Wastewater treatment by stabilization pond: Marrakesh experiment

Abstract

This paper presents results of two years of investigations on three types of wastewater stabilization pond treatment systems, purifying a raw urban wastewater, in the arid climate of Marrakesh. The systems tested were: two lined water hyacinth ponds, two lined facultative ponds and one anaerobic pond. During the course of the experiment, organic load, nutrients and parasitical load were studied. Results show that the macrophytic ponds were more efficient to reduce organic load (90% of TSS and 78% of COD) that the microphtic ponds; these ones were more efficient to eliminate nutrients (NTK 71%, NH4 60%, Ptotal 80% and PO4 62%). The anaerobic pond presents a lower efficiency, less than 40% for organic and less than 20% for nutrients. About sanitary concerns, all of the year, the macrophytic and microphytic pond effluents correspond to B category (WHO, 1989). The anaerobic pond yields B category effluent except in autumn when it corresponds to C category.

Sanitation Assessment of Wastewater Treated by Stabilization Ponds for Potential Reuse in Agricultural Irrigation Sanitation Assessment

“…From Figure 3, it can be observed that, only in two situations (6.7%), fecal coliform counts were in agreement with category A of the WHO guidelines (1989). Similar results on coliform counts were observed in studies carried out worldwide ( Devaux et al, 2001 ; Madera et al, 2002 ; Oron et al, 2001 ; Ouazzani et al, 1995 ). In Brazil, no microbiological and physicochemical standards for wastewater reuse in agricultural irrigation have been established.…”

“…Similar results were observed by Amahmid et al (2002) and Semenas et al (1999) . Cutolo et al (2006) emphasized that the presence of these organisms is the main problem in wastewater reuse, although other researchers reported total elimination of helminth eggs from treated wastewater with the use of stabilization pond systems ( Ceballos et al, 1995 ; Madera et al, 2002 ; Marecos do Monte et al, 1996 ; Ouazzani et al, 1995 ). In general, effluents carry a massive egg load.…”

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

“…In addition, it is a region with hot climate where conditions for the treatment of wastewater by stabilization ponds are very favorable. Waste stabilization ponds are a simple, low-cost and low-maintenance extensive process for treating wastewater, and well adapted to low socio-economic conditions in developing countries [23,24]. A typical system consists of several constructed ponds operating in series.…”

Avaliação da atividade microbiana metanogênica na lagoa de estabilização anaeróbia da estação de tratamento de esgotos sanitários do município de Cajati, Vale do Ribeira do Iguape, Estado de São Paulo

“…Estudos realizados por pesquisadores mostraram que os efluentes de sistemas de lagoas de estabilização são adequados para irrigação restrita, que inclui sua utilização em culturas de cereais, forragem, pastos e culturas arbóreas (OUAZZANI et al, 1995). Outros estudos indicaram a utilização de efluentes de sistemas de lagoas para irrigação irrestrita, desde que submetidos a tratamento final em lagoas de maturação ou armazenamento do efluente em reservatórios para tratamento, nos quais os patógenos são eliminados (MARA, 1996;MARA et al, 1996;PEARSON et al, 1996a, MARA e PEARSON, 1999.…”

“…Por outro lado, processos adicionais estão disponíveis para melhorar a qualidade dos efluentes, dentre as quais estão os filtros de pedra, a filtração intermitente em leito de areia, a aplicação no solo para irrigação de culturas ou sistemas alagados (wetlands). Ouazzani et al (1995) compararam a eficiência de remoção de matéria orgânica, nutrientes e parasitas em três tipos de lagoas, lagoa macrofítica, lagoa facultativa e lagoa anaeróbia alimentadas com esgoto sanitário. Os resultados mostraram que a utilização de macrófitas na lagoa gerou uma melhor eficiência de redução de matéria orgânica (90% de redução de sólidos suspensos totais -SST -e 78% de redução nos valores de DQO) em comparação com a lagoa facultativa (37% para SST e 50% para DQO).…”