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The prevalence and the identification of the helminth eggs load of raw sewage sludge was assessed of three different wastewater treatment systems. The results showed a variety of parasite species with following average concentrations; five taxa belonging to three classes nematodes, cestodes and trematodes were inventoried. The class of nematodes is the most diverse with 5 taxa. It is represented by the eggs of Ascaris sp., Capillaria sp., Trichuris sp., Toxocara sp., and Ankylostome sp., then comes the cestodes class, this is represented by the eggs of Taenia sp. The trematode class is represented by Schistosoma sp. The lagooning station of Chichaoua shows the highest load 7 species with Ascaris 21 eggs/g; Capillaria sp., 11 eggs/g; Trichuris sp., 6 eggs/g; Toxocara sp., 2 eggs/g and Ankylostome sp., 1 egg/g; Taenia sp., 2eggs/g; and Schistosoma sp., 1 egg/g. Infiltration-percolation sludge show the presence of 4 species of helminths eggs in sludge from anaerobic settling with different rates: 15 eggs/g for Ascaris sp., 15 eggs/g for Trichuris sp., 13 eggs/g for Capillaria sp., and 8 eggs/g for Taenia sp. However, in sand filter pool, the sludge helminth eggs load was decreased by 47% of Ascaris sp., 85% of Capillaria sp., and 75% of Taenia sp., Nevertheless, an increase of Trichuris eggs load was noted in the second sludge by 17%. Five helminth eggs was detected in primary sludge coming from decantation pools in activated sludge plant in Marrakech, that is Ascaris sp., with a load of 16 eggs/g; Capillaria sp., with 3 eggs/g, Trichuris eggs with 2 eggs/g; Taenia sp., with 4 eggs/g; and Schistosoma sp., with 2 eggs/g. The abatement load of Ascaris sp. with 81% and Schistosoma and Taenia sp., with 100% was noted in biological sludge. Nevertheless, an increase load of Capillaria and Trichuris eggs 81% and 75% respectively was observed in this sludge coming from biological pools. The distribution of parasitic helminth eggs is linked to the differences in demographic and socio-economic status, seasonal variation, physico-chemical characteristic of helminth eggs, and the purification wastewater system performance.

The purpose of this study is to assess the maturity and stability of the lagooning sludge (LS) with green waste (GW) during semi-industrial composting. Physico-chemical parameters, spectroscopy analysis and germination test were monitored. After 105 days, the decomposition rate of about 33.6; 39 and 36%, a stabilization of pH around neutrality; NH4+/NO3− ratio decreased to 0.922, 0.974 and 1.038; the C/N ratio decreased to 9.47, 9.24 and 10.10 respectively for mixture 1 (M1), mixture 2 (M2) and mixture 3 (M3). This reduction is explained by the bio-oxidation of organic matter. The intense microbial activity was characterized by the rise of temperature (between 40 and 50 °C) during the first weeks. Humification process was characterized by the increase of humification index (HI), which was approximately 62.1%; 73.6%; 61.5% respectively for M1, M2 and M3. The progress of humification process was determined by the decrease of aliphatic absorbance bands and the increase of aromatic absorbance bands. The increase in germination index (GI) (> 50%) for the four seeds: cress, alfalfa, turnip and radish, at the end of composting indicated that the composts are phytotoxic-free and are rich in stable organic compounds and nutrients. The results show that all three composts are mature, which opens the way for their application in agriculture without risk for the soil–plant system.

In this work, we assessed the drying and composting effectiveness of helminth eggs removal from sewage sludge of a lagoon wastewater treatment plant located in Chichaoua city. The composting was run after mixing sludge with green waste in different proportions: M1 (½ sludge + ½ green waste), M2 ([Formula: see text] sludge + [Formula: see text] green waste), and M3 ([Formula: see text] sludge + [Formula: see text] green waste) for 105 days. The analysis of the dewatered sewage sludge showed a load of 8-24 helminth eggs/g of fresh matter identified as Ascaris spp. eggs (5-19 eggs/g) followed by Toxocara spp. (0.2 to 2.4 eggs/g); Hookworm spp. and Capillaria spp. (0.4-1 egg/g); Trichuris spp., Taenia spp., and Shistosoma spp. (

