Natrialba sp. strain C21 was isolated from oil contaminated saline water in Ain Salah (Algeria) and has exhibited a good potential for degrading phenol (3% v/v), naphthalene (3% v/v), and pyrene (3% v/v) at high salinity with high growth, enzymatic activity and biosurfactant production. Successful metabolism of aromatic hydrocarbon compounds of the strain Natrialba sp. C21 appears to require the ortho-cleavage pathway. Indeed, assays of the key enzymes involved in the ring cleavage of catechol 1, 2-dioxygenase indicated that degradation of the phenol, naphthalene and pyrene by strain Natrialba sp. C21 was via the ortho-cleavage pathway. Cells grown on aromatic hydrocarbons displayed greater ortho-activities mainly towards catechol, while the meta-activity was very low. Besides, biosurfactants derived from the strain C21 were capable of effectively emulsifying both aromatic and aliphatic hydrocarbons and seem to be particularly promising since they have particular adaptations like the increased stability at high temperature and salinity conditions. This study clearly demonstrates for the first time that strain belonging to the genera Natrialba is able to grow at 25% (w/v) NaCl, utilizing phenol, naphthalene, and pyrene as the sole carbon sources. The results suggest that the isolated halophilic archaeon could be a good candidate for the remediation process in extreme environments polluted by aromatic hydrocarbons. Moreover, the produced biosurfactant offers a multitude of interesting potential applications in various fields of biotechnology.

Adsorption of several chemical contaminants onto clay minerals is the most recommended technique applied in the wastewater treatment field, owing to its low economic cost, efficiency, and low power consumption. In this context, natural bentonite particles with 80-μm diameter were investigated for the ammonium adsorption in aqueous solution using an incubator that kept the constant temperature and stirring speed at 200 RPM. The study of different experimental parameters effect on the adsorption process revealed that the raw bentonite have adsorbed approximately 53.36 % of the initial ammonium concentration at pH 7 and temperature of 30 °C. This percentage has been improved by increasing the adsorbent dosage in solution, which could reach up to 81.2 % at 40 g/L of bentonite with an initial ammonium concentration of 10 mg-NH/L. Moreover, experimental data modeling allowed us to conclude that the adsorption isotherm obeys to both models of Langmuir and Freundlich.

The electrochemical techniques are the subject of increasing interest on the environmental remediation methods thanks to their efficiency and their selectivity. It was classified among the cleanest methods because it does not produce sludge and undesirable intermediate byproducts. For these reasons, we have chosen this technology for the reduction of nitrites and nitrates ions from aqueous solutions. The objective of our study is the comparison of several cathodes materials performances, in order to promote an optimal electro-reduction of these ions. Indeed, we have used the copper, graphite, stainless steel and zinc as cathodes; among them, we have selected the most efficient on which we have optimized the operational conditions. The results suggested that the copper cathode was the most efficient for the reduction of both tested ions compared to the other tested materials. Therefore, the optimization of operational conditions allows us to fixed them at: scan rate=50mV/s, initial effluent concentration=100 mg/L, pH=7 and potential range of the cyclic voltammetry scanning of [-1,+1]V/SCE for both ions. Under these optimal parameters, the reduction yield after 45min was important that can achieve 96.5% and 99% for nitrites and nitrates respectively.

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Agricultural activities lead excessive emission of ammonia nitrogen in the environment and can profoundly interfere the equilibrium of the natural ecosystems leading to their contamination. Actually, the biological purification of wastewaters is the most adopted technique thanks to its several advantages such as high performance and low energy consumption. For this reason, two novel strains of Alcaligenes sp. S84S3 and Proteus sp.