ENIVRONMENT ASIA

Volume 12, No. 01, Month JANUARY, Year 2019, Pages 178 - 186

Decentralized biological compact unit for the removal of parasitic helminth ova during sewage treatment

Fayza Aly Nasr, Mahmoud Afw Gad, Ahmad Zakaria Al-Herrawy

Abstract Download PDF

A decentralized cost effective biological compact unit (BCU) wastewater treatment system was operated to investigate its capability in removing parasitic helminth ova. A total of twenty four batches of four wastewater stages (raw sewage, anaerobic effluent, aerobic effluent and BCU effluent) were collected. The samples were concentrated and purified then examined by light microscopy to detect and identify helminths ova. Other parameters for examining the wastewater quality as COD, BOD, TSS and FC were measured. The highest prevalence of helminth ova was recorded in raw wastewater (75%), followed by 37.5%, 25% and 4.2% in anaerobic, aerobic and BCU effluents, respectively. Ascaris ova were the most prevalent nematode genus in raw and treated wastewater. The overall removal of helminth ova reached 50% and 66.7% by anaerobic and aerobic treatment steps, respectively. The BCU had a strong significant effect in reducing the count of the parasitic helminth ova (P=0.002), but it did not eliminate them completely. The results also indicated that the treated wastewater quality produced in terms of COD, BOD, TSS, FC and plastic nematode ova after 12 h reached 78 mg/L, 38 mg/L, 19 mg/L, 560 MPN index /100ml and one ova/L, respectively. These values proved to be satisfactory and complying with the Egyptian law for restricted crops irrigation. In conclusion, the BCU was easy to operate. Nevertheless, its effluent quality in terms of parasitic with treated wastewater helminth ova was found to be comparable with typical centralized wastewater treatment units.

Keywords

Reduction; Parasitic helminthes; Biological compact unit; Sewage; Reuse

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