The objective of the study was to characterise co-composting dynamics and maturity of the end products of sewage sludge/ green waste mixtures. We analysed all initial substrates and co-composts, sampled at different composting times for studying (1) physicochemical parameters and (2) organic matter biodegradation and biotransformation using pyrolysis coupled to gas chromatography and mass spectrometry. Physicochemical analysis indicated compost maturity of the three co-composting mixtures after 200 days. Pyrolysis-GCMS showed that organic matter in sewage sludge generated a large number of different pyrolysis products, most of which had unspecific origin. The pyrolysis products of the three co-compost were classified according to their chemical composition (benzene derivatives, N-containing compounds, phenol derivatives, furan derivates) and according to their chemical structure (polyaromatics, aromatics compounds and aliphatic compounds). These compound classes evolved differently during composting. We suggest two new specific ratios of peak areas from pyrolysis products to describe the biodegradation and to evaluate the degree of maturity during co-composting sludge-green waste: (1) the ratio benzene, methyl (methylethenyl) /benzene, which decrease during composting, and (2) the ratio of Indene/2-methoxy-4 vinyl-phenol which increase during composting. The good correlation between these ratios and physico-chemical parameters confirms their usefulness to evaluate the co-compost maturity.

Composting is a suitable solution to reduce the high quantity of sewage sludge produced every year. Microbiological quality of compost should be evaluated before its use. In this circumstance, researching the faecal bacteria indicators becomes more interesting to confirm the compost safety in terms of pathogenic microorganisms, which can cause health risk for the soil–plant–human​ system. This work monitored the evolution of pathogenic bacteria (faecal coliforms, faecal streptococci, Shigella spp and Salmonella spp.) during windrows co-composting of three mixtures with different proportion of lagooning sludge and green waste under semi-arid climate. It also investigated the evolution of two bacteriophages (Coliphages and Salmonella-phages) as an indicator of long-term compost hygienization. The final composts showed a high reduction that reached 99% for faecal coliforms, faecal streptococci; and 100% for Shigella spp. and Salmonella spp. These reductions revealed the efficiency of composting on bacteria inactivation. Comparison between the survivals of the two bacteriophages showed that Salmonella-phages have less tolerance to inactivation than coliphages, it was totally eliminated after 45 days of composting, while coliphages were completely inactivated after 200 days. The complete destruction of the bacteriophages showed the safety and the good microbial quality of the three co-composting trials. These findings revealed that in the case of composting on windrows, a maximum temperature about 50 °C and time which, exceeds 5 months are essential to decrease pathogenic bacteria and virus to a safe level. We conclude that co-composting conditions of mixtures containing half and one-third of the sludge were more adequate for a rapid destruction of pathogens, compared to mixture containing two-third of the sludge. Based on this study, we anticipate that the proposed analysis will yield a rapid indicator of co-composting hygienization design with less dependency simple and fast technique.

Lagooning sludge (LS), which is used as soil amendment in Morocco, may contain microplastics (MPs). The aim of this study was to examine the effect of dewatering and co-composting of LS with green waste (GW) on the MPs’ evolution. In this context the present study proposes fast-preliminary steps to detect plastics in lagooning sewage sludge before the extraction and identification process. We used pyrolysis GC/MS spectrometry to investigate the presence of chemical compounds possibly derived from plastics, and fluorescence staining by Nile Red to detect fluorescent particles suspected as plastics. Thereafter, we quantified the MPs particles after density fractionation and investigated their nature by Raman spectroscopy. Results indicated the presence of an average of 40.5 ± 11.9 × 103 MPs particles/kg (dry matter) and 36 ± 9.7 × 103 MPs particles/kg (dry matter) in fresh sludge and dewatered sludge respectively. Sludge dewatering in drying beds resulted a loss of small MPs (

Recycling by composting presents a sustainable and a cost-effective approach to reduce the high quantity of sewage sludge. In addition, the relationship between compost stability and functional microflora is reflected in the evolution of several parameters as C/N and NH4+/NO3− ratios. However, the microorganisms that populate the substrates during composting reflect the evolution and the performance of structural stability of amended soils, the water retention capacity, and the biodegradation-humification process in compost and soil. Therefore, monitoring humic substance variation during composting is one of the methods used to estimate microorganism activity. In this study, two different mixtures were prepared. The physicochemical indices of maturity changed during composting to reach C/N around 10 and NH4+/NO3− < 1. These two physicochemical indices of maturity presented a linear correlation with mesophilic actinobacteria with R2 = 0.3 and 0.29 for C/N and R2 = 0.29 and 0.41 for NH4+/NO3, respectively, for mixtures A and B. However, for thermophilic actinobacteria, R2 = 0.78 and 0.25 for C/N, and R2 = 0.73 and 0.37 for NH4+/NO3−, respectively, for mixtures A and B. The progress of physicochemical and microbial parameters is justified by the germination of turnip seeds, which exceed 100% by using final composting products. These findings clearly demonstrate that exploitation of treated sewage sludge as a soil amendment could regulate the carbon, nitrogen, phosphorus, and organic matter requirements for a sustainable agriculture in Morocco where, for example, more than 6.25 million tons of organic matter is needed.