5 +/- 5.4 micrograms/g and 12.5 +/- 3.5 micrograms/g, respectively). However, for Cd the boys had more metal (2.9 +/- 0.6 and 2.2 +/- 0.4, respectively) but the difference was not statistically significant and metal levels decreased with age. Family occupation, direct contact with wastewater, customs and food habits were the most significant factors influencing the metal content of children's hair. The average Pb and Cd content were higher in the exposed children (14.8 +/- 4.5 micrograms/g and 2.5 +/- 0.5 micrograms/g, respectively) than in the non-exposed children (4.6 +/- 2.2 micrograms/g and 0.6 +/- 0.2, respectively), but the difference was not statistically significant. This study shows that in this area all the population (especially children) was extremely exposed to the danger caused by potentially toxic metals.

Primary structure of a myohemerythrin-like cadmium-binding protein, isolated from a terrestrial annelid oligochaete.

Two isoforms of a cadmium-binding protein (Cd-BP 14a and Cd-BP 14b) were isolated from the terrestrial oligochaete annelid, Allolobophora caliginosa. The complete amino acid sequence of the major isoform Cd-BP 14a (molecular mass: 13441 Da; 119 residues) and the amino-terminal sequence (57 residues) of Cd-BP 14b were determined. The sequence of Cd-BP 14a is highly similar to that of myohemerythrins present in marine invertebrates. Furthermore, as myohemerythrins, Cd-BP 14a and Cd-BP 14b bind two atoms of iron and their ultraviolet/visible spectra are typical of non-heme iron-binding proteins. Three substitutions were found in the amino-terminal half of the proteins at positions 19, 21 and 41. The substitutions at positions 19 and 21 are conservative, whereas that at position 41 consists of the replacement of an aspartate residue in isoform a by a lysine residue in isoform b. To our knowledge, it is the first report of a protein belonging to the hemerythrin family in a terrestrial invertebrate.

Isolation and characterization of a Cd-binding protein from Allolobophora caliginosa (Annelida, Oligochaeta): distinction from metallothioneins.

1. One Cd-binding peak was detected after gel filtration chromatography on Sephadex G75 in an extract from Allolobophora caliginosa contaminated with Cd. 2. Two subsequent cation-exchange chromatographies allowed the isolation of a Cd-binding protein which was called Cd-BP14. This protein is a monomer with a molecular weight of 14 kDa and has an isoelectric point of 6.5. 3. Amino acid analysis showed the presence of a high level of aromatic amino acids and a lack of cysteine. 4. On the basis of these results we conclude that Cd-BP14 is different from metallothioneins described in mammals or other invertebrates.