Aquatic Oligochaetes of Iraq's Southern Marshes

Aquatic Oligochaetes community in the Iraqi southern marshes, Al- Hawiezah, Al-Chibayish and Al-Hammar, have been studied for the period from July 2006 to June 2007. Two sites within each marsh, in addition to a reference site located at Shatt Al-Garma, have been chosen for sample collection using Ekman dredge. The results revealed that the highest average annual density was 16800 individual / m2 recorded in Al-Hawiezah marsh, while in Al-Chibayish and al-Hammar marsh the density did not exceed 5111 individual/m2. In contrast, the density of Oligochaetes recorded in Shatt Al-Garma was about 10500 individual / m2. The highest monthly density was recorded in April 2007.The highest local percentage occurrence was 96% recorded in Al-Hawiezah marsh, while the highest average monthly percentage occurrence was recorded in January 2007.The study revealed the presence of 19 Oligochaetes species belonging to 14 genera and 4 families. Naididae was represented by 8 spp.; Tubuficidae 8 spp.; Lumbriculidae 2 spp. and Lumbricidae 1 spp. Tubificid worms formed about 73% of the total count while Naididae formed 15%, Lumbriculidae 8% and Lumbricidae 4%.Among Tubificidae, Limnodrilus was the most abundant genus composed about 35% of L. hoffmeisteri; 11.5% L. claparedianus; 8% L. profundicola and 4.7% L. maumeensis, followed by Tubifex tubifex 23%. Other species were Branchuira sowerbyi formed 15%; 2.8 and 2 % for Peloscolex velutinus and Aulodrilus pigueti respectively. Naididae worms comprised 8 species including 32% of Dero digitata, 24% of Nais variabilis, 14% of Amphichaeta sp. and 11% of each of D.obtuse and Pristina longiseta. However, D. dorsalis represented only 7.5% of the total Naididae. Few individuals of B. sowerbyi and Lumbriculus variegates, with two regenerated parts at the posterior end were also detected in some samples. This case was considered a rare observation within the population of these worms in this particular area

Moving bed biofilm reactor technology as batch system in wastewater treatment

Biofilm slime layer is one of the advanced biological treatment technologies for industrial and municipal wastewater treatment with the capacity to reuse of treated water for agricultural purposes. Bacterial, fungal and algal biofilm slime layer were grown on the interior surfaces of polyethylene pellet (carrier) and suspended in municipal wastewater for organic pollutants removal. Bacterial species (Pseudomonas aeruginosa, Bacillus megaterium, Sphingobacterium thalpophilum), fungal species (Penicillium citrinum, Aspergillus niger, Trichoderma harzianum) and algal species (Nostoc linckia, Scendesmus dimorphus) were used separately for biofilm slime layer growth under controlled laboratory conditions (pH, temperature, and aeration). Bacterial biofilm layer thickness was measured and recorded 9, 6 and 5 mm respectively as compared with 3mm for control group through the retention time of 16 day. Bacterial P. aeruginosa biofilm slime layer showed an efficiency for COD, TOC, NO3 and PO4 removal after 24 hour of 75%, 65%, 69% and56% respectively while the removal rates of the same factors using the fungal biofilm layer of P. citrinum was 83%, 78%, 53% and 60% after 48 hour respectively. The algal biofilm reactor with S. dimorphus showed the highest percentage removal rate of total nitrogen 93% as compared to control group 87% after 72 hours of treatment due to the biofilm slime thickness of S. dimorphus 7.5mm as compared to the thickness of the N. linckia slime layer 5.3mm. Mixture of microbial species biofilm layer was used for wastewater treatment through 18 and 24 hours, using aerobic and anoxia. The mixture of microbial species biofilm layer showed removal rates for TOC, COD, and TN of 90%, 83%, and 59% respectively in an aerobic condition, while the removal rates were 66%, 52%, and 84% in an anoxic condition. From the above results, one concludes that controlling the biofilm slim layer is a promising technology for municipal wastewater treatment, as long as it is used under the suitable conditions

Moving bed biofilm reactor technology as batch system in wastewater treatment

Biofilm slime layer is one of the advanced biological treatment technologies for industrial and municipal wastewater treatment with the capacity to reuse of treated water for agricultural purposes. Bacterial, fungal and algal biofilm slime layer were grown on the interior surfaces of polyethylene pellet (carrier) and suspended in municipal wastewater for organic pollutants removal. Bacterial species (Pseudomonas aeruginosa, Bacillus megaterium, Sphingobacterium thalpophilum), fungal species (Penicillium citrinum, Aspergillus niger, Trichoderma harzianum) and algal species (Nostoc linckia, Scendesmus dimorphus) were used separately for biofilm slime layer growth under controlled laboratory conditions (pH, temperature, and aeration). Bacterial biofilm layer thickness was measured and recorded 9, 6 and 5 mm respectively as compared with 3mm for control group through the retention time of 16 day. Bacterial P. aeruginosa biofilm slime layer showed an efficiency for COD, TOC, NO3 and PO4 removal after 24 hour of 75%, 65%, 69% and56% respectively while the removal rates of the same factors using the fungal biofilm layer of P. citrinum was 83%, 78%, 53% and 60% after 48 hour respectively. The algal biofilm reactor with S. dimorphus showed the highest percentage removal rate of total nitrogen 93% as compared to control group 87% after 72 hours of treatment due to the biofilm slime thickness of S. dimorphus 7.5mm as compared to the thickness of the N. linckia slime layer 5.3mm. Mixture of microbial species biofilm layer was used for wastewater treatment through 18 and 24 hours, using aerobic and anoxia. The mixture of microbial species biofilm layer showed removal rates for TOC, COD, and TN of 90%, 83%, and 59% respectively in an aerobic condition, while the removal rates were 66%, 52%, and 84% in an anoxic condition. From the above results, one concludes that controlling the biofilm slim layer is a promising technology for municipal wastewater treatment, as long as it is used under the suitable conditions.</jats:p