污水污泥,污染物和病原体的复杂混合物,在安全处置之前需要处理或稳定如厌氧消化(AD)。AD衍生的产物(固体消化物和液体部分)可用作肥料。在AD期间,还产生了沼气,用于能源目的。所有这些馏分都可能被各种化合物污染,其量取决于AD中使用的原料(及其相互比例)。本文回顾了有关AD馏分中有机污染物分布的研究(固体消化物,液体馏分,和沼气),深入研究污染物耗散背后的机制,并提出未来的研究方向。AD被证明是一种相对有效的去除多氯联苯的方法,多环芳烃,制药,抗生素抗性基因和碳氢化合物。污染物主要通过生物降解去除,但是很多化合物,尤其是疏水性(例如全氟烷基和多氟烷基物质),也吸附在消化颗粒上。建议吸附过程降低污染物的生物利用度。由于吸附,污染物在固体消化物中积累的量最大,而在其他AD产品中含量较少。极性药物(例如二甲双胍)特别浸出,而挥发性甲基硅氧烷和多环芳烃,具有很高的亨利定律常数,挥发到沼气中。化合物的去除会受到AD操作参数的影响,污泥的类型,污染物的物理化学性质,和使用的污泥预处理。
Sewage sludge, a complex mixture of contaminants and pathogenic agents, necessitates treatment or stabilization like anaerobic digestion (AD) before safe disposal. AD-derived products (solid digestate and liquid fraction) can be used as fertilizers. During AD,
biogas is also produced, and used for energy purposes. All these fractions can be contaminated with various compounds, whose amount depends on the feedstocks used in AD (and their mutual proportions). This paper reviews studies on the distribution of organic contaminants across AD fractions (solid digestate, liquid fraction, and
biogas), delving into the mechanisms behind contaminant dissipation and proposing future research directions. AD proves to be a relatively effective method for removing polychlorinated biphenyls, polycyclic aromatic hydrocarbons, pharmaceuticals, antibiotic resistance genes and hydrocarbons. Contaminants are predominantly removed through biodegradation, but many compounds, especially hydrophobic (e.g. per- and polyfluoroalkyl substances), are also sorbed onto digestate particles. The process of sorption is suggested to reduce the bioavailability of contaminants. As a result of sorption, contaminants accumulate in the largest amount in the solid digestate, whereas in smaller amounts in the other AD products. Polar pharmaceuticals (e.g. metformin) are particularly leached, while volatile methylsiloxanes and polycyclic aromatic hydrocarbons, characterized by a high Henry\'s law constant, are volatilized into the
biogas. The removal of compounds can be affected by AD operational parameters, the type of sludge, physicochemical properties of contaminants, and the sludge pretreatment used.