M. A. AKHERE

A study on the effect of brewery effluent on two microalgae Thalassiosira sp. and Chaetoceros gracilis was carried out for fourteen (14) days. The experiment was done in triplicate using concentrations 0% (control), 5%, 10%, 15%, 20%, 25% and 30% of brewery effluent. Growth responses were measured using a visible spectrophotometer at 750nm and some physicochemical parameters were analyzed before and after the experiment using standard methods. Descriptive statistics, inferential (one way analysis of variance) ANOVA repeated measures, paired t-test and Tukey test were done using Microsoft excel 2010 and statistical package for social sciences SPSS20. The results showed that there was a significant difference (p < 0.05) in the growth
response of both microalgae. Different concentrations of brewery effluent affected the growth of Thalassiosira sp. and Chaetoceros gracilis. Higher concentrations (20%, 25% and 30%) had more stimulatory effect than lower concentrations (5%, 10% and 15%) when Thalassiosira sp. was used. Chaetoceros gracilis grew best in lower concentrations of 10%, 15% and 20%. A decrease in temperature was observed in all treatments while TOC and COD decreased at lower
concentrations of brewery effluent then remained constant at higher concentrations

Antibiotics play a crucial role in medicine, aquaculture, and agriculture, but their persistence in wastewater and runoff poses significant environmental risks, particularly for aquatic ecosystems. This study evaluated the effects of tetracycline and chloraphenicol on the growth of Acutodesmus acutiformis, a freshwater green microalga.. The experiment involved culturing A. acutiformis with varying concentrations (0, 5%, 10%, 20%,30%,40%,50%) of tetracycline and chloramphenicol under controlled laboratory conditions at the University of Benin. Microalgal growth was monitored spectrophotometrically at 750 nm over 14 days, alongside physicochemical parameters such as temperature, total dissolved solids (TDS), pH, conductivity, turbidity, dissolved oxygen (DO), chemical oxygen demand (COD), and total organic carbon (TOC). Statistical analysis (one-way ANOVA, paired t-test descriptive statistics) revealed significant differences (p < 0.05) in growth response and water quality parameters except for tetracycline and for chloramphenicol which had no significant difference with regards the antibiotic concentrations with a percentage yield of (P<.05). Tetracycline exhibited a dose- dependent effect, promoting growth at 50% concentration but inhibiting it at higher levels, while chloramphenicol significantly promoted growth possibly due to the presence of proteisynthesis. The growth response of Acutodesmus acutiformis was revealed using an interval of 0 -14days. Meanwhile the result of the physicochemical parameters such as temperature, pH, TD and conductivity after been acted by antibiotic concentration of tetracycline and chloramphenicol were revealed in various upward and downward trend, it was observed that both antibiotics influenced algal growth.