Sackey Lyndon N A, Koomson Joana, Kumi Richard, Hayford Anthony A, Kayoung Phebe
Department of Environmental Science, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
Heliyon. 2023 Aug 26;9(9):e19550. doi: 10.1016/j.heliyon.2023.e19550. eCollection 2023 Sep.
Agricultural application is the primary method of recycling sewage sludge. It is an alternative for recycling this residue, providing nutrients and organic matter to crops and soil. However, sewage treatment and management issues may impact its quality. The main objective of the research was to determine the quality of sewage sludge generated at the Kumasi Wastewater Treatment Plant (KWTP). Understanding the effects of using sludge on soil and plants is critical. To overcome this constraint, the soil microbial biomass was used to quantify the growth of microorganisms. The levels of potentially toxic elements in the sludge using atomic absorption spectrometry (AAS) are based on US EPA part 503 regulations for the disposal and management of biosolids. This study found that trace metal concentrations in the biosolids were lower than the referenced background standards threshold. Although the microbial biomass, nutrients and bacteria levels were within the accepted values for their possible use as soil fertilizer. The ecological risk index (135.10) indicated that the level of arsenic was high in the sludge. The salinity in the sludge was low, with electrical conductivity (EC) being high (60.80-436.00 μS/cm) and pH decreasing with age (6.73-7.69). The sludge produced at KWTP is of good quality and meets international standards with only a high concentration of As. This can be used for soil amendment when As is reduced in the sludge.
农业应用是污水污泥回收利用的主要方法。它是回收这种残渣的一种替代方式，能为作物和土壤提供养分及有机质。然而，污水处理和管理问题可能会影响其质量。该研究的主要目的是确定库马西污水处理厂（KWTP）产生的污水污泥的质量。了解使用污泥对土壤和植物的影响至关重要。为克服这一限制，利用土壤微生物生物量来量化微生物的生长情况。采用原子吸收光谱法（AAS）测定污泥中潜在有毒元素的含量，这是基于美国环保署第503部分关于生物固体处置和管理的规定。本研究发现，生物固体中的痕量金属浓度低于参考背景标准阈值。尽管微生物生物量、养分和细菌水平在其用作土壤肥料的可接受值范围内。生态风险指数（135.10）表明污泥中砷含量较高。污泥中的盐分较低，电导率（EC）较高（60.80 - 436.00 μS/cm），且pH值随时间下降（6.73 - 7.69）。KWTP产生的污泥质量良好，除了砷含量较高外，符合国际标准。当污泥中的砷含量降低后，可用于土壤改良。
