生物载体内孔径对生物膜微型动物多样性与稳定性影响

为了给废水处理生产中最佳孔径的生物载体选型提供依据，本研究系统考察聚氨酯海绵生物载体5种孔径（0.6~4mm）大小对生物膜微型动物群落多样性以及稳定性的影响.结果表明：鞭毛虫、肉足虫等是运行前期与中期的优势种属，游泳型与固着型纤毛虫、轮虫是后期的优势种属.不同孔径载体在不同时期，微型动物多样性、稳定性等参数变化具有明显差异.小孔径（0.6mm）载体微型动物仅在运行中期内表现出较高多样性，中小孔径（1mm）载体多样性总体偏低，中大孔径（3mm）和大孔径（4mm）载体微型动物多样性波动剧烈.小孔径、中小孔径载体内微型动物稳定性好，中大孔径载体稳定性波动大，而大孔径载体最不稳定.中等孔径（2mm）载体内微型动物群落物种丰富度、均匀度高，多样性高且稳定（后期H=2.12、R=1.19、λ=0.16），其微型动物群落最为稳定（后期W_H=0.13），且表现出较好的废水处理效果，中等孔径是理想的生物载体内部孔径大小.在生物膜系统中，微型动物多样性稳定指数W_H可作为废水中CODc_r去除效果的指标参数.

Effect of inner-pore diameter of bio-carrier on community diversity and stability of microfauna in biofilm

In order to provide the basis for the selection of biological carrier with the best pore size in wastewater treatment production, polyurethane sponges with five kinds of inner-pore diameter (0.6~4.0mm) were used as the biological carriers in this study. The effects of the inner-pore diameter on the species diversity and stability of microfauna were systematically investigated. The results showed that flagellates, sarcodina etc., were the dominant species in the intial and middle periods of reactor operation. Whereas, the swimming and sessile ciliates and rotifers mainly occurred in the later stage. Diversity, stability and other parameters of microfauna in different carrier pore sizes exhibited significantly divergence at three distinct periods. The microfauna in the carrier with small pore size (0.6mm) showed high diversity only during the middle period of reactor operation, while the diversity of microfauna in the carriers of 1.0mm diameter was generally lower. However, the diversity of microfauna in the carriers with larger (3.0mm) and big pore size (4.0mm) fluctuated dramatically during the whole process. The stability of microfauna in the carriers with small (0.6mm) and small-moderate pore size (1.0mm) were superior to the carriers with larger pore in the middle and later periods of reactor operation, but worse in the intial periods of reactor operation. Notably, the stability of big pore bio-carrier (4.0mm)was the most undesirable throughout the reactor process. Compared to other size of bio-carriers, the microfauna community in the bio-carrier with moderate pore (2.0mm) possessed higher species richness and uniformity, resulting in a high and stable diversity (H=2.12, R=1.19, λ=0.16 in the later period). In addition, microfauna community on the moderate-pore bio-carrier emerged the strongest stability (W_H=0.13 in later period) with an excellent efficiency of wastewater treatment. In the biofilm system, the stability index W_H can be used as the index parameter of CODc_r removal efficiency.