7、fulcompounds.排入水体的污染物在数量上超过了该物质在水体中的本底含量和自净能力即水体的环境容量,从而导致水体的物理特征、化学特征发生不良变化,破坏了水中固有的生态系统,破坏了水体的功能及其在人类生活和生产中的作用biologicalwastewatertreatment:This is a brief summary of the various techniques that have been developed to treat wastewater by biological means. They acc
8、omplish what is generally called secondary treatment.aerobicsewagetreatment:Aerobicbiologicaltreatmentisperformedinthepresenceofoxy