Water quality near three sources of potential contamination of the Taquari River - RS

Abstract The Taquari Valley has several food industries and tanneries which release their effluents into the Taquari River, as well as a cemetery in a Permanent Preservation Area in Muçum town. This study performed physicochemical and microbiological analyses of water from before and after three Taquari River sites considered potentially polluting and compared the results of those samples. The chosen sites were a cemetery and a tannery in Muçum and a tannery next to a poultry processing plant located in Roca Sales. We analyzed pH, turbidity, dissolved oxygen (O2), total nitrogen (N) and thermotolerant coliforms. We also isolated Escherichia coli and performed resistance tests to neomycin, rifampicin, clindamycin and penicillin antibiotics. The physicochemical analyses showed that only turbidity, in four out of the six analyzed spots, had values above the established threshold of class I water. These elevated values are probably of inorganic origin. Bacteria isolated from the samples collected after the cemetery and both before and after the Roca Sales industries were sensitive to neomycin, rifampicin and clindamycin, and resistant to penicillin. It can be concluded, therefore, that even the release of the pollutant effluents does not substantially interfere with the water quality of the three analyzed sites.

摘要：塔夸里谷内分布有多家食品加工企业与制革厂，其生产废水均汇入塔夸里河；此外穆辛镇（Muçum）的一处永久保护区（Permanent Preservation Area）内还设有一座公墓。本研究针对塔夸里河三处被认定为存在潜在污染风险的点位的上下游水体，开展了理化与微生物学检测分析，并对各采集样本的检测结果进行对比研究。所选点位分别为穆辛镇的一处公墓与一家制革厂，以及罗卡萨利斯镇（Roca Sales）毗邻家禽加工厂的一家制革厂。本次检测分析的指标包括pH值、浊度、溶解氧（O₂）、总氮以及耐热大肠菌群（thermotolerant coliforms）；同时完成了大肠杆菌（Escherichia coli）的分离培养，并开展了其对新霉素（neomycin）、利福平（rifampicin）、克林霉素（clindamycin）与青霉素（penicillin）四种抗生素的耐药性试验。理化检测结果显示，在六个检测点位中，仅有四处的浊度值超出了Ⅰ类水体的既定限值，且此类浊度升高现象大概率由无机污染源引发。从公墓下游水体、罗卡萨利斯镇两处工业点位上下游水体中分离得到的菌株，均对新霉素、利福平与克林霉素表现敏感，而对青霉素呈现耐药性。综上可见，即便有污染废水排入，也未对本次分析的三处点位的水体质量造成显著影响